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Sample records for acute intermittent porphyria

  1. Acute Intermittent Porphyria (AIP)

    Science.gov (United States)

    ... sold as Panhematin ® , from Recordati Rare Diseases. Most hospitals do not stock it. Therefore the pharmacy must be notified at the time the patient’s ... the Acute Porphyrias - Clarification of Testing Results** Important Update ... & Immunology, University Hospital of Wales, for assistance in the preparation of ...

  2. Acute intermittent porphyria in the puerperium

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    Sparić Radmila

    2010-01-01

    Full Text Available Introduction. Acute intermittent porphyria emerges as a result of partial defect of porphobilinogen deaminase and is manifested by repeated episodes of somatic, psychiatric and neurological disorders. The disease is conducted via the autosomaldominant gene of variable penetration, so most of the carriers never experience seizures. Timely making of diagnosis, screening of blood relatives of the patient and education of patients on avoidance of provoking factors are the key to adequate treatment. Case Outline. A 23-year-old patient having born the third child was hospitalized due to pains in the abdomen and convulsive seizures nine days after the vaginal delivery. At admittance, she suffered a generalized convulsive seizure of clonic-tonic type. The patient immediately underwent a complete clinical, laboratory, bacteriological and ultrasound examination. Bearing in mind the fact that the patient had several convulsive seizures even after the given neurological therapy, haem-arginate was introduced into therapy during four days. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The patient was treated by a team of doctors, in the intensive care ward, with the use of medicaments, which are allowed in the case of acute porphyria. Sixteen days after the admittance, with clean neurological status and gynaecological and ultra-sound findings, she was released for ambulatory treatment. Conclusion. The presented case exhibits the gravity of making a diagnosis of acute intermittent porphyria in puerperium and the necessity of multi-disciplinary approach in treating this disease. Acute intermittent porphyria should be considered in cases of ambiguous abdominal pain, as well as in patients having abdominal pains followed by neuro-psychiatric disorders.

  3. Epidemiological, clinical anf pathogenetic studies of acute intermittent porphyria

    OpenAIRE

    Bylesjö, Ingemar

    2008-01-01

    Porphyrias are inherited metabolic disorders characterised by an impairment of heme biosynthesis. Acute intermittent porphyria (AIP) is the most common of the acute porphyrias in Sweden. Acute attacks of AIP are characterised by neuro-psychiatric symptoms, including epileptic seizures. Environmental and acquired factors are related to the induction of symptoms. Acute attacks of AIP are treated with high doses of glucose and/or hematin infusions. The pathogenesis of the neuro-psychiatric sympt...

  4. [Acute intermittent porphyria and inappropriate ADH syndrome].

    Science.gov (United States)

    Tébar, M T; Aguilera, L

    2010-05-01

    A 44-year-old woman complained of abdominal pain of 4 days' duration accompanied by vomiting and painful urination. The admitting physician noted neurologic signs consistent with axonal polyneuropathy and hyponatremia. In the absence of other explanations for the syndrome, SIADH was diagnosed. Because of the nonspecific nature of the observations, the patient was assessed by various specialists and admitted to the anesthetic recovery unit due to worsening of neurologic signs and suspicion of acute intermittent porphyria. The diagnosis was confirmed by laboratory findings of elevated d-aminolevulinic acid and porphobilinogen levels and normal stool porphyrins. The patient improved with intravenous hematin infused over 4 days.

  5. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

    OpenAIRE

    Mayra Gonçalves Menegueti; Alkmim-Teixeira Gil Cezar; Karin Aparecida Casarini; Kátia Simone Muniz Cordeiro; Anibal Basile-Filho; Olindo Assis Martins-Filho; Maria Auxiliadora-Martins

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroen...

  6. Acute intermittent porphyria, women and sex hormones. Screening for hepatocellular carcinoma in porphyria

    OpenAIRE

    Innala, Eva

    2010-01-01

    Background:   Porphyrias are inherited disorders with impaired heme biosynthesis. Acute intermittent porphyria (AIP) is the most common porphyria in Sweden. AIP attacks may be life-threatening. Female sex hormones are regarded as important precipitating factors. Hepatocellular carcinoma (HCC) is a severe complication in the older AIP population. The aim of the thesis was to describe the clinical expression of AIP in women, experience of hormonal contraception and hormonal replacement therapie...

  7. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

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    Mayra Gonçalves Menegueti

    2011-01-01

    Full Text Available Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential.

  8. Acute intermittent porphyria associated with respiratory failure: a multidisciplinary approach.

    Science.gov (United States)

    Menegueti, Mayra Gonçalves; Gil Cezar, Alkmim-Teixeira; Casarini, Karin Aparecida; Muniz Cordeiro, Kátia Simone; Basile-Filho, Anibal; Martins-Filho, Olindo Assis; Auxiliadora-Martins, Maria

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential. PMID:21687623

  9. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

    Science.gov (United States)

    Menegueti, Mayra Gonçalves; Gil Cezar, Alkmim-Teixeira; Casarini, Karin Aparecida; Muniz Cordeiro, Kátia Simone; Basile-Filho, Anibal; Martins-Filho, Olindo Assis; Auxiliadora-Martins, Maria

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential. PMID:21687623

  10. Communication with acute intermittent porphyria patients who have tracheostomy

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    Sevda Arslan

    2013-07-01

    Full Text Available Objective: Introducing acute intermittent porphyria disease and investigating the communication techniques for acute intermittent porphyria patients who have tracheostomyCase Report: 26 years old woman patient consulted to the hospital when she was 13 years old with nausea and vomiting complaints. In 2008, because of respiratory arrest, tracheostomy was implemented to the patient who had acute intermittent porphyria diagnose. The patient had two bullous lesions on the left hand and hyperpigmentation’s on the face and legs. As a result of metabolic acidosis (because of urine disease, the patient was taken to dialysis. After six months of dialysis, hypernatremia was found in the laboratory tests (Na: 85.Period of acute crisis developed In the patient with hypertension, atrophy in the muscles, fainting, abdominal pain, nausea, vomiting and diarrhea. Because of serious diarrhea, TPN was started for the patient who was fed with gavage before. Laboratory test results are Na:126, K:8.1, BUN:23.83, Urine:51, Creatinine:0.94, Leukocyte:20.4, erytrocyte:2.22, Hb:6.87g/dl, Hct: %20.9, Plt:106. Result: It is really difficult to communicate with these patients with lifespan limited because of an extremely severe clinical condition and tracheostomy.

  11. Tissue-specific splicing mutation in acute intermittent porphyria

    International Nuclear Information System (INIS)

    An inherited deficiency of porphobilinogen deaminase in humans is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. It was previously demonstrated that porphobilinogen deaminase is encoded by two distinct mRNA species expressed in a tissue-specific manner. Analysis of the genomic sequences indicated that these two mRNAs are transcribed from two promoters and only differ in their first exon. The first mutation identified in the human porphobilinogen deaminase gene is a single-base substitution (G → A) in the canonical 5' splice donor site of intron 1. This mutation leads to a particular subtype of acute intermittent porphyria characterized by the restriction of the enzymatic defect to nonerythropoietic tissues. Hybridization analysis using olignonucleotide probes after in vitro amplification of genomic DNA offers another possibility of detecting asymptomatic carriers of the mutation in affected families

  12. Liver transplantation for acute intermittent porphyria:a viable treatment?

    Institute of Scientific and Technical Information of China (English)

    Faisal S Dar; Koji Asai; Ali Raza Haque; Thomas Cherian; Mohamed Rela; Nigel Heaton

    2010-01-01

    BACKGROUND:Acute intermittent porphyria (AIP) is the most common hepatic porphyria. Its clinical presentation includes severe disabling and life-threatening neurovisceral symptoms and acute psychiatric symptoms. These symptoms result from the overproduction and accumulation of porphyrin precursors, 5-aminoleuvulinic acid (ALA) and porphobilinogen (PBG). The effect of medical treatment is transient and is not effective once irreversible neurological damage has occurred. Liver transplantation (LT) replaces hepatic enzymes and can restore normal excretion of ALA and PBG and prevent acute attacks. METHOD:Two cases of LT for AIP were identiifed retro-spectively from a prospectively maintained LT database. RESULT:LT was successful with resolution of AIP in two patients who suffered from repeated acute attacks. CONCLUSION:LT can correct the underlying metabolic abnormality in AIP and improves quality of life signiifcantly.

  13. An update of clinical management of acute intermittent porphyria

    Directory of Open Access Journals (Sweden)

    Pischik E

    2015-09-01

    Full Text Available Elena Pischik,1,2 Raili Kauppinen,11Porphyria Research Unit, Division of Endocrinology, Department of Medicine, University Central Hospital of Helsinki, Helsinki, Finland; 2Department of Neurology, Consultative and Diagnostic Centre with Polyclinics, St Petersburg, Russia Abstract: Acute intermittent porphyria (AIP is due to a deficiency of the third enzyme, the hydroxymethylbilane synthase, in heme biosynthesis. It manifests with occasional neuropsychiatric crises associated with overproduction of porphyrin precursors, aminolevulinic acid and porphobilinogen. The clinical criteria of an acute attack include the paroxysmal nature and various combinations of symptoms, such as abdominal pain, autonomic dysfunction, hyponatremia, muscle weakness, or mental symptoms, in the absence of other obvious causes. Intensive abdominal pain without peritoneal signs, acute peripheral neuropathy, and encephalopathy usually with seizures or psychosis are the key symptoms indicating possible acute porphyria. More than fivefold elevation of urinary porphobilinogen excretion together with typical symptoms of an acute attack is sufficient to start a treatment. Currently, the prognosis of the patients with AIP is good, but physicians should be aware of a potentially fatal outcome of the disease. Mutation screening and identification of type of acute porphyria can be done at the quiescent phase of the disease. The management of patients with AIP include following strategies: A, during an acute attack: 1 treatment with heme preparations, if an acute attack is severe or moderate; 2 symptomatic treatment of autonomic dysfunctions, polyneuropathy and encephalopathy; 3 exclusion of precipitating factors; and 4 adequate nutrition and fluid therapy. B, during remission: 1 exclusion of precipitating factors (education of patients and family doctors, 2 information about on-line drug lists, and 3 mutation screening for family members and education about precipitating factors in

  14. Acute intermittent porphyria: A critical diagnosis for favorable outcome.

    Science.gov (United States)

    Divecha, Chhaya; Tullu, Milind S; Gandhi, Akanksha; Deshmukh, Chandrahas T

    2016-07-01

    Acute intermittent porphyria (AIP) is an inherited metabolic disorder characterized by the accumulation of toxic metabolites of the heme pathway. It rarely presents in the prepubertal age group. AIP often presents with nonspecific and nonlocalizing symptoms. Moreover, several commonly used medications and stress states are known to precipitate an attack. We present the case of a previously healthy 5 years female who was diagnosed as acute central nervous system infection/inflammation at admission. It was the presence of red flags that led to a correct diagnosis. Besides supportive management, a dedicated search for intravenous hemin (chemically heme arginate, aminolevulinic acid synthase inhibitor, and drug of choice) was attempted. Unexpected help was rendered by doctors from a medical college in Gujarat, and two ampoules could be obtained. The patient received three doses of intravenous hemin; however, she succumbed later. This case is presented for the diagnostic and therapeutic challenges faced in developing countries. PMID:27555700

  15. Guillain Barré Syndrome, Systemic Lupus Erythematosus and Acute Intermittent Porphyria - A Deadly Trio.

    Science.gov (United States)

    Patil, Ankita D; Karnik, Niteen D; Nadkar, Milind Y; Gupta, Vishal A; Muralidhara, Krithika; Passidhi, Suresh

    2015-11-01

    Peripheral nervous system involvement occurs in 3-18% patients of systemic lupus erythematosus (SLE) cases. American College of Rheumatology (ACR) includes 19 neuropsychiatric syndromes for diagnosis of SLE divided into neurological syndromes of central, peripheral and autonomic nervous systems along with the psychiatric syndromes. Sensorimotor quadriparesis in a suspected case of SLE could be due to a Guillain Barré (GBS)-like illness, mononeuritis multiplex presenting as plexopathies, an anterior spinal artery syndrome or it can present like an acute transverse myelitis or hypokalemic periodic paralysis related to Sjogren's syndrome with renal tubular acidosis. We here report a case of a fulminant quadriparesis due to a SLE flare which subsequently was also found to be a case of Acute Intermittent Porphyria. PMID:27608785

  16. High prevalence of and potential mechanisms for chronic kidney disease in patients with acute intermittent porphyria.

    Science.gov (United States)

    Pallet, Nicolas; Mami, Iadh; Schmitt, Caroline; Karim, Zoubida; François, Arnaud; Rabant, Marion; Nochy, Dominique; Gouya, Laurent; Deybach, Jean-Charles; Xu-Dubois, Yichum; Thervet, Eric; Puy, Hervé; Karras, Alexandre

    2015-08-01

    Acute intermittent porphyria (AIP) is a genetic disorder of the synthesis of heme caused by a deficiency in hydroxymethylbilane synthase (HMBS), leading to the overproduction of the porphyrin precursors δ-aminolevulinic acid and porphobilinogen. The aim of this study is to describe the clinical and biological characteristics, the renal pathology, and the cellular mechanisms of chronic kidney disease associated with AIP. A total of 415 patients with HMBS deficiency followed up in the French Porphyria Center were enrolled in 2003 in a population-based study. A follow-up study was conducted in 2013, assessing patients for clinical, biological, and histological parameters. In vitro models were used to determine whether porphyrin precursors promote tubular and endothelial cytotoxicity. Chronic kidney disease occurred in up to 59% of the symptomatic AIP patients, with a decline in the glomerular filtration rate of ~1 ml/min per 1.73 m(2) annually. Proteinuria was absent in the vast majority of the cases. The renal pathology was a chronic tubulointerstitial nephropathy, associated with a fibrous intimal hyperplasia and focal cortical atrophy. Our experimental data provide evidence that porphyrin precursors promote endoplasmic reticulum stress, apoptosis, and epithelial phenotypic changes in proximal tubular cells. In conclusion, the diagnosis of chronic kidney disease associated with AIP should be considered in cases of chronic tubulointerstitial nephropathy and/or focal cortical atrophy with severe proliferative arteriosclerosis.

  17. MR imaging of acute intermittent porphyria mimicking reversible posterior leukoencephalopathy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Utz, N.; Kinkel, B.; Hedde, J.P.; Bewermeyer, H. [Staedtisches Krankenhaus Koeln-Merheim, Koeln (Germany). Neurologische Klinik

    2001-12-01

    Reversible posterior leukoencephalopathy syndrome (PLS) is characterized by headache, altered mental function, visual disturbances and seizures. Neuroimaging studies suggest a white-matter oedema, predominantly in the posterior parietal-temporal-occipital regions of the brain. We present the case of a 30-year-old woman who had suffered her first attack of acute intermittent porphyria (AIP). Following 1 week of abdominal pain she developed several generalized seizures, and hallucinations, and exhibited a progressive deterioration of the consciousness. T2-weighted images, especially fluid-attenuated inversion recovery (FLAIR) sequences showed bilateral lesions in the posterior frontal, parietal and occipital cortex and subcortical white matter. Following treatment with haematin and a high carbohydrate diet the patient's condition improved. Follow-up magnetic resonance imaging (MRI) revealed complete resolution of the lesions. To our knowledge, this is the first report concerning a completely reversible PLS in AIP. (orig.)

  18. Glucose Effect in the Acute Porphyrias

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    ... You are here Home Diet and Nutrition The glucose effect in acute porphyrias The disorders Acute Intermittent ... are treated initially with the administration of carbohydrate/glucose. This therapy has its basis in the ability ...

  19. Haplotype Analysis of Norwegian and Swedish Patients with Acute Intermittent Porphyria (AIP: Extreme Haplotype Heterogeneity for the Mutation R116W

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    Kjersti Tjensvoll

    2003-01-01

    Full Text Available Acute intermittent porphyria (AIP, the most common of the acute porphyrias, is caused by mutations in the gene encoding hydroxymethylbilane synthase (HMBS also called porphobilinogen deaminase (PBGD. The mutation spectrum in the HMBS gene is characterized by a majority of family specific mutations. Among the exceptions are R116W and W198X, with high prevalence in both the Dutch and Swedish populations. These two mutations were also detected in unrelated Norwegian patients. Thus, Norwegian and Swedish patients were haplotyped using closely linked flanking microsatellites and intragenic single nucleotide polymorphisms (SNPs to see if the high frequency of these two mutations is due to a founder effect. Twelve intragenic SNPs were determined by a method based on fluorescent restriction enzyme fingerprinting single-strand conformation polymorphism (F-REF-SSCP.

  20. Markers for vulnerability in acute porphyria. A hypothesis paper.

    Science.gov (United States)

    Thunell, S; Andersson, C; Carlmark, B; Floderus, Y; Grönqvist, S O; Harper, P; Henrichson, A; Lindh, U

    1995-04-01

    Previously symptomatic and permanently asymptomatic carriers of a gene mutation for acute intermittent porphyria as well as matched controls were screened with regard to a series of variables of possible relevance to the development of porphyric symptoms. The basis for the study was a concept of acute porphyria as a condition of a permanent system overload of oxidative stress, with long term effects on hepatic and renal tissue, and with instances of periodic overload of free radicals giving rise to acute neurologic involvement. Leukocyte concentrations of manganese, calcium, iron and zinc, as well as erythrocyte calcium differed between the groups, acute intermittent porphyria gene carriers, irrespective of previous porphyric illness, showing significantly higher levels than the controls. Manganese was found to be the most discriminative component of all the 78 variables investigated, accounting for about 98 per cent of the variance between the groups. An increment, by a factor of four, in cellular manganese is suggestive of an increase, in acute intermittent porphyria, of a manganese associated enzyme, e.g. glutamine synthetase, pyruvate carboxylase or mitochondrial superoxide dismutase. The best fit into the model considered is provided by a theory focused on superoxide dismutase, induced in response to superoxide anion radical produced from aminolaevulinic acid. In porphyria gene carriers seemingly resistant to porphyric manifestations, an increase in potentially prooxidant cellular iron is matched by a proportional increment in manganese, i.e. presumably by a corresponding mitochondrial superoxide dismutase induction. This mechanism is not operative in porphyric individuals prone to development of neuropsychiatric symptoms. In acute intermittent porphyria with a history of porphyric illness there is a positive correlation between erythrocyte manganese and serum folate and a negative correlation between leukocyte ferrochelatase activity and serum cobalamin

  1. Markers for vulnerability in acute porphyria. A hypothesis paper.

    Science.gov (United States)

    Thunell, S; Andersson, C; Carlmark, B; Floderus, Y; Grönqvist, S O; Harper, P; Henrichson, A; Lindh, U

    1995-04-01

    Previously symptomatic and permanently asymptomatic carriers of a gene mutation for acute intermittent porphyria as well as matched controls were screened with regard to a series of variables of possible relevance to the development of porphyric symptoms. The basis for the study was a concept of acute porphyria as a condition of a permanent system overload of oxidative stress, with long term effects on hepatic and renal tissue, and with instances of periodic overload of free radicals giving rise to acute neurologic involvement. Leukocyte concentrations of manganese, calcium, iron and zinc, as well as erythrocyte calcium differed between the groups, acute intermittent porphyria gene carriers, irrespective of previous porphyric illness, showing significantly higher levels than the controls. Manganese was found to be the most discriminative component of all the 78 variables investigated, accounting for about 98 per cent of the variance between the groups. An increment, by a factor of four, in cellular manganese is suggestive of an increase, in acute intermittent porphyria, of a manganese associated enzyme, e.g. glutamine synthetase, pyruvate carboxylase or mitochondrial superoxide dismutase. The best fit into the model considered is provided by a theory focused on superoxide dismutase, induced in response to superoxide anion radical produced from aminolaevulinic acid. In porphyria gene carriers seemingly resistant to porphyric manifestations, an increase in potentially prooxidant cellular iron is matched by a proportional increment in manganese, i.e. presumably by a corresponding mitochondrial superoxide dismutase induction. This mechanism is not operative in porphyric individuals prone to development of neuropsychiatric symptoms. In acute intermittent porphyria with a history of porphyric illness there is a positive correlation between erythrocyte manganese and serum folate and a negative correlation between leukocyte ferrochelatase activity and serum cobalamin

  2. Acute intermittent porphyria: A single-base deletion and a nonsense mutation in the human hydroxymethylbilane synthase gene, predicting truncations of the enzyme polypeptide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G.L.; Astrin, K.H.; Desnick, R.J. [Mount Sinai School of Medicine, New York, NY (United States)

    1995-08-28

    Acute intermittent porphyria (AIP) is an autosomal-dominant inborn error of metabolism that results from the half-normal activity of the third enzyme in the heme biosynthetic pathway, hydroxymethylbilane synthase (HMB-synthase). AIP is an ecogenetic condition, since the life-threatening acute attacks are precipitated by various factors, including drugs, alcohol, fasting, and certain hormones. Biochemical diagnosis is problematic, and the identification of mutations in the HMB-synthase gene provides accurate detection of presymptomatic heterozygotes, permitting avoidance of the acute precipitating factors. By direct solid-phase sequencing, two mutations causing AIP were identified, an adenine deletion at position 629 in exon 11(629delA), which alters the reading frame and predicts premature truncation of the enzyme protein after amino acid 255, and a nonsense mutation in exon 12 (R225X). These mutations were confirmed by either restriction enzyme analysis or family studies of symptomatic patients, permitting accurate presymptomatic diagnosis of affected relatives. 29 refs., 2 figs.

  3. Porphyria and anorexia: cause and effect

    OpenAIRE

    Martins, Carlos R.; Bandeira, Barbara E.S.; Martinez, Alberto R. M.; Dalgalarrondo, Paulo; França, Marcondes C.

    2014-01-01

    Porphyrias are hereditary disorders related to impaired biosynthesis of heme and characterized by multisystemic manifestations. Acute intermittent porphyria (AIP) is the most common acute subtype of the disease, and often associated with psychiatric symptoms. We here report a patient who developed acute flaccid paralysis after remarkable weight loss, which was related to an eating disorder (anorexia nervosa). After an extensive neurologic workup, he was diagnosed with AIP. This case emphasize...

  4. Porphyria Presenting as Diffuse Encephalopathy

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    J Gordon Millichap

    2005-05-01

    Full Text Available An 18-year-old female presenting with seizures, myalgias, abdominal pain, headache and vomiting had multiple large contrast-enhancing white matter lesions on MRI and was diagnosed with acute intermittent porphyria (AIP, in a report from the Department of Neurology, Mayo Clinic, Rochester, MN.

  5. (Far) Outside the box: genomic approach to acute porphyria.

    Science.gov (United States)

    Thunell, S

    2006-01-01

    If I were living in Caucasus I would be writing fairy tales there Chekov, 1888 The question of the reasons for the extreme variation in morbidity among the gene carriers of acute porphyria and the great diversity of the precipitating factors are approached by the aid of a model of interacting genomic circuits. It is based on the current paradigm of the acute porphyric attack as a result of a toxic proximal overload of the enzyme-deficient heme-biosynthetic patway. Porphyrogenic influx of precursors is seen as a consequence of uncontrolled induction of its gate-keeping enzyme, ubiquitous 5-aminolevulinate synthase (ALAS1), due to attenuated post-translational control of the enzyme combined with activated gene transcription. Focus is directed on the genomic control of the master-regulator of ALAS1-transcription, the nuclear receptor pair constitutively active receptor (CAR) and pregnane xenobiotic receptor (PXR). On activation by their ligands, i.e. lipophilic drugs, solvents, alcohols, hormonal steroids and biocides, these DNA-binding proteins transform xenobiotic or steroid stimuli to coordinated activations of gene transcription-programs for ALAS1 and apo-cytochromes P450 (apo-CYPs), thus effecting the formation of xenobiotic-metabolizing cytochrome P450 enzymes. The potency of the CAR/PXR-transduction axis is enhanced by co-activators generated in at least four other genomic circuits, each triggered by different external and internal stimuli clinically experienced to be porphyrogenic, and each controlled by co-activating and co-repressing modulators. The expressions of the genes for CAR and PXR are thus augmented by binding glucocorticoid receptor (GR) activated by a steroid hormone, e.g, cortisol generated in fasting, infection or different forms of stress. The promotor regions of ALAS1 and apoCYPs contain binding sites for at least three co-activating transcription factors enhancing CAR/PXR transduction: i.e. the ligand-independent growth hormone (GH

  6. 表现为可逆性后部白质脑病综合征的急性间歇性卟啉病(附1例报告)%Acute intermittent porphyria appeaed as reversible posterior leukoencephalopathy syndrome ( report of 1 case)

    Institute of Scientific and Technical Information of China (English)

    高海凤; 鲁琳; 李永秋

    2012-01-01

    Objective To explore the clinical features of acute intermittent porphyria ( AIP) apperaed as reversible posterior leukoencephalopathy syndrome (RPLS). Methods The clinical date of one AIP patient apperaed as RPLS was retrospectively analyzed. Results This patient was a young woman. The main clinical manifastations were abdominal pain, seizures, psychological symptoms and autonomie nervous dysfunction. The laboratory examination showed hyponatremia, hypochloridemia and uroporphyrin positive. The MR1 indicate diffusely lesions located in bilateral posterior frontal lobe, parital and temporal lobe and bilateral cerebellar hemisphere, which were low signals in T, WI and high signals in T2WI and Flair imaging. The symptom was improved after treated with high volume of glucose and adenosine triphosphate, and the symptomatic treatments like correcting electrolyte turbulence etc. The reexamination of MRI showed the lesions were almost disappeared. Conclusions AIP is a rare cause of RPLS. The AIP patient apperaed as RPLS may suffer abdominal pain and nervous and psychological symptoms. Urine test and MRI may be helpful to diagnose.%目的 探讨表现为可逆性白质脑病综合征(RPLs)的急性间歇性卟啉病(AIP)的临床特点.方法 回顾性分析1例表现为RPLS的AIP患者的临床资料.结果 本例患者为青年女性,临床表现为腹痛、癫痫发作、精神症状、植物神经受累表现,检查发现低钠、低氯血症,尿卟啉定性阳性;头颅MRI示两侧额叶后部、顶叶、颞叶皮质和两侧小脑半球弥漫对称性片状异常信号,T1WI为等或低信号,T2WI及Flair序列呈高信号.经高糖、三磷酸腺苷以及纠正电解质紊乱等治疗后症状改善.复查头颅MRI示病变基本消失.结论 AIP是RPLS的罕见原因之一.表现为RPLS的AIP可有腹痛和神经精神症状等,尿检和影像学检查对诊断有帮助.

  7. Audit of the Use of Regular Haem Arginate Infusions in Patients with Acute Porphyria to Prevent Recurrent Symptoms.

    Science.gov (United States)

    Marsden, Joanne T; Guppy, Simon; Stein, Penelope; Cox, Timothy M; Badminton, Michael; Gardiner, Tricia; Barth, Julian H; Stewart, M Felicity; Rees, David C

    2015-01-01

    The National Acute Porphyria Service (NAPS) provides acute care support and clinical advice for patients in England with active acute porphyria requiring haem arginate treatment and patients with recurrent acute attacks.This audit examined the benefits and complications of regular haem arginate treatment started with prophylactic intent to reduce the frequency of recurrent acute attacks in a group of patients managed through NAPS. We included 22 patients (21 female and 1 male) and returned information on diagnosis, indications for prophylactic infusions, frequency and dose, analgesia, activity and employment and complications including thromboembolic disease and iron overload.The median age at presentation with porphyria was 21 years (range 9-44), with acute abdominal pain as the predominant symptom. Patients had a median of 12 (1-400) attacks before starting prophylaxis and had received a median of 52 (0-1,350) doses of haem arginate. The median age at starting prophylaxis was 28 years (13-58) with a median delay of 4 years (0.5-37) between presentation and prophylaxis. The frequency of prophylactic haem arginate varied from 1 to 8 per month, and 67% patients were documented as having a reduction in pain frequency on prophylaxis. Only one patient developed clinically significant iron overload and required iron chelation, but the number of venous access devices required varied from 1 to 15, with each device lasting a median of 1.2 years before requiring replacement. Six patients stopped haem arginate and in three this was because their symptoms had improved. Prophylactic haem arginate appears to be beneficial in patients with recurrent acute porphyria symptoms, but maintaining central venous access may prove challenging. PMID:25762493

  8. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Directory of Open Access Journals (Sweden)

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  9. Preclinical Development of a Subcutaneous ALAS1 RNAi Therapeutic for Treatment of Hepatic Porphyrias Using Circulating RNA Quantification.

    Science.gov (United States)

    Chan, Amy; Liebow, Abigail; Yasuda, Makiko; Gan, Lin; Racie, Tim; Maier, Martin; Kuchimanchi, Satya; Foster, Don; Milstein, Stuart; Charisse, Klaus; Sehgal, Alfica; Manoharan, Muthiah; Meyers, Rachel; Fitzgerald, Kevin; Simon, Amy; Desnick, Robert J; Querbes, William

    2015-01-01

    The acute hepatic porphyrias are caused by inherited enzymatic deficiencies in the heme biosynthesis pathway. Induction of the first enzyme 5-aminolevulinic acid synthase 1 (ALAS1) by triggers such as fasting or drug exposure can lead to accumulation of neurotoxic heme intermediates that cause disease symptoms. We have demonstrated that hepatic ALAS1 silencing using siRNA in a lipid nanoparticle effectively prevents and treats induced attacks in a mouse model of acute intermittent porphyria. Herein, we report the development of ALN-AS1, an investigational GalNAc-conjugated RNAi therapeutic targeting ALAS1. One challenge in advancing ALN-AS1 to patients is the inability to detect liver ALAS1 mRNA in the absence of liver biopsies. We here describe a less invasive circulating extracellular RNA detection assay to monitor RNAi drug activity in serum and urine. A striking correlation in ALAS1 mRNA was observed across liver, serum, and urine in both rodents and nonhuman primates (NHPs) following treatment with ALN-AS1. Moreover, in donor-matched human urine and serum, we demonstrate a notable correspondence in ALAS1 levels, minimal interday assay variability, low interpatient variability from serial sample collections, and the ability to distinguish between healthy volunteers and porphyria patients with induced ALAS1 levels. The collective data highlight the potential utility of this assay in the clinical development of ALN-AS1, and in broadening our understanding of acute hepatic porphyrias disease pathophysiology. PMID:26528940

  10. Acute Interstitial Nephritis induced by Intermittent use of Rifampicin in Patient with Brucellosis

    Directory of Open Access Journals (Sweden)

    Salih S

    2008-01-01

    Full Text Available Acute oliguric renal failure (ARF developed in a patient 2 days after she was started on intermittent anti-Brucella therapy including rifampicin. The clinical picture was compatible with acute allergic interstitial nephritis. Renal histology revealed mainly acute tubular necrosis with mild tubulo-intertitial mononuclear cellular infiltrate. Intermittent therapy, as in our patient, has been the major factor in the development of rifampicin induced ARF in cases reviewed in literature.

  11. Diet and Nutrition in Porphyria

    Science.gov (United States)

    ... You are here Home About Porphyria Diet and Nutrition A proper diet is important to all individuals, ... alter food intake. Therefore, attention to diet and nutrition is important in almost any disease. Porphyrias are ...

  12. Clinical and genetic features of variegate porphyria in a Chinese patient

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.

  13. Hepatoerythropoietic porphyria: neuroimaging findings.

    Science.gov (United States)

    Berenguer, J; Blasco, J; Cardenal, C; Pujol, T; Cruces Prado, M J; Herrero, C; Mascaró, J M; de la Torre, C; Mercader, J M

    1997-09-01

    CT and MR findings in two patients with hepatoerythropoietic porphyria are presented. CT scans showed atrophy and cortical mineralization at the same level. MR examination performed in one of the two patients showed mainly frontal cortical atrophy and punctate bright signal on T1- and T2-weighted sequences.

  14. Disease: H00202 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available oietic porphyria; Acute Intermittent Porphyria (AIP); Variegate porphyria (VP); ALA-dehydratase deficiency porphyria (ALADP); Heredit...ary Coproporphyria (HCP) Hepatic porphyrias are diseases due to marked deficiencies

  15. [Porphyria cutanea tara].

    Science.gov (United States)

    Merk, H F

    2016-03-01

    Porphyria cutanea tara (PCT) has a prevelance of about 40 new diagnoses per 1 million people per year and is the most frequently occurring type of porphyria worldwide. Inhibition of the uroporphyrinogen decarboxylase (UROD) is the main cause of the disease, which can be the result of a heterozygous or homozygous mutation of the UROD gene; however, xenobiotics or other diseases may play an important role for the precipitation of the disease. Risk factors include alcohol, estrogen, iron overload, and hemochromatosis, hepatitis C or poisoning, e.g., with polyhalogenated aromatic compounds such as hexachlorobenzene. Signs and symptoms are blisters, skin fragility, erosions hyperpigmentation, sclerodermoid plaques. Therapy includes sun protection, prevention of risk factors, phlebotomy, and chloroquine. PMID:26743054

  16. Congenital erythropoietic porphyria in three siblings.

    Science.gov (United States)

    Bari, Arfan Ul

    2007-01-01

    Congenital erythropoietic porphyria is a rare autosomal recessive disorder that usually presents with marked skin photosensitivity, hypertrichosis, blistering, scarring, milia formation and dyspigmentation of the photo-exposed areas. Three adult siblings (two sisters and one brother) are presented here with variable degree of skin manifestations. During early childhood, all the siblings started showing signs of photosensitivity with darkening of urine color followed by skin blistering over the face and hands. The oldest showed severe sclerodermiform mutilation and the youngest exhibited an initial involvement with hypertrichosis. None of them had any history of convulsions, acute abdominal pain or joint pain. Woods lamp examination and laboratory investigations confirmed the diagnosis. PMID:17921617

  17. Porphyria Cutanea Tarda and Agent Orange

    Science.gov (United States)

    ... ZIP code here Porphyria Cutanea Tarda and Agent Orange VA presumes porphyria cutanea tarda (PCT) is related to Veterans' exposure to Agent Orange or other herbicides during military service when the ...

  18. Diaphragm long-term facilitation following acute intermittent hypoxia during wakefulness and sleep

    OpenAIRE

    Terada, J.; Mitchell, G.S.

    2011-01-01

    Acute intermittent hypoxia (AIH) elicits a form of respiratory plasticity known as long-term facilitation (LTF). Here, we tested four hypotheses in unanesthetized, spontaneously breathing rats using radiotelemetry for EEG and diaphragm electromyography (Dia EMG) activity: 1) AIH induces LTF in Dia EMG activity; 2) diaphragm LTF (Dia LTF) is more robust during sleep vs. wakefulness; 3) AIH (or repetitive AIH) disrupts natural sleep-wake architecture; and 4) preconditioning with daily AIH (dAIH...

  19. LIPOPOLYSACCHARIDE ATTENUATES PHRENIC LONG-TERM FACILITATION FOLLOWING ACUTE INTERMITTENT HYPOXIA

    OpenAIRE

    Vinit, Stéphane; Windelborn, James A; Mitchell, Gordon S.

    2011-01-01

    Lipopolysaccharide (LPS) induces inflammatory responses, including microglial activation in the central nervous system. Since LPS impairs certain forms of hippocampal and spinal neuroplasticity, we hypothesized that LPS would impair phrenic long-term facilitation (pLTF) following acute intermittent hypoxia (AIH) in outbred Sprague-Dawley (SD) and inbred Lewis (L) rats.. Approximately three hours following a single LPS injection (i.p.), the phrenic response during hypoxic episodes is reduced i...

  20. Effects of Acutely Intermittent Hypoxic Exposure on Running Economy and Physical Performance in Basketball Players.

    Science.gov (United States)

    Kilding, Andrew E; Dobson, Bryan P; Ikeda, Erika

    2016-07-01

    Kilding, AE, Dobson, BP, and Ikeda, E. Effects of acutely intermittent hypoxic exposure on running economy and physical performance in basketball players. J Strength Cond Res 30(7): 2033-2042, 2016-The aim of this study was to determine the effect of short duration intermittent hypoxic exposure (IHE) on physical performance in basketball players. Using a single-blind placebo-controlled group design, 14 trained basketball players were subjected to 15 days of passive short duration IHE (n = 7), or normoxic control (CON, n = 7), using a biofeedback nitrogen dilution device. A range of physiological, performance, and hematological variables were measured at baseline, and 10 days after IHE. After intervention, the IHE group, relative to the CON group, exhibited improvements in the Yo-Yo intermittent recovery level 1 (+4.8 ± 1.6%; effect size [ES]: 1.0 ± 0.4) and repeated high-intensity exercise test performance (-3.5 ± 1.6%; ES: -0.4 ± 0.2). Changes in hematological parameters were minimal, although soluble transferrin receptor increased after IHE (+9.2 ± 10.1%; ES: 0.3 ± 0.3). Running economy at 11 km·h (-9.0 ± 9.7%; ES: -0.7 ± 0.7) and 13 km·h was improved (-8.2 ± 6.9%; ES: -0.7 ± 0.5), but changes to V[Combining Dot Above]O2peak, HRpeak, and lactate were unclear. In summary, acutely IHE resulted in worthwhile changes in physical performance tests among competitive basketball players. However, physiological measures explaining the performance enhancement were in most part unclear. PMID:26677826

  1. Phase II study of profiromycin vs mitomycin-C utilizing acute intermittent schedules.

    Science.gov (United States)

    Baker, L H; Izbicki, R M; Vaitkevicius, V K

    1976-01-01

    A randomized prosective study of Mitomycin-C and its N-methyl derivative, Porfiromycin, was conducted. Thirty-two patients with disseminated gastrointestinal cancer or other disseminated abdominal adenocarcinoma were treated with Mitomycin-C; 31 patients received Porfiromycin. Both drugs were given by acute intermittent bolus schedule (Mitomucin-C , 22.5 mg/M2 or Porfiromycin, 75 mg/M2 every 6--8 weeks as a single bolus i.v. injection). Eleven patients (34%) who received Mitomycin-C entered into partial remission. In 10 of the 31 patients (32%) receiving Porfiromycin, partial remission occured. Analysis by tumor type demonstrated that in the Mitomycin-C treated group responses occured in 4 of 12 patients with colorectal carcinoma, in 4 of 9 with upper GI cancers, and in 3 of 11 with ovarian cancer. Correspondingly in Porfiromycin group responses occured in 2 of 12 colorectal carcinoma patients, in 3 of 7 upper GI cancer patients, and in 5 of 12 ovarian cancer patients. Both drugs produced significant myelosuppression; however, Porfiromycin toxicity appeared more cumulative. Further clinical trial of Mitomycin in an acute intermittent bolus schedule appears justified. PMID:958162

  2. Past and future: porphyria and porphyrins.

    Science.gov (United States)

    Norman, Robert A

    2005-01-01

    Porphyria is a compelling disease--disrupted enzyme pathways, heightened sensitivities, and a fascinating history tied in with tales of Dracula. This review discusses the history, pathophysiology, classification, and treatment of porphyria. It further discusses the way in which research on the etiologies of the various porphyrias has led to the development of porphyrin-based photodynamic therapy, which shows great promise in targeted therapy for a variety of serious pathologies.

  3. Acute effects of cigarette smoking on inflammation in healthy intermittent smokers

    Directory of Open Access Journals (Sweden)

    Vonk Judith M

    2005-03-01

    Full Text Available Abstract Background Chronic smoking is the main risk factor for chronic obstructive pulmonary disease. Knowledge on the response to the initial smoke exposures might enhance the understanding of changes due to chronic smoking, since repetitive acute smoke effects may cumulate and lead to irreversible lung damage. Methods We investigated acute effects of smoking on inflammation in 16 healthy intermittent smokers in an open randomised cross-over study. We compared effects of smoking of two cigarettes on inflammatory markers in exhaled air, induced sputum, blood and urine at 0, 1, 3, 6, 12, 24, 48, 96 and 192 hours and outcomes without smoking. All sputum and blood parameters were log transformed and analysed using a linear mixed effect model. Results Significant findings were: Smoking increased exhaled carbon monoxide between 0 and 1 hour, and induced a greater decrease in blood eosinophils and sputum lymphocytes between 0 and 3 hours compared to non-smoking. Compared to non-smoking, smoking induced a greater interleukin-8 release from stimulated blood cells between 0 and 3 hours, and a greater increase in sputum lymphocytes and neutrophils between 3 and 12 hours. Conclusion We conclude that besides an increase in inflammation, as known from chronic smoking, there is also a suppressive effect of smoking two cigarettes on particular inflammatory parameters.

  4. Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients.

    Directory of Open Access Journals (Sweden)

    Jonathan C Jun

    Full Text Available Obstructive Sleep Apnea (OSA describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep.Nine obese (BMI = 40.4 ± 3.5 subjects with severe OSA (AHI = 88.9 ± 6.8 adherent to CPAP were studied during one night in the sleep laboratory. Nasal CPAP was delivered at therapeutic (11.1 ± 0.6 cm H20 or atmospheric pressure, in alternating fashion for 1-hour periods during the night. We compared sleep architecture and metrics of OSA during CPAP-on and CPAP-off periods.8/9 subjects tolerated CPAP withdrawal. The average AHI during CPAP-on and CPAP-off periods was 3.6 ± 0.6 and 15.8 ± 3.6 respectively (p<0.05. The average 3% ODI during CPAP-on and CPAP-off was 4.7 ± 2 and 20.4 ± 4.7 respectively (p<0.05. CPAP depressurization also induced more awake (p<0.05 and stage N1 (p<0.01 sleep, and less stage REM (p<0.05 with a trend towards decreased stage N3 (p = 0.064.Acute intermittent depressurization of CPAP during sleep led to deterioration of sleep architecture but only partial re-emergence of OSA. These observations suggest carryover effects of CPAP.

  5. Chronic intermittent hypoxia alters ventilatory and metabolic responses to acute hypoxia in rats.

    Science.gov (United States)

    Morgan, Barbara J; Adrian, Russell; Wang, Zun-Yi; Bates, Melissa L; Dopp, John M

    2016-05-15

    We determined the effects of chronic exposure to intermittent hypoxia (CIH) on chemoreflex control of ventilation in conscious animals. Adult male Sprague-Dawley rats were exposed to CIH [nadir oxygen saturation (SpO2), 75%; 15 events/h; 10 h/day] or normoxia (NORM) for 21 days. We assessed the following responses to acute, graded hypoxia before and after exposures: ventilation (V̇e, via barometric plethysmography), V̇o2 and V̇co2 (analysis of expired air), heart rate (HR), and SpO2 (pulse oximetry via neck collar). We quantified hypoxia-induced chemoreceptor sensitivity by calculating the stimulus-response relationship between SpO2 and the ventilatory equivalent for V̇co2 (linear regression). An additional aim was to determine whether CIH causes proliferation of carotid body glomus cells (using bromodeoxyuridine). CIH exposure increased the slope of the V̇e/V̇co2/SpO2 relationship and caused hyperventilation in normoxia. Bromodeoxyuridine staining was comparable in CIH and NORM. Thus our CIH paradigm augmented hypoxic chemosensitivity without causing glomus cell proliferation. PMID:26917692

  6. Effects of acute intermittent hypoxia on energy balance and hypothalamic feeding pathways.

    Science.gov (United States)

    Moreau, J M; Ciriello, J

    2013-12-01

    This study was done to investigate the effects of acute intermittent hypoxia (IH) on metabolic factors associated with energy balance and body weight, and on hypothalamic satiety-inducing pathways. Adult male Sprague-Dawley rats were exposed to either 8h IH or normoxic control conditions. Food intake, locomotion and body weights were examined after IH. Additionally, plasma levels of leptin, adiponectin corticosterone, insulin and blood glucose were measured following exposure to IH. Furthermore, adipose tissue was removed and analyzed for leptin and adiponectin content. Finally, the hypothalamic arcuate nucleus (ARC) was assessed for alterations in protein signaling associated with satiety. IH reduced body weight, food intake and active cycle locomotion without altering adipose tissue mass. Leptin protein content was reduced while adiponectin content was elevated in adipose tissue after IH. Plasma concentration of leptin was significantly increased while adiponectin decreased after IH. No changes were found in plasma corticosterone, insulin and blood glucose. In ARC, phosphorylation of signal transducer and activator of transcription-3 and pro-opiomelanocortin (POMC) expression were elevated. In addition, POMC-expressing neurons were activated as determined by immediate early gene FRA-1/2 expression. Finally, ERK1/2 and its phosphorylation were reduced in response to IH. These data suggest that IH induces significant alterations to body energy balance through changes in the secretion of leptin which exert effects on satiety-inducing pathways within the hypothalamus.

  7. Sporadic porphyria cutanea tarda due to haemochromatosis

    OpenAIRE

    Geus, Hilde; Dees, A.

    2006-01-01

    textabstractHaemochromatosis is a hereditary iron-overload syndrome caused by increased intestinal iron absorption and characterised by accumulation of potentially toxic iron in the tissues. Sometimes this disease presents as a cutanea porphyria. We describe a patient with joint complaints and blistering skin lesions on sun-exposed skin. After identifying the porphyria cutanea tarda by urine analysis we found that the serum activity of uroporphyrinogen decarboxylase (UROD) was normal, meaning...

  8. Repetitive acute intermittent hypoxia increases growth/neurotrophic factor expression in non-respiratory motor neurons.

    Science.gov (United States)

    Satriotomo, I; Nichols, N L; Dale, E A; Emery, A T; Dahlberg, J M; Mitchell, G S

    2016-05-13

    Repetitive acute intermittent hypoxia (rAIH) increases growth/trophic factor expression in respiratory motor neurons, thereby eliciting spinal respiratory motor plasticity and/or neuroprotection. Here we demonstrate that rAIH effects are not unique to respiratory motor neurons, but are also expressed in non-respiratory, spinal alpha motor neurons and upper motor neurons of the motor cortex. In specific, we used immunohistochemistry and immunofluorescence to assess growth/trophic factor protein expression in spinal sections from rats exposed to AIH three times per week for 10weeks (3×wAIH). 3×wAIH increased brain-derived neurotrophic factor (BDNF), its high-affinity receptor, tropomyosin receptor kinase B (TrkB), and phosphorylated TrkB (pTrkB) immunoreactivity in putative alpha motor neurons of spinal cervical 7 (C7) and lumbar 3 (L3) segments, as well as in upper motor neurons of the primary motor cortex (M1). 3×wAIH also increased immunoreactivity of vascular endothelial growth factor A (VEGFA), the high-affinity VEGFA receptor (VEGFR-2) and an important VEGF gene regulator, hypoxia-inducible factor-1α (HIF-1α). Thus, rAIH effects on growth/trophic factors are characteristic of non-respiratory as well as respiratory motor neurons. rAIH may be a useful tool in the treatment of disorders causing paralysis, such as spinal injury and motor neuron disease, as a pretreatment to enhance motor neuron survival during disease, or as preconditioning for cell-transplant therapies. PMID:26944605

  9. Intermittent and continuous high-intensity exercise training induce similar acute but different chronic muscle adaptations.

    Science.gov (United States)

    Cochran, Andrew J R; Percival, Michael E; Tricarico, Steven; Little, Jonathan P; Cermak, Naomi; Gillen, Jenna B; Tarnopolsky, Mark A; Gibala, Martin J

    2014-05-01

    High-intensity interval training (HIIT) performed in an 'all-out' manner (e.g. repeated Wingate tests) is a time-efficient strategy to induce skeletal muscle remodelling towards a more oxidative phenotype. A fundamental question that remains unclear, however, is whether the intermittent or 'pulsed' nature of the stimulus is critical to the adaptive response. In study 1, we examined whether the activation of signalling cascades linked to mitochondrial biogenesis was dependent on the manner in which an acute high-intensity exercise stimulus was applied. Subjects performed either four 30 s Wingate tests interspersed with 4 min of rest (INT) or a bout of continuous exercise (CONT) that was matched for total work (67 ± 7 kJ) and which required ∼4 min to complete as fast as possible. Both protocols elicited similar increases in markers of adenosine monophosphate-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase activation, as well as Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) mRNA expression (main effects for time, P ≤ 0.05). In study 2, we determined whether 6 weeks of the CONT protocol (3 days per week) would increase skeletal muscle mitochondrial content to a similar extent to what we have previously reported after 6 weeks of INT. Despite similar acute signalling responses to the CONT and INT protocols, training with CONT did not increase the maximal activity or protein content of a range of mitochondrial markers. However, peak oxygen uptake was higher after CONT training (from 45.7 ± 5.4 to 48.3 ± 6.5 ml kg(-1) min(-1); P muscle adaptations to low-volume, all-out HIIT. Despite the lack of skeletal muscle mitochondrial adaptations, our data show that a training programme based on a brief bout of high-intensity exercise, which lasted <10 min per session including warm-up, and performed three times per week for 6 weeks, improved peak oxygen uptake in young healthy subjects.

  10. Intermittent acute aortic valve regurgitation: A case report of a prosthetic valve dysfunction

    NARCIS (Netherlands)

    S.E. Karagiannis (Stefanos); G. Karatasakis (George); K. Spargias (Konstantinos); L. Louka; D. Poldermans (Don); D.V. Cokkinos (Dennis)

    2008-01-01

    textabstractComplications of any mechanical prosthesis include thrombus or pannus formation. In our case report we demonstrate that prosthetic aortic valve regurgitation due to pannus formation may be intermittent and non-cyclic in pattern and therefore not obvious at the time of original clinical e

  11. Herbicide-induced experimental variegate porphyria in mice: tissue porphyrinogen accumulation and response to porphyrogenic drugs.

    Science.gov (United States)

    Krijt, J; Stranska, P; Maruna, P; Vokurka, M; Sanitrak, J

    1997-01-01

    Administration of oxadiazon or oxyfluorfen (1000 ppm in the diet) to male BALB/c mice for 9 days resulted in experimental porphyria, resembling the acute phase of human variegate porphyria. Urinary concentrations of 5-aminolevulinic acid and porphobilinogen reached 1500 and 3000 mumol/L, respectively. Both herbicides caused a decrease of protoporphyrinogen oxidase activity in liver and kidney. Brain protoporphyrinogen oxidase activity was not altered. Liver and kidney porphyrin content increased to 11 and 17 nmol/g, respectively (control mice, 2 nmol/g). Over 50% of liver and kidney porphyrins were in the reduced (porphyrinogen) form. Bile of oxadiazon-treated mice contained 700 nmol/mL of protoporphyrinogen (control mice, 15 nmol/mL). Porphyrin content of the trigeminal nerve increased from 1 nmol/g in control animals to 11 nmol/g in oxadiazon-treated animals, suggesting a possible contribution of peripheral nerve porphyrins to porphyric neuropathy. Mice treated with 125 ppm of oxadiazon in the diet for 9 days excreted moderately elevated levels of porphobilinogen in urine (control mice, less than 50 mumol/L; treated mice, 330 mumol/L). Administration of phenobarbital or phenytoin (single injections on days 7, 8, and 9) increased the urinary porphobilinogen concentration to 3500 mumol/L. This response to porphyrogenic drugs resembles the response observed in human acute porphyrias. PMID:9431441

  12. Porphyria cutanea tarda in a HIV- positive patient.

    Science.gov (United States)

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  13. Porphyria cutanea tarda in a HIV- positive patient*

    Science.gov (United States)

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  14. Intermittent Exposure to Social Defeat and Open-field Test in Rats : Acute and Long-term Effects on ECG, Body Temperature and Physical Activity

    NARCIS (Netherlands)

    Sgoifo, Andrea; Pozzato, Chiara; Meerlo, Peter; Costoli, Tania; Manghi, Massimo; Stilli, Donatella; Olivetti, Giorgio; Musso, Ezio

    2002-01-01

    This study investigated the effects of exposure to an intermittent homotypic stressor on: (i) habituation of acute autonomic responsivity (i.e. cardiac sympathovagal balance and susceptibility to arrhythmias), and (ii) circadian rhythmicity of heart rate, body temperature, and physical activity. Aft

  15. Human Immunodeficiency Virus Associated Sporadic Nonfamilial Porphyria Cutanea Tarda.

    Science.gov (United States)

    Guha, Sibashish Kamal; Bandyopadhyay, Debabrata; Saha, Abanti; Lal, Niharika Ranjan

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT. PMID:27293254

  16. Acute effects of plyometric jumping and intermittent running on serum bone markers in young males.

    Science.gov (United States)

    Lin, Che-Fu; Huang, Tsang-hai; Tu, Kuo-Cheng; Lin, Linda L; Tu, Yi-Hsuan; Yang, Rong-Sen

    2012-04-01

    The purpose of this study was to investigate whether different modes of single-bout exercise would cause different responses in short-term bone metabolism. 24 untrained male college students (19.1 ± 0.1 years old) were recruited and randomly assigned to three groups: (1) a single-bout plyometric exercise group (the PL group, n = 8), (2) a 200-meter × 10 intermittent running group (the IR group, n = 8) and (3) a sedentary control group, which followed the same time schedule of experimentation without performing any exercise (the CON group, n = 8). Serial blood samples were collected before (baseline) and 5 min, 15 min, 1 h, 3 h, 6 h, 24 h, 48 h, and 72 h after exercise trials. Within 15 min of exercise, the PL and IR groups showed significantly higher serum phosphorus than did the control group (P < 0.05). Osteocalcin levels were significantly higher in the PL group at 5 min and 1 h after exercise (P < 0.05), while serum tartrate-resistant acid phosphatase (TRAP) showed no differences among groups. Exercises with different mechanical impact levels responded differently in serum bone formation markers as shown by osteocalcin. Because the increase in osteocalcin in the PL group was revealed shortly after the exercise bout, the changes might due to an exercise-induced mechanical impact rather than bone cellular activities. PMID:21837450

  17. The effects of acute intermittent hypoxia on cardiovascular parameters in normotensive and chronic hypobaric hypoxia-induced hypertensive rabbits.

    Science.gov (United States)

    Yaman, Muhittin O; Guner, Ibrahim; Uzun, Hafize; Sahin, Gulderen; Yelmen, Nermin

    2014-01-01

    The effects of both chronic hypoxia and acute intermittent hypoxia (AIH) on cardiovascular system are unclear. We designed this study to develop a rabbit model of hypertension by exposure to chronic hypobaric hypoxia (CHH) and to investigate the effects of AIH on hypertensive rabbits. Present study was performed in 13 albino rabbits that divided into CHH and control groups. To develop hypertension, the rabbits were placed in a hypobaric chamber (390 mmHg; 22 hours/day, 30 days). Afterwards, AIH protocol was applied (8% FIO2 (Fraction of Inspired Oxygen) 1 min + 5 min normoxia, 20 cycles, 2 hours) to rabbits anesthetized with urethane and alpha-chloralose. Mean arterial pressure (MAP), heart rate (HR) and hematocrit values have been determined. Also asymmetric dimethylarginine (ADMA), endothelial nitric oxide synthase (eNOS), endothelin-1 and norepinephrine values have been analyzed in blood. We developed a model of hypertension in rabbits via exposure to severe CHH and we believe that ADMA is an important parameter in the development and permanence of CHH-induced hypertension. The main finding of this sudy was the depressor effect of AIH on blood pressure and heart rate in CHH- induced hypertension model. Finally, we believe that AIH protocol may be applicable for prevention and treatment of hypertension if properly developed. PMID:24448370

  18. Intermittent exposure to social defeat and open-field test in rats: acute and long-term effects on ECG, body temperature and physical activity.

    Science.gov (United States)

    Sgoifo, Andrea; Pozzato, Chiara; Meerlo, Peter; Costoli, Tania; Manghi, Massimo; Stilli, Donatella; Olivetti, Giorgio; Musso, Ezio

    2002-02-01

    This study investigated the effects of exposure to an intermittent homotypic stressor on: (i) habituation of acute autonomic responsivity (i.e. cardiac sympathovagal balance and susceptibility to arrhythmias), and (ii) circadian rhythmicity of heart rate, body temperature, and physical activity. After implantation of a transmitter for the radiotelemetric recording of electrocardiogram (ECG), body temperature and physical activity, adult male rats (Rattus norvegicus, Wild Type Groningen strain) were repeatedly exposed (10 consecutive times, on alternate days) to either a social stressor (defeat by a con-specific, n = 15) or an open-field, control challenge (transfer to a new cage; n = 8). ECGs, body temperature and physical activity were continuously recorded in baseline, test and recovery periods (each lasting 15 min), at the 1st and 10th episodes of both defeat and open-field challenge. The circadian rhythms of heart rate, body temperature and physical activity were monitored before (5 days), during (16 days) and after (21 days) the intermittent stress protocol. This study indicates that there is no clear habituation of either acute cardiac autonomic responsivity (as estimated by means of time-domain indexes of heart rate variability) or arrhythmia occurrence to a brief, intermittent, homotypic challenge, regardless of the nature of the stressor (social or non-social). On the other hand, rats exposed to social challenge also failed to show adaptation of acute temperature and activity stress responsiveness, whereas rats facing open-field challenge developed habituation of activity and sensitization of temperature responses. Repeated social challenge produced remarkable reductions of the heart rate circadian rhythm amplitude (this effect being significantly greater than that produced by intermittent open-field), but only minor changes in the daily rhythms of body temperature and physical activity. PMID:12171764

  19. Acute impact of intermittent pneumatic leg compression frequency on limb hemodynamics, vascular function, and skeletal muscle gene expression in humans.

    Science.gov (United States)

    Sheldon, Ryan D; Roseguini, Bruno T; Thyfault, John P; Crist, Brett D; Laughlin, M H; Newcomer, Sean C

    2012-06-01

    The mechanisms by which intermittent pneumatic leg compression (IPC) treatment effectively treats symptoms associated with peripheral artery disease remain speculative. With the aim of gaining mechanistic insight into IPC treatment, the purpose of this study was to investigate the effect of IPC frequency on limb hemodynamics, vascular function, and skeletal muscle gene expression. In this two study investigation, healthy male subjects underwent an hour of either high-frequency (HF; 2-s inflation/3-s deflation) or low-frequency (LF; 4-s inflation/16-s deflation) IPC treatment of the foot and calf. In study 1 (n = 11; 23.5 ± 4.7 yr), subjects underwent both HF and LF treatment on separate days. Doppler/ultrasonography was used to measure popliteal artery diameter and blood velocity at baseline and during IPC treatment. Flow-mediated dilation (FMD) and peak reactive hyperemia blood flow (RHBF) were determined before and after IPC treatment. In study 2 (n = 19; 22.0 ± 4.6 yr), skeletal muscle biopsies were taken from the lateral gastrocnemius of the treated and control limb at baseline and at 30- and 150-min posttreatment. Quantitative PCR was used to assess mRNA concentrations of genes associated with inflammation and vascular remodeling. No treatment effect on vascular function was observed. Cuff deflation resulted in increased blood flow (BF) and shear rate (SR) in both treatments at the onset of treatment compared with baseline (P inflation. IPC decreased the mRNA expression of cysteine-rich protein 61 from baseline and controls (P <0 .01) and connective tissue growth factor from baseline (P < 0.05) in a frequency-dependent manner. In conclusion, a single session of IPC acutely impacts limb hemodynamics and skeletal muscle gene expression in a frequency-dependent manner but does not impact vascular function.

  20. Intermittent use of amifostine during postoperative radiochemotherapy and acute toxicity in rectal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Dunst, J.; Semlin, S.; Pigorsch, S.; Mueller, A.C.; Reese, T. [Halle-Wittenberg Univ., Halle (Germany). Abt. fuer Radiotherapie

    2000-09-01

    From September 1997 through October 1998, 30 patients with stage II/III rectal cancer underwent postoperative radiochemotherapy at our department. All patients had undergone curative (R0) resection and received 50.4 Gy to the pelvis with a 3-field technique using a belly board followed by a boost of 5.4 Gy to the presacral space in conventional fractionation with 1.8 Gy per fraction. 5-FU chemotherapy was administered as 120-hours continuous infusion in the first and fifth radiation week via a central venous catheter in a daily dosage of 1000 mg/m{sup 2}. All patients were offered to participate in a phase-II study using additional amifostine. Fifteen patients participated and received 500 mg amifostine daily on chemotherapy days (days 1 to 5 and 29 to 33) immediately prior to the daily radiation fraction. Fifteen patients did not participate and served as non-randomized control. The study was approved by the ethical committee of the Martin-Luter-University and informed consent was obtained from all patients. Results: The distribution of patients' characteristics and prognostic parameters was comparable in both groups. Side effects of amifostine were mild and included hypotension (53% grade I, 7% grade II) and nausea (47% grade I, 13% grade II). Antiemetics were not routinely used. All patients completed radiochemotherapy plus amifostine without unplanned breaks or dose reductions. One patients developed a cerebral infraction which was considered to be not related to the use of amifostine. As compared to the non-randomized control group, patients with additional amifostine had less acute skin and bowel toxicity (maximum erythema score 1.47{+-}0.64 without vs 0.87{+-}0.52 with amifostine, p=0.009 and maximum diarrhea score 1.07{+-}1.03 vs 0.40{+-}0.63, p=0.044). Oral 5-FU-related mucositis and hematological toxicity were not significantly different. (orig.) [German] Zwischen September 1997 und Oktober 1998 wurden 15 Patienten mit postoperativer

  1. Acute Flaccid paralysis in adults: Our experience

    Directory of Open Access Journals (Sweden)

    Rupesh Kaushik

    2014-01-01

    Full Text Available Acute flaccid paralysis (AFP is a complex clinical syndrome with a broad array of potential etiologies that vary with age. We present our experience of acute onset lower motor neuron paralysis. Materials and Methods: One hundred and thirty-three consecutive adult patients presenting with weakness of duration less than four weeks over 12 months period were enrolled. Detailed history, clinical examination, and relevant investigations according to a pre-defined diagnostic algorithm were carried out. The patients were followed through their hospital stay till discharge or death. Results: The mean age was 33.27 (range 13-89 years with male preponderance (67.7%. The most common etiology was neuroparalytic snake envenomation (51.9%, followed by Guillain Barre syndrome (33.1%, constituting 85% of all patients. Hypokalemic paralysis (7.5% and acute intermittent porphyria (4.5% were the other important conditions. We did not encounter any case of acute polio mylitis in adults. In-hospital mortality due to respiratory paralysis was 9%. Conclusion: Neuroparalytic snakebite and Guillain Barre syndrome were the most common causes of acute flaccid paralysis in adults in our study.

  2. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    Directory of Open Access Journals (Sweden)

    Chang SC

    2016-05-01

    Full Text Available Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective: We evaluated pressure-regulated volume control (PRVC ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods: Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results: Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2, and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2 levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both; after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05. Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05. The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48

  3. Predicting Changes in High-Intensity Intermittent Running Performance with Acute Responses to Short Jump Rope Workouts in Children

    Directory of Open Access Journals (Sweden)

    Martin Buchheit

    2014-09-01

    Full Text Available The aims of the present study were to 1 examine whether individual HR and RPE responses to a jump rope workout could be used to predict changes in high-intensity intermittent running performance in young athletes, and 2 examine the effect of using different methods to determine a smallest worthwhile change (SWC on the interpretation of group-average and individual changes in the variables. Before and after an 8-week high-intensity training program, 13 children athletes (10.6 ± 0.9 yr performed a high-intensity running test (30-15 Intermittent Fitness Test, VIFT and three jump rope workouts, where HR and RPE were collected. The SWC was defined as either 1/5th of the between-subjects standard deviation or the variable typical error (CV. After training, the large ~9% improvement in VIFT was very likely, irrespective of the SWC. Standardized changes were greater for RPE (very likely-to-almost certain, ~30-60% changes, ~4-16 times >SWC than for HR (likely-to-very likely, ~2-6% changes, ~1-6 times >SWC responses. Using the CV as the SWC lead to the smallest and greatest changes for HR and RPE, respectively. The predictive value for individual performance changes tended to be better for HR (74-92% than RPE (69%, and greater when using the CV as the SWC. The predictive value for no-performance change was low for both measures (<26%. Substantial decreases in HR and RPE responses to short jump rope workouts can predict substantial improvements in high-intensity running performance at the individual level. Using the CV of test measures as the SWC might be the better option.

  4. Similar Anti-Inflammatory Acute Responses from Moderate-Intensity Continuous and High-Intensity Intermittent Exercise

    Directory of Open Access Journals (Sweden)

    Carolina Cabral-Santos, José Gerosa-Neto, Daniela Sayuri Inoue, Valéria Leme Gonçalves Panissa, Luís Alberto Gobbo, Alessandro Moura Zagatto, Eduardo Zapaterra Campos, Fábio Santos Lira

    2015-12-01

    Full Text Available The purpose of this study was to compare the effect of high-intensity intermittent exercise (HIIE versus volume matched steady state exercise (SSE on inflammatory and metabolic responses. Eight physically active male subjects completed two experimental sessions, a 5-km run on a treadmill either continuously (70% vVO2max or intermittently (1:1 min at vVO2max. Blood samples were collected at rest, immediately, 30 and 60 minutes after the exercise session. Blood was analyzed for glucose, non-ester fatty acid (NEFA, uric acid, lactate, cortisol, and cytokines (IL-6, IL-10 and TNF-α levels. The lactate levels exhibited higher values immediately post-exercise than at rest (HIIE 1.34 ± 0.24 to 7.11 ± 2.85, and SSE 1.35 ± 0.14 to 4.06±1.60 mmol·L-1, p 0.05. Cortisol, IL-6, IL-10 and TNF-α levels showed time-dependent changes under the different conditions (p < 0.05, however, the area under the curve of TNF-α in the SSE were higher than HIIE (p < 0.05, and the area under the curve of IL-6 in the HIIE showed higher values than SSE (p < 0.05. In addition, both exercise conditions promote increased IL-10 levels and IL-10/TNF-α ratio (p < 0.05. In conclusion, our results demonstrated that both exercise protocols, when volume is matched, promote similar inflammatory responses, leading to an anti-inflammatory status; however, the metabolic responses are different.

  5. Acute and delayed effects of intermittant ozone on cardiovascular and thermoregulatory responses of young and aged rats

    Science.gov (United States)

    Ozone (03) is associated with cardiovascular and respiratory diseases. The aged population is considered to be more sensitive to air pollutants but relatively few studies have demonstrated increased susceptibility in animal models of aging. To study the acute and delayed physiolo...

  6. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    International Nuclear Information System (INIS)

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P < 0.05). Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P < 0.05). A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase) was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05). These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity

  7. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, A.M. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bagatini, M.D. [Curso de Enfermagem, Campus Chapecó, Universidade Federal da Fronteira Sul, Chapecó, SC (Brazil); Roth, M.A. [Departamento de Desportos Individuais, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Martins, C.C.; Rezer, J.F.P. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Mello, F.F. [Departamento de Desportos Individuais, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Lopes, L.F.D. [Departamento de Administração, Centro de Ciências Sociais e Humanas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Morsch, V.M.; Schetinger, M.R.C. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2012-10-26

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P < 0.05). Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P < 0.05). A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase) was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05). These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity.

  8. Congenital erythropoietic porphyria in an African hedgehog (Atelerix albiventris).

    Science.gov (United States)

    Wolff, Carlos; Corradini, Paulina; Cortés, Galaxia

    2005-06-01

    A 6-mo-old, male African hedgehog (Atelerix albiventris) presented with a history of pink urine and demonstrating pink-colored teeth and mild hepatomegaly on examination. Urinalysis revealed no physical, chemical, or cellular abnormalities other than a pink color and fluorescence under ultraviolet light (UV). Also under UV, intense fluorescence of teeth, feet, and spines was noted. Porphyria was suspected. Spectrophotometric evaluation of urine showed extremely elevated levels of copro- and uroporphyrins. Analysis of the urine by thin-layer chromatography showed an abnormal pattern of excreted porphyrin intermediates. Urine high-performance thin-layer chromatography showed that excreted porphyrins were 90-95% of the type-I isomeric form, suggestive of congenital erythropoietic porphyria. PMID:17323578

  9. The acute effects of intermittent treadmill running on hunger and plasma acylated ghrelin concentration in individuals with obesity

    Directory of Open Access Journals (Sweden)

    Gholipour M

    2011-05-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Body weight is regulated by both food intake and energy expenditure. Ghrelin, a hormone produced by the stomach and pancreas, enhances appetite. This study was undertaken to determine the effects of intermittent treadmill running on acylated ghrelin and appetite in individuals with obesity."n"nMethods : Nine inactive male students, with a mean age of 20.56±0.48 yrs, a body mass index of 32.68±0.84 kg/m2 and a maximum oxygen uptake of 34.21±1.48 ml/kg/min, participated in the study in two trials (control and exercise in a counterbalanced, randomized design. The protocol included intermittent running with a constant intensity at 65% of VO2 max on a treadmill. Blood samples were collected before, during, and 2h after cessation of the exercise."n"nResults : Acylated ghrelin concentrations and hunger ratings decreased significantly in the second phase and remained lower than baseline (P=0.006 and P=0.002, respectively at the end of the exercise. The total area under the curve values and hunger ratings (all P<0.0005 were significantly lower in the exercise trial compared with the control state. Similarly, growth hormone rose significantly at the second phase and remained higher than baseline (P=0.033 at the

  10. Uroporphyrinogen decarboxylase gene mutations in Danish patients with porphyria cutanea tarda

    DEFF Research Database (Denmark)

    Christiansen, L; Bygum, A; Jensen, A;

    2000-01-01

    Decreased uroporphyrinogen decarboxylase (UROD) activity is a characteristic feature of the most common of the porphyrias, porphyria cutanea tarda (PCT). A subgroup of the clinically overt PCT cases is associated with mutations in the gene encoding UROD and inherited as an autosomal-dominant trai...

  11. Acute inhibition of glial cells in the NTS does not affect respiratory and sympathetic activities in rats exposed to chronic intermittent hypoxia.

    Science.gov (United States)

    Costa, Kauê M; Moraes, Davi J A; Machado, Benedito H

    2013-02-16

    Recent studies suggest that neuron-glia interactions are involved in multiple aspects of neuronal activity regulation. In the nucleus tractus solitarius (NTS) neuron-glia interactions are thought to participate in the integration of autonomic responses to physiological challenges. However, it remains to be shown whether NTS glial cells might influence breathing and cardiovascular control, and also if they could be integral to the autonomic and respiratory responses to hypoxic challenges. Here, we investigated whether NTS glia play a tonic role in the modulation of central respiratory and sympathetic activities as well as in the changes in respiratory-sympathetic coupling induced by exposure to chronic intermittent hypoxia (CIH), a model of central autonomic and respiratory plasticity. We show that bilateral microinjections of fluorocitrate (FCt), a glial cell inhibitor, into the caudal and intermediate subnuclei of the NTS did not alter baseline respiratory and sympathetic parameters in in situ preparations of juvenile rats. Similar results were observed in rats previously exposed to CIH. Likewise, CIH-induced changes in respiratory-sympathetic coupling were unaffected by FCt-mediated inhibition. However, microinjection of FCt into the ventral medulla produced changes in respiratory frequency. Our results show that acute glial inhibition in the NTS does not affect baseline respiratory and sympathetic control. Additionally, we conclude that NTS glial cells may not be necessary for the continuous manifestation of sympathetic and respiratory adaptations to CIH. Our work provides evidence that neuron-glia interactions in the NTS do not participate in baseline respiratory and sympathetic control.

  12. Porfiria cutânea tardia Porphyria cutanea tarda

    Directory of Open Access Journals (Sweden)

    Fátima Mendonça Jorge Vieira

    2006-12-01

    Full Text Available Trata-se de revisão sobre a porfiria cutânea tardia em que são abordados a fisiopatogenia, as características clínicas, as doenças associadas, os fatores desencadeantes, a bioquímica, a histopatologia, a microscopia eletrônica, a microscopia de imunofluorescência e o tratamento da doença.This is a review article of porphyria cutanea tarda addressing pathophysiology, clinical features, associated conditions, triggering factors, biochemistry, histopathology, electronic microscopy, immunofluorescence microscopy and treatment of the disease.

  13. Allogeneic corneoscleral limbus tissue transplantation for treatment of the necrosis in porphyria eye disease

    Institute of Scientific and Technical Information of China (English)

    Feng; Yan; Yan; Lu; Jie; Yin; Feng; Jiang; Zhen-Ping; Huang

    2014-01-01

    · Porphyria cutanea tarda(PCT) with ocular complications are rarely reported. To the best of our knowledge, no reports exist on allogeneic corneoscleral limbus tissue transplantation for treatment of these.Amniotic membrane grafting had been performed in their patient suffering from porphyria eye disease, but necrosis developed in the grafts. Nevertheless, in our patient, allogeneic corneoscleral limbus transplantation prevented necrosis from development at corneoscleral limbus. So we considered that the allogeneic corneoscleral limbus transplantation might be an option to repair the necrosis in porphyria eye disease with avoiding sunlight and using artificial tear drops.

  14. Intermittent hypoxia and neurorehabilitation.

    Science.gov (United States)

    Gonzalez-Rothi, Elisa J; Lee, Kun-Ze; Dale, Erica A; Reier, Paul J; Mitchell, Gordon S; Fuller, David D

    2015-12-15

    In recent years, it has become clear that brief, repeated presentations of hypoxia [i.e., acute intermittent hypoxia (AIH)] can boost the efficacy of more traditional therapeutic strategies in certain cases of neurologic dysfunction. This hypothesis derives from a series of studies in animal models and human subjects performed over the past 35 yr. In 1980, Millhorn et al. (Millhorn DE, Eldridge FL, Waldrop TG. Respir Physiol 41: 87-103, 1980) showed that electrical stimulation of carotid chemoafferent neurons produced a persistent, serotonin-dependent increase in phrenic motor output that outlasts the stimulus for more than 90 min (i.e., a "respiratory memory"). AIH elicits similar phrenic "long-term facilitation" (LTF) by a mechanism that requires cervical spinal serotonin receptor activation and de novo protein synthesis. From 2003 to present, a series of studies demonstrated that AIH can induce neuroplasticity in the injured spinal cord, causing functional recovery of breathing capacity after cervical spinal injury. Subsequently, it was demonstrated that repeated AIH (rAIH) can induce recovery of limb function, and the functional benefits of rAIH are greatest when paired with task-specific training. Since uncontrolled and/or prolonged intermittent hypoxia can elicit pathophysiology, a challenge of intermittent hypoxia research is to ensure that therapeutic protocols are well below the threshold for pathogenesis. This is possible since many low dose rAIH protocols have induced functional benefits without evidence of pathology. We propose that carefully controlled rAIH is a safe and noninvasive modality that can be paired with other neurorehabilitative strategies including traditional activity-based physical therapy or cell-based therapies such as intraspinal transplantation of neural progenitors. PMID:25997947

  15. Fluorescence microscopy test in porphyrias, photodermatoses and lead exposed persons.

    Science.gov (United States)

    Kansky, A

    1975-07-18

    Fluorescence microscopy tests were carried out in different groups of patients Peripheral blood diluted with saline was used and 200 high power fields were inspected in every case. The results were presented as the number of fluorescing erythrocytes (FE) per 100000 red blood cells (or 200 fields). In the controls, porphyria cutanea tarda patients and patients with photodermatoses other than erythopoietic protoporphyria and pellagra almost no FE were detected. In erythropoietic protoporphyria the mean value was 10600, in lead poisoning 1032, in patients exposed to lead 48.2, in sideropenic anaemia 123 and in patients with pellagra 8.1 FE/100000 red blood cells. The conclusion is made that one has to take care, when using this test for detection of latent carriers in genetic studies of the relatives of patients with erythropoietic protoporphyria. The test is useful for the confirmation of the diagnosis of erythropoietic protoporphyria.

  16. Dialysis complications in acute kidney injury patients treated with prolonged intermittent renal replacement therapy sessions lasting 10 versus 6 hours: results of a randomized clinical trial.

    Science.gov (United States)

    Albino, Bianca Ballarin; Balbi, André Luis; Abrão, Juliana Maria Gera; Ponce, Daniela

    2015-05-01

    Prolonged intermittent renal replacement therapy (PIRRT) has emerged as an alternative to continuous renal replacement therapy in the management of acute kidney injury (AKI) patients. This trial aimed to compare the dialysis complications occurring during different durations of PIRRT sessions in critically ill AKI patients. We included patients older than 18 years with AKI associated with sepsis admitted to the intensive care unit and using noradrenaline doses ranging from 0.3 to 0.7 µg/kg/min. Patients were divided into two groups randomly: in G1, 6-h sessions were performed, and in G2, 10-h sessions were performed. Seventy-five patients were treated with 195 PIRRT sessions for 18 consecutive months. The prevalence of hypotension, filter clotting, hypokalemia, and hypophosphatemia was 82.6, 25.3, 20, and 10.6%, respectively. G1 was composed of 38 patients treated with 100 sessions, whereas G2 consisted of 37 patients treated with 95 sessions. G1 and G2 were similar in male predominance (65.7 vs. 75.6%, P = 0.34), age (63.6 ± 14 vs. 59.9 ± 15.5 years, P = 0.28) and Sequential Organ Failure Assessment score (SOFA; 13.1 ± 2.4 vs. 14.2 ± 3.0, P = 0.2). There was no significant difference between the two groups in hypotension (81.5 vs. 83.7%, P = 0.8), filter clotting (23.6 vs. 27%, P = 0.73), hypokalemia (13.1 vs. 8.1%, P = 0.71), and hypophosphatemia (18.4 vs. 21.6%, P = 0.72). However, the group treated with sessions of 10 h were refractory to clinical measures for hypotension, and dialysis sessions were interrupted more often (9.5 vs. 30.1%, P = 0.03). Metabolic control and fluid balance were similar between G1 and G2 (blood urea nitrogen [BUN]: 81 ± 30 vs. 73 ± 33 mg/dL, P = 1.0; delivered Kt/V: 1.09 ± 0.24 vs. 1.26 ± 0.26, P = 0.09; actual ultrafiltration: 1731 ± 818 vs. 2332 ± 947 mL, P = 0.13) and fluid balance (-731 ± 125 vs. -652 ± 141

  17. The severity of hereditary porphyria is modulated by the porphyrin exporter and Lan antigen ABCB6.

    Science.gov (United States)

    Fukuda, Yu; Cheong, Pak Leng; Lynch, John; Brighton, Cheryl; Frase, Sharon; Kargas, Vasileios; Rampersaud, Evadnie; Wang, Yao; Sankaran, Vijay G; Yu, Bing; Ney, Paul A; Weiss, Mitchell J; Vogel, Peter; Bond, Peter J; Ford, Robert C; Trent, Ronald J; Schuetz, John D

    2016-08-10

    Hereditary porphyrias are caused by mutations in genes that encode haem biosynthetic enzymes with resultant buildup of cytotoxic metabolic porphyrin intermediates. A long-standing open question is why the same causal porphyria mutations exhibit widely variable penetrance and expressivity in different individuals. Here we show that severely affected porphyria patients harbour variant alleles in the ABCB6 gene, also known as Lan, which encodes an ATP-binding cassette (ABC) transporter. Plasma membrane ABCB6 exports a variety of disease-related porphyrins. Functional studies show that most of these ABCB6 variants are expressed poorly and/or have impaired function. Accordingly, homozygous disruption of the Abcb6 gene in mice exacerbates porphyria phenotypes in the Fech(m1Pas) mouse model, as evidenced by increased porphyrin accumulation, and marked liver injury. Collectively, these studies support ABCB6 role as a genetic modifier of porphyria and suggest that porphyrin-inducing drugs may produce excessive toxicities in individuals with the rare Lan(-) blood type.

  18. Partial protoporphyrinogen oxidase (PPOX gene deletions, due to different Alu-mediated mechanisms, identified by MLPA analysis in patients with variegate porphyria

    Directory of Open Access Journals (Sweden)

    Barbaro Michela

    2013-01-01

    Full Text Available Abstract Variegate porphyria (VP is an autosomal dominantly inherited hepatic porphyria. The genetic defect in the PPOX gene leads to a partial defect of protoporphyrinogen oxidase, the penultimate enzyme of heme biosynthesis. Affected individuals can develop cutaneous symptoms in sun-exposed areas of the skin and/or neuropsychiatric acute attacks. The identification of the genetic defect in VP families is of crucial importance to detect the carrier status which allows counseling to prevent potentially life threatening neurovisceral attacks, usually triggered by factors such as certain drugs, alcohol or fasting. In a total of 31 Swedish VP families sequence analysis had identified a genetic defect in 26. In the remaining five families an extended genetic investigation was necessary. After the development of a synthetic probe set, MLPA analysis to screen for single exon deletions/duplications was performed. We describe here, for the first time, two partial deletions within the PPOX gene detected by MLPA analysis. One deletion affects exon 5 and 6 (c.339-197_616+320del1099 and has been identified in four families, most probably after a founder effect. The other extends from exon 5 to exon 9 (c.339-350_987+229del2609 and was found in one family. We show that both deletions are mediated by Alu repeats. Our findings emphasize the usefulness of MLPA analysis as a complement to PPOX gene sequencing analysis for comprehensive genetic diagnostics in patients with VP.

  19. Porphyria cutanea tarda in a chronic hemodialysis patient

    Directory of Open Access Journals (Sweden)

    Labidi Jannet

    2010-01-01

    Full Text Available End-stage renal failure and long-term hemodialysis (HD treatment promote the development of genetically conditioned porphyria cutanea tarda (PCT. Iron overload is often asso-ciated with this disease and is thought to play a role in its pathogenesis. We report a case of HD-related PCT, which improved with deferoxamine treatment. A 33-year-old woman, with end-stage renal failure on HD since 1998, presented with a history of blisters on the face and dorsum of the hands, of several months duration. Laboratory analysis showed: hemoglobin 10.4 g/dL; a moderate hepatic cytolysis; ferritin 1300 μg/L (Nl: 8-120 μg/L and negative serology for HIV, HBV and HCV. Porphyrin analyses showed a PCT pattern. Skin biopsy findings and direct immunofluo-rescence were consistent with PCT. The patient received deferoxamine (40 mg/kg intravenously every week for 6 weeks which led to dramatic improvement of the symptoms. Several treatments are proposed in the management of dialysis-related PCT. This case confirms that deferoxamine can induce rapid and prolonged remission.

  20. INTERMITTENT DEGRADATION AND SCHIZOTYPY

    OpenAIRE

    Roché, Matthew W.; Silverstein, Steven M.; Lenzenweger, Mark F.

    2015-01-01

    Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy) is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-repo...

  1. Porphyria cutanea tarda associated with autoimmune hypothyroidism, vitiligo and alopecia universalis.

    Science.gov (United States)

    Sabán, J; Rodríguez-García, J L; Gil, J; País, J R; Medina, S

    1991-12-01

    The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient. PMID:1803247

  2. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    OpenAIRE

    Chang SC; Shi JD; Fu CP; Wu X; Li SQ

    2016-01-01

    Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive car...

  3. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    OpenAIRE

    Chang, Su Chi

    2016-01-01

    Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Inten...

  4. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  5. Intermittency in particle physics

    International Nuclear Information System (INIS)

    This thesis presents an analysis of intermittency as it appears in high energy multiparticle production. Momentum space particle distributions are scale invariant and fluctuate from events to events. This phenomenon originates from Hydrodynamics. Some results about hydrodynamics intermittency are by the way deduced using random diffusion processes and the Landau-Ginzburg equation. A phenomenological approach utilizing random cascading models is used to describe the morphology and intermittent features of particle distributions. Along these lines, a thorough study of random cascades is performed. The origin of intermittent fluctuation is to be found within the Framework of Quantum Field Theory. Indeed intermittency is intimately linked to the perturbative cascade of Quantum Chromodynamics. The long distance behaviour of perturbative QCD is intermittent at the leading collinear logarithm approximation. Moreover fluctuations of matter density along the rapidity axis suggest that the gluon cascade undergoes a phase transition towards a valley landscape where gluons are prone to get clumped within small regions. This is compatible with the so-called preconfinement

  6. Renal function in tyrosinaemia type I after liver transplantation : A long-term follow-up

    NARCIS (Netherlands)

    Pierik, LJWM; van Spronsen, FJ; Bijleveld, CMA; van Dael, CML

    2005-01-01

    Hereditary tyrosinaemia type I is an autosomal recessive inborn error of tyrosine catabolism caused by a deficiency of the enzyme fumarylacetoacetase that results in liver failure, hepatocellular carcinoma, renal tubular dysfunction and acute intermittent porphyria. When treated with liver transplan

  7. Metabolic consequences of intermittent hypoxia.

    Science.gov (United States)

    O'Donnell, Christopher P

    2007-01-01

    Insulin resistance is being recognized increasingly as the basis for the constellation of metabolic abnormalities that make up the metabolic syndrome, or Syndrome X. Insulin resistance is also the primary risk factor for the development of type 2 diabetes mellitus, which is currently reaching epidemic proportions by affecting more than 170 million people worldwide. A combination of environmental and genetic factors have led to a dramatic rise in visceral adiposity, the predominant factor causing insulin resistance and type 2 diabetes. Visceral adiposity is also the major risk factor for the development of Sleep Apnea (SA)--an association that has fueled interest in the co-morbidity of SA and the metabolic syndrome, but hampered attempts to ascribe an independent causative role for Sleep Apnea in the development of insulin resistance and type 2 diabetes. Numerous population and clinic-based epidemiologic studies have shown associations, often independent of obesity, between SA (or surrogates such as snoring) and measures of glucose dysregulation or type 2 diabetes. However, treatment of SA with continuous positive airway pressure (CPAP) has not been conclusive in demonstrating improvements in insulin resistance, perhaps due to the overwhelming effects of obesity. Here we show that in lean, otherwise healthy mice that exposure to intermittent hypoxia produced whole-body insulin resistance as determined by the hyperinsulinemic euglycemic clamp and reduced glucose utilization in oxidative muscle fibers, but did not cause a change in hepatic glucose output. Furthermore, the increase in insulin resistance was not affected by blockade of the autonomic nervous system. We conclude that intermittent hypoxia can cause acute insulin resistance in otherwise lean healthy animals, and the response occurs independent of activation of the autonomic nervous system. PMID:18269187

  8. Desferrioxamine treatment of porphyria cutanea tarda in a patient with HIV and chronic renal failure.

    Science.gov (United States)

    Vasconcelos, Pedro; Luz-Rodrigues, H; Santos, Carla; Filipe, Paulo

    2014-01-01

    Porphyria cutanea tarda (PCT) can occur in HIV patients. Current evidence suggests that HIV infection may interfere with the hepatic cytochrome oxidase system, leading to porphyrin metabolism impairment. Moreover, chronic hemodialysis in renal failure may be a risk factor for PCT. In addition to the contributory factors for PCT associated to HIV infection, it is possible that porphyrin accumulation secondary to renal failure may play a role in the expression of this disease. We report a case of PCT in an HIV-1 infected patient under blood dialysis, refractory to antimalarials and controlled with desferrioxamine.

  9. Fate in intermittent claudication

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Gaardsting, O; Hougaard Jensen, K;

    1986-01-01

    113 of the patients (44%) had died. Causes of death were no different from those in the general population. Mortality was twice that of the general population matched for age and sex. Mortality among the men was twice that among the women. In men under 60 mortality was four times that expected......, or an ankle/arm pressure index below 50% were individually significantly associated with progression of the arteriosclerotic disease. These findings show the importance of peripheral blood pressure measurements in the management of patients with intermittent claudication due to arteriosclerotic disease....

  10. Interventions for intermittent exotropia

    Science.gov (United States)

    Hatt, Sarah R; Gnanaraj, Lawrence

    2014-01-01

    Background The clinical management of intermittent exotropia has been discussed extensively in the literature, yet there remains a lack of clarity regarding indications for intervention, the most effective form of treatment and whether or not there is an optimal time in the evolution of the disease at which any treatment should be carried out. Objectives The objective of this review was to analyse the effects of various surgical and non-surgical treatments in randomised trials of participants with intermittent exotropia, and to report intervention criteria and determine the significance of factors such as age with respect to outcome. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2012), MEDLINE (January 1966 to May 2012), EMBASE (January 1980 to May 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to May 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 4 May 2012. We are no longer searching the UK Clinical Trials Gateway (UKCTG) for this review. We manually searched the British Orthoptic Journal up to 2002, and the proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS) up to 2001. We contacted researchers who are active in the field for information about further published or unpublished studies. Selection criteria We included randomised controlled trials of any surgical or non-surgical treatment for intermittent exotropia. Data collection and

  11. Comment on "Intermittent plate tectonics?".

    Science.gov (United States)

    Korenaga, Jun

    2008-06-01

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  12. Porphyria cutanea tarda as a complication of therapy for chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    James Azim; Heather McCurdy; Richard H Moseley

    2008-01-01

    There is a strong association between porphyria cutanea tarda (PCT) and chronic viral hepatitis C. Therapy for chronic viral hepatitis C may improve PCT. However, there are only a few reports of the de novo development of PCT during therapy for chronic viral hepatitis C. We describe the development of PCT in a 56-year-old patient with chronic viral hepatitis C after 12 wk of peginterferon/ribavirin therapy. In addition, the patient was homozygous for the H63D hereditary hemochromatosis gene (HFE) mutation. The association of PCT with chronic viral hepatitis C and the possible role of hepatic iron overload and ribavirin-induced hemolytic anemia in the development of PCT during therapy for chronic viral hepatitis C are discussed.

  13. Accumulation of uroporphyrin does not provoke further inhibition of liver uroporphyrinogen decarboxylase activity in hexachlorobenzene-induced porphyria.

    Science.gov (United States)

    Adjarov, D G; Elder, G H

    1986-01-01

    The inhibition of uroporphyrinogen decarboxylase (Uro-D) is the basic pathogenetic mechanism in porphyria caused by hexachlorobenzene (HCB). This study aimed to establish whether hepatic accumulation of uroporphyrin in this porphyria could provoke a further decrease of Uro-D activity. Male C57Bl/6 mice were treated for 8 weeks with a diet containing 0.02% HCB. In some of them the deposition of liver porphyrins was additionally increased by intraperitoneal application of delta-aminolaevulinic acid (ALA). Uro-D activity was determined by measuring unconverted substrate uroporphyrinogen after its oxidation to uroporphyrin by reversed-phase high performance liquid chromatography. The value of endogenously formed uroporphyrin was also obtained from the sample by subtraction, using a blank assay. HCB treatment resulted in reduced activity of hepatic Uro-D, but this activity was not significantly less in animals loaded with ALA than in non-loaded mice. Uroporphyrin deposition tended to decrease 6 weeks after withdrawal of HCB, but the activity of Uro-D was still markedly inhibited. There was no evidence that the accumulation of uroporphyrin promoted a supplementary decrease of Uro-D activity in HCB porphyria. PMID:3596742

  14. Intermedia and Intermittency

    Directory of Open Access Journals (Sweden)

    Veres Bálint

    2014-12-01

    Full Text Available It is commonly known that medial reflections have been initiated by attempts to secure the borders of discrete medial forms and to define the modus operandi of each essentialized medial area. Later on, the focus of study has shifted to plurimedial formations and the interactions between predefined medial genres. In the last few decades, taxonomic approaches to various multi-, inter-, and transmedial phenomena dominated the discussions, which offered invaluable support in mapping the terrain, but at the same time hindered the analysis of the ephemeral, time-dependent aspects of plurimedial operations. While we explore the properties of each medial configuration, we lose sight of the actual historical drivers that produce ever-new configurations. My thesis is that any discourse on intermediality should be paralleled by a discourse on cultural intermittency, and consequently, media studies should involve an approach that focuses on the “ecosystem” of the constantly renewing media configurations from the point of view of their vitalizing potential and capability to trigger heightened experiences. This approach draws much inspiration from K. Ludwig Pfeiffer’s media anthropology that gives orientation in my paper.

  15. Intermittency Growth in Fluid Turbulence

    Institute of Scientific and Technical Information of China (English)

    ZHU Jian-Zhou

    2006-01-01

    @@ Measurement and phenomenological analyses of intermittency growth in an experimental turbulent pipe flow and numerical turbulence are performed, for which working definitions such as degree, increment, and growth rate of intermittency are introduced with the help of quasiscaling theory. The logarithmic-normal inertial scaling model is extended to quasiscaling as the second-order truncation of the Taylor expansion and is used for studying the intermittency growth problem. The extended self-similarity properties are shown to be not consistent with the monotonicity of the third order local quasiscaling exponent and the nonmonotonic behaviour of the intermittency growth rate as a result of bottleneck. Digestions of the results with scale-dependent multifractals are provided.

  16. Spinal Plasticity following Intermittent Hypoxia: Implications for Spinal Injury

    OpenAIRE

    Dale-Nagle, Erica A.; Hoffman, Michael S.; MacFarlane, Peter M.; Satriotomo, Irawan; Lovett-Barr, Mary Rachael; Vinit, Stéphane; Mitchell, Gordon S.

    2010-01-01

    Plasticity is a fundamental property of the neural system controlling breathing. One frequently studied model of respiratory plasticity is long-term facilitation of phrenic motor output (pLTF) following acute intermittent hypoxia (AIH). pLTF arises from spinal plasticity, increasing respiratory motor output through a mechanism that requires new synthesis of brain derived neurotrophic factor (BDNF), activation of its high affinity receptor, tropomyosin-related kinase B (TrkB) and extracellular...

  17. [Intermittent hemodialysis, irreplaceable in specific cases of severe poisoning].

    Science.gov (United States)

    Ventresca, M; Teta, D; Burnier, M; Kissling, S

    2015-02-25

    The medical practitioner is in general well aware of the indications for hemodialysis in severe, acute or chronic renal insufficiency. Apart from the traditional indications for renal replacement therapy, there are some cases such as metfomin and ethylene glycol poisoning, lithium intoxication severe hypercalcemia and tumor lysis syndrome, in which intermittent hemodialysis is the most effective treatment, or sometimes the only effective one. Although these situations remain infrequent, it is crucial to recognize them as quickly as possible. PMID:25898458

  18. High-Intensity Intermittent Exercise: Effect on Young People's Cardiometabolic Health and Cognition.

    Science.gov (United States)

    Cooper, Simon B; Dring, Karah J; Nevill, Mary E

    2016-01-01

    With only a quarter of young people currently meeting physical activity guidelines, two key areas of concern are the effects of exercise on cardiometabolic health and cognition. Despite the fact that physical activity in young people is typically high intensity and intermittent in nature, much of the literature examines traditional endurance-type exercise. This review provides an update on the effects of high-intensity intermittent exercise on young people's cardiometabolic health and cognition. High-intensity intermittent exercise has acute beneficial effects on endothelial function and postprandial lipemia and chronic positive effects on weight management. In addition, there is emerging evidence regarding chronic benefits on the blood lipid profile, blood pressure, and proinflammatory and anti-inflammatory cytokines. Furthermore, emerging evidence suggests beneficial acute and chronic effects of high-intensity intermittent exercise on cognition. However, further research is required in both cardiometabolic health and cognition, particularly regarding the impact of school-based interventions in adolescents. PMID:27399821

  19. Bursts in intermittent aeolian saltation

    CERN Document Server

    Carneiro, M V; Herrmann, H J

    2014-01-01

    Close to the onset of Aeolian particle transport through saltation we find in wind tunnel experiments a regime of intermittent flux characterized by bursts of activity. Scaling laws are observed in the time delay between each burst and in the measurements of the wind fluctuations at the critical Shields number $\\theta_c$. The time delay between each burst decreases on average with the increase of the Shields number until saltation becomes non-intermittent and the sand flux becomes continuous. A numerical model for saltation including the wind-entrainment from the turbulent fluctuations can reproduce these observations and gives insight about their origin. We present here also for the first time measurements showing that with feeding it becomes possible to sustain intermittent flux even below the threshold $\\theta_c$ for natural saltation initiation.

  20. Elastic wave turbulence and intermittency

    Science.gov (United States)

    Chibbaro, Sergio; Josserand, Christophe

    2016-07-01

    We investigate the onset of intermittency for vibrating elastic plate turbulence in the framework of the weak wave turbulence theory using a numerical approach. The spectrum of the displacement field and the structure functions of the fluctuations are computed for different forcing amplitudes. At low forcing, the spectrum predicted by the theory is observed, while the fluctuations are consistent with Gaussian statistics. When the forcing is increased, the spectrum varies at large scales, corresponding to the oscillations of nonlinear structures made of ridges delimited by d cones. In this regime, the fluctuations exhibit small-scale intermittency that can be fitted via a multifractal model. The analysis of the nonlinear frequency shows that the intermittency is linked to the breakdown of the weak turbulence at large scales only.

  1. Successful cord blood stem cell transplantation for congenital erythropoietic porphyria (Gunther's disease).

    Science.gov (United States)

    Zix-Kieffer, I; Langer, B; Eyer, D; Acar, G; Racadot, E; Schlaeder, G; Oberlin, F; Lutz, P

    1996-07-01

    Congenital erythropoietic porphyria (Gunther's disease, GD) is a rare autosomal recessive disease. It results from the deficiency of uroporphyrinogen III synthase, the fourth enzyme on the metabolic pathway of heme synthesis. GD leads to severe scarring of the face and hands as a result of photosensitivity and fragility of the skin due to uroporphyrin I and coproporphyrin I accumulation. It also causes erythrocyte fragility leading to haemolytic anaemia. The other clinical features include hirsutism, red discolouration of teeth, finger-nails and urine and stunted growth. The outcome is poor, and the disfiguring nature of GD may partly explain the legend of the werewolf. No curative treatment was known until 1991, when the first case of BMT in GD was reported. The clinical and biological outcome after transplantation was encouraging, with an important regression of the symptoms of the disease, but the child died of CMV-infection 11 months after BMT. We report the second case of GD treated successfully by stem cell transplantation using umbilical cord blood from an HLA-identical brother in a 4-year-old girl suffering from severe GD. Our patient is very well 10 months after transplantation. We confirm that stem cell transplantation is curative for GD.

  2. Intermittency in spherical Couette dynamos

    CERN Document Server

    Raynaud, Raphaël; 10.1103/PhysRevE.87.033011

    2013-01-01

    We investigate dynamo action in three-dimensional numerical simulations of turbulent spherical Couette flows. Close to the onset of dynamo action, the magnetic field exhibits an intermittent behavior, characterized by a series of short bursts of the magnetic energy separated by low-energy phases. We show that this behavior corresponds to the so-called on-off intermittency. This behavior is here reported for dynamo action with realistic boundary conditions. We investigate the role of magnetic boundary conditions in this phenomenon.

  3. Molecular heterogeneity of familial porphyria cutanea tarda in Spain: characterization of 10 novel mutations in the UROD gene

    OpenAIRE

    Méndez, Manuel; Poblete-Gutiérrez, Pamela; García-Bravo, María; Wiederholt, T.; Morán-Jiménez, María Josefa; Merk, H. F.; Garrido Astray, María Concepción; Frank, Jorge; Fontanellas, Antonio; Enríquez de Salamanca, Rafael

    2007-01-01

    Porphyria cutanea tarda (PCT) results from decreased hepatic uroporphyrinogen decarboxylase (UROD) activity. In the majority of patients, the disease is sporadic (S-PCT or type I) and the enzyme deficiency is limited to the liver. Familial PCT (F-PCT or type II) is observed in 20-30% of patients in whom mutations on one allele of the UROD gene reduce UROD activity by approximately 50% in all tissues. Another variant of PCT (type III) is characterized by family history of the disease although ...

  4. Intermittent control of coexisting attractors.

    Science.gov (United States)

    Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

    2013-06-28

    This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method. PMID:23690639

  5. An unhappy triad: Hemochromatosis, porphyria cutanea tarda and hepatocellular carcinoma-A case report

    Institute of Scientific and Technical Information of China (English)

    Martina T Mogl; Andreas Pascher; Sabine J Presser; Michael Schwabe; Peter Neuhaus; Natascha C Nuessler

    2007-01-01

    Liver fibrosis and cirrhosis are predisposing factors for the development of hepatocellular carcinoma (HCC). Hemosiderosis has also been described to trigger carcinogenesis. A significant iron overload, as found in hereditary hemochromatosis (HHC), is a risk factor for HCC and may also promote the symptoms of porphyria cutanea tarda (PCT). A 68-year old male patient presented to our clinic with a suspected HCC,elevated alpha-fetoprotein but normal liver function tests. He reported a 25 year-old history of vitiligo upon exposure to sunlight. The patient underwent an extended left hemihepatectomy, and the recovery was uneventful, with the exception of a persistent hyperbilirubinemia. Perfusion problems and extrahepatic cholestasis were ruled out by CT-scan with angiography and MR-cholangiopancreatography. However, MRI showed an iron overload. Histology confirmed the HCC (pT3, pN0, G3, R0) and revealed a portal fibrosis and hemosiderosis. Based on the skin lesions we suspected a PCT that was confirmed by laboratory tests showing elevated porphyrin, uroporphyrin, coproporphyrin and porphobilinogen. Concurrently, molecular diagnostics revealed homozygosity for the C282Y mutation within the hemochromatosis HFE gene. After phlebotomy and normalization of liver function tests the patient was discharged. This is the first case ever showing the unusual combination of HCC in a fibrotic liver with HHC and PCT. This diagnosis not only warrants oncological follow-up but also symptomatic therapy to normalize iron metabolism and thereby improve liver function and alleviate the symptoms of HHC and PCT. Thus progression of fibrosis may be prevented and liver regeneration supported.

  6. Optical diagnostics of intermittent flows

    DEFF Research Database (Denmark)

    Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær

    2007-01-01

    image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach......The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle...

  7. Intermittent torsion of accessory hepatic lobe: An unusual cause of recurrent right upper quadrant pain

    Directory of Open Access Journals (Sweden)

    Jambhekar Kedar

    2010-01-01

    Full Text Available An accessory lobe of the liver is a rare congenital anomaly that can undergo torsion and present as an acute surgical emergency. It is rarely diagnosed preoperatively. We report the preoperative utility of CT scan and MRI in the diagnosis and surgical planning of a case of intermittent accessory hepatic lobe torsion.

  8. Intermittent torsion of accessory hepatic lobe: An unusual cause of recurrent right upper quadrant pain

    International Nuclear Information System (INIS)

    An accessory lobe of the liver is a rare congenital anomaly that can undergo torsion and present as an acute surgical emergency. It is rarely diagnosed preoperatively. We report the preoperative utility of CT scan and MRI in the diagnosis and surgical planning of a case of intermittent accessory hepatic lobe torsion

  9. Acute lymphocytic Leukemia masquerading as acute osteomyelitis

    International Nuclear Information System (INIS)

    Two children each developed a focal destructive bone lesion accompanied by intermittent fever, swelling, tenderness and elevated ESR. Blood counts were normal; bone marrow aspiration showed acute leukemia. The bone lesions healed in both patients after anti-leukemic therapy. We suggest that the similar roentgenographic appearance of osteomyelitis, bone infarction and focal destructive lesions in leukemia probably reflects a common, basically ischemic process of bone. (orig.)

  10. Congenital erythropoietic porphyria with two mutations of the uroporphyrinogen III synthase gene (Cys73Arg, Thr228Met

    Directory of Open Access Journals (Sweden)

    Zoran Gucev

    2011-01-01

    Full Text Available Congenital erythropoietic porphyria (CEP is an autosomal recessive inborn error of metabolism that results from the markedly deficient activity of uroporphyrinogen III synthase (UROS. We describe a 14-year-old girl with red urine since infancy, progressive blistering and scarring of the skin, and moderate hemolytic anemia. After years of skin damage, her face is mutilated; she has a bald patch on the scalp, hypertrichosis of the neck, areas of skin darkening, and limited joint movements of the hands. Total urine excretion and fecal total porphyrin were both markedly raised above normal levels. Sequencing of the UROS gene identified two mutations causing CEP (Cys73Arg, Thr228Met. The patient lesions are progressing. Bone marrow transplantation and/or gene therapy are proposed as the next steps in her treatment. In brief, we describe a CEP with confirmed two pathogenic mutations, severe phenotype and discuss the various treatment options available.

  11. Long-term tolerability of telcagepant for acute treatment of migraine in a randomized trial

    DEFF Research Database (Denmark)

    Connor, Kathryn M; Aurora, Sheena K; Loeys, Tom;

    2011-01-01

    To evaluate the long-term tolerability of telcagepant for acute treatment of intermittent migraine attacks. Background.- Telcagepant is a calcitonin gene-related peptide (CGRP) receptor antagonist being investigated for the acute treatment of migraine....

  12. Improved Intermittency Analysis of Individual Events

    OpenAIRE

    Janik, R. A.; Ziaja, B.

    1998-01-01

    Recent progress on the event-by-event analysis of intermittent data by R. A. Janik and myself is reported. The intermittency analysis of single event data (particle moments) in multiparticle production is improved, taking into account corrections due to the reconstruction of history of a particle cascade. This approach is tested within the framework of the $\\alpha$-model.}

  13. Radiation characteristics of intermittence exhaust noise

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shengdun; SHANG Chunyang; ZHAO Zhigang; SHI Weixiang

    2000-01-01

    Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole source in the intermittence exhaust noise are established. The effects of all parameters in pneumatic system on the noise are also comprehensively studied.

  14. COHO SALMON DEPENDENCE ON INTERMITTENT STREAMS

    Science.gov (United States)

    In February 2006, the US Supreme Court heard cases that may affect whether intermittent streams are jurisdictional waters under the Clean Water Act. In June 2006, however, the cases were remanded to the circuit court, leaving the status of intermittent streams uncertain once agai...

  15. Kinetic intermittency in magnetized plasma turbulence

    CERN Document Server

    Teaca, Bogdan; Told, Daniel; Jenko, Frank

    2016-01-01

    We employ magnetized plasma turbulence, described by a gyrokinetic formalism in an interval ranging from the end of the fluid scales to the electron gyroradius, to introduce the first study of kinetic intermittency, in which nonlinear structures formed directly in the distribution functions are analyzed by accounting for velocity space correlations generated by linear (Landau resonance) and nonlinear phase mixing. Electron structures are found to be strongly intermittent and dominated by linear phase mixing, while nonlinear phase mixing dominates the weakly intermittent ions. This is the first time spatial intermittency and linear phase mixing are shown to be self-consistently linked for the electrons and, as the magnetic field follows the intermittency of the electrons at small scales, explain why magnetic islands are places dominated by Landau damping in steady state turbulence.

  16. Intermittent dystonia in Hartnup disease.

    Science.gov (United States)

    Darras, B T; Ampola, M G; Dietz, W H; Gilmore, H E

    1989-01-01

    A 6-month-old girl developed intermittent dystonic posture of the legs and eczematous dermatitis without ataxia. Qualitative and quantitative urine amino acid testing confirmed the diagnosis of Hartnup disease. Cranial computed tomography, electroencephalogram, electromyogram/nerve conduction study, posterior tibial somatosensory evoked potentials, 24-hour electroencephalographic telemetry, and metrizamide myelogram were normal. Spinal fluid hydroxy-indoleacetic acid concentration was less than or equal to 2 S.D. of normal; oral tryptophan loading (70 mg/kg) resulted in a two-fold rise in cerebrospinal fluid 5-hydroxy-indoleacetic acid concentration. Tryptophan administered alone or with nicotinic acid failed to improve the dystonia; however, trihexyphenidyl (1-2 mg/kg/day) dramatically improved it. Hartnup disease should be considered in children with unexplained dystonia. PMID:2712944

  17. Intermittent transport in edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.; Juul Rasmussen, J. [Association EURATOM-Riso National Laboratory, Optics and Plasma Research, Roskilde (Denmark)

    2004-07-01

    The properties of low-frequency convective fluctuations and transport are investigated for the boundary region of magnetized plasmas. We employ a two-dimensional fluid model for the evolution of the global plasma quantities in a geometry and with parameters relevant to the scrape-off layer of confined toroidal plasmas. Strongly intermittent plasma transport is regulated by self-consistently generated sheared poloidal flows and is mediated by burst ejection of particles and heat from the bulk plasma in the form of blobs. Coarse grained probe signals reveal a highly skewed and flat distribution on short time scales, but tends towards a normal distribution at large time scales. Conditionally averaged signals are in perfect agreement with experimental measurements. (authors)

  18. Anisotropic Intermittency of Magnetohydrodynamic Turbulence

    CERN Document Server

    Osman, K T; Chapman, S C; Hnat, B

    2013-01-01

    A higher-order multiscale analysis of spatial anisotropy in inertial range magnetohydrodynamic turbulence is presented using measurements from the STEREO spacecraft in fast ambient solar wind. We show for the first time that, when measuring parallel to the local magnetic field direction, the full statistical signature of the magnetic and Els\\"asser field fluctuations is that of a non-Gaussian globally scale-invariant process. This is distinct from the classic multi-exponent statistics observed when the local magnetic field is perpendicular to the flow direction. These observations are interpreted as evidence for the weakness, or absence, of a parallel magnetofluid turbulence energy cascade. As such, these results present strong observational constraints on the statistical nature of intermittency in turbulent plasmas.

  19. Analytical approach to continuous and intermittent bottleneck flows

    DEFF Research Database (Denmark)

    Helbing, D.; Johansson, A.; Mathiesen, Joachim Kaj;

    2006-01-01

    Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20......Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20...

  20. Experiences of living with intermittent claudication.

    Science.gov (United States)

    Egberg, Louise; Andreassen, Sissel; Mattiasson, Anne-Cathrine

    2012-03-01

    Intermittent claudication is a symptom caused by peripheral arterial disease (PAD) and is associated with pain, impaired mobility and loss of control. Walking ability is reduced due to the pain, and both physical and social functions are often negatively affected, which may lead to patients feeling they are a burden to others. An interview study using a qualitative descriptive design to describe experiences of living with intermittent claudication caused by PAD was carried out during Winter and Spring 2009/2010. Fifteen people suffering from intermittent claudication were interviewed, and the interviews were analyzed using qualitative thematic analysis. Intermittent claudication greatly affects daily living. Six themes were identified: "Experiencing discomfort in the legs," "Moving around in a new way," "Feeling inconvenient when forced to stop," "Missing previous life," "Incorporating intermittent claudication in daily life," and "To lead a strenuous life." The main theme was "Adjusting to a restricted life." The findings show that intermittent claudication has a major impact on daily life. Apart from the severity of symptoms, how the illness is experienced differs among patients, depending on how active the ill person is or wants to be. These findings suggest that increased knowledge about living with intermittent claudication is important to understand the effects on the ill person's life, as a complement to physical examinations when planning individual treatment. PMID:22321401

  1. Intermittency and rough-pipe turbulence

    CERN Document Server

    Mehrafarin, Mohammad

    2008-01-01

    Recently, by analyzing the measurement data of Nikuradze, it has been proposed (N. Goldenfeld, Phys. Rev. Lett. {\\bf{96}}, 044503, 2006) that the friction factor, $f$, of rough pipe flow obeys a scaling law in the turbulent regime. Here, we provide a phenomenological scaling argument to explain this law and demonstrate how intermittency modifies the scaling form, thereby relating $f$ to the intermittency exponent, $\\eta$. By statistically analyzing the measurement data of $f$, we infer a satisfactory estimate for $\\eta$ ($\\approx 0.02$), the inclusion of which is shown to improve the data-collapse curve. This provides empirical evidence for intermittency other than the direct measurement of velocity fluctuations.

  2. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  3. Intermittent sea-level acceleration

    Science.gov (United States)

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  4. Porfiria cutánea tardía: Reporte de 5 casos Porphyria cutanea tarda: Five cases report

    Directory of Open Access Journals (Sweden)

    J L Iribas

    2008-03-01

    Full Text Available La PCT es la más común de las porfirias. Es una fotodermatosis que resulta de la deficiencia de la UPD, enzima perteneciente a la vía de síntesis del hemo. Presentamos la evolución de cinco casos de PCT; cuatro de PCT familiar y uno de PCT esporádica. En dos de los pacientes pertenecientes al grupo de PCT tipo II, encontramos como factor de riesgo, el consumo de alcohol, y en la paciente con PCT tipo I se detectó serología positiva para VHC. Todos los pacientes fueron tratados con cloroquina y flebotomías repetidas. Rápidamente se detectó mejoría clínica y bioquímica. Se observó que la porfirinuria continuó en descenso aún luego de suspendida la terapéutica. Tres de los pacientes con PCT familiar persisten en remisión clínica y con ausenciade recaídas tras más de 10 años de seguimiento. Aconsejamos en pacientes que padecen PCT la búsqueda de factores asociados (VHC, HIV, genes de HH y desencadenantes exógenos (consumo excesivo de alcohol, hierro en la dieta e ingesta de estrógenos que de ser controlados o evitados, junto con el tratamiento oportuno, contribuyen a un satisfactorio control de la enfermedad.The porphyria cutanea tarda is the most frequent porphyria, it is a photodermatosis secondary to uroporphyrinogen decarboxylase deficiency; this enzyme belongs to the haem synthesis pathway. We present on this paper the evolution of five cases of PCT, four of them with familiar type and one of them sporadic type. In two patients belonging to PCT type II, we found alcohol addiction as a serious risk, while on the other patients PCT type I we found HCV positive serology. All patients were treated with chloroquine and phlebotomies. We could observe a good response not only clinical but biochemical. We could also see that the porphyrins urinary level continued descending once the drug was withdrew. Three of the patients with familiar PCT remains in clinical remission without any relapses in ten years of control. We advice

  5. Improved Intermittency Analysis of Single Event Data

    OpenAIRE

    Janik, R. A.; Ziaja, B.

    1998-01-01

    The intermittency analysis of single event data (particle moments) in multiparticle production is improved, taking into account corrections due to the reconstruction of history of a particle cascade. This approach is tested within the framework of the $\\alpha$-model.

  6. Scalings of intermittent structures in magnetohydrodynamic turbulence

    CERN Document Server

    Zhdankin, Vladimir; Uzdensky, Dmitri A

    2016-01-01

    Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strong guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulat...

  7. On-line intermittent connector anomaly detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper investigates a non-traditional use of differential current sensor and current sensor to detect intermittent disconnection problems in connectors. An...

  8. The Comparison of Continuous and Intermittent Enteral Nutrition In Cerebrovascular Patients

    Directory of Open Access Journals (Sweden)

    Levent Güngör

    2011-06-01

    Full Text Available OBJECTIVE: Dysphagia and malnutrition are not so rare in stroke patients, and have an unfavorable influence on recovery. Nutritional support may reduce infections, duration of hospital stay and mortality. However, there is no clear evidence about the modality of nasogastric nutrition. In this study, intermittent and continuous enteral nutrition is compared by means of pulmonary infections and gastrointestinal tolerance, among acute cerebrovascular patients. METHODS: Sixty two acute cerebrovascular patients with dysphagia were included the study. The same volume of nutrition product was infused 4 times daily to 31 patients, and continuously for 24 hours to the remaining 31. After 10 days of follow-up, the rates of pulmonary infections, diarrhea, increased gastric residual volumes, vomiting and tube occlusion were compared between two groups. RESULTS: Twenty patients developed pneumonia (32% and 8 diarrhea (13%. Mortality due to complications associated with tube feeding was 6%. Aspiration and related pneumonia was present in 11 patients in the intermittent nutrition group (35%, and in 9 patients in the continuous nutrition group (29%. The rate of pulmonary infection was not statistically different between two groups (p>0.05. Diarrhea was observed in 7 intermittently fed patients (23%, while was present only in 1 patient (3% in the continuously fed group. Diarrhea was more common in the intermittent nutrition group, just at the statistical border (p=0.05. None of the patients developed tube occlusion, vomiting and gastric retention. The rate of mortality and the interruption of feeding was not significantly different between two groups (p>0.05. CONCLUSION: Diarrhea and pulmonary infections are more prevalent with intermittent tube feeding with respect to continuous enteral nutrition, though the difference is not so conspicuous. The reason may be contamination of the equipments and the feeding solution because of frequent manipulation and

  9. Insights from Intermittent Binocular Rivalry and EEG

    OpenAIRE

    Pitts, Michael A.; Juliane eBritz

    2011-01-01

    Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical...

  10. Intermittent cyclophosphamide in refractory rheumatoid arthritis

    OpenAIRE

    Hørslev-Petersen, Kim; Beyer, Jannie M; Helin, Pekka

    1983-01-01

    Three patients with refractory rheumatoid arthritis were treated with oral cyclophosphamide; in two cases this was supplemented with pulse treatment with methylprednisolone. Long term remission was induced in all three patients and was sustained until follow up at least nine months after the methylprednisolone was stopped. Leucopenia occurred but resolved when cyclophosphamide was reduced from daily to intermittent dosing. Intermittent treatment with cyclophosphamide, possibly in conjunction ...

  11. Scalings of intermittent structures in magnetohydrodynamic turbulence

    Science.gov (United States)

    Zhdankin, Vladimir; Boldyrev, Stanislav; Uzdensky, Dmitri A.

    2016-05-01

    Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strong guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulations, intermittent structures in the current density, vorticity, and Elsässer vorticities all have nearly identical statistical properties. We propose phenomenological explanations for the scalings based on general considerations of Elsässer vorticity structures. Finally, we examine the broader implications of intermittency for astrophysical systems.

  12. Intermittent Noise Induces Physiological Stress in a Coastal Marine Fish.

    Directory of Open Access Journals (Sweden)

    Tye A Nichols

    Full Text Available Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field on a coastal marine fish (the giant kelpfish, Heterostichus rostratus were investigated by measuring the stress responses (cortisol concentration of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound. These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur.

  13. Intermittent Noise Induces Physiological Stress in a Coastal Marine Fish.

    Science.gov (United States)

    Nichols, Tye A; Anderson, Todd W; Širović, Ana

    2015-01-01

    Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field) on a coastal marine fish (the giant kelpfish, Heterostichus rostratus) were investigated by measuring the stress responses (cortisol concentration) of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound). These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur. PMID:26402068

  14. Intermittency in 2D soap film turbulence

    CERN Document Server

    Cerbus, R T

    2013-01-01

    The Reynolds number dependency of intermittency for 2D turbulence is studied in a flowing soap film. The Reynolds number used here is the Taylor microscale Reynolds number R_{\\lambda}, which ranges from 20 to 800. Strong intermittency is found for both the inverse energy and direct enstrophy cascades as measured by (a) the pdf of velocity differences P(\\delta u(r)) at inertial scales r, (b) the kurtosis of P(\\partial_x u), and (c) the scaling of the so-called intermittency exponent \\mu, which is zero if intermittency is absent. Measures (b) and (c) are quantitative, while (a) is qualitative. These measurements are in disagreement with some previous results but not all. The velocity derivatives are nongaussian at all R_{\\lambda} but show signs of becoming gaussian as R_{\\lambda} increases beyond the largest values that could be reached. The kurtosis of P(\\delta u(r)) at various r indicates that the intermittency is scale dependent. The structure function scaling exponents also deviate strongly from the Kraichn...

  15. Magnetic field generation by intermittent convection

    CERN Document Server

    Chertovskih, R; Chimanski, E V

    2016-01-01

    Magnetic field generation by convective flows in transition to weak turbulence is studied numerically. By fixing the Prandtl number at P=0.3 and varying the Rayleigh number (Ra) as a control parameter in three-dimensional Rayleigh-Benard convection of an electrically conducting fluid, a recently reported route to hyperchaos involving quasiperiodic regimes, crises and chaotic intermittent attractors is followed, and the critical magnetic Prandtl number ($P_m^c$) for dynamo action is determined as a function of Ra. A mechanism for the onset of on-off intermittency in the magnetic energy is described, the most beneficial convective regimes for dynamo action are identified, and how intermittency affects the dependence of $P_m^c$ on Ra is discussed.

  16. Intermittency and rough-pipe turbulence.

    Science.gov (United States)

    Mehrafarin, Mohammad; Pourtolami, Nima

    2008-05-01

    Recently, by analyzing the measurement data of Nikuradze [NACA Tech. Memo No. 1292 (1950)], it has been proposed [N. Goldenfeld, Phys. Rev. Lett. 96, 044503 (2006)] that the friction factor, f , of rough-pipe flow obeys a scaling law in the turbulent regime. Here, we provide a phenomenological scaling argument to explain this law and demonstrate how intermittency modifies the scaling form, thereby relating f to the intermittency exponent, eta . By statistically analyzing the measurement data of f , we infer a satisfactory estimate for eta ( approximately 0.02) , the inclusion of which is shown to improve the data-collapse curve. This provides empirical evidence for intermittency other than the direct measurement of velocity fluctuations.

  17. Chaos synchronization based on intermittent state observer

    Institute of Scientific and Technical Information of China (English)

    Li Guo-Hui; Zhou Shi-Ping; Xu De-Ming

    2004-01-01

    This paper describes the method of synchronizing slave to the master trajectory using an intermittent state observer by constructing a synchronizer which drives the response system globally tracing the driving system asymptotically. It has been shown from the theory of synchronization error-analysis that a satisfactory result of chaos synchronization is expected under an appropriate intermittent period and state observer. Compared with continuous control method,the proposed intermittent method can target the desired orbit more efficiently. The application of the method is demonstrated on the hyperchaotic Rossler systems. Numerical simulations show that the length of the synchronization interval rs is of crucial importance for our scheme, and the method is robust with respect to parameter mismatch.

  18. Dynamics of desynchronized episodes in intermittent synchronization

    Directory of Open Access Journals (Sweden)

    Leonid L Rubchinsky

    2014-06-01

    Full Text Available Intermittent synchronization is observed in a variety of different experimental settings in physics and beyond and is an established research topic in nonlinear dynamics. When coupled oscillators exhibit relatively weak, intermittent synchrony, the trajectory in the phase space spends a substantial fraction of time away from a vicinity of a synchronized state. Thus to describe and understand the observed dynamics one may consider both synchronized episodes and desynchronized episodes (the episodes when oscillators are not synchronous. This mini-review discusses recent developments in this area. We explain how one can consider variation in synchrony on the very short time-scales, provided that there is some degree of overall synchrony. We show how to implement this approach in the case of intermittent phase locking, review several recent examples of the application of these ideas to experimental data and modeling systems, and discuss when and why these methods may be useful.

  19. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence.......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...

  20. Intermittent versus continuous androgen deprivation therapy.

    Science.gov (United States)

    Higano, Celestia S

    2014-05-01

    Androgen deprivation therapy (ADT) has been the standard of care for metastatic prostate cancer for decades; however, the choice of continuous or intermittent administration is a matter of debate. Two large phase III trials have reported results comparing these 2 forms of ADT administration. The National Cancer Institute of Canada (NCIC) PR-7 trial studied men with an increasing prostate-specific antigen (PSA) level and no evidence of metastatic disease after definitive or salvage radiation therapy and radical prostatectomy. The Southwest Oncology Group 9346 trial studied men with newly diagnosed hormone-sensitive metastatic disease. The primary end point in both trials was overall survival with a noninferiority design. The NCIC trial showed that the overall survival in men treated with intermittent ADT was not inferior to that of men treated with continuous ADT, but the SWOG trial was inconclusive regarding noninferiority. Certain domains of quality of life were better in the intermittent arms of both trials. If using ADT in the setting of biochemical relapse, intermittent ADT should be strongly considered over continuous ADT, except perhaps in patients with Gleason score of 8 or higher. In men with metastatic disease, continuous ADT remains the standard of care, because the SWOG trial did not establish noninferiority of intermittent ADT with respect to survival. However, for those with significant side effects from ADT, establishing the risk group, as determined by PSA value after 7 months of ADT or the presence of pain at diagnosis, may help guide the choice of intermittent versus continuous ADT in men with metastatic disease. PMID:24812139

  1. Intermittent heat exposure and thirst in rats

    OpenAIRE

    Barney, Christopher C.; Kuhrt, David M.

    2016-01-01

    Abstract Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague‐Dawley rats exposed to 37.5°C for 4 h/day. After 7 ...

  2. Intermittently connected mobile ad hoc networks

    CERN Document Server

    Jamalipour, Abbas

    2011-01-01

    In the last few years, there has been extensive research activity in the emerging area of Intermittently Connected Mobile Ad Hoc Networks (ICMANs). By considering the nature of intermittent connectivity in most real word mobile environments without any restrictions placed on users' behavior, ICMANs are eventually formed without any assumption with regard to the existence of a end-to-end path between two nodes wishing to communicate. It is different from the conventional Mobile Ad Hoc Networks (MANETs), which have been implicitly viewed as a connected graph with established complete paths betwe

  3. The D519G Polymorphism of Glyceronephosphate O-Acyltransferase Is a Risk Factor for Familial Porphyria Cutanea Tarda

    Science.gov (United States)

    Farrell, Colin P.; Overbey, Jessica R.; Naik, Hetanshi; Nance, Danielle; McLaren, Gordon D.; McLaren, Christine E.; Zhou, Luming; Desnick, Robert J.; Parker, Charles J.

    2016-01-01

    Both familial and sporadic porphyria cutanea tarda (PCT) are iron dependent diseases. Symptoms of PCT resolve when iron stores are depleted by phlebotomy, and a sequence variant of HFE (C282Y, c.843G>A, rs1800562) that enhances iron aborption by reducing hepcidin expression is a risk factor for PCT. Recently, a polymorphic variant (D519G, c.1556A>G, rs11558492) of glyceronephosphate O-acyltransferase (GNPAT) was shown to be enriched in male patients with type I hereditary hemochromatosis (HFE C282Y homozygotes) who presented with a high iron phenotype, suggesting that GNPAT D519G, like HFE C282Y, is a modifier of iron homeostasis that favors iron absorption. To challenge this hypothesis, we investigated the frequency of GNPAT D519G in patients with both familial and sporadic PCT. Patients were screened for GNPAT D519G and allelic variants of HFE (both C282Y and H63D). Nucleotide sequencing of uroporphyrinogen decarboxylase (URO-D) identified mutant alleles. Patients with low erythrocyte URO-D activity or a damaging URO-D variant were classified as familial PCT (fPCT) and those with wild-type URO-D were classified as sporadic PCT (sPCT). GNPAT D519G was significantly enriched in the fPCT patient population (p = 0.0014) but not in the sPCT population (p = 0.4477). Both HFE C282Y and H63D (c.187C>G, rs1799945) were enriched in both PCT patient populations (p<0.0001) but showed no greater association with fPCT than with sPCT. Conclusion: GNPAT D519G is a risk factor for fPCT, but not for sPCT. PMID:27661980

  4. Intermittent demand : Linking forecasting to inventory obsolescence

    NARCIS (Netherlands)

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied

    2011-01-01

    The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand

  5. Current drive induced by intermittent trapping

    Energy Technology Data Exchange (ETDEWEB)

    Nakach, R. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint-Paul-lez-Durance (France); Gell, Y. [CET, Israel (Israel)

    1999-02-01

    We propose a mechanism for driving a current in a dispersive plasma based on intermittent trapping of electrons in a ponderomotive well generated by two- counterpropagating electron cyclotron waves. By choosing properly the parameters of the system, this mechanism is expected to induce a high efficiency current drive. (authors)

  6. Temporal and spatial intermittencies within Newtonian turbulence

    Science.gov (United States)

    Kushwaha, Anubhav; Graham, Michael

    2015-11-01

    Direct numerical simulations of a pressure driven turbulent flow are performed in a large rectangular channel. Intermittent high- and low-drag regimes within turbulence that have earlier been found to exist temporally in minimal channels have been observed both spatially and temporally in full-size turbulent flows. These intermittent regimes, namely, ''active'' and ''hibernating'' turbulence, display very different structural and statistical features. We adopt a very simple sampling technique to identify these intermittent intervals, both temporally and spatially, and present differences between them in terms of simple quantities like mean-velocity, wall-shear stress and flow structures. By conditionally sampling of the low wall-shear stress events in particular, we show that the Maximum Drag Reduction (MDR) velocity profile, that occurs in viscoelastic flows, can also be approached in a Newtonian-fluid flow in the absence of any additives. This suggests that the properties of polymer drag reduction are inherent to all flows and their occurrence is just enhanced by the addition of polymers. We also show how the intermittencies within turbulence vary with Reynolds number. The work was supported by AFOSR grant FA9550-15-1-0062.

  7. Aggression induced by intermittent positive reinforcement.

    Science.gov (United States)

    Looney, T A; Cohen, P S

    1982-01-01

    Mammalian and non-mammalian species engage in aggressive behavior toward animate and inanimate targets when exposed to intermittent access to a positive reinforcer. This behavior, called extinction- or schedule-induced aggression, typically includes a biting or striking topography that inflicts damage on a target. This paper critically reviews research and theoretical issues concerning such aggression and suggests directions for future investigation.

  8. An Elderly Woman With Intermittent Claudication

    OpenAIRE

    Wazir, Nayyer Naveed

    2006-01-01

    This case report illustrates the misdiagnosis of intermittent claudication in an elderly with multiple cardiac risk factors. Careful clinical evaluation and imaging shifts the diagnosis from peripheral vascular disease to spinal stenosis. The decision whether to offer conservative therapy or proceed to spinal surgery requires an accurate assessment of the severity of the symptoms without ignoring the important role of patient preferences.

  9. Intermittent Aeration in Biological Treatment of Wastewater

    Directory of Open Access Journals (Sweden)

    H. Doan

    2009-01-01

    Full Text Available Problem statement: E-coating process is widely used to provide a protective coating layer on metal parts in the automotive and metal finishing industry. The wastewater from the coating process contains organic compounds that are used in the cleaning, pretreatment and coating steps. Organic pollutants can be removed biologically. In the aerobic biological treatment, water aeration accounts for a significant portion of the total operating cost of the treatment process. Intermittent aeration is thus of benefit since it would reduce the energy consumption in the wastewater treatment. In the present study, wastewater from an electro-coating process was treated biologically using a packed column as an aerator where the wastewater was aerated by a countercurrent air flow. The objective was to obtain an optimum aeration cycle. Approach: Intermittent aeration time was varied at different preset cycles. An operational optimum of the aeration time (or air-water contacting time in the column was determined from the BOD5 removal after a certain treatment period. For continuous aeration of the wastewater, the air-liquid contacting time in the column was 52 min for 24 h of treatment. A unit energy consumption for pumping liquid and air, which was defined as the energy consumption per percent BOD5 removed, was used as a criterion to determine the optimum contacting time. Results: Optimum air-liquid contacting times were found to be about 38, 26 and 22 min for the treatment times of 24, 48 and 72 h, consecutively. This indicates that 27-58% saving on the unit energy consumption can be achieved using intermittent aeration of the wastewater. On the basis of the overall BOD5 removal, 17% and 23% savings in energy were observed with the intermittent aeration as compared to the continuous aeration of the wastewater for 48 and 72 h. Conclusion: The results obtained indicate that an appropriate intermittent aeration cycle can bring about a substantial energy saving

  10. Intermittent heat exposure and thirst in rats.

    Science.gov (United States)

    Barney, Christopher C; Kuhrt, David M

    2016-04-01

    Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague-Dawley rats exposed to 37.5°C for 4 h/day. After 7 days of intermittent heat exposure, reductions in evaporative water loss were observed in all animals and reductions in water intake following heat exposure occurred as the days of heat exposure increased. Rats that were not allowed water during the 7 days of exposure had decreased rehydration levels, however, rats allowed access to water increased water intake during exposure and exhibited higher overall rehydration levels over the same time period. Peripheral administration of angiotensinII, mimicking activation of volemic thirst, or hypertonic saline solution, activating intracellular thirst, did not result in alteration of water intake in rats exposed to heat with access to water compared to control rats. In contrast, rats exposed to heat without access to water had reduced water intake after administration of hypertonic saline and increased water intake after administration of angiotensinIIcompared to control rats. These experiments demonstrate that thirst responses to intermittent heat exposure are altered by providing water during heat exposure and that intermittent heat exposure without access to water alters drinking responses to both intracellular and extracellular thirst challenges. PMID:27095836

  11. INTERMITTENCY AND SCALING IN TURBULENT CONVECTION

    Institute of Scientific and Technical Information of China (English)

    Emily S. C. CHING

    2003-01-01

    Both the velocity and temperature measurements taken in turbulent Rayleigh-B'enard convection experiments have been analyzed. It is found that both the velocity and temperature fluctuations are intermittent and can be well-described by the She-Leveque hierarchical structure. A positive correlation between the vertical velocity and the temperature differences is found both at the center,near the sidewall and near the bottom of the convection cell, supporting that buoyancy is significant in the Bolgiano regime. Moreover, the intermittent nature of the temperature fluctuations in the Bolgiano regime can be attributed to the variations in the temperature dissipation rate. However, the relations between the velocity and temperature structure functions and their correlations implied by the Bolgiano-Obukhov scaling are not supported by experimental measurements.

  12. Insights from intermittent binocular rivalry and EEG

    Directory of Open Access Journals (Sweden)

    Michael A Pitts

    2011-09-01

    Full Text Available Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical approaches, including EEG microstates, event-related potentials, and statistically-based source estimation, and propose a spatio-temporal model that integrates findings from several studies. Finally, we discuss the advantages and limitations of using binocular rivalry as a tool to investigate the neural basis of perceptual awareness.

  13. Correcting intermittent central suppression improves binocular marksmanship.

    Science.gov (United States)

    Hussey, Eric S

    2007-04-01

    Intermittent central suppression (ICS) is a defect in normal binocular (two-eyed) vision that causes confusion in visual detail. ICS is a repetitive intermittent loss of visual sensation in the central area of vision. As the central vision of either eye "turns on and off", aiming errors in sight can occur that must be corrected when both eyes are seeing again. Any aiming errors in sight might be expected to interfere with marksmanship during two-eyed seeing. We compared monocular (one-eyed, patched) and binocular (two-eyed) marksmanship with pistol shooting with an Army ROTC cadet before and after successful therapy for diagnosed ICS. Pretreatment, monocular marksmanship was significantly better than binocular marksmanship, suggesting defective binocularity reduced accuracy. After treatment for ICS, binocular and monocular marksmanship were essentially the same. Results confirmed predictions that with increased visual stability from correcting the suppression, binocular and monocular marksmanship accuracies should merge. PMID:17484315

  14. Scaling and Intermittency in Animal Behavior

    CERN Document Server

    Harnos, A; Lawrence, A B; Vattay, G

    1999-01-01

    Scale-invariant spatial or temporal patterns and Lévy flight motion have been observed in a large variety of biological systems. It has been argued that animals in general might perform Lévy flight motion with power law distribution of times between two changes of the direction of motion. Here we study the temporal behaviour of nesting gilts. The time spent by a gilt in a given form of activity has power law probability distribution without finite average. Further analysis reveals intermittent eruption of certain periodic behavioural sequences which are responsible for the scaling behaviour and indicates the existence of a critical state. We show that this behaviour is in close analogy with temporal sequences of velocity found in turbulent flows, where random and regular sequences alternate and form an intermittent sequence.

  15. Intermittence and roughening of periodic elastic media

    International Nuclear Information System (INIS)

    We analyze intermittence and roughening of an elastic interface or domain wall pinned in a periodic potential, in the presence of random-bond disorder in 1+1 and 2+1 dimensions. Though the ensemble average behavior is smooth, the typical behavior of a large sample is intermittent, and does not self-average to a smooth behavior. Instead, large fluctuations occur in the mean location of the interface and the onset of interface roughening is via an extensive fluctuation which leads to a jump in the roughness of order λ, the period of the potential. Analytical arguments based on extreme statistics are given for the number of the minima of the periodicity visited by the interface and for the roughening crossover, which is confirmed by extensive exact ground state calculations

  16. Intermittent enhancement in chronic nodular calcified neurocysticercosis

    Directory of Open Access Journals (Sweden)

    Martin Oselkin, MD

    2015-01-01

    Full Text Available Neurocysticercosis (NCC is the most common cause of new onset seizures and epilepsy in the developing and tropical world. There has been a marked increase in domestic cases of diseases traditionally associated with developing countries, and now NCC should be high on a radiologist's differential diagnosis list for a patient with seizures. Radiologic findings of NCC correlate with the parasite's life cycle within the host. The calcified granulomas signify the final stage (nodular calcified as nonenhancing punctate calcifications on imaging and are traditionally known to remain without enhancement. Here we describe a unique case of intermittent enhancement of a cortical calcified nodule secondary to NCC that was followed for over 10 years. Radiologists must challenge the traditionally accepted progression of imaging findings and accept that calcified nodules of chronic NCC may intermittently enhance.

  17. Radial evolution of solar wind intermittency in the inner heliosphere

    CERN Document Server

    Bruno, R; Sorriso-Valvo, L; Bavassano, B

    2003-01-01

    We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our analysis focused on the property that probability distribution functions of a fluctuating field affected by intermittency become more and more peaked at smaller and smaller scales. Since the peakedness of a distribution is measured by its flatness factor we studied the behavior of this parameter for different scales to estimate the degree of intermittency of our time series. We confirmed that both magnetic field and velocity fluctuations are rather intermittent and that compressive magnetic fluctuations are generally more intermittent than the corresponding velocity fluctuations. In addition, we observed that compressive fluctuations are always more intermittent than directional fluctuations and that while slow wind intermittency does not depend on the radial distance from the ...

  18. Intermittent permeation of cylindrical nanopores by water

    OpenAIRE

    Allen, Rosalind; Melchionna, Simone; Hansen, Jean-Pierre

    2002-01-01

    Molecular Dynamics simulations of water molecules in nanometre sized cylindrical channels connecting two reservoirs show that the permeation of water is very sensitive to the channel radius and to electric polarization of the embedding material. At threshold, the permeation is {\\emph{intermittent}} on a nanosecond timescale, and strongly enhanced by the presence of an ion inside the channel, providing a possible mechanism for gating. Confined water remains surprisingly fluid and bulk-like. It...

  19. Intermittent chaotic chimeras for coupled rotators.

    Science.gov (United States)

    Olmi, Simona; Martens, Erik A; Thutupalli, Shashi; Torcini, Alessandro

    2015-09-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other jumps erratically between laminar and turbulent phases. These states have finite lifetimes diverging as a power law with N and m. Lyapunov analyses reveal chaotic properties in quantitative agreement with theoretical predictions for globally coupled dissipative systems.

  20. Intermittently Flowing Rivers of Quantized Magnetic Flux

    OpenAIRE

    Nori, Franco

    1997-01-01

    Recent experiments and realistic flux-gradient-driven computer simulations provide evidence of plastic flow of flux lines in a superconductor. The striking videos of the onset of vortex motion vividly illustrate the existence of flowing "rivers" of quantized magnetic flux that intermittently form, freeze, and reappear at different locations in the sample. These rivers flow around "islands" (or domains) of flux lines which are temporarily trapped by the pinning sites. The shape and size of the...

  1. Challenging Oneself Intermittently to Improve Health

    OpenAIRE

    Mattson, Mark P.

    2014-01-01

    Humans and their predecessors evolved in environments where they were challenged intermittently with: 1) food scarcity; 2) the need for aerobic fitness to catch/kill prey and avoid or repel attackers; and 3) exposure to biological toxins present in foodstuffs. Accordingly, cells and organ systems acquired and retained molecular signaling and metabolic pathways through which the environmental challenges enhanced the functionality and resilience of the cells and organisms. Within the past 60 ye...

  2. Intermittent control of unstable multivariate systems.

    Science.gov (United States)

    Loram, I; Gawthrop, P; Gollee, H

    2015-08-01

    A sensorimotor architecture inspired from biological, vertebrate control should (i) explain the interface between high dimensional sensory analysis, low dimensional goals and high dimensional motor mechanisms and (ii) provide both stability and flexibility. Our interest concerns whether single-input-single-output intermittent control (SISO_IC) generalized to multivariable intermittent control (MIC) can meet these requirements.We base MIC on the continuous-time observer-predictorstate-feedback architecture. MIC uses event detection. A system matched hold (SMH), using the underlying continuoustime optimal control design, generates multivariate open-loop control signals between samples of the predicted state. Combined, this serial process provides a single-channel of control with optimised sensor fusion and motor synergies. Quadratic programming provides constrained, optimised equilibrium control design to handle unphysical configurations, redundancy and provides minimum, necessary reduction of open loop instability through optimised joint impedance. In this multivariate form, dimensionality is linked to goals rather than neuromuscular or sensory degrees of freedom. The biological and engineering rationale for intermittent rather than continuous multivariate control, is that the generalised hold sustains open loop predictive control while the open loop interval provides time within the feedback loop for online centralised, state dependent optimisation and selection. PMID:26736539

  3. Comparison in continuous or intermittent intravenous injections of furosemide in patients with acute decompensated heart failure%急性失代偿性心力衰竭患者连续与间歇注射呋塞米的对比研究

    Institute of Scientific and Technical Information of China (English)

    陈瑜; 季顺民; 丁卫东

    2013-01-01

    Objective To discuss the curative effects of continuous intravenous injection (cIV) or intermittent intravenous injection (iIV) of furosemide in the patients with acute decompensated heart failure (ADHF). Methods The patients with ADHF (n=56) were chosen from the Nanmo Health Center, Hai’an County of Nantong City of Jiangsu Province from Jun. 2011 to Nov. 2012, and then divided into cIV group (n=26) and iIV group (n=30). The primary end point was net urine output (nUOP)/24 h, and secondary end points included nUOP/furosemide, total urine output (tUOP)/24 h, tUOP/furosemide, weight loss during the study, additional treatment for ADHF, continuing time of drug administration, hospitalization days and safety reviewing (electrolyte loss and hemodynamic instability). Results The levels of nUOP and tUOP [nUOP:(2098±1132) mL vs. (1575±1100) mL, P=0.086;tUOP:(3726± 1121) mL vs. (2955±1267) mL, P=0.019], and tUOP/furosemide [(38.6±31.0) mL/mg vs. (22.2±12.5) mL/mg, P=0.021] were higher in cIV group than those in iIV group. The other indexes, including nUOP/furosemide, weight loss during the study, additional treatment for ADHF, continuing time of drug administration, and safety had no differences between two groups, and average body weight had no significant difference in two groups before and after treatment. The hospitalization time was shorter in cIV group than that in iIV group [(6.9±3.7) vs. (10.9±8.3 days), P=0.006]. Conclusion cIV has better curative effect than iIV on the clinical symptoms such as anhelation in ADHF patients, and patients’ tolerance is higher.%目的:比较连续(cIV)或间歇(iIV)静注给予呋塞米对急性失代偿性心力衰竭(ADHF)患者的疗效和安全性的差异。方法纳入2011年6月~2012年11月江苏省南通市海安县南莫中心卫生院ADHF患者56例,其中26例采用cIV方式给药的患者纳入cIV组,30例采用iIV方式给药的患者纳入iIV组,主要终点为每日净尿量(nUOP)

  4. Soren Kierkegaard (1813-55): a bicentennial pathographical review.

    Science.gov (United States)

    Schioldann, Johan; Søgaard, Ib

    2013-12-01

    Researchers in the fields of psychology, psychiatry, medicine and theology have made exhaustive efforts to shed light on the elusive biography/pathography of the great Danish philosopher Søren Kierkegaard (1813-55). This 'bicentennial' article reviews his main pathographical diagnoses of, respectively, possible manic-depressive [bipolar] disease, epilepsy, complex partial seizure disorder, Landry-Guillain-Barré's acute ascending paralysis, acute intermittent porphyria with possible psychiatric manifestations, and syphilidophobia. PMID:24573750

  5. Infiltration Effects on Residential Pollutant Concentrations for Continuous and Intermittent Mechanical Ventilation Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Logue, Jennifer; Singer, Brett

    2010-06-01

    The prevailing residential ventilation standard in North America, American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62.2, specifies volumetric airflow requirements as a function of the overall size of the home and the number of bedrooms, assumes a fixed, minimal amount of infiltration, and requires mechanical ventilation to achieve the remainder. The standard allows for infiltration credits and intermittent ventilation patterns that can be shown to provide comparable performance. Whole-house ventilation methods have a substantial effect on time-varying indoor pollutant concentrations. If alternatives specified by Standard 62.2, such as intermittent ventilation, are used, short-term pollutant concentrations could exceed acute health standards even if chronic health standards are met.The authors present a methodology for comparing ASHRAE- and non-ASHRAE-specified ventilation scenarios on relative indoor pollutant concentrations. We use numerical modeling to compare the maximum time-averaged concentrations for acute exposure relevant (1-hour, 8-hour, 24-hour ) and chronic exposure relevant (1-year) time periods for four different ventilation scenarios in six climates with a range of normalized leakage values. The results suggest that long-term concentrations are the most important metric for assessing the effectiveness of whole-house ventilation systems in meeting exposure standards and that, if chronic health exposure standards are met, acute standards will also be met.

  6. Behavioural and neurochemical comparison of chronic intermittent cathinone, mephedrone and MDMA administration to the rat.

    Science.gov (United States)

    Shortall, Sinead E; Macerola, Alice E; Swaby, Rabbi T R; Jayson, Rebecca; Korsah, Chantal; Pillidge, Katharine E; Wigmore, Peter M; Ebling, Francis J P; Richard Green, A; Fone, Kevin C F; King, Madeleine V

    2013-09-01

    The synthetic cathinone derivative, mephedrone, is a controlled substance across Europe. Its effects have been compared by users to 3,4-methylenedioxymethamphetamine (MDMA), but little data exist on its pharmacological properties. This study compared the behavioural and neurochemical effects of mephedrone with cathinone and MDMA in rats. Young-adult male Lister hooded rats received i.p. cathinone (1 or 4 mg/kg), mephedrone (1, 4 or 10mg/kg) or MDMA (10mg/kg) on two consecutive days weekly for 3 weeks or as a single acute injection (for neurochemical analysis). Locomotor activity (LMA), novel object discrimination (NOD), conditioned emotional response (CER) and prepulse inhibition of the acoustic startle response (PPI) were measured following intermittent drug administration. Dopamine, 5-hydroxytryptamine (5-HT) and their major metabolites were measured in striatum, frontal cortex and hippocampus by high performance liquid chromatography 7 days after intermittent dosing and 2h after acute injection. Cathinone (1, 4 mg/kg), mephedrone (10mg/kg) and MDMA (10mg/kg) induced hyperactivity following the first and sixth injections and sensitization to cathinone and mephedrone occurred with chronic dosing. All drugs impaired NOD and mephedrone (10mg/kg) reduced freezing in response to contextual re-exposure during the CER retention trial. Acute MDMA reduced hippocampal 5-HT and 5-HIAA but the only significant effect on dopamine, 5-HT and their metabolites following chronic dosing was altered hippocampal 3,4-dihydroxyphenylacetic acid (DOPAC), following mephedrone (4, 10mg/kg) and MDMA. At the doses examined, mephedrone, cathinone, and MDMA induced similar effects on behaviour and failed to induce neurotoxic damage when administered intermittently over 3 weeks.

  7. Green Tea, Intermittent Sprinting Exercise, and Fat Oxidation

    Directory of Open Access Journals (Sweden)

    Daniel Gahreman

    2015-07-01

    Full Text Available Fat oxidation has been shown to increase after short term green tea extract (GTE ingestion and after one bout of intermittent sprinting exercise (ISE. Whether combining the two will result in greater fat oxidation after ISE is undetermined. The aim of the current study was to investigate the combined effect of short term GTE and a single session of ISE upon post-exercise fat oxidation. Fourteen women consumed three GTE or placebo capsules the day before and one capsule 90 min before a 20-min ISE cycling protocol followed by 1 h of resting recovery. Fat oxidation was calculated using indirect calorimetry. There was a significant increase in fat oxidation post-exercise compared to at rest in the placebo condition (p < 0.01. After GTE ingestion, however, at rest and post-exercise, fat oxidation was significantly greater (p < 0.05 than that after placebo. Plasma glycerol levels at rest and 15 min during post-exercise were significantly higher (p < 0.05 after GTE consumption compared to placebo. Compared to placebo, plasma catecholamines increased significantly after GTE consumption and 20 min after ISE (p < 0.05. Acute GTE ingestion significantly increased fat oxidation under resting and post-exercise conditions when compared to placebo.

  8. UNSTEADY INTERMITTENT FLOW IN A ROTATING CURVED PIPE

    Institute of Scientific and Technical Information of China (English)

    YIN Jian-an; SHEN Xin-rong; CHEN Hua-jun; ZHANG Ben-zhao

    2004-01-01

    The effects of rotation and intermittent fre quency on the flow transition of secondary flow and, main flow were examined in detail. Certain hitherto unknown flow patterns were found. A numerical study was performed to study the characteristics of unsteady intermittent flow in a rotating curved pipe. Due to the rotation, both the Coriolis force and the centrifugal force could contribute to the unsteady intermittent flow and some complicated phenomena can be found. The results indicate that the unsteady intermittent flow are mainly characterized by five parameters: the Dean number Dn , the curvatureκ, the maximal force ratio F (of the Coriolis force to the centrifugal force in a cycle), the intermittent frequency parameter η(the ratio of a pulslating time to the cycle period), and the Womersley number α. Present works shows the natures of the unsteady intermittent flow in a rotating curved pipe.

  9. Intermittency pattern of fluctuations in nuclear multifragmentation

    International Nuclear Information System (INIS)

    The method of scaled factorial moments is used to study fluctuations of the fragment size distribution in the percolation model and in nuclear multifragmentation following the breakup of the high energy nuclei in the nuclear emulsion. The percolation model accounts well for the fluctuations in the nuclear fragmentation process. An intermittent pattern of fluctuations is found in the data suggesting a self-similarity in the fragment size distribution and a random character for the scaling law. However, no evidence of the critical behaviour in nuclear multifragmentation is found. (orig.)

  10. Transition to turbulence, intermittence, and vortex fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Bershadskii, A.G.

    1985-09-01

    A model is developed which describes the fluctuation coalescence of vortices at moderately high Reynolds numbers. The model is found to be in good agreement with experimental data on (1) flow intermittence in a boundary layer, a round jet, and a plane wake; (2) the effect of a magnetic field on the formation of a turbulent energy spectrum behind a grid and on turbulent fluctuations and friction in ducts; (3) formation of a turbulent energy spectrum in a boundary layer and in ducts. 12 references.

  11. The Yo-Yo intermittent recovery test

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Iaia, F. Marcello; Krustrup, Peter

    2008-01-01

    (Yo-Yo IR2) determines an individual's ability to recover from repeated exercise with a high contribution from the anaerobic system. Evaluations of elite athletes in various sports involving intermittent exercise showed that the higher the level of competition the better an athlete performs in the Yo......-Yo IR tests. Performance in the Yo-Yo IR tests for young athletes increases with rising age. The Yo-Yo IR tests have shown to be a more sensitive measure of changes in performance than maximum oxygen uptake. The Yo-Yo IR tests provide a simple and valid way to obtain important information...

  12. Enhanced sarcoplasmic reticulum Ca(2+) release following intermittent sprint training

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Lunde, Per; Levin, Kasper;

    2000-01-01

    To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after...... the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% (P sprint training induced a significantly higher (P

  13. Regionalization of patterns of flow intermittence from gauging station records

    OpenAIRE

    Snelder, T.H.; Datry, T.; Lamouroux, N.; Larned, S. T.; E. Sauquet; Pella, H.; C. Catalogne

    2013-01-01

    Understanding large-scale patterns in flow intermittence is important for effective water resource management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times-series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero-flow) in each year of record (FREQ; yr−1)...

  14. Acute pollution of recipients in urban areas

    DEFF Research Database (Denmark)

    Rauch, W.; Harremoës, P.

    1997-01-01

    Oxygen and ammonia concentration are key parameters of acute water pollution in urban rivers. These two abiotic parameters are statistically assessed for a historical rain series by means of a simplified deterministic model of the integrated drainage system. Continuous simulation of the system...... performance indicates that acute water pollution is caused by intermittent discharges from both sewer system and wastewater treatment plant. Neglecting one of them in the evaluation of the environmental impact gives a wrong impression of total system behavior. Detention basins and alternative operational...... modes in the treatment plant under wet weather loading have a limited positive effect for minimizing acute water pollution. (C) 1997 IAWQ. Published by Elsevier Science Ltd....

  15. Intermittent lag synchronization in a driven system of coupled oscillators

    Indian Academy of Sciences (India)

    Alexander N Pisarchik; Rider Jaimes-Reátegui

    2005-04-01

    We study intermittent lag synchronization in a system of two identical mutually coupled Duffing oscillators with parametric modulation in one of them. This phenomenon in a periodically forced system can be seen as intermittent jump from phase to lag synchronization, during which the chaotic trajectory visits a periodic orbit closely. We demonstrate different types of intermittent lag synchronizations, that occur in the vicinity of saddle-node bifurcations where the system changes its dynamical state, and characterize the simplest case of period-one intermittent lag synchronization.

  16. Projective synchronization of a hyperchaotic system via periodically intermittent control

    Institute of Scientific and Technical Information of China (English)

    Huang Jun-Jian; Li Chuan-Dong; Zhang Wei; Wei Peng-Cheng

    2012-01-01

    We further study the projective synchronization of a new hyperchaotic system.Different from the most existing methods,intermittent control is applied to chaotic synchronization in the present paper.We formulate the intermittent control system that governs the dynamics of the projective synchronization error,then derive the sufficient conditions for the exponential stability of intermittent control system by using the Lyapunov stability theory,and finally establish the periodically intermittent controller according to the stability criterion by which the projective synchronization is expected to be achieved.The analytical results are also demonstrated by several numerical simulations.

  17. Strain intermittency in shape-memory alloys

    Science.gov (United States)

    Balandraud, Xavier; Barrera, Noemi; Biscari, Paolo; Grédiac, Michel; Zanzotto, Giovanni

    2015-05-01

    We study experimentally the intermittent progress of the mechanically induced martensitic transformation in a Cu-Al-Be single crystal through a full-field measurement technique: the grid method. We utilize an in-house, specially designed gravity-based device, wherein a system controlled by water pumps applies a perfectly monotonic uniaxial load through very small force increments. The sample exhibits hysteretic superelastic behavior during the forward and reverse cubic-monoclinic transformation, produced by the evolution of the strain field of the phase microstructures. The in-plane linear strain components are measured on the sample surface during the loading cycle, and we characterize the strain intermittency in a number of ways, showing the emergence of power-law behavior for the strain avalanching over almost six decades of magnitude. We also describe the nonstationarity and the asymmetry observed in the forward versus reverse transformation. The present experimental approach, which allows for the monitoring of the reversible martensitic transformation both locally and globally in the crystal, proves useful and enhances our capabilities in the analysis and possible control of transition-related phenomena in shape-memory alloys.

  18. Intermittent heat instabilities in an air plume

    Science.gov (United States)

    Le Mouël, Jean-Louis; Kossobokov, Vladimir G.; Perrier, Frederic; Morat, Pierre

    2016-08-01

    We report the results of heating experiments carried out in an abandoned limestone quarry close to Paris, in an isolated room of a volume of about 400 m3. A heat source made of a metallic resistor of power 100 W was installed on the floor of the room, at distance from the walls. High-quality temperature sensors, with a response time of 20 s, were fixed on a 2 m long bar. In a series of 24 h heating experiments the bar had been set up horizontally at different heights or vertically along the axis of the plume to record changes in temperature distribution with a sampling time varying from 20 to 120 s. When taken in averages over 24 h, the temperatures present the classical shape of steady-state plumes, as described by classical models. On the contrary, the temperature time series show a rich dynamic plume flow with intermittent trains of oscillations, spatially coherent, of large amplitude and a period around 400 s, separated by intervals of relative quiescence whose duration can reach several hours. To our knowledge, no specific theory is available to explain this behavior, which appears to be a chaotic interaction between a turbulent plume and a stratified environment. The observed behavior, with first-order factorization of a smooth spatial function with a global temporal intermittent function, could be a universal feature of some turbulent plumes in geophysical environments.

  19. Influence of Dehydration on Intermittent Sprint Performance.

    Science.gov (United States)

    Davis, Jon-Kyle; Laurent, C Matt; Allen, Kimberly E; Green, J Matt; Stolworthy, Nicola I; Welch, Taylor R; Nevett, Michael E

    2015-09-01

    This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

  20. Shearing of Materials with Intermittent Joints

    Science.gov (United States)

    Gerolymatou, Eleni; Triantafyllidis, Theodoros

    2016-07-01

    The strength of fractures is much lower as a rule than that of intact rock. As a result they play a controlling part in the mechanical behaviour in general and the failure in particular of rock mass. Though a large volume of experimental data is available on the shear resistance of joints, as well as on the propagation of single cracks, the same is not true for the mechanical behaviour of intermittent joints. The experimental data available in this case are limited and the strength of rock mass with intermittent joints is usually modelled using averaged values of cohesion or assuming the fractures to be continuous. In the present work, the results of simple shear tests on a series of gypsum specimens with pre-existing cracks are presented. Twelve different crack orientations and two normal stresses were tested. The hypothesis of averaged cohesion and the theory of fracture mechanics are used to reproduce the results. It is found that fracture mechanics provides a more suitable model for the experimental results, especially when crack interaction is taken into account.

  1. Challenging oneself intermittently to improve health.

    Science.gov (United States)

    Mattson, Mark P

    2014-12-01

    Humans and their predecessors evolved in environments where they were challenged intermittently with: 1) food scarcity; 2) the need for aerobic fitness to catch/kill prey and avoid or repel attackers; and 3) exposure to biological toxins present in foodstuffs. Accordingly, cells and organ systems acquired and retained molecular signaling and metabolic pathways through which the environmental challenges enhanced the functionality and resilience of the cells and organisms. Within the past 60 years there has been a precipitous diminution of such challenges in modern societies because of the development of technologies that provide a continuous supply of energy-dense processed foods and that largely eliminate the need for physical exertion. As a consequence of the modern 'couch potato' lifestyle, signaling pathways that mediate beneficial effects of environmental challenges on health and disease resistance are disengaged, thereby rendering people vulnerable to obesity, diabetes, cardiovascular disease, cancers and neurodegenerative disorders. Reversal of the epidemic of diseases caused by unchallenging lifestyles will require a society-wide effort to re-introduce intermittent fasting, exercise and consumption of plants containing hormetic phytochemicals into daily and weekly routines. PMID:25552960

  2. Sustained acclimatization in Chilean mine workers subjected to chronic intermittent hypoxia.

    Science.gov (United States)

    Farias, Jorge G; Osorio, Jorge; Soto, Gustavo; Brito, Julio; Siques, Patricia; Reyes, Juan G

    2006-01-01

    Farias, Jorge G., Jorge Osorio, Gustavo Soto, Julio Brito, Patricia Siques, and Juan G. Reyes. Sustained acclimatization in Chilean mine workers subjected to chronic intermittent hypoxia. High Alt. Med. Biol. 7:302-306, 2006--We wanted to know if sea-level mine workers exposed previously to chronic intermittent hypoxia reached a steady acclimatization at 36 months under hypobaric hypoxia. An intermittently exposed group of mine workers (IE, n = 25) were subjected to submaximal exercise (100 W) at 4500 m. Their systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and hemoglobin oxygen saturation (HbSatO(2)) were monitored. Two comparison groups of unacclimatized sea-level workers (n = 17) were studied. A nonexposed group (NE) performed 5 min of submaximal exercise at sea level. Some kind of exercise was performed both by an acutely exposed group (AE) and IE group at 4500 m. No statistical differences were found for HR, SBP, and DBP (p > 0.05) during exercise between IE and AE groups. Resting HbSatO(2) of IE (87 +/- 6%) was lower than NE (97 +/- 3%) (p < 0.05), but was higher than AE (82 +/- 4%) (p < 0.05). In the exercise condition, HbSatO(2) of IE (85 +/- 5%) was lower than NE (95 +/- 3%) (p < 0.05), but was higher than AE (76 +/- 2%) (p < 0.05). These responses were maintained through the 6 months of the study period. Thus, mine workers subjected to intermittent hypobaric condition for 3 years showed a good degree of acclimatization that was maintained through time. PMID:17173515

  3. Regionalization of patterns of flow intermittence from gauging station records

    Science.gov (United States)

    Snelder, T. H.; Datry, T.; Lamouroux, N.; Larned, S. T.; Sauquet, E.; Pella, H.; Catalogne, C.

    2013-07-01

    Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow) in each year of record (FREQ; yr-1), and the total number of zero-flow days in each year of record (DUR; days). These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr-1), and the mean duration of zero-flow periods (mDUR; days). Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR) and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF) models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35). Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape

  4. Regionalization of patterns of flow intermittence from gauging station records

    Directory of Open Access Journals (Sweden)

    T. H. Snelder

    2013-01-01

    Full Text Available Understanding large-scale patterns in flow intermittence is important for effective water resource management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times-series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero-flow in each year of record (FREQ; yr−1, and the total number of zero-flow days in each year of record (DUR; days. These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr−1, and the mean duration of zero-flow periods (mDUR; days. Approximately 20% of stations had recorded at least one zero-flow period. Dissimilarities between pairs of gauges calculated from the annual times-series (FREQ and DUR and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero-flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used Random Forest (RF models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35. Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape and slope. However, we suggest that the fair-to-poor performance of the classification models is because intermittence is also controlled by

  5. Genetics Home Reference: porphyria

    Science.gov (United States)

    ... Aug 16;143(4):316. Citation on PubMed Badminton MN, Elder GH. Molecular mechanisms of dominant expression ... SD, Ducamp S, Gouya L, Grandchamp B, Beaumont C, Badminton MN, Elder GH, Holme SA, Anstey AV, Parker ...

  6. Porphyria Cutanea Tarda (PCT)

    Science.gov (United States)

    ... liver tests are generally abnormal even in PCT patients without Hepatitis C infection. Diagnosis The preferred screening test for ... 2016 Chicago Patient Meeting date: Dec 6, 2015 Patient Education Meeting in Orlando Florida » More upcoming events John ...

  7. Learning about Porphyria

    Science.gov (United States)

    ... Care Online Health Resources For Health Professionals Competency & Curricular Resources Genetics 101 Genomic Medicine and Health Care ... by a specific abnormality in the heme production process. Heme is a chemical compound that contains iron ...

  8. Congenital Erythropoietic Porphyria (CEP)

    Science.gov (United States)

    ... and some types of artificial light, such as fluorescent lights (photosensitivity). After exposure to light, the photo-activated ... and some types of artificial light, such as fluorescent lights (photosensitivity). However, they typically do not have the ...

  9. Chronic intermittent hypoxia and obstructive sleep apnea: an experimental and clinical approach

    Directory of Open Access Journals (Sweden)

    Sforza E

    2016-04-01

    Full Text Available Emilia Sforza, Fréderic Roche Service de Physiologie Clinique et de l'Exercice, Pole NOL, CHU, EA SNA-EPIS 4607, Faculté de Médecine J. Lisfranc, UJM Saint-Etienne, Université de Lyon, Saint-Etienne, France Abstract: Obstructive sleep apnea (OSA is a prevalent sleep disorder considered as an independent risk factor for cardiovascular consequences, such as systemic arterial hypertension, ischemic heart disease, cardiac arrhythmias, metabolic disorders, and cognitive dysfunction. The pathogenesis of OSA-related consequence is assumed to be chronic intermittent hypoxia (IH inducing alterations at the molecular level, oxidative stress, persistent systemic inflammation, oxygen sensor activation, and increase of sympathetic activity. Overall, these mechanisms have an effect on vessel permeability and are considered to be important factors for explaining vascular, metabolic, and cognitive OSA-related consequences. The present review attempts to examine together the research paradigms and clinical studies on the effect of acute and chronic IH and the potential link with OSA. We firstly describe the literature data on the mechanisms activated by acute and chronic IH at the experimental level, which are very helpful and beneficial to explaining OSA consequences. Then, we describe in detail the effect of IH in patients with OSA that we can consider "the human model" of chronic IH. In this way, we can better understand the specific pathophysiological mechanisms proposed to explain the consequences of IH in OSA. Keywords: hypoxia, intermittent hypoxia, experimental studies, obstructive sleep apnea

  10. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868.5955 Section 868.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  11. Intermittent Versus Continuous Phototherapy for Reducing Neonatal Hyperbilirubinemia

    OpenAIRE

    Nikoo Niknafs; Bahare Bahman-Bijari; Mohammad Hossein Torabinejad; Abdol-Ali Mortazavi; Pedram Niknafs

    2008-01-01

    Objective: Clinical studies comparing intermittent versus continuous phototherapy for reducing neonatal hyperbilirubinemia have produced conflicting results. This study was conducted to compare the efficacy of intermittent with continuous phototherapy. Methods: This study was performed on 114 neonates with indirect hyperbilirubinemia. Inclusion criteria were body weight above 2000 grams, absence of other concomitant diseases, and hyperbilirubinemia neither requiring intensive phototherapy nor...

  12. Bound by Children: Intermittent Cohabitation and Living Together Apart

    Science.gov (United States)

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-01-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these…

  13. Intermittent versus Continuous Physiotherapy in Children with Cerebral Palsy

    Science.gov (United States)

    Christiansen, Annette Sandahl; Lange, Christa

    2008-01-01

    The aim of this study was to compare the effect of the delivery of the same amount of intermittent versus continuous physiotherapy given to children with cerebral palsy (CP). This was organized either in an intermittent regime four times a week for 4 weeks alternating with a 6-week treatment pause, or a continuous once or twice a week regime, both…

  14. Intermittent drying of beans in a spouted bed

    Directory of Open Access Journals (Sweden)

    C. A. Oliveira

    2007-12-01

    Full Text Available Carioca beans are a highly nutritious grain, in terms of the amount of protein, iron and potassium as well as carbohydrates and fiber and as a source of vitamins. The moisture content of recently picked beans is too high for good preservation and storage, resulting in the need for drying before packaging. In this work, the drying of Carioca beans in a laboratory scale spouted bed under intermittent conditions of the drying air was experimentally analyzed. Experiments carried out consisted of two types of intermittent regime: intermittence in the spout regime, referred to as spouted/fixed bed and intermittence of the air supply to the bed, called spouted bed/rest. The results were compared to those for bean drying in a spouted bed dryer without intermittence.

  15. Voltage Stability Evaluation Incorporating Wind Power Intermittency

    Institute of Scientific and Technical Information of China (English)

    Libao SHI; Yang ZHAO; Yixin NI; Liangzhong YAO; Masoud BAZARGAN

    2013-01-01

    A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly,the power output modelings of three types of wind turbines are discussed.Secondly,the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly,the relative sensitivity index (RSI) is calculated to identify weak buses during analysis.Finally,case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability,expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.

  16. Towards an intermittency-friendly energy system

    DEFF Research Database (Denmark)

    Blarke, Morten

    2012-01-01

    still has to offer. The solution is for distributed operators to adapt their technology and operational strategies to achieve a better co-existence between cogeneration and wind power. Four options for doing so are analysed including a new concept that integrates a high pressure compression heat pump...... are capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration...... using low-temperature heat recovered from flue gasses in combination with an intermediate cold storage, which enables the independent operation of heat pump and cogenerator. It is found that an electric boiler provides consistent improvements in the intermittency-friendliness of distributed cogeneration...

  17. Intermittency of Energy Dissipation in Alfvenic Turbulence

    CERN Document Server

    Zhdankin, Vladimir; Chen, Christopher H K

    2015-01-01

    We investigate the intermittency of energy dissipation in Alfvenic turbulence by considering the statistics of the coarse-grained energy dissipation rate, using direct measurements from numerical simulations of magnetohydrodynamic turbulence and surrogate measurements from the solar wind. We compare the results to the predictions of the log-normal and log-Poisson random cascade models. We find that, to a very good approximation, the log-normal model describes the probability density function for the energy dissipation over a broad range of scales, but does not accurately describe the scaling exponents of the moments. The log-Poisson model better describes the scaling exponents of the moments, while the comparison with the probability density function is not straightforward.

  18. Muscle coordination changes during intermittent cycling sprints.

    Science.gov (United States)

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-01

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, Pversus sprint 10: -90.2 ms, Pcycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue. PMID:15862899

  19. Scintillation-Induced Intermittency in SETI

    CERN Document Server

    Cordes, J M; Sagan, Carl Edward; Cordes, James M.; Sagan, Carl

    1997-01-01

    We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant sources (> 100 pc), while making redetections improbable. We consider three models in order to assess the non-repeating, narrowband events found in recent SETI and to analyze large surveys in general: (I) Radiometer noise; (II) A population of constant Galactic sources undergoing interstellar scintillation,; and (III) Real, transient signals (or hardware errors) of either terrestrial or ET origin. We apply likelihood and Bayesian tests of the models to The Planetary Society/Harvard META data. We find that Models II and III are both highly preferred to Model I, but that Models II and III are about equally likely. Ruling out Model II in favor of Model III requires many more reobservations than were conducted in META *or* the reobservation threshold must be much lower than wa...

  20. Finite dissipation and intermittency in magnetohydrodynamics

    CERN Document Server

    Mininni, P D

    2009-01-01

    We present an analysis of data stemming from numerical simulations of decaying magnetohydrodynamic (MHD) turbulence up to grid resolution of 1536^3 points and up to Taylor Reynolds number of 1200. The initial conditions are such that the initial velocity and magnetic fields are helical and in equipartition, while their correlation is negligible. Analyzing the data at the peak of dissipation, we show that the dissipation in MHD seems to asymptote to a constant as the Reynolds number increases, thereby strengthening the possibility of fast reconnection events in the solar environment for very large Reynolds numbers. Furthermore, intermittency of MHD flows, as determined by the spectrum of anomalous exponents of structure functions of the velocity and the magnetic field, is stronger than for fluids, confirming earlier results; however, we also find that there is a measurable difference between the exponents of the velocity and those of the magnetic field, as observed recently in the solar wind. Finally, we discu...

  1. Intermittent drinking, oxytocin and human health.

    Science.gov (United States)

    Pruimboom, L; Reheis, D

    2016-07-01

    Looking at a waterhole, it is surprising that so many animals share the same space without visible signs of anxiety or aggression. Although waterholes are the preferred feeding locations of large carnivores, waterholes are shared by all type of herbivores of all sizes and shapes, including elephants. Recent research shows that the homeostatic disturbances leading to the "thirst feeling" not only activate specific substances regulating water and mineral household, but also the "trust and love" hormone oxytocin, while decreasing the production of the typical stress hormone cortisol. People using drugs, seem to be in search for oxytocin, as evidenced in studies with individuals on drugs such as ecstasy and gamma-hydroxybyturate. Hot environment, drought and increased sweating also activate specific oxytocin-producing parts of the hypothalamus, just as breastfeeding does in mother and infant. Water homeostasis is the only allostatic system activating trust neuro-anatomy and we suggest that this is due to the fact that all animals depend on water, whereas food type is species specific. Our hypothesis; regulating drinking behaviour through intermittent bulk drinking could increase oxytocin signalling, recover human trust and increase health by down-regulation of stress axis activity and inflammatory activity of the immune system. Intermittent bulk drinking should be defined as water (including tea and coffee) drinking up to a feeling of satiety and regulated by a mild feeling of thirst. This would mean that people would not drink less quantity but less frequently and that's how all animals, but also human newborns behave. It is the latter group, which is probably the only group of humans with a normal fluid homeostasis. PMID:27241263

  2. Acute Bronchitis

    Science.gov (United States)

    ... of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your cough ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when people ...

  3. Mixing and diffusion in intermittent overturning turbulence

    Science.gov (United States)

    Redondo, Jose M.; Mahjoub, Otman B.; Gonzalez-Nieto, Pilar L.; Lawry, Andrew

    2014-05-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form a Rayleigh-Taylor mixing front. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2-7]. We parametrize the role of unstable stratification by means of the Atwood number and compare both the scaling and the multifractal and the maximum local fractal structure functions of the different markers used to visualize the front. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overal turbulent process evaluated [6-7]. An interesting approach, relating the Multi-Fractal dimension spectra, the intermittency and the spectral exponent is to find relationships that may be used to parameterise the sub-grid turbulence in terms of generalized diffusivities [4 ] that take into account the topology and the self-similarity of the Mixing RT and RM flows. As an example, a relationship between the diffusivity, the exponent β, the intermittency μ, and D(i), may be found for the volume fraction or the concentration, at the same time other locally measured parameters such as the enstrophy or the gradient alignment as well as their multi-fractal structures may turn out to be physically relevant indicators of the local turbulence and the mixing. Several methods of deriving local eddy diffusivity and local entrainment should give more realistic estimates of the spatial/temporal non-homogeneities (and intermittencies in the Kolmogorov 62 sense obtained as spatial correlations of the turbulent dissipation, or from structure functions) and these values may be used to parameterise turbulence at a variety

  4. Identification of intermittent control in man and machine.

    Science.gov (United States)

    Loram, Ian D; van de Kamp, Cornelis; Gollee, Henrik; Gawthrop, Peter J

    2012-09-01

    Regulation by negative feedback is fundamental to engineering and biological processes. Biological regulation is usually explained using continuous feedback models from both classical and modern control theory. An alternative control paradigm, intermittent control, has also been suggested as a model for biological control systems, particularly those involving the central nervous system. However, at present, there is no identification method explicitly formulated to distinguish intermittent from continuous control; here, we present such a method. The identification experiment uses a special paired-step set-point sequence. The corresponding data analysis use a conventional ARMA model to relate a theoretically derived equivalent set-point to control signal; the novelty lies in sequentially and iteratively adjusting the timing of the steps of this equivalent set-point to optimize the linear time-invariant fit. The method was verified using realistic simulation data and was found to robustly distinguish not only between continuous and intermittent control but also between event-driven intermittent and clock-driven intermittent control. When applied to human pursuit tracking, event-driven intermittent control was identified, with an intermittent interval of 260-310 ms (n = 6, p < 0.05). This new identification method is applicable for machine and biological applications. PMID:22491973

  5. Intermittent Renewable Management Pilot Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Homan, Gregory [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Anderson, Robert [Olivine, Inc., San Ramon, CA (United States); Hernandez, John [Pacific Gas & Electric Company, San Francisco, CA (United States)

    2015-04-01

    The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets. The customer had the option of committing to either three contiguous hour blocks for 24 days or six contiguous hours for 12 days a month with day-ahead notification that aligned with the CAISO integrated forward market. As a result of their being available, the customer was paid $10/ kilowatt (kW)-month for capacity in addition to CAISO energy settlements. The participants were limited to no more than a 2 megawatt (MW) capacity with a six-month commitment. Four participants successfully engaged in the pilot. In this report, we provide the description of the pilot, participant performance results, costs and value to participants as well as outline some of the issues encountered through the pilot. Results show that participants chose to participate with storage and the value of CAISO settlements were significantly lower than the capacity payments provided by the utility as incentive payments. In addition, this pilot revealed issues both on the participant side and system operations side. These issues are summarized in the report.The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with

  6. Evaluation of continuous and intermittent myocardial topical negative pressure

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil;

    2008-01-01

    Topical negative pressure, commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. In wound therapy, intermittent negative pressure is often preferred to continuous negative pressure as tissue exposed...... to intermittent therapy shows twice as much granulation tissue formation than that exposed to continuous pressure after 2 weeks of therapy. The present study was designed to elucidate the differences in microvascular blood flow in the left anterior descending artery area between continuous and intermittent...

  7. Photoluminescence intermittency of semiconductor quantum dots in dielectric environments

    Energy Technology Data Exchange (ETDEWEB)

    Isaac, A.

    2006-08-11

    The experimental studies presented in this thesis deal with the photoluminescence intermittency of semiconductor quantum dots in different dielectric environments. Detailed analysis of intermittency statistics from single capped CdSe/ZnS, uncapped CdSe and water dispersed CdSe/ZnS QDs in different matrices provide experimental evidence for the model of photoionization with a charge ejected into the surrounding matrix as the source of PL intermittency phenomenon. We propose a self-trapping model to explain the increase of dark state lifetimes with the dielectric constant of the matrix. (orig.)

  8. Sex differences associated with intermittent swim stress.

    Science.gov (United States)

    Warner, Timothy A; Libman, Matthew K; Wooten, Katherine L; Drugan, Robert C

    2013-11-01

    Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for novel research in this area, as many individuals suffering from depression are resistant to current treatment methods. Women have a higher rate of depression, highlighting the need to investigate mechanisms of sex differences. Therefore, we employed a new animal model to assess symptoms of depression, known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already been shown to cause signs of behavioral depression in males, but has yet to be assessed in females. Following ISS exposure, we looked at sex differences in the Morris water maze and forced swim test. The results indicated a spatial learning effect only in the hidden platform task between male and female controls, and stressed and control males. A consistent spatial memory effect was only seen for males exposed to ISS. In the forced swim test, both sexes exposed to ISS exhibited greater immobility, and the same males and females also showed attenuated climbing and swimming, respectively. The sex differences could be due to different neural substrates for males and females. The goal of this study was to provide the first behavioral examination of sex differences following ISS exposure, so the stage of estrous cycle was not assessed for the females. This is a necessary future direction for subsequent experiments. The current article highlights the importance of sex differences in response to stress.

  9. Cutaneous sporotrichosis. Intermittent treatment (pulses) with itraconazole.

    Science.gov (United States)

    Bonifaz, Alexandro; Fierro, Leonel; Saúl, Amado; Ponce, Rosa María

    2008-01-01

    Sporotrichosis is a subcutaneous and exceptionally deep mycosis caused by a dimorphic fungus, Sporothrix schenckii. Itraconazole is a triazole derivative leading to good results in the treatment of sporotrichosis. Patients with cutaneous sporotrichosis proven with mycological tests (direct examination and culture) were enrolled. All patients underwent laboratory tests (at baseline and on a monthly basis) and received oral itraconazole 400 mg/day for one week with a 3-week break (pulses); thereafter the drug was administered as pulses until clinical and mycological cure was achieved. Five patients with sporotrichosis were enrolled, 4 with cutaneous lymphangitic form and one with fixed cutaneous form. Clinical and mycological cure was achieved in 4/5 cases (80%), with a mean number of pulses of 3.5. No patient had side effects and no laboratory test abnormalities occurred. Intermittent or pulsed itraconazole was effective in treating cutaneous sporotrichosis. It may be considered as a new treatment choice that entails an important reduction in total medication use.

  10. Finite dissipation and intermittency in magnetohydrodynamics.

    Science.gov (United States)

    Mininni, P D; Pouquet, A

    2009-08-01

    We present an analysis of data stemming from numerical simulations of decaying magnetohydrodynamic (MHD) turbulence up to grid resolution of 1536(3) points and up to Taylor Reynolds number of approximately 1200 . The initial conditions are such that the initial velocity and magnetic fields are helical and in equipartition, while their correlation is negligible. Analyzing the data at the peak of dissipation, we show that the dissipation in MHD seems to asymptote to a constant as the Reynolds number increases, thereby strengthening the possibility of fast reconnection events in the solar environment for very large Reynolds numbers. Furthermore, intermittency of MHD flows, as determined by the spectrum of anomalous exponents of structure functions of the velocity and the magnetic field, is stronger than that of fluids, confirming earlier results; however, we also find that there is a measurable difference between the exponents of the velocity and those of the magnetic field, reminiscent of recent solar wind observations. Finally, we discuss the spectral scaling laws that arise in this flow. PMID:19792189

  11. Long-range forecasting of intermittent streamflow

    Directory of Open Access Journals (Sweden)

    F. F. van Ogtrop

    2011-01-01

    Full Text Available Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  12. Intermittency is a consequence of turbulent transport in nonlinear systems

    OpenAIRE

    Newell, Benno Rumpf Alan C.

    2003-01-01

    Intermittent high-amplitude structures emerge in a damped and driven discrete nonlinear Schroedinger equation whose solutions transport both energy and particles from sources to sinks. These coherent structures are necessary for any solution that has statistically stationary transport properties.

  13. Factors relevant to utility integration of intermittent renewable technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Yih-huei; Parsons, B.K.

    1993-08-01

    This study assesses factors that utilities must address when they integrate intermittent renewable technologies into their power-supply systems; it also reviews the literature in this area and has a bibliography containing more than 350 listings. Three topics are covered: (1) interface (hardware and design-related interconnection), (2) operability/stability, and (3) planning. This study finds that several commonly held perceptions regarding integration of intermittent renewable energy technologies are not valid. Among findings of the study are the following: (1) hardware and system design advances have eliminated most concerns about interface; (2) cost penalties have not occurred at low to moderate penetration levels (and high levels are feasible); and (3) intermittent renewable energy technologies can have capacity values. Obstacles still interfering with intermittent renewable technologies are also identified.

  14. Sensing and characterization of EMI during intermittent connector anomalies

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a new on-line methodology for detecting intermittent disconnection failures. The detection principle operates on the fundamental Lorentz Law...

  15. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Directory of Open Access Journals (Sweden)

    Rajsrinivas Parthasarathy

    2016-01-01

    Full Text Available Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA. The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo.

  16. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Science.gov (United States)

    Parthasarathy, Rajsrinivas; Derksen, Carol; Saqqur, Maher; Khan, Khurshid

    2016-01-01

    Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA). The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo. PMID:26933370

  17. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery.

    Science.gov (United States)

    Parthasarathy, Rajsrinivas; Derksen, Carol; Saqqur, Maher; Khan, Khurshid

    2016-01-01

    Embryonic carotid - basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA). The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo. PMID:26933370

  18. Drift Intermittent Synchronization and Controllability in a Simple Model

    Institute of Scientific and Technical Information of China (English)

    XIE Bai-Song; YU Ming-Young

    2005-01-01

    A simple model of three coupled oscillators as an approximation of main modes behaviors in a spatial extended system is proposed. Multi-looping generalized synchronization and drift intermittent lag phase synchronization phenomena are found in this simple model. For a certain of parameters in which chaotic-like intermittent behavior exhibit the amplitudes and phases of three modes are controlled to be synchronized states via coupling them with an external periodic mode.

  19. Intermittent Turbulence in the Very Stable Ekman Layer

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, James C.

    2001-01-05

    INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends to relaminarize because of the very strong ambient stratification. We adopt Mahrt?s (1999) definition of the very stable boundary layer as a boundary layer in which intermittent, rather than continuous turbulence, is observed. Numerical experiments were used to test various hypothesis of where in ?stability parameter space? the very stable boundary layer is found. These experiments support the findings of Howell and Sun (1999) that the boundary layer will exhibit intermittency and therefore be categorized as ?very stable?, when the stability parameter, z/L, exceeds unity. Another marker for the very stable boundary layer, Derbyshire?s (1990) maximum heat flux criterion, was also examined. Using a case study drawn from the simulations where turbulence intermittency was observed, the mechanism that causes the intermittence was investigated. It was found that patchy turbulence originates from a vigorous inflectional, Ekman-like instability -- a roll cell -- that lifts colder air over warmer air. The resulting convective instability causes an intense burst of turbulence. This turbulence is short-lived because the lifting motion of the roll cell, as well as the roll cell itself, is partially destroyed after the patchy turbulence is generated. Examples of intermittent turbulence obtained from the simulations appear to be consistent with observations of intermittency even though the Reynolds number of the DNS is relatively low (400).

  20. The minimum transition hypothesis for intermittent hierarchical motor control

    Directory of Open Access Journals (Sweden)

    Amir eKarniel

    2013-02-01

    Full Text Available In intermittent control, instead of continuously calculating the control signal, the controller occasionally changes this signal at certain sparse points in time. The control law may include feedback, adaptation, optimization, or any other control strategies. When, where, and how does the brain employ intermittency as it controls movement? These are open questions in motor neuroscience. Evidence for intermittency in human motor control has been repeatedly observed in the neural control of movement literature. Moreover, some researchers have provided theoretical models to address intermittency. Even so, the vast majority of current models, and I would dare to say the dogma in most of the current motor neuroscience literature involves continuous control. In this paper, I focus on an area in which intermittent control has not yet been thoroughly considered, the structure of muscle synergies. A synergy in the muscle space is a group of muscles activated together by a single neural command. Under the assumption that the motor control is intermittent, I present the minimum transition hypothesis and its predictions with regards to the structure of muscle synergies. The minimum transitions hypothesis (MTH asserts that the purpose of synergies is to minimize the effort of the higher level in the hierarchy by minimizing the number of transitions in an intermittent control signal. The implications of the MTH are not only for the structure of the muscle synergies but also to the intermittent and hierarchical nature of the motor system, with various predictions as to the process of skill learning, and important implications to the design of brain machine interfaces and human robot interaction.

  1. Identification of intermittent control in man and machine

    OpenAIRE

    Loram, Ian D.; van de Kamp, Cornelis; Gollee, Henrik; Gawthrop, Peter J.

    2012-01-01

    Regulation by negative feedback is fundamental to engineering and biological processes. Biological regulation is usually explained using continuous feedback models from both classical and modern control theory. An alternative control paradigm, intermittent control, has also been suggested as a model for biological control systems, particularly those involving the central nervous system. However, at present, there is no identification method explicitly formulated to distinguish intermittent fr...

  2. Decarbonizing electricity generation with intermittent sources of energy

    OpenAIRE

    Ambec, Stefan; Crampes, Claude

    2015-01-01

    We examine the impact of public policies that aim to decarbonate electricity production by replacing fossil fuel energy by intermittent renewable sources, namely wind and solar power. We consider a model of energy investment and production with two sources of energy: one is clean but intermittent (e.g. wind), whereas the other one is reliable but polluting (e.g. coal). A carbon tax decreases electricity production while simultaneously increasing investment in wind power. This tax may however ...

  3. INTERMITTENT CLONAZEPAM IN THE PREVENTION OF RECURRENT FEBRILE SEIZURES

    OpenAIRE

    Touran MAHMOUDIAN; Omid YAGHINI; Shirin BAJOGHLI

    2010-01-01

    ObjectiveTo evaluate the efficacy and common side effects of intermittent clonazepam in febrile  seizures.Materials & MethodsThis study was an experimental trial designed to determine the efficacy of intermittent clonazepam in febrile seizures .Thirty patients with an age range of 6 months to 5 years (60% male, 40% female) were studied. Children with a history of psychomotor delay, abnormal  neurological examination, a history of antiepileptic drug consumption, and afebrile seizures were excl...

  4. Non-locality and Intermittency in 3D Turbulence

    OpenAIRE

    Laval, J. -P.; B. Dubrulle; Nazarenko, S.(Russian Federal Nuclear Center (VNIIEF), Sarov, Russia)

    2001-01-01

    Numerical simulations are used to determine the influence of the non-local and local interactions on the intermittency corrections in the scaling properties of 3D turbulence. We show that neglect of local interactions leads to an enhanced small-scale energy spectrum and to a significantly larger number of very intense vortices (tornadoes) and stronger intermittency. On the other hand, neglect of the non-local interactions results in even stronger small-scale spectrum but significantly weaker ...

  5. Critical velocity during continuous and intermittent exercises in children.

    Science.gov (United States)

    Berthoin, Serge; Baquet, Georges; Dupont, Gregory; Van Praagh, Emmanuel

    2006-09-01

    The purpose of this study was to apply the "critical velocity" concept to short intermittent high-intensity running exercises in prepubescent girls and boys and to compare the running performances obtained either by intermittent or continuous exercise runs. Eleven 8 to 11-year-old children underwent a maximal graded field test to determine peak oxygen uptake (peakVO2) and maximal aerobic velocity (MAV). During the six following sessions, they randomly performed three continuous runs (90, 100, and 110% of MAV) and three intermittent runs (120, 130, and 140% of MAV) until exhaustion. Intermittent exercises consisted of repeated 15 s runs each one separated by a 15 s passive recovery interval. For continuous as well as intermittent exercises, distance versus time to exhaustion (TTE) relationships were calculated to determine continuous (CVc) and intermittent (CVi) critical velocities. Values for peakVO2 and MAV were 45.8 +/- 5.3 ml x kg(-1) x min(-1) and 10.5 +/- 1.0 km h(-1), respectively. For the whole population, a significant relationship was found between the distance to exhaustion (DTE) and TTE for continuous (r2= 0.99, P < 0.05) and intermittent exercises (r2 = 0.99, P < 0.05). Significant relationships were found between peakVO2 and both CVc (r2= 0.60, P < 0.01) and CVi (r2= 0.47, P < 0.05). In conclusion, as for continuous exercises, a linear relationship was found between DTE and TTE for short high-intensity intermittent exercises. CVc was significantly related to peakVO2, while a significant lower relationship was found between peakVO2 and CVi.

  6. The Prismatic Effect on Stereoacuity in Intermittent Exotropia

    OpenAIRE

    Choi, Kyoung Sub; Chung, Seung Ah; Lee, Kyu Sung; Lee, Jong Bok

    2009-01-01

    Purpose To evaluate the effect of acrylic refractive prism and Fresnel membrane prism on stereoacuity in intermittent exotropia. Materials and Methods Stereoacuities of fifty-two patients (mean age, 12.4 years; range 6 to 45 years) with intermittent exotropia were measured using the Titmus and TNO stereotests, while they wore prisms of varying power on nonfixating eye or evenly on each eye. Results Stereoacuities were significantly reduced with increasing prism power for both prisms, ranging ...

  7. Regionalization of patterns of flow intermittence from gauging station records

    OpenAIRE

    Snelder, T.H.; Datry, T.; Lamouroux, N.; Larned, S. T.; E. Sauquet; Pella, H.; C. Catalogne

    2013-01-01

    Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times...

  8. Análise de variáveis fisiológicas de adolescentes com diagnóstico clínico de asma leve intermitente ou leve persistente quando submetidos a hipóxia aguda e teste de esforço máximo Analysis of physiological variables during acute hypoxia and maximal stress test in adolescents clinically diagnosed with mild intermittent or mild persistent asthma

    Directory of Open Access Journals (Sweden)

    Martin Maldonado

    2011-12-01

    -sectional study involving 48 adolescents (12-14 years of age who were divided into three groups: mild intermittent asthma (MIA, n = 12; mild persistent asthma (MPA, n = 12; and control (n = 24. All subjects were induced to acute hypoxia and were submitted to maximal stress testing. Anthropometric data were collected, and functional variables were assessed before and after the maximal stress test. During acute hypoxia, the time to a decrease in SpO2 and the time to recovery of SpO2 (at rest were determined. RESULTS: No significant differences were found among the groups regarding the anthropometric variables or regarding the ventilatory variables during the stress test. Significant differences were found in oxygen half-saturation pressure of hemoglobin prior to the test and in PaO2 prior to the test between the MPA and control groups (p = 0.0279 and p = 0.0116, respectively, as was in the oxygen extraction tension prior to the test between the MIA and MPA groups (p = 0.0419. There were no significant differences in terms of the SpO2 times under any of the conditions studied. Oxygen consumption and respiratory efficiency were similar among the groups. The use of a bronchodilator provided no significant benefit during the hypoxia test. No correlations were found between the hypoxia test results and the physiological variables. CONCLUSIONS: Our findings suggest that adolescents with mild persistent asthma have a greater capacity to adapt to hypoxia than do those with other types of asthma.

  9. Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication

    Science.gov (United States)

    Werncke, Thomas; Steffen, Ingo G.; Hamm, Bernd; Elgeti, Thomas

    2016-01-01

    Aim To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD? Material and Methods Retrospective re-evaluation of CTAs performed in patients with acute or chronic intermittent claudication (i.e., Fontaine stages I to IIB) between January 2005 and October 2013. Allocation to one of three categories of underlying causes of IC symptoms: vascular, musculoskeletal (MSK) or both. Clinically relevant extravascular incidental findings were evaluated. Medical records were reviewed to verify specific therapies as well as main and incidental findings. Results While focused on vascular imaging, CTA image quality was sufficient for evaluation of the MSK system in all cases. The underlying cause of IC was diagnosed in run-off CTA as vascular, MSK and a combination in n = 138 (65%), n = 10 (4%), and n = 66 (31%) cases, respectively. Specific vascular or MSK therapy was recorded in n = 123 and n = 9 cases. In n = 82, no follow-up was possible. Clinically relevant extravascular incidental findings were detected in n = 65 patients (30%) with neoplasia, ascites and pleural effusion being the most common findings. Discussion Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment. PMID:27054846

  10. Run-Off Computed Tomography Angiography (CTA for Discriminating the Underlying Causes of Intermittent Claudication.

    Directory of Open Access Journals (Sweden)

    Alexandra Preuß

    Full Text Available To evaluate run-off computed tomography angiography (CTA of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC and suspected peripheral arterial disease (PAD. Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD?Retrospective re-evaluation of CTAs performed in patients with acute or chronic intermittent claudication (i.e., Fontaine stages I to IIB between January 2005 and October 2013. Allocation to one of three categories of underlying causes of IC symptoms: vascular, musculoskeletal (MSK or both. Clinically relevant extravascular incidental findings were evaluated. Medical records were reviewed to verify specific therapies as well as main and incidental findings.While focused on vascular imaging, CTA image quality was sufficient for evaluation of the MSK system in all cases. The underlying cause of IC was diagnosed in run-off CTA as vascular, MSK and a combination in n = 138 (65%, n = 10 (4%, and n = 66 (31% cases, respectively. Specific vascular or MSK therapy was recorded in n = 123 and n = 9 cases. In n = 82, no follow-up was possible. Clinically relevant extravascular incidental findings were detected in n = 65 patients (30% with neoplasia, ascites and pleural effusion being the most common findings.Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment.

  11. Neuroprotective Role of Intermittent Hypobaric Hypoxia in Unpredictable Chronic Mild Stress Induced Depression in Rats.

    Directory of Open Access Journals (Sweden)

    Neetu Kushwah

    Full Text Available Hypoxic exposure results in several pathophysiological conditions associated with nervous system, these include acute and chronic mountain sickness, loss of memory, and high altitude cerebral edema. Previous reports have also suggested the role of hypoxia in pathogenesis of depression and related psychological conditions. On the other hand, sub lethal intermittent hypoxic exposure induces protection against future lethal hypoxia and may have beneficial effect. Therefore, the present study was designed to explore the neuroprotective role of intermittent hypobaric hypoxia (IHH in Unpredictable Chronic Mild Stress (UCMS induced depression like behaviour in rats. The IHH refers to the periodic exposures to hypoxic conditions interrupted by the normoxic or lesser hypoxic conditions. The current study examines the effect of IHH against UCMS induced depression, using elevated plus maze (EPM, open field test (OFT, force swim test (FST, as behavioural paradigm and related histological and molecular approaches. The data indicated the UCMS induced depression like behaviour as evident from decreased exploration activity in OFT with increased anxiety levels in EPM, and increased immobility time in the FST; whereas on providing the IHH (5000m altitude, 4hrs/day for two weeks these behavioural changes were ameliorated. The morphological and molecular studies also validated the neuroprotective effect of IHH against UCMS induced neuronal loss and decreased neurogenesis. Here, we also explored the role of Brain-Derived Neurotrophic Factor (BDNF in anticipatory action of IHH against detrimental effect of UCMS as upon blocking of BDNF-TrkB signalling the beneficial effect of IHH was nullified. Taken together, the findings of our study demonstrate that the intermittent hypoxia has a therapeutic potential similar to an antidepressant in animal model of depression and could be developed as a preventive therapeutic option against this pathophysiological state.

  12. Neuroprotective Role of Intermittent Hypobaric Hypoxia in Unpredictable Chronic Mild Stress Induced Depression in Rats.

    Science.gov (United States)

    Kushwah, Neetu; Jain, Vishal; Deep, Satayanarayan; Prasad, Dipti; Singh, Shashi Bala; Khan, Nilofar

    2016-01-01

    Hypoxic exposure results in several pathophysiological conditions associated with nervous system, these include acute and chronic mountain sickness, loss of memory, and high altitude cerebral edema. Previous reports have also suggested the role of hypoxia in pathogenesis of depression and related psychological conditions. On the other hand, sub lethal intermittent hypoxic exposure induces protection against future lethal hypoxia and may have beneficial effect. Therefore, the present study was designed to explore the neuroprotective role of intermittent hypobaric hypoxia (IHH) in Unpredictable Chronic Mild Stress (UCMS) induced depression like behaviour in rats. The IHH refers to the periodic exposures to hypoxic conditions interrupted by the normoxic or lesser hypoxic conditions. The current study examines the effect of IHH against UCMS induced depression, using elevated plus maze (EPM), open field test (OFT), force swim test (FST), as behavioural paradigm and related histological and molecular approaches. The data indicated the UCMS induced depression like behaviour as evident from decreased exploration activity in OFT with increased anxiety levels in EPM, and increased immobility time in the FST; whereas on providing the IHH (5000m altitude, 4hrs/day for two weeks) these behavioural changes were ameliorated. The morphological and molecular studies also validated the neuroprotective effect of IHH against UCMS induced neuronal loss and decreased neurogenesis. Here, we also explored the role of Brain-Derived Neurotrophic Factor (BDNF) in anticipatory action of IHH against detrimental effect of UCMS as upon blocking of BDNF-TrkB signalling the beneficial effect of IHH was nullified. Taken together, the findings of our study demonstrate that the intermittent hypoxia has a therapeutic potential similar to an antidepressant in animal model of depression and could be developed as a preventive therapeutic option against this pathophysiological state. PMID:26901349

  13. Regionalization of patterns of flow intermittence from gauging station records

    Directory of Open Access Journals (Sweden)

    T. H. Snelder

    2013-07-01

    Full Text Available Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow in each year of record (FREQ; yr−1, and the total number of zero-flow days in each year of record (DUR; days. These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr−1, and the mean duration of zero-flow periods (mDUR; days. Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35. Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also

  14. Intermittency and Topology of Shock Induced Mixing

    Science.gov (United States)

    Tellez, Jackson; Redondo, Jose M.; Ben Mahjoub, Otman; Malik, Nadeem; Vila, Teresa

    2016-04-01

    The advance of a Rayleigh-Taylor front is described in Linden & Redondo (1991),[1-3] and may be shown to follow a quadratic law in time where the width of the growing region of instability depends on the local mixing efficiency of the different density fluids that accelerate against each other g is the acceleration and A is the Atwood number defined as the diference of densities divided by their sum. This results show the independence of the large amplitude structures on the initial conditions the width of the mixing region depends also on the intermittency of the turbulence. Then dimensional analysis may also depend on the relevant reduced acceleration driven time and the molecular reactive time akin to Damkholer number and the fractal structure of the contact zone [2,4]. Detailed experiments and simulations on RT and RM shock induced fronts analized with respect to structure functions are able to determine which mechanisms are most effective in local mixing which increase the effective fractal dimension, as well as the effect of higher order geometrical parameters, such as the structure functions, in non-homogeneous fluids (Mahjoub et al 1998)[5]. The structure of a Mixing blob shows a relatively sharp head with most of the mixing taking place at the sides due to what seems to be shear instability very similar to the Kelvin-Helmholtz instabilities, but with sideways accelerations. The formation of the blobs and spikes with their secondary instabilities produces a turbulent cascade, evident just after about 1 non-dimensional time unit, from a virtual time origin that takes into account the linear growth phase, as can be seen by the growth of the fractal dimension for different volume fractions. Two-dimensional cuts of the 3D flow also show that vortex flows have closed or spiral streamlines around their core. Examples of such flows can be also seen in the laboratory, for example at the interface of atwo-layer stratified fluid in a tank in which case streamlines

  15. Acute Pancreatitis and Pregnancy

    Science.gov (United States)

    ... Acute Pancreatitis > Acute Pancreatitis and Pregnancy test Acute Pancreatitis and Pregnancy Timothy Gardner, MD Acute pancreatitis is ... of acute pancreatitis in pregnancy. Reasons for Acute Pancreatitis and Pregnancy While acute pancreatitis is responsible for ...

  16. The Effects of Montmorency Tart Cherry Concentrate Supplementation on Recovery Following Prolonged, Intermittent Exercise

    Directory of Open Access Journals (Sweden)

    Phillip G. Bell

    2016-07-01

    Full Text Available This study investigated Montmorency tart cherry concentrate (MC supplementation on markers of recovery following prolonged, intermittent sprint activity. Sixteen semi-professional, male soccer players, who had dietary restrictions imposed for the duration of the study, were divided into two equal groups and consumed either MC or placebo (PLA supplementation for eight consecutive days (30 mL twice per day. On day 5, participants completed an adapted version of the Loughborough Intermittent Shuttle Test (LISTADAPT. Maximal voluntary isometric contraction (MVIC, 20 m Sprint, counter movement jump (CMJ, agility and muscle soreness (DOMS were assessed at baseline, and 24, 48 and 72 h post-exercise. Measures of inflammation (IL-1-β, IL-6, IL-8, TNF-α, hsCRP, muscle damage (CK and oxidative stress (LOOH were analysed at baseline and 1, 3, 5, 24, 48 and 72 h post-exercise. Performance indices (MVIC, CMJ and agility recovered faster and muscle soreness (DOMS ratings were lower in the MC group (p < 0.05. Additionally, the acute inflammatory response (IL-6 was attenuated in the MC group. There were no effects for LOOH and CK. These findings suggest MC is efficacious in accelerating recovery following prolonged, repeat sprint activity, such as soccer and rugby, and lends further evidence that polyphenol-rich foods like MC are effective in accelerating recovery following various types of strenuous exercise.

  17. The Effects of Montmorency Tart Cherry Concentrate Supplementation on Recovery Following Prolonged, Intermittent Exercise.

    Science.gov (United States)

    Bell, Phillip G; Stevenson, Emma; Davison, Gareth W; Howatson, Glyn

    2016-01-01

    This study investigated Montmorency tart cherry concentrate (MC) supplementation on markers of recovery following prolonged, intermittent sprint activity. Sixteen semi-professional, male soccer players, who had dietary restrictions imposed for the duration of the study, were divided into two equal groups and consumed either MC or placebo (PLA) supplementation for eight consecutive days (30 mL twice per day). On day 5, participants completed an adapted version of the Loughborough Intermittent Shuttle Test (LISTADAPT). Maximal voluntary isometric contraction (MVIC), 20 m Sprint, counter movement jump (CMJ), agility and muscle soreness (DOMS) were assessed at baseline, and 24, 48 and 72 h post-exercise. Measures of inflammation (IL-1-β, IL-6, IL-8, TNF-α, hsCRP), muscle damage (CK) and oxidative stress (LOOH) were analysed at baseline and 1, 3, 5, 24, 48 and 72 h post-exercise. Performance indices (MVIC, CMJ and agility) recovered faster and muscle soreness (DOMS) ratings were lower in the MC group (p < 0.05). Additionally, the acute inflammatory response (IL-6) was attenuated in the MC group. There were no effects for LOOH and CK. These findings suggest MC is efficacious in accelerating recovery following prolonged, repeat sprint activity, such as soccer and rugby, and lends further evidence that polyphenol-rich foods like MC are effective in accelerating recovery following various types of strenuous exercise. PMID:27455316

  18. Bronchitis - acute

    Science.gov (United States)

    ... sharing features on this page, please enable JavaScript. Acute bronchitis is swelling and inflammation in the main passages ... present only for a short time. Causes When acute bronchitis occurs, it almost always comes after having a ...

  19. Acute pancreatitis

    OpenAIRE

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline) addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingest...

  20. Acute pancreatitis

    OpenAIRE

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline) addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion....

  1. Effects of continuous and intermittent exercise on executive function in children aged 8-10 years.

    Science.gov (United States)

    Lambrick, Danielle; Stoner, Lee; Grigg, Rebecca; Faulkner, James

    2016-09-01

    Understanding the effects of acute exercise on executive function in prepubescent children may be important for the enhancement of school performance. This study assessed the effect of an acute bout of continuous (CONT) or intermittent (INT), moderate-intensity treadmill exercise on executive function in young children. Twenty healthy children, mean (SD); age: 8.8 (0.8) years; height: 140 (9) cm; weight: 36 (11) kg; boys: n = 9, performed a graded-exercise test to determine maximal oxygen uptake, and two 15-min submaximal bouts of treadmill exercise; protocols were either CONT or INT. During CONT, participants ran at 90% of gas exchange threshold. During INT, participants performed six consecutive 2.5 min blocks of exercise, which were designed to reflect children's typical activity patterns, comprising 45 s at a heavy intensity, 33 s at a moderate intensity, 10 s at a severe intensity, and 62 s at a low intensity. Participants performed the Stroop task before the submaximal exercise bouts and after, at 1-, 15-, and 30-min intervals. Near-infrared spectroscopy (NIRS) measured cerebral perfusion and oxygenation. Regardless of condition, Stroop performance was improved at 1 min after compared to before, 54.9 (9.8) s versus 57.9 (11) s, respectively, p Stroop performance for INT only (49%, p exercise, of either an intermittent or continuous nature, improves executive function in children, and effects are maintained for ≤ 30 min following exercise cessation. Accordingly, it is recommended that children should engage in physical activity during periods of school recess. PMID:27314635

  2. Intermittent attendance at breast cancer screening

    Directory of Open Access Journals (Sweden)

    Padraic Fleming

    2013-09-01

    Full Text Available Background. To determine why women skip rounds and factors influencing return of previous non attenders (PNAs to breast screening. Design and methods. Retrospective, quantitative, structured questionnaire posted to 2500 women. First PNAs did not attend their first screening appointment in 2007/2008 but then attended in 2010; First Controls first attended in 2010 without missed previous appointments. Women who attended screening in 2006 or earlier then skipped a round but returned in 2010 were Subsequent PNAs; Subsequent Controls attended all appointments.Results. More First Controls than First PNAs had family history of cancer (72.7% vs 63.2%; P=0.003; breast cancer (31.3% vs 24.8%; P=0.04. More PNAs lived rurally; more First PNAs had 3rd level education (33.2% vs 23.6%; P=0.002 and fewer had private insurance than First Controls (57.7% vs 64.8%; P=0.04. Excellent/good health was reported in First PNAs and First Controls (82.9% vs 83.2%, but fewer Subsequent PNAs than Subsequent Controls (72.7% vs 84.9%; P=0.000. Common considerations at time of missed appointment were had mammogram elsewhere (33% First PNA and postponed to next round (16% First PNA, 18.8% Subsequent PNA. Considerations when returning to screening were similar for First PNAs and Subsequent PNAs: I am older (35.4%, 29.6%, I made sure I remembered (29%, 23.6%, could reschedule (17.6%, 20.6%, illness of more concern (16.5%, 19%. More First PNAs stated my family/friends advised (22.3% vs 15.2% or my GP (12.6% vs 4.6% advised me to attend, heard good things about BreastCheck (28.8% vs 13.6%.Conclusions. Intermittent attenders do not fit socio-demographic patterns of non-attenders; GP recommendation and word of mouth were important in women’s return to screening. Fear and anxiety seem to act as a screening facilitator rather than an inhibitor.

  3. Cardioprotective adaptation of rats to intermittent hypobaric hypoxia is accompanied by the increased association of hexokinase with mitochondria.

    Science.gov (United States)

    Waskova-Arnostova, Petra; Elsnicova, Barbara; Kasparova, Dita; Hornikova, Daniela; Kolar, Frantisek; Novotny, Jiri; Zurmanova, Jitka

    2015-12-15

    Chronic hypoxia increases the myocardial resistance to acute ischemia-reperfusion injury by affecting the mitochondrial redox balance. Hexokinase (HK) bears a high potential to suppress the excessive formation of reactive oxygen species because of its increased association with mitochondria, thereby inhibiting the membrane permeability transition pore opening and preventing cell death. The purpose of this study was to determine the effect of severe intermittent hypobaric hypoxia (7,000 m, 8 h/day, 5 wk) on the function and colocalization of HK isoforms with mitochondria in the left (LV) and right ventricles of rat myocardium. The real-time RT-PCR, Western blot, enzyme coupled assay, and quantitative immunofluorescence techniques were used. Our results showed significantly elevated expression of HK isoforms (HK1 and HK2) in the hypoxic LV. In addition, intermittent hypoxia increased the total HK activity and the association of HK isoforms with mitochondria in both ventricles. These findings suggest that HK may contribute to the cardioprotective phenotype induced by adaptation to severe intermittent hypobaric hypoxia. PMID:26494452

  4. Intermittency on simultaneous observations of riometer at several Antarctic locations

    Science.gov (United States)

    Ovalle, E. M.; Foppiano, A. J.; Stepanova, M. V.; Weatherwax, A. T.

    2016-03-01

    It is well known that auroral radio wave absorption, as measured by riometers, consists of periods of relative quiescence which are interrupted by short bursts of activity. Such patterns in activity are observed in systems ranging from the stock market to turbulence, i.e. they exhibit intermittency. In the case of the auroral absorption it has also been found that intermittency strongly depends on the magnetic local time, being largest in the night-time sector. This can be interpreted as indicating that the precipitating particles responsible of the absorption exhibit intermittency, especially near the substorm eye, where the level of turbulence increases. Here, we analyse simultaneous observations of riometer absorption at seven Antarctic locations, to determine whether they exhibit intermittency. We determine the Probability Distribution Functions of the fluctuations of riometer absorption for absorption events larger than 0.1 dB, as well as those for the time-intervals between absorption events. Observations are for locations within the austral auroral absorption zone and on the polar cap. It is found that the parameters of a power law used to describe the calculated PDFs are consistent with the formation of coherent structures being more frequent within the auroral zone, as a manifestation of intermittency.

  5. Mathematically modelling and controlling prostate cancer under intermittent hormone therapy

    Institute of Scientific and Technical Information of China (English)

    Yoshito Hirata; Gouhei Tanaka; Nicholas Bruchovsky; Kazuyuki Aihara

    2012-01-01

    In this review,we summarize our recently developed mathematical models that predict the effects of intermittent androgen suppression therapy on prostate cancer (PCa).Although hormone therapy for PCa shows remarkable results at the beginning of treatment,cancer cells frequently acquire the ability to grow without androgens during long-term therapy,resulting in an eventual relapse.To circumvent hormone resistance,intermittent androgen suppression was investigated as an alternative treatment option.However,at the present time,it is not possible to select an optimal schedule of on- and off-treatment cycles for any given patient.In addition,clinical trials have revealed that intermittent androgen suppression is effective for some patients but not for others.To resolve these two problems,we have developed mathematical models for PCa under intermittent androgen suppression.The mathematical models not only explain the mechanisms of intermittent androgen suppression but also provide an optimal treatment schedule for the on- and off-treatment periods.

  6. Entropic-Skins Geometry to Describe Wall Turbulence Intermittency

    Directory of Open Access Journals (Sweden)

    Diogo Queiros-Conde

    2015-04-01

    Full Text Available In order to describe the phenomenon of intermittency in wall turbulence and, more particularly, the behaviour of moments  and and intermittency exponents ζP with the order p and distance to the wall, we developed a new geometrical framework called “entropic-skins geometry” based on the notion of scale-entropy which is here applied to an experimental database of boundary layer flows. Each moment has its own spatial multi-scale support Ωp (“skin”. The model assumes the existence of a hierarchy of multi-scale sets Ωp ranged from the “bulk” to the “crest”. The crest noted characterizes the geometrical support where the most intermittent (the highest fluctuations in energy dissipation occur; the bulk is the geometrical support for the whole range of fluctuations. The model assumes then the existence of a dynamical flux through the hierarchy of skins. The specific case where skins display a fractal structure is investigated. Bulk fractal dimension  and crest dimension  are linked by a scale-entropy flux defining a reversibility efficiency  (d is the embedding dimension. The model, initially developed for homogeneous and isotropic turbulent flows, is applied here to wall bounded turbulence where intermittency exponents are measured by extended self-similarity. We obtained for intermittency exponents the analytical expression with γ ≈ 0.36 in agreement with experimental results.

  7. Study on Intermittent Irrigation for Paddy Rice: II. Crop Responses

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effect of intermittent irrigation on the production of paddy rice was studied in a well-puddled paddy field with four treatments and 2 replicates: continuous flooding irrigation (CFI), and intermittent irrigation II-0, II-1 and II-2, in which plants were re-irrigated when the soil water potential fell below 0, -10, and -20 kPa, respectively, at soil depth of about 5 cm. Results showed that the reduction in soil water potential to about -10 or -20 kPa did not significantly affect the number of grains and the percentage of ripened grains. While, a lower crop growth rate (CGR) resulted from a decrease in the net assimilation rate (NAR) during intermittent irrigation II-1 and II-2, and there was also a reduction in the leaf area index (LAI) during intermittent irrigation II-2. Senescence of lower leaves on stems was promoted in treatments II-1 and II-2 at the ripening stage. Early senescence at ripening stage and water stress around midday decreased the rate of photosynthesis in leaves, causing the lower NAR. These physiological responses of the plants were responsible for the reduction in the dry matter production and grain yield in the intermittent irrigation treatments.

  8. Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

    Science.gov (United States)

    Akoz, Emre; Moored, Keith

    2015-11-01

    Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

  9. Subacute fulminant hepatic failure with intermittent fever

    Institute of Scientific and Technical Information of China (English)

    Cong-Xin Chen; Bo Liu; Yong Hu; Joyce E. Johnson; Yi-Wei Tang

    2009-01-01

    BACKGROUND:Viral hepatitis B accounts for over 80%of acute hepatic failures in China and the patients die mainly of its complications. A patient with hepatic failure and fever is not uncommon, whereas repeated fever is rare. METHODS:A 32-year-old female was diagnosed with subacute hepatic failure and hepatitis B viral infection because of hyperbilirubinemia, coagulopathy, hepatic encephalopathy, serum anti-HBs-positive without hepatitis B vaccination, and typical intrahepatic pathological features of chronic hepatitis B. Plasma exchange was administered twice and she awoke with hyperbilirubinemia and discontinuous fever. RESULTS:Urethritis was conifrmed and medication-induced fever and/or spontaneous bacterial peritonitis (Gram-negative bacillus infection) was suspected. The patient was treated with antibiotics, steroids and a Chinese herbal medicine, matrine, for three months and she recovered. CONCLUSION:The survival rate of patients with hepatic failure might be improved with comprehensive supporting measures and appropriate, timely management of com-plications.

  10. Acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Bo-Guang Fan

    2010-01-01

    Full Text Available Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions : Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  11. Acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Bo-Guang Fan

    2010-05-01

    Full Text Available Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions: Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  12. Intermittency in e+e- and lepton-hadron collisions

    International Nuclear Information System (INIS)

    The intermittency data in e+e- and lepton-hadron collisions are reviewed. The power-law behavior of the moments has been established by various e+e- experiments and a μp experiment. The intermittency in the two-dimensional space of rapidity and azimuthal angle is much stronger than in the rapidity space only. The neutrino-nucleus data indicate significant effects from nuclear reinteractions. The LUND parton shower model fits the data better than the matrix element model without special retuning. The relations among the moments of different orders are in good agreement with the predictions by the negative binomial and pure birth distributions. The origin of the intermittency in e+e- and μp collisions is consistent with the self-similar cascade mechanism of jet formation. 11 refs., 7 figs

  13. Multiparticle correlations and intermittency in high energy collisions

    CERN Document Server

    Bozek, P

    1992-01-01

    In this work the analysis of the intermittency signal observed in high energy experi- ments is done using multiparticle distributions and correlation functions. The effect of the dimensional projection of the multiparticle distributions on one or two-dimensional subspace is discussed. The structure of the multiparticle cumulants is analyzed for the DELPHI e + e~ annihilation data. The language of the self-similar distribution func- tions, which is used in this work, is shown to be largely equivalent to the well known a-model. In the case of the ultrarelativistic nuclear collisions, where the Monte-Carlo simulations fail to reproduce the data, we argue that the observed intermittency pattern is a signal of some nonlinear effect beyond the simple superposition of nucleon-nucleon collisions. The model of spatiotemporal intermittency is discussed in details and is shown to reproduce qualitatively the dependence of t...

  14. Multiparticle correlations and intermittency in high energy collisions

    International Nuclear Information System (INIS)

    The analysis of the intermittency signal observed in high energy experiments is presented using multiparticle distributions and correlation functions. The effect of the dimensional projection of the multiparticle distributions on one or two-dimensional subspace is discussed. The structure of the multiparticle cumulants is analyzed for the DELPHI e+e- annihilation data. The model of spatiotemporal intermittency is discussed in details and is shown to reproduce qualitatively the dependence of the intermittency strength on the target and projectile nuclei. A 1-dimensional (1D) cellular-automaton and a 1D forest-fire model is studied. On the example of the noncritical 1D Ising model the difficulties of the scaled factorial moment (SFM) method in extracting genuine scaling behaviour is illustrated. All these studies could serve as tools to test the sensibility of the SFM method as used in the analysis of the high energy production. (K.A.) 122 refs.; 38 figs.; 3 tabs

  15. Temporal intermittency of energy dissipation in magnetohydrodynamic turbulence.

    Science.gov (United States)

    Zhdankin, Vladimir; Uzdensky, Dmitri A; Boldyrev, Stanislav

    2015-02-13

    Energy dissipation in magnetohydrodynamic (MHD) turbulence is known to be highly intermittent in space, being concentrated in sheetlike coherent structures. Much less is known about intermittency in time, another fundamental aspect of turbulence which has great importance for observations of solar flares and other space or astrophysical phenomena. In this Letter, we investigate the temporal intermittency of energy dissipation in numerical simulations of MHD turbulence. We consider four-dimensional spatiotemporal structures, "flare events," responsible for a large fraction of the energy dissipation. We find that although the flare events are often highly complex, they exhibit robust power-law distributions and scaling relations. We find that the probability distribution of dissipated energy has a power-law index close to α≈1.75, similar to observations of solar flares, indicating that intense dissipative events dominate the heating of the system. We also discuss the temporal asymmetry of flare events as a signature of the turbulent cascade.

  16. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    Science.gov (United States)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  17. Intermittency in Fractal Fourier Hydrodynamics: Lessons from the Burgers Equation

    CERN Document Server

    Buzzicotti, Michele; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-01-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension $D$. We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing $D$. We find that a very small percentage of mode-reduction ($D \\lesssim 1$) is enough to destroy most of the characteristics of the original non-decimated equation. In particular, we observe a suppression of intermittent fluctuations for $D <1$ and a quasi-singular transition from the fully intermittent ($D=1$) to the non-intermittent case for $D \\lesssim 1$. Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes.

  18. Generalized description of intermittency in turbulence via stochastic methods

    CERN Document Server

    Friedrich, J

    2016-01-01

    We present a generalized picture of intermittency in turbulence that is based on the theory of stochastic processes. To this end, we rely on the experimentally and numerically verified finding by R.~Friedrich and J.~Peinke [Phys. Rev. Lett. 78, 863 (1997)] that allows for an interpretation of the turbulent energy cascade as a Markov process of the velocity increments in scale. It is explicitly shown that all known phenomenological models of turbulence can be reproduced by the Kramers-Moyal expansion of the velocity increment probability density function that is associated to a Markov process. We compare the different sets of Kramers-Moyal coefficients of each phenomenology and deduce that an accurate description of intermittency should take into account an infinite number of coefficients. This is demonstrated in more detail for the case of Burgers turbulence that exhibits the strongest intermittency effects. Moreover, the influence of nonlocality on the Kramers-Moyal coefficients is investigated by direct num...

  19. Temporal Intermittency of Energy Dissipation in Magnetohydrodynamic Turbulence

    CERN Document Server

    Zhdankin, Vladimir; Boldyrev, Stanislav

    2015-01-01

    Energy dissipation in magnetohydrodynamic (MHD) turbulence is known to be highly intermittent in space, being concentrated in sheet-like coherent structures. Much less is known about intermittency in time, another fundamental aspect of turbulence which has great importance for observations of solar flares and other space/astrophysical phenomena. In this Letter, we investigate the temporal intermittency of energy dissipation in numerical simulations of MHD turbulence. We consider four-dimensional spatiotemporal structures, "flare events", responsible for a large fraction of the energy dissipation. We find that although the flare events are often highly complex, they exhibit robust power-law distributions and scaling relations. We find that the probability distribution of dissipated energy has a power law index close to -1.75, similar to observations of solar flares, indicating that intense dissipative events dominate the heating of the system. We also discuss the temporal asymmetry of flare events as a signatu...

  20. Scenedesmus dimorphus biofilm: Photoefficiency and biomass production under intermittent lighting.

    Science.gov (United States)

    Toninelli, Andrea Efrem; Wang, Junfeng; Liu, Mingshen; Wu, Hong; Liu, Tianzhong

    2016-01-01

    This study investigated the effect of intermittent lighting on the growth performances of a Scenedesmus dimorphus biofilm. Flashing light effect (FLE) is common in traditional suspended cultures of microalgae; yet, publications about this phenomenon, in the context of biofilm cultivation, are scarce. In this work we demonstrate that, thanks to intermittent illumination, it is possible for attached cultivations to fulfill FLE, improve photoefficiency and productivity as well as providing protection from photoinhibition using much lower flashing light frequencies than those usually required with suspended cultures. Medium frequency intermittent lighting (0.1 Hz) guaranteed excellent light integration resulting in 9.13 g m(-2) d(-1) biomass productivity, which was 8.9% higher than with continuous lighting. Results showed that a light fraction value of 0.5 always improved photoefficiency values as related to continuous light with a 118.8% maximum increase. PMID:27561323

  1. Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Chen, Xiaofei; Zhao, Tong; Huang, Xin; Wu, Liying; Wu, Kuiwu; Fan, Ming; Zhu, Lingling

    2016-05-01

    Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p  0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, pintermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular glycogenesis may play a role in the underlying mechanism. PMID:26902078

  2. Turbulence and intermittent transport at the boundary of magnetized plasmas

    DEFF Research Database (Denmark)

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.;

    2005-01-01

    Numerical fluid simulations of interchange turbulence for geometry and parameters relevant to the boundary region of magnetically confined plasmas are shown to result in intermittent transport qualitatively similar to recent experimental measurements. The two-dimensional simulation domain features...... a forcing region with spatially localized sources of particles and heat outside which losses due to the motion along open magnetic-field lines dominate, corresponding to the edge region and the scrape-off layer, respectively. Turbulent states reveal intermittent eruptions of hot plasma from the edge region...

  3. Intermittency-friendly and high-efficiency cogeneration

    DEFF Research Database (Denmark)

    Blarke, Morten; Dotzauer, Erik

    2011-01-01

    -efficiency and widely applicable option in distributed cogeneration better supporting the co-existence between cogenerators and intermittent renewables in the energy system. The concept involves integrating an efficient high-temperature compression heat pump that uses only waste heat recovered from flue gases as low....... It is found that CHP-HP-FG-CS offers significant reductions in fuel consumption (−8.9%) and operational production costs (−11.4%). The plant’s fuel-to-energy efficiency increases from 88.9 to 95.5%, which is state-of-the-art. The plant’s intermittency-friendliness coefficient Rc improves only marginally due...

  4. Challenges to Cabin Humidity Removal Presented by Intermittent Condensing Conditions

    Science.gov (United States)

    vonJouanne, Roger G.; Williams, David E.

    2007-01-01

    On-orbit temperature and humidity control (THC) is more easily accomplished when the THC hardware is either consistently dry (i.e., no humidity control is occurring), or consistently wet. The system is especially challenged when intermittent wet/dry conditions occur. The first six years of on-orbit ISS operations have revealed specific concerns within the THC system, specifically in the condensing heat exchanger and the downstream air/water separator. Failed or degraded hardware has been returned to ground and investigated. This paper presents the investigation findings, and the recommended hardware and procedural revisions to prevent and recover from the effects of intermittent condensing conditions.

  5. Solar flare intermittency and the earth's temperature anomalies.

    Science.gov (United States)

    Scafetta, Nicola; West, Bruce J

    2003-06-20

    We argue that Earth's short-term temperature anomalies and the solar flare intermittency are linked. The analysis is based upon the study of the scaling of both the spreading and the entropy of the diffusion generated by the fluctuations of the temperature time series. The joint use of these two methods evidences the presence of a Lévy component in the temporal persistence of the temperature data sets that corresponds to the one that would be induced by the solar flare intermittency. The mean monthly temperature data sets cover the period from 1856 to 2002. PMID:12857233

  6. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    Science.gov (United States)

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits. PMID:26438184

  7. INTERMITTENT CLONAZEPAM IN THE PREVENTION OF RECURRENT FEBRILE SEIZURES

    Directory of Open Access Journals (Sweden)

    Touran MAHMOUDIAN

    2010-10-01

    Full Text Available ObjectiveTo evaluate the efficacy and common side effects of intermittent clonazepam in febrile  seizures.Materials & MethodsThis study was an experimental trial designed to determine the efficacy of intermittent clonazepam in febrile seizures .Thirty patients with an age range of 6 months to 5 years (60% male, 40% female were studied. Children with a history of psychomotor delay, abnormal  neurological examination, a history of antiepileptic drug consumption, and afebrile seizures were excluded from the study. Patients received a single dose of prophylactic Clonazepam (0.05 mg/kg/ day on the first day of febrile illness and twice daily during the course of fever.An antipyretic medication (Acetaminophen was advised if fever exceeded 38oC. Patients were followed up for one year after the study inclusion date.ResultsThree patients were excluded from study since they didnot follow the tritment and three patients experienced afebrile seizures. Twenty four patients had 162 febrile episodes during the course of the study and all patients were seizure-free after 1 year.ConclusionClonazepam was 100% effective but lethargy and ataxia were common side effects in patients. Fortunately, their parents continued treatment because they had prior awareness of the  possible side effects of clonazepam. Clonazepam is efficacious as an intermittent therapy for febrile seizures if parents are informed of its side effects.Keywords: recurrent febrile seizures, clonazepam, intermittent prophylaxis

  8. Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation

    Science.gov (United States)

    Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

    2010-01-01

    This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

  9. Serum bilirubin kinetics in intermittent phototherapy of physiological jaundice.

    OpenAIRE

    Lau, S. P.; Fung, K P

    1984-01-01

    Thirty four term babies with physiological jaundice were subjected to continuous phototherapy and to two regimens of intermittent phototherapy. The difference in serum bilirubin kinetics between the three groups of treated babies was insignificant; a schedule of one in four hours of irradiation achieved the same treatment effect as continuous phototherapy.

  10. Intermittent Versus Continuous Phototherapy for Reducing Neonatal Hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Nikoo Niknafs

    2008-09-01

    Full Text Available Objective: Clinical studies comparing intermittent versus continuous phototherapy for reducing neonatal hyperbilirubinemia have produced conflicting results. This study was conducted to compare the efficacy of intermittent with continuous phototherapy. Methods: This study was performed on 114 neonates with indirect hyperbilirubinemia. Inclusion criteria were body weight above 2000 grams, absence of other concomitant diseases, and hyperbilirubinemia neither requiring intensive phototherapy nor exceeding the range of exchange transfusion. The neonates were randomly divided into two groups. Continuous phototherapy group received phototherapy on and off for 2 hours and half an hour respectively and the intermittent phototherapy group on and off for one hour. The phototherapy units were identical and serum total bilirubin levels were measured every 12 hours after starting phototherapy. Findings: Two groups were matched regarding weight and risk factors such as ABO and Rh incompatibility. The difference of total serum bilirubin levels between two groups was insignificant at the start of phototherapy and also after 12, 24, 36 and 48 hours (P>0.2.Conclusion: Intermittent phototherapy defined as one hour on and one hour off is as effective as continuous phototherapy defined as 2 hours on and half an hour off, in reducing total serum bilirubin level in full term babies.

  11. Intermittent versus continuous administration of growth hormone treatment.

    OpenAIRE

    Hakeem, V; Hindmarsh, P. C.; Brook, C G

    1993-01-01

    Growth hormone treatment given by daily injection was compared with growth hormone given for three weeks of every four. All children had received recombinant human growth hormone for two years before randomisation. Growth velocity decreased in both groups in years one and two of the study but the effect was significantly greater in the group receiving intermittent growth hormone.

  12. Quasi-one-dimensional intermittent flux behavior in superconducting films

    DEFF Research Database (Denmark)

    Qviller, A. J.; Yurchenko, V. V.; Galperin, Y. M.;

    2012-01-01

    Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa2Cu3O7-δ deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. ...

  13. Two-scale analysis of intermittency in fully developed turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Badii, R.; Talkner, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A self-affinity test for turbulent time series is applied to experimental data for the estimation of intermittency exponents. The method employs exact relations satisfied by joint expectations of observables computed across two different length scales. One of these constitutes a verification tool for the existence and the extent of the inertial range. (author) 2 figs., 13 refs.

  14. Mathematical analysis of intermittent gas injection model in oil production

    Science.gov (United States)

    Tasmi, Silvya, D. R.; Pudjo, S.; Leksono, M.; Edy, S.

    2016-02-01

    Intermittent gas injection is a method to help oil production process. Gas is injected through choke in surface and then gas into tubing. Gas forms three areas in tubing: gas column area, film area and slug area. Gas column is used to propel slug area until surface. A mathematical model of intermittent gas injection is developed in gas column area, film area and slug area. Model is expanding based on mass and momentum conservation. Using assume film thickness constant in tubing, model has been developed by Tasmi et. al. [14]. Model consists of 10 ordinary differential equations. In this paper, assumption of pressure in gas column is uniform. Model consist of 9 ordinary differential equations. Connection of several variables can be obtained from this model. Therefore, dynamics of all variables that affect to intermittent gas lift process can be seen from four equations. To study the behavior of variables can be analyzed numerically and mathematically. In this paper, simple mathematically analysis approach is used to study behavior of the variables. Variables that affect to intermittent gas injection are pressure in upstream valve and in gas column. Pressure in upstream valve will decrease when gas mass in valve greater than gas mass in choke. Dynamic of the pressure in the gas column will decrease and increase depending on pressure in upstream valve.

  15. Intermittent breeding as a cost of site fidelity

    NARCIS (Netherlands)

    Bruinzeel, Louis

    2007-01-01

    Intermittent breeding (skipping a breeding season) can be the result of an adaptive decision by a focal individual, trading current reproductive success in favour of future reproductive success (residual reproductive value hypothesis). In contrast, an individual can also be forced by conspecifics to

  16. Intermittency and multifractional Brownian character of geomagnetic time series

    Directory of Open Access Journals (Sweden)

    G. Consolini

    2013-07-01

    Full Text Available The Earth's magnetosphere exhibits a complex behavior in response to the solar wind conditions. This behavior, which is described in terms of mutifractional Brownian motions, could be the consequence of the occurrence of dynamical phase transitions. On the other hand, it has been shown that the dynamics of the geomagnetic signals is also characterized by intermittency at the smallest temporal scales. Here, we focus on the existence of a possible relationship in the geomagnetic time series between the multifractional Brownian motion character and the occurrence of intermittency. In detail, we investigate the multifractional nature of two long time series of the horizontal intensity of the Earth's magnetic field as measured at L'Aquila Geomagnetic Observatory during two years (2001 and 2008, which correspond to different conditions of solar activity. We propose a possible double origin of the intermittent character of the small-scale magnetic field fluctuations, which is related to both the multifractional nature of the geomagnetic field and the intermittent character of the disturbance level. Our results suggest a more complex nature of the geomagnetic response to solar wind changes than previously thought.

  17. Bochdalek Hernia As A Cause Of Intermittent AV Block

    OpenAIRE

    Etsadashvili, Kakhaber; Rashid, Haroon Mohammed; Jalabadze, Khatuna; Melia, Anzor

    2011-01-01

    Congenital diaphragmatic hernia is very rare cause of AV block. We report such a patient with sick sinus node syndrome and previous AAIR pacemaker implantation, in which intermittent AV block was diagnosed by 24-hours ECG monitoring and upgrade of pacing system to DDDR was suggested.

  18. Optimizing supervised exercise therapy for patients with intermittent claudication

    NARCIS (Netherlands)

    Nicolaï, Saskia P A; Hendriks, Erik J M; Prins, Martin H; Teijink, Joep A W; van Asselt, Thea

    2010-01-01

    BACKGROUND: The first-line intervention for intermittent claudication is usually supervised exercise therapy (SET). The literature describes a range of exercise programs varying in setting, duration, and content. The purpose of the present study was to examine the exercise protocols offered and to i

  19. Radial evolution of intermittency of density fluctuations in the fast solar wind

    CERN Document Server

    Bruno, R; Primavera, L; Pietropaolo, E; D'Amicis, R; Sorriso-Valvo, L; Carbone, V; Malara, F; Veltri, P

    2014-01-01

    We study the radial evolution of intermittency of density fluctuations in the fast solar wind. The study is performed analyzing the plasma density measurements provided by Helios 2 in the inner heliosphere between $0.3$ and $0.9$ AU. The analysis is carried out by means of a complete set of diagnostic tools, including the flatness factor at different time scales to estimate intermittency, the Kolmogorov-Smirnov test to estimate the degree of intermittency, and the Fourier transform to estimate the power spectral densities of these fluctuations. Density fluctuations within fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with distance from the Sun, at odds with intermittency of both magnetic field and all the other plasma parameters. Furthermore, the intermittent events are strongly correlated, exhibiting temporal clustering. This indicates that the mechanism underlying their generation departs from a time-varying Poisson process....

  20. Study of drying of small diameter Larch lumbers with intermittent heating

    Institute of Scientific and Technical Information of China (English)

    GUO Ming-hui; ZHAO Xi-ping

    2006-01-01

    Intermittent heating for drying of small diameter Larch lumbers is investigated experimentally. The lumbers were dried using an experimental drying schedule. Moisture content (MC) of the lumber was continuously recorded and final drying defects were examined. The drying curves showed that the drying rate was a constant in the early stage of intermittent heating drying and decreased evidently when the MC was about 18% ( intermittent 2h) and 20% (intermittent 6h). The drying quality reached the second (intermittent 2h) and first grade (intermittent 6h) of the Chinese National Standard. The visual drying defects, especially the check extent along grains were reduced with intermittent heating. When the intermittent time increased, the effect was more obvious.

  1. Characterizing spatial and temporal patterns of intermittent rivers

    Science.gov (United States)

    de Vries, Stefan B.; Hoeve, Jasper; Sauquet, Eric; Leigh, Catherine; Bonada, Núria; Fike, Kimberly; Dahm, Clifford; Booij, Martijn J.; Datry, Thibault

    2015-04-01

    Intermittent rivers (IRs) support high biodiversity due to their dynamic alternations between terrestrial and aquatic phases. They represent a large proportion of the river network. However the current knowledge on these ecosystems is limited. The international research project "Intermittent River Biodiversity Analysis and Synthesis" (IRBAS, www.irbas.fr) aims to collect and analyze data on IR biodiversity from France, Spain, North America and Australia. These activities ultimately should help in identifying relationships between flow regime components and ecological responses. The IRBAS project will provide guidelines for policy-makers and resource managers for effective water and habitat management, restoration and preservation. This work examines one of the aspects in the IRBAS project: studying the large-scale spatial distribution of IRs as well as the year-to-year variability of zero-flow events. IRs were described by two variables: the frequency of periods without flow (FREQ) per time period (months or years) and the total number of zero-flow days (DUR) in a specified time window (month or year). Daily discharge data from more than 1700 gauging stations with no significant human influence on flow were collected from France, Spain, Australia and conterminous United States. A minimum length of 30 years of data starting from 1970 was required with less than 5% of missing data. Climate data for France and Australia were also collected. A classification of perennial versus intermittent rivers was defined, with 455 stations out of the 1684 considered "intermittent", i.e. the gauging station records had, on average, at least 5 zero-flow days per year. The analysis of the subset of IRs showed that: - Greater than 50% of the IRs in the database is located in Australia, where only 35% of the stations are considered perennial. In Spain the proportion of IRs reaches 25%. The proportion of intermittent rivers in France (7%) is certainly underestimated as a consequence of

  2. Randomized double-blind placebo-controlled crossover study of caffeine in patients with intermittent claudication

    DEFF Research Database (Denmark)

    Momsen, A H; Jensen, M B; Norager, C B;

    2010-01-01

    Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication.......Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication....

  3. The influence of continuous and intermittent traffic noise on sleep

    Science.gov (United States)

    Eberhardt, J. L.; Stråle, L.-O.; Berlin, M. H.

    1987-08-01

    The effects of road traffic noise on sleep were studied in the laboratory using nine young male adults (aged 20-26). The subjects were exposed to noise with different temporal characteristics: (i) continuous traffic noise of 36 dB(A) or 45 dB(A), (ii) intermittent noise of 50 truck passages with L pmax = 45 dB(A) ( L eq = 29 dB(A)) or L pmax = 55 dB(A) ( L eq = 36 dB(A)), and (iii) a combination of continuous (45 dB(A)) and intermittent ( L pmax = 55 dB(A)) traffic noise. For one noise condition (intermittent 55 dB(A)) the effect of the use of ear plugs was also studied. The intermittent noise of L pmax = 45 dB(A) caused transitions towards lighter sleep, whereas 55 dB(A) was needed to induce awakening effects. It could be shown that the probability for arousal reactions depends on the emergence of the noise peaks from the background, rather than the absolute noise peak level. Continuous traffic noise of 45 dB(A) caused REM sleep deficits, while intermittent traffic noise of L pmax = 45 dB(A) caused stage III+IV deficits. The night with ear plugs was virtually undisturbed. After nights with REM sleep deficits the subjective sleep quality was rated lower and mood was influenced adversely. For the types of exposure used in the present investigation L eq alone is not an adequate descriptor of the noise dose, relating to the sleep disturbances observed. From the present experiment, together with other existing data, it might be concluded that the WHO recommendation of L eq = 35 dB(A) is adequate, but should be supplemented with a maximum noise level, as expressed for example in L pmax or LI, that should not be exceeded.

  4. Demographics and frequency of the intermittently upturned omentum at CT

    Energy Technology Data Exchange (ETDEWEB)

    Penn, Alex; Wang, Wilbur; Wang, Zhen Jane; Yee, Judy; Webb, Emily M.; Yeh, Benjamin M., E-mail: ben.yeh@ucsf.edu

    2013-11-01

    Objectives: To describe the demographics and frequency of the intermittently upturned omentum at CT. Methods: We retrospectively reviewed abdominal CT scans of 336 consecutive patients (189 men and 147 women) who were imaged between June 1 and June 17, 2010 and who had prior comparison scans. Readers recorded the presence or absence of an intermittently upturned omentum, defined as a thick rind of fat interposed between the liver and the anterior abdominal wall seen on one but not the other scan. At chart review, we recorded patient demographics and other clinical characteristics (prior surgical history, presence of cirrhosis). Results: An intermittently upturned omentum was found in 10 of 336 (3.0%) patients. An intermittently upturned omentum was seen more commonly in men than in women (9 of 189 men, or 4.8% versus 1 of 147 women, or 0.7%, p = 0.047) and in cirrhotics (4 of 37 cirrhotics, or 10.8% versus 6 of 299 non-cirrhotics, or 2.0%, p = 0.023). In a sub-analysis of patients without prior abdominal surgery, this finding was again seen more commonly in men than women (7 of 163 men, or 4.3% versus 0 of 134 women, or 0%, p = 0.018) and in cirrhotics (3 of 33 cirrhotics, or 9.1% versus 4 of 264 non-cirrhotics, or 1.5%, p = 0.032). Conclusions: An intermittently upturned omentum is not uncommon and is more frequently seen in men and in patients with cirrhosis who may have a larger anterior hepatic space.

  5. Observation of intermittency in gene expression on cDNA microarrays

    CERN Document Server

    Peterson, L E

    2002-01-01

    We used scaled factorial moments to search for intermittency in the log expression ratios (LERs) for thousands of genes spotted on cDNA microarrays (gene chips). Results indicate varying levels of intermittency in gene expression. The observation of intermittency in the data analyzed provides a complimentary handle on moderately expressed genes, generally not tackled by conventional techniques.

  6. A Carrier Signal Approach for Intermittent Fault Detection and Health Monitoring for Electronics Interconnections System

    Directory of Open Access Journals (Sweden)

    Syed Wakil Ahmad

    2015-12-01

    Full Text Available Intermittent faults are completely missed out by traditional monitoring and detection techniques due to non-stationary nature of signals. These are the incipient events of a precursor of permanent faults to come. Intermittent faults in electrical interconnection are short duration transients which could be detected by some specific techniques but these do not provide enough information to understand the root cause of it. Due to random and non-predictable nature, the intermittent faults are the most frustrating, elusive, and expensive faults to detect in interconnection system. The novel approach of the author injects a fixed frequency sinusoidal signal into electronics interconnection system that modulates intermittent fault if persist. Intermittent faults and other channel effects are computed from received signal by demodulation and spectrum analysis. This paper describes technology for intermittent fault detection, and classification of intermittent fault, and channel characterization. The paper also reports the functionally tests of computational system of the proposed methods. This algorithm has been tested using experimental setup. It generate an intermittent signal by external vibration stress on connector and intermittency is detected by acquiring and processing propagating signal. The results demonstrate to detect and classify intermittent interconnection and noise variations due to intermittency. Monitoring the channel in-situ with low amplitude, and narrow band signal over electronics interconnection between a transmitter and a receiver provides the most effective tool for continuously watching the wire system for the random, unpredictable intermittent faults, the precursor of failure.

  7. Ring intermittency near the boundary of the synchronous time scales of chaotic oscillators

    OpenAIRE

    Zhuravlev, Maxim O.; Koronovskii, Alexey A.; Moskalenko, Olga I.; Ovchinnikov, Alexey A.; Hramov, Alexander E.

    2013-01-01

    In this paper we study both experimentally and numerically the intermittent behavior taking place near the boundary of the synchronous time scales of chaotic oscillators being in the regime of time scale synchronization. We have shown that the observed type of the intermittent behavior should be classified as the ring intermittency.

  8. Ring intermittency near the boundary of the synchronous time scales of chaotic oscillators.

    Science.gov (United States)

    Zhuravlev, Maxim O; Koronovskii, Alexey A; Moskalenko, Olga I; Ovchinnikov, Alexey A; Hramov, Alexander E

    2011-02-01

    In this Brief Report we study both experimentally and numerically the intermittent behavior taking place near the boundary of the synchronous time scales of chaotic oscillators being in the regime of time scale synchronization. We have shown that the observed type of the intermittent behavior should be classified as the ring intermittency.

  9. Synthesis of Intermittent-Motion Linkages with Slight Difference in Length Between Links

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin-bo; YU Zhen

    2006-01-01

    The design of intermittent-motion linkages using traditional methods iS usually complicated.In this paper,(1)a new method for realizing intermittent motion,using linkages with a slight difference in length between links,is studied;(2)some new types of intermittent-motion linkages and their software for visual analysis and design are developed;and(3)influences of some design parameters on intermittent.motion characteristics are clarifled.Results confirmed that the theory and the software are useful,making the synthesis of intermittent-motion linkages clear and easy.

  10. Acute Abdominal Pain Secondary to Chilaiditi Syndrome

    Directory of Open Access Journals (Sweden)

    David Kang

    2013-01-01

    Full Text Available Chilaiditi syndrome is a rare condition occurring in 0.025% to 0.28% of the population. In these patients, the colon is displaced and caught between the liver and the right hemidiaphragm. Patients' symptoms can range from asymptomatic to acute intermittent bowel obstruction. Diagnosis is best achieved with CT imaging. Identification of Chilaiditi syndrome is clinically significant as it can lead to many significant complications such as volvulus, perforation, and bowel obstruction. If the patient is symptomatic, treatment is usually conservative. Surgery is rarely indicated with indications including ischemia and failure of resolution with conservative management.

  11. [Intermittent thrombolytic treatment. Results during severe, chronic arterial diseases].

    Science.gov (United States)

    Fiessinger, J N; Aiach, M; Lagneau, P; Cormier, J M; Housset, E

    1975-04-20

    38 patients with severe chronic arteritis of the lower limbs were treated with streptokinase intermittently. All had been refused for surgical operation. One patient died, 4 others had early interruption of treatment. Eleven of the 38 patients had efficient thrombolysis confirmed by arteriography. The facts confirm the possibility of thrombolysis during chronic arterial disease. The fact that the aggravation was recent was favourable factor in prognosis. The eleven patients improved, had severe aggravation of symptomes for less than 2 months. Thus thrombolytic treatment has a place of choice in the treatment of severe arterial disease where surgery is impossible, or dangerous, owing to the uncertain state of the vascular bed below the lesion. Efficacious, it permits reconstructive surgery in cases where it had been at first refused. The use of intermittent treatment, apart from advantages of confort and cost, seems to increase the efficacy of treatment. PMID:176733

  12. Intermittency in an optomechanical cavity near a subcritical Hopf bifurcation

    Science.gov (United States)

    Suchoi, Oren; Ella, Lior; Shtempluk, Oleg; Buks, Eyal

    2014-09-01

    We experimentally study an optomechanical cavity consisting of an oscillating mechanical resonator embedded in a superconducting microwave transmission line cavity. Tunable optomechanical coupling between the mechanical resonator and the microwave cavity is introduced by positioning a niobium-coated single-mode optical fiber above the mechanical resonator. The capacitance between the mechanical resonator and the coated fiber gives rise to optomechanical coupling, which can be controlled by varying the fiber-resonator distance. We study radiation-pressure-induced self-excited oscillation as a function of microwave driving parameters (frequency and power). Intermittency between limit-cycle and steady-state behaviors is observed with blue-detuned driving frequency. The experimental results are accounted for by a model that takes into account the Duffing-like nonlinearity of the microwave cavity. A stability analysis reveals a subcritical Hopf bifurcation near the region where intermittency is observed.

  13. Synchronization of intermittent behavior in ensembles of multistable dynamical systems.

    Science.gov (United States)

    Sevilla-Escoboza, R; Buldú, J M; Pisarchik, A N; Boccaletti, S; Gutiérrez, R

    2015-03-01

    We propose a methodology to analyze synchronization in an ensemble of diffusively coupled multistable systems. First, we study how two bidirectionally coupled multistable oscillators synchronize and demonstrate the high complexity of the basins of attraction of coexisting synchronous states. Then, we propose the use of the master stability function (MSF) for multistable systems to describe synchronizability, even during intermittent behavior, of a network of multistable oscillators, regardless of both the number of coupled oscillators and the interaction structure. In particular, we show that a network of multistable elements is synchronizable for a given range of topology spectra and coupling strengths, irrespective of specific attractor dynamics to which different oscillators are locked, and even in the presence of intermittency. Finally, we experimentally demonstrate the feasibility and robustness of the MSF approach with a network of multistable electronic circuits.

  14. On the intermittent character of interplanetary magnetic field fluctuations

    CERN Document Server

    Bruno, Roberto; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca; 10.1063/1.2711429

    2009-01-01

    Interplanetary magnetic field magnitude fluctuations are notoriously more intermittent than velocity fluctuations in both fast and slow wind. This behaviour has been interpreted in terms of the anomalous scaling observed in passive scalars in fully developed hydrodynamic turbulence. In this paper, the strong intermittent nature of the interplanetary magnetic field is briefly discussed comparing results performed during different phases of the solar cycle. The scaling properties of the interplanetary magnetic field magnitude show solar cycle variation that can be distinguished in the scaling exponents revealed by structure functions. The scaling exponents observed around solar maximum coincide, within the errors, to those measured for passive scalars in hydrodynamic turbulence. However, it is also found that the values are not universal in the sense that the solar cycle variation may be reflected in dependence on the structure of the velocity field.

  15. Intermittency in fractal Fourier hydrodynamics: Lessons from the Burgers equation.

    Science.gov (United States)

    Buzzicotti, Michele; Biferale, Luca; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-03-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension D. We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing D. We find that a very small percentage of mode-reduction (D ≲ 1) is enough to destroy most of the characteristics of the original nondecimated equation. In particular, we observe a suppression of intermittent fluctuations for D < 1 and a quasisingular transition from the fully intermittent (D=1) to the nonintermittent case for D ≲ 1. Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes. PMID:27078449

  16. Intermittency and correlations in hadronic $Z^0$ decays

    CERN Document Server

    Abbiendi, G; Alexander, Gideon; Allison, J; Altekamp, N; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Blobel, Volker; Bloodworth, Ian J; Bock, P; Böhme, J; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Davis, R; De Jong, S; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Fiedler, F; Fierro, M; Fleck, I; Folman, R; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon, J; Gascon-Shotkin, S M; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gibson, V; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herndon, M; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Hoch, M; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanzaki, J I; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Lee, A M; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Markopoulos, C; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Menke, S; Merritt, F S; Mes, H; Meyer, J; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mir, R; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Oreglia, M J; Orito, S; Pálinkás, J; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Sittler, A; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Steuerer, J; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trigger, I; Trócsányi, Z L; Tsur, E; Turcot, A S; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Wagner, A; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Yekutieli, G; Zacek, V; Zer-Zion, D

    1999-01-01

    A multidimensional study of local multiplicity fluctuations and multiparticle correlations of hadrons produced in Z decays is performed. The study is based on the data sample of more than 4 million events recorded with the OPAL detector at LEP. The fluctuations and correlations are analysed in terms of the normalized scaled factorial moments and cumulants up to the fifth order. The moments are observed to have intermittency-like behaviour, which is found to be more pronounced with increasing dimension. The large data sample allows for the first time a study of the factorial cumulants in e+e- annihilation. The analysis of the cumulants shows the existence of genuine multiparticle correlations with a strong intermittency rise up to higher orders. These correlations are found to be stronger in higher dimensions. The decomposition of the factorial moments into lower-order correlations that the dynamical fluctuations have important contributions from genuine many-particle correlations. The Monte Carlo models JETSE...

  17. Intermittency and local heating in the solar wind.

    Science.gov (United States)

    Osman, K T; Matthaeus, W H; Wan, M; Rappazzo, A F

    2012-06-29

    Evidence for nonuniform heating in the solar wind plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only constitute 19% of the data, but contribute 50% of the total plasma internal energy. Intermittent heating manifests as elevations in proton temperature near current sheets, resulting in regional heating and temperature enhancements extending over several hours. The number density of non-Gaussian structures is found to be proportional to the mean proton temperature and solar wind speed. These results suggest magnetofluid turbulence drives intermittent dissipation through a hierarchy of coherent structures, which collectively could be a significant source of coronal and solar wind heating.

  18. [Intermittent thrombolytic treatment. Results during severe, chronic arterial diseases].

    Science.gov (United States)

    Fiessinger, J N; Aiach, M; Lagneau, P; Cormier, J M; Housset, E

    1975-04-20

    38 patients with severe chronic arteritis of the lower limbs were treated with streptokinase intermittently. All had been refused for surgical operation. One patient died, 4 others had early interruption of treatment. Eleven of the 38 patients had efficient thrombolysis confirmed by arteriography. The facts confirm the possibility of thrombolysis during chronic arterial disease. The fact that the aggravation was recent was favourable factor in prognosis. The eleven patients improved, had severe aggravation of symptomes for less than 2 months. Thus thrombolytic treatment has a place of choice in the treatment of severe arterial disease where surgery is impossible, or dangerous, owing to the uncertain state of the vascular bed below the lesion. Efficacious, it permits reconstructive surgery in cases where it had been at first refused. The use of intermittent treatment, apart from advantages of confort and cost, seems to increase the efficacy of treatment.

  19. Acute dyspnea

    International Nuclear Information System (INIS)

    Radiodiagnosis is applied to determine the causes of acute dyspnea. Acute dyspnea is shown to aggravate the course of pulmonary diseases (bronchial asthma, obstructive bronchitis, pulmonary edema, throboembolism of pulmonary arteries etc) and cardiovascular diseases (desiseas of myocardium). The main tasks of radiodiagnosis are to determine volume and state of the lungs, localization and type of pulmonary injuries, to verify heart disease and to reveal concomitant complications

  20. Low Dose Intermittent Isotretinoin Therapy in Moderate Acne Vulgaris

    OpenAIRE

    Belçın İzol; Emel Bülbül Başkan; Zübeyde Başar; Şükran Tunalı; Hayriye Sarıcaoğlu

    2012-01-01

    Objective: In this study, we aimed to investigate the efficiency and side effects of intermittent low dose isotretinoin therapy in moderate acne. Materials and Methods: Patients followed up at our acne outpatient clinic between September 2007 and April 2009 were evaluated. Those treated with 20 mg/day isotretinoin three times a week were included in the study. Relevant data were recorded from patient files. We recorded the age and weight of the cases, duration of acne, previous treatments, ac...

  1. Intermittent ion trajectories and focusing in spherical inertial electromagnetic confinement

    International Nuclear Information System (INIS)

    Performance of spherical magnetic electrostatic confinement fusion is analyzed. Magnetic field lines in spherical cusps provide a chaotic scattering system that improves the ion focusing due to synergetic effect of intermittent ion trajectories. Confined ions are bounced within electrostatic well reflecting from magnetic barriers shaped by convex field lines. The concept offers a means of enhancing ion reactivity provided by caustic formation that are resulted from an intersection of ion orbits within confinement volume. Parameters of the experimental device are estimated. (author)

  2. Intermittent control models of human standing: similarities and differences

    OpenAIRE

    Gawthrop, Peter; Loram, Ian; Gollee, Henrik; Lakie, Martin

    2014-01-01

    Two architectures of intermittent control are compared and contrasted in the context of the single inverted pendulum model often used for describing standing in humans. The architectures are similar insofar as they use periods of open-loop control punctuated by switching events when crossing a switching surface to keep the system state trajectories close to trajectories leading to equilibrium. The architectures differ in two significant ways. Firstly, in one case, the open-loop control trajec...

  3. Functions of intermittent locomotion in mustached tamarins ( Saguinus mystax)

    OpenAIRE

    Stojan-Dolar, Mojca; Heymann, Eckhard W.

    2015-01-01

    Many animals interrupt their moving with brief pauses, which appear to serve several different functions. We examined the function of such intermittent locomotion in wild living mustached tamarins (Saguinus mystax), small arboreal New World primates that form mixed-species groups with saddleback tamarins (Saguinus fuscicollis). We investigated how different environmental and social factors affect pausing during locomotion and used these data to infer the function of this behavior. As measures...

  4. Intermittent Jolts of Galactic UV Radiation: Mutagenetic Effects

    OpenAIRE

    Scalo, John M.; Wheeler, J. Craig; Williams, Peter

    2001-01-01

    We estimate the frequency of intermittent hypermutation events and disruptions of planetary/satellite photochemistry due to ultraviolet radiation from core collapse supernova explosions. Calculations are presented for planetary systems in the local Milky Way, including the important moderating effects of vertical Galactic structure and UV absorption by interstellar dust. The events are particularly frequent for satellites of giant gas planets at \\gtrsim 5-10 AU distance from solar-type parent...

  5. Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment

    OpenAIRE

    Vasconcelos, Andrea R; Yshii, Lidia M; Viel, Tania A; Buck, Hudson S; Mark P Mattson; Scavone, Cristoforo; Kawamoto, Elisa M

    2014-01-01

    Background Systemic bacterial infections often result in enduring cognitive impairment and are a risk factor for dementia. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that intermittent fasting (IF) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of IF on the cognitive sequelae of systemic and brain inflammation is unknown. Methods Rats on ...

  6. The experience of aggressive outbursts in intermittent explosive disorder

    OpenAIRE

    Kulper, Daniel A.; Kleiman, Evan M.; McCloskey, Michael S.; Berman, Mitchell E.; Coccaro, Emil F.

    2014-01-01

    Conceptualizations of Intermittent Explosive Disorder (IED) have suffered from a scarcity of research investigating the subjective experience and phenomenology of the aggressive outbursts among those with IED relative to those who partake in more normative forms of aggression. Furthermore, though some studies have shown that individuals with IED are more impaired and have a poorer quality of life, few studies looked at negative outcomes specific to an individual with IED’s aggressive behavior...

  7. Intermittent Preventive Antimalarial Treatment for Children with Anaemia.

    OpenAIRE

    Athuman, Mwaka; Kabanywanyi, Abdunoor M; Rohwer, Anke C

    2015-01-01

    Background Anaemia is a global public health problem. Children under five years of age living in developing countries (mostly Africa and South-East Asia) are highly affected. Although the causes for anaemia are multifactorial, malaria has been linked to anaemia in children living in malaria-endemic areas. Administering intermittent preventive antimalarial treatment (IPT) to children might reduce anaemia, since it could protect children from new Plasmodium parasite infection (the parasites tha...

  8. Intermittent drying of beans in a spouted bed

    OpenAIRE

    de Oliveira, C A; S.C.S. Rocha

    2007-01-01

    Carioca beans are a highly nutritious grain, in terms of the amount of protein, iron and potassium as well as carbohydrates and fiber and as a source of vitamins. The moisture content of recently picked beans is too high for good preservation and storage, resulting in the need for drying before packaging. In this work, the drying of Carioca beans in a laboratory scale spouted bed under intermittent conditions of the drying air was experimentally analyzed. Experiments carried out consisted of ...

  9. Merit order effect and strategic investments in intermittent generation technologies

    OpenAIRE

    Silvia Concettini

    2014-01-01

    This paper studies the strategic interactions between two electricity generators, the first producing with a \\traditional" technology and the second employing a \\renewable" technology characterized by the random availability of capacity due to the intermittency of its power source. The competition between the \\traditional" and the \\renewable" power producers is examined through a modified version of the two stage Dixit model for entry deterrence (Dixit, 1980) with Cournot competition in the p...

  10. Consensus of Multiagent Networks with Intermittent Interaction and Directed Topology

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2014-01-01

    Full Text Available Intermittent interaction control is introduced to solve the consensus problem for second-order multiagent networks due to the limited sensing abilities and environmental changes periodically. And, we get some sufficient conditions for the agents to reach consensus with linear protocol from the theoretical findings by using the Lyapunov control approach. Finally, the validity of the theoretical results is validated through the numerical example.

  11. Predicting intermittent running performance: critical velocity versus endurance index.

    Science.gov (United States)

    Buchheit, M; Laursen, P B; Millet, G P; Pactat, F; Ahmaidi, S

    2008-04-01

    The aim of the present study was to examine the ability of the critical velocity (CV) and the endurance index (EI) to assess endurance performance during intermittent exercise. Thirteen subjects performed two intermittent runs: 15-s runs intersected with 15 s of passive recovery (15/15) and 30-s runs with 30-s rest (30/30). Runs were performed until exhaustion at three intensities (100, 95 and 90 % of the speed reached at the end of the 30 - 15 intermittent fitness test, V (IFT)) to calculate i) CV from the slope of the linear relationship between the total covered distance and exhaustion time (ET) (iCV); ii) anaerobic distance capacity from the Y-intercept of the distance/duration relationship (iADC); and iii) EI from the relationship between the fraction of V (IFT) at which the runs were performed and the log-transformed ET (iEI). Anaerobic capacity was indirectly assessed by the final velocity achieved during the Maximal Anaerobic Running Test (VMART). ET was longer for 15/15 than for 30/30 runs at similar intensities. iCV (15/15) and iCV (30/30) were not influenced by changes in ET and were highly dependent on V (IFT). Neither iADC (15/15) nor iADC (30/30) were related to VMART. In contrast, iEI (15/15) was higher than iEI (30/30), and corresponded with the higher ET. In conclusion, only iEI estimated endurance capacity during repeated intermittent running.

  12. Functional independence measure in patients with intermittent claudication

    OpenAIRE

    Caroline Shihara de Assis; Letícia de Carvalho Batista; Nelson Wolosker; Antonio Eduardo Zerati; Rita de Cassia Gengo e Silva

    2015-01-01

    AbstractOBJECTIVEOf this study were to evaluate the functional independence of patients with intermittent claudication and to verify its association with sociodemographic and clinical variables, walking ability and physical activity level.METHODThis was a descriptive, exploratory, cross-sectional study with a quantitative approach. Fifty participants (66.4 years; 68% male) were recruited from Claudication Unit of a tertiary hospital. Functional Independence Measure were used to evaluate funct...

  13. CAN INTERMITTENT VIDEO SAMPLING CAPTURE INDIVIDUAL DIFFERENCES IN NATURALISTIC DRIVING?

    OpenAIRE

    Aksan, Nazan; Schall, Mark; Anderson, Steven; Dawson, Jeffery; Tippin, Jon; Rizzo, Matthew

    2013-01-01

    We examined the utility and validity of intermittent video samples from black box devices for capturing individual difference variability in real-world driving performance in an ongoing study of obstructive sleep apnea (OSA) and community controls. Three types of video clips were coded for several dimensions of interest to driving research including safety, exposure, and driver state. The preliminary findings indicated that clip types successfully captured variability along targeted dimension...

  14. The efficacy of antihypertensive drugs in chronic intermittent hypoxia conditions

    OpenAIRE

    Lucilia Neves Diogo; Emília Carreira Monteiro

    2014-01-01

    Sleep apnea/hypopnea disorders include centrally originated diseases and obstructive sleep apnea (OSA). This last condition is renowned as a frequent secondary cause of hypertension (HT). The mechanisms involved in the pathogenesis of HT can be summarized in relation to two main pathways: sympathetic nervous system stimulation mediated mainly by activation of carotid body (CB) chemoreflexes and/or asphyxia, and, by no means the least important, the systemic effects of chronic intermittent hyp...

  15. Prolapsed bilateral ureteroceles leading to intermittent outflow obstruction.

    LENUS (Irish Health Repository)

    Stunell, H

    2012-02-01

    A ureterocele refers to a cystic dilatation of the distal ureter. It may be unilateral or bilateral and may be associated with a duplex system in some cases. We present an unusual case where a young patient was found to have large bilateral ureteroceles which prolapsed into the urethra, causing intermittent incontinence and obstruction. We discuss the case and review the literature concerning this rare anomaly.

  16. Single Stage Surgical Outcomes for Large Angle Intermittent Exotropia.

    Directory of Open Access Journals (Sweden)

    Min Yang

    Full Text Available Although there were many prior studies about exotropia, few focused on large-angle intermittent exotropia. The goal of this study was to evaluate single-stage surgical outcomes for large-angle intermittent exotropia and analyze risk factors that may affect the success of surgery. Records from intermittent exotropia patients with exodeviations >60 prism diopters(PD who were surgically treated at the Zhongshan Ophthalmic Center, of Sun Yat-Sen University were reviewed. Included within this review were data on, pre- and post-operative ocular motility, primary alignment, binocular vision and complications. Patients with exodeviations ≤70PD received two-muscle surgery, while those with exodeviations >70PD were subjected to a three-muscle procedure. A total of 40 records were reviewed. The mean exodeviation was 73±9PD at distance and 75±26PD at near. There were 25 patients received two-muscle surgery and 15 the three-muscle procedure. Orthophoria (deviation within 8PD was obtained in 77.5% of these patients and the ratios of surgical under-correction and over-correction were 15% and 7.5% respectively. However, when combining ocular alignment with binocular vision as the success criteria, success rates decreased to 30%. No statistically significant differences in success rates were obtained between the two- and three-muscle surgery groups. Seven subjects experienced an abduction deficit during the initial postoperative stages, but eventually showed a full recovery. One patient required a second surgery for overcorrection. No statistically significant risk factors for poor outcome were revealed. Our data showed that single-stage two- and three-muscle surgeries for large-angle intermittent exotropia are effective in achieving a favorable outcome.

  17. Verbal versus Physical Aggression in Intermittent Explosive Disorder

    OpenAIRE

    Look, Amy E.; McCloskey, Michael S.; Coccaro, Emil F.

    2014-01-01

    Intermittent Explosive Disorder (IED) is the only adult psychiatric diagnosis for which pathological aggression is primary. DSM-IV criteria focused on physical aggression, but DSM-5 allows for an IED diagnosis in the presence of frequent verbal aggression with or without concurrent physical aggression. It remains unclear how individuals with verbal aggression differ from those with physical aggression with respect to cognitive-affective deficits and psychosocial functioning. The current study...

  18. Spontaneous chylous peritonitis mimicking acute appendicitis: A case report and review of literature

    Institute of Scientific and Technical Information of China (English)

    Fu-Chi Fang; Sheng-Der Hsu; Chuang-Wei Chen; Teng-Wei Chen

    2006-01-01

    Acute abdominal pain with signs and symptoms of peritonitis due to sudden extravasation of chyle into the peritoneal cavity is a rare condition that is often mistaken for other disease processes. The diagnosis is rarely suspected preoperatively. We report a case of spontaneous chylous peritonitis that presented with typical symptoms of acute appendicitis such as intermittent fever and epigastric pain radiating to the lower right abdominal quadrant before admission.

  19. Non-locality and Intermittency in 3D Turbulence

    CERN Document Server

    Laval, J P; Nazarenko, S

    2001-01-01

    Numerical simulations are used to determine the influence of the non-local and local interactions on the intermittency corrections in the scaling properties of 3D turbulence. We show that neglect of local interactions leads to an enhanced small-scale energy spectrum and to a significantly larger number of very intense vortices (tornadoes) and stronger intermittency. On the other hand, neglect of the non-local interactions results in even stronger small-scale spectrum but significantly weaker intermittency. Based on these observations, a new model of turbulence is proposed, in which non-local (RDT-like) interactions couple large and small scale via a multiplicative process with additive noise and the local interactions are modeled by a turbulent viscosity. This model is used to derive a simple toy version of the Langevin equations for small-scale velocity increments. A Gaussian approximation for the large scale fields yields the Fokker-Planck equation for the probability distribution function of the velocity i...

  20. Sulfide elimination by intermittent nitrate dosing in sewer sediments

    Institute of Scientific and Technical Information of China (English)

    Yanchen Liu; Chen Wu; Xiaohong Zhou; David Z.Zhu; Hanchang Shi

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards,and requires expensive programs for its prevention.The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments.The study was carried out based on lab-scale experiments and batch tests using real sewer sediments.The intermittent nitrate dosing mode and the optimal control condition were investigated.The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment.The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions ofefficient sulfide control with lower carbon source loss.The opth-nal control condition is feasible for the sulfide elimination in sewer systems.

  1. Intermittency of rheological regimes in uniform liquid-granular flows.

    Science.gov (United States)

    Armanini, Aronne; Larcher, Michele; Fraccarollo, Luigi

    2009-05-01

    We present a detailed analysis of a free surface-saturated liquid-granular mixture flowing over a static loose bed of grains, where the coexistence of layers dominated by collisional and frictional interactions among particles was observed. Kinetic theory was applied to the flow described above and it proved suitable for describing a realistic behavior of the collisional layers, although it failed to interpret the regions of the flow domain dominated by the frictional contacts. The paper provides a conceptual scheme with which to overcome this problem by focusing on the mechanisms governing the transition from the frictional to the collisional regime. In particular we observed that in highly concentrated flows the transition layer exhibits a typical intermittency of the dominating rheological regime, switching alternately from the frictional to the collisional one. By filtering the velocity signal, we introduced an intermittency function that made it possible to extend the validity of the equations derived from dense gas analogy, typical of the collisional regimes, also in the intermittent phase of the flow. Owing to the small values of the Stokes number, in the application of the kinetic theory we accounted for the possible variation of the elastic restitution coefficient along the flow depth. PMID:19518448

  2. Intermittency and velocity fluctuations in hopper flows prone to clogging

    Science.gov (United States)

    Thomas, C. C.; Durian, D. J.

    2016-08-01

    We study experimentally the dynamics of granular media in a discharging hopper. In such flows, there often appears to be a critical outlet size Dc such that the flow never clogs for D >Dc . We report on the time-averaged velocity distributions, as well as temporal intermittency in the ensemble-averaged velocity of grains in a viewing window, for both D Dc , near and far from the outlet. We characterize the velocity distributions by the standard deviation and the skewness of the distribution of vertical velocities. We propose a measure for intermittency based on the two-sample Kolmogorov-Smirnov DKS statistic for the velocity distributions as a function of time. We find that there is no discontinuity or kink in these various measures as a function of hole size. This result supports the proposition that there is no well-defined Dc and that clogging is always possible. Furthermore, the intermittency time scale of the flow is set by the speed of the grains at the hopper exit. This latter finding is consistent with a model of clogging as the independent sampling for stable configurations at the exit with a rate set by the exiting grain speed [C. C. Thomas and D. J. Durian, Phys. Rev. Lett. 114, 178001 (2015), 10.1103/PhysRevLett.114.178001].

  3. Prolapsing Gastric Polyp Causing Intermittent Gastric Outlet Obstruction.

    Science.gov (United States)

    Kosai, Nik Ritza; Gendeh, Hardip Singh; Norfaezan, Abdul Rashid; Razman, Jamin; Sutton, Paul Anthony; Das, Srijit

    2015-06-01

    Gastric polyps are often an incidental finding on upper gastrointestinal endoscopy, with an incidence up to 5%. The majority of gastric polyps are asymptomatic, occurring secondary to inflammation. Prior reviews discussed Helicobacter pylori (H pylori)-associated singular gastric polyposis; however, we present a rare and unusual case of recurrent multiple benign gastric polyposis post H pylori eradication resulting in intermittent gastric outlet obstruction. A 70-year-old independent male, Chinese in ethnicity, with a background of diabetes mellitus, hypertension, and a simple renal cyst presented with a combination of melena, anemia, and intermittent vomiting of partially digested food after meals. Initial gastroscopy was positive for H pylori; thus he was treated with H pylori eradication and proton pump inhibitors. Serial gastroscopy demonstrated multiple sessile gastric antral polyps, the largest measuring 4 cm. Histopathologic examination confirmed a benign hyperplastic lesion. Computed tomography identified a pyloric mass with absent surrounding infiltration or metastasis. A distal gastrectomy was performed, whereby multiple small pyloric polyps were found, the largest prolapsing into the pyloric opening, thus explaining the intermittent nature of gastric outlet obstruction. Such polyps often develop from gastric ulcers and, if left untreated, may undergo neoplasia to form malignant cells. A distal gastrectomy was an effective choice of treatment, taking into account the polyp size, quantity, and potential for malignancy as opposed to an endoscopic approach, which may not guarantee a complete removal of safer margins and depth. Therefore, surgical excision is favorable for multiple large gastric polyps with risk of malignancy.

  4. Improving Forecasting Accuracy in the Case of Intermittent Demand Forecasting

    Directory of Open Access Journals (Sweden)

    Daisuke Takeyasu

    2014-06-01

    Full Text Available In making forecasting, there are many kinds of data. Stationary time series data are relatively easy to make forecasting but random data are very difficult in its execution for forecasting. Intermittent data are often seen in industries. But it is rather difficult to make forecasting in general. In recent years, the needs for intermittent demand forecasting are increasing because of the constraints of strict Supply Chain Management. How to improve the forecasting accuracy is an important issue. There are many researches made on this. But there are rooms for improvement. In this paper, a new method for cumulative forecasting method is proposed. The data is cumulated and to this cumulated time series, the following method is applied to improve the forecasting accuracy. Trend removing by the combination of linear and 2nd order non-linear function and 3rd order non-linear function is executed to the production data of X-ray image intensifier tube device and Diagnostic X-ray image processing apparatus. The forecasting result is compared with those of the non-cumulative forecasting method. The new method shows that it is useful for the forecasting of intermittent demand data. The effectiveness of this method should be examined in various cases.

  5. Intermittency of solar system plasma turbulence near Venus and Earth

    Science.gov (United States)

    Teodorescu, Eliza; Echim, Marius; Chang, Tom

    2016-04-01

    We analyze magnetic field data from Venus Express (VEX) and CLUSTER to investigate the turbulent properties of the solar wind and the Earth's and Venus' magnetosheaths. A systematic study of the PDFs (Probability Distribution Functions) of the measured magnetic fluctuations and their fourth order moments (kurtosis) reveals numerous intermittent time series. The presence of intermittency is marked by non-Gaussian PDFs with heavy wings and a scale dependent kurtosis. Higher order analyses on the scale dependence of several moment orders of the PDFs, the structure functions, along with the scaling of the kurtosis allow for a selection of scales that pertain to different scaling regimes, governed by different physics. On such sub-ranges of scales we investigate the fractal structure of fluctuations through the Rank Ordered Multifractal Analysis - ROMA (Chang and Wu, 2008). ROMA is applied to a selection of intermittent magnetic field time series in the solar wind and planetary magnetosheaths and helps to quantify the turbulence properties through the estimation of a spectrum of local Hurst exponents. Research supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 313038/STORM, and a grant of the Romanian Ministry of National Education, CNCS - UEFISCDI, project number PN-II-ID-PCE-2012-4-0418.

  6. Structure functions and intermittency in ionospheric plasma turbulence

    Directory of Open Access Journals (Sweden)

    L. Dyrud

    2008-11-01

    Full Text Available Low frequency electrostatic turbulence in the ionospheric E-region is studied by means of numerical and experimental methods. We use the structure functions of the electrostatic potential as a diagnostics of the fluctuations. We demonstrate the inherently intermittent nature of the low level turbulence in the collisional ionospheric plasma by using results for the space-time varying electrostatic potential from two dimensional numerical simulations. An instrumented rocket can not directly detect the one-point potential variation, and most measurements rely on records of potential differences between two probes. With reference to the space observations we demonstrate that the results obtained by potential difference measurements can differ significantly from the one-point results. It was found, in particular, that the intermittency signatures become much weaker, when the proper rocket-probe configuration is implemented. We analyze also signals from an actual ionospheric rocket experiment, and find a reasonably good agreement with the appropriate simulation results, demonstrating again that rocket data, obtained as those analyzed here, are unlikely to give an adequate representation of intermittent features of the low frequency ionospheric plasma turbulence for the given conditions.

  7. Effect of intermittent sitting time on acute postprandial lipemia in children

    Directory of Open Access Journals (Sweden)

    Kara Ross

    2015-06-01

    Conclusion: When sitting was interrupted by short bouts of moderate intensity exercise there was a reduction in triglyceride concentrations in eight out of 12 participants. Possible reasons to account for the difference in response may include sexual maturation, gender differences, genetic conditions, or the rate of digestion and intestinal absorption.

  8. Characterization of wind power resource and its intermittency

    Science.gov (United States)

    Gunturu, U. B.; Schlosser, C. A.

    2011-12-01

    Wind resource in the continental and offshore United States has been calculated and characterized using metrics that describe - apart from abundance - its availability, persistence and intermittency. The Modern Era Retrospective-Analysis for Research and Applications (MERRA) boundary layer flux data has been used to construct wind power density profiles at 50, 80, 100 and 120 m turbine hub heights. The wind power density estimates at 50 m are qualitatively similar to those in the US wind atlas developed by the National Renewable Energy Laboratory (NREL), but quantitatively a class less in some regions, but are within the limits of uncertainty. We also show that for long tailed distributions like those of the wind power density, the mean is an overestimation and median is a more robust metric for summary representation of wind power resource.Generally speaking, the largest and most available wind power density resources are found in off-shore regions of the Atlantic and Pacific coastline, and the largest on-shore resource potential lies in the central United States. However, the intermittency and widespread synchronicity of on-shore wind power density are substantial, and highlights areas where considerable back-up generation technologies will be required. Generation-duration curves are also presented for the independent systems operator (ISO) zones of the U.S. to highlight the regions with the largest capacity factor (MISO, ERCOT, and SWPP) as well as the periods and extent to which all ISOs contain no wind power and the potential benefits of aggregation on wind power intermittency in each region. The impact of raising the wind turbine hub height on metrics of abundance, persistence, variability and intermittency is analyzed. There is a general increase in availability and abundance of wind resource but there is also an increase in intermittency with respect to a 'usable wind power' crossing level in low resource regions. A similar perspective of wind resource for

  9. Acute myelogenous leukemia (AML) - children

    Science.gov (United States)

    Acute myelogenous leukemia - children; AML; Acute myeloid leukemia - children; Acute granulocytic leukemia - children; Acute myeloblastic leukemia - children; Acute non-lymphocytic leukemia (ANLL) - children

  10. Changes in carotid body and nTS neuronal excitability following neonatal sustained and chronic intermittent hypoxia exposure.

    Science.gov (United States)

    Mayer, C A; Wilson, C G; MacFarlane, P M

    2015-01-01

    We investigated whether pre-treatment with neonatal sustained hypoxia (SH) prior to chronic intermittent hypoxia (SH+CIH) would modify in vitro carotid body (CB) chemoreceptor activity and the excitability of neurons in the caudal nucleus of the solitary tract (nTS). Sustained hypoxia followed by CIH exposure simulates an oxygen paradigm experienced by extremely premature infants who developed persistent apnea. Rat pups were treated with 5 days of SH (11% O2) from postnatal age 1 (P1) followed by 10 days of subsequent chronic intermittent hypoxia (CIH, 5% O2/5 min, 8 h/day, between P6 and P15) as described previously (Mayer et al., Respir. Physiol. Neurobiol. 187(2): 167-75, 2013). At the end of SH+CIH exposure (P16), basal firing frequency was enhanced, and the hypoxic sensory response of single unit CB chemoafferents was attenuated. Further, basal firing frequency and the amplitude of evoked excitatory post-synaptic currents (ESPC's) of nTS neurons was augmented compared to age-matched rats raised in normoxia. These effects were unique to SH+CIH exposure as neither SH or CIH alone elicited any comparable effect on chemoafferent activity or nTS function. These data indicated that pre-treatment with neonatal SH prior to CIH exposure uniquely modified mechanisms of peripheral (CB) and central (nTS) neural function in a way that would be expected to disturb the ventilatory response to acute hypoxia.

  11. Efficacious intermittent dosing of a novel JAK2 inhibitor in mouse models of polycythemia vera.

    Directory of Open Access Journals (Sweden)

    Manfred Kraus

    Full Text Available A high percentage of patients with the myeloproliferative disorder polycythemia vera (PV harbor a Val617→Phe activating mutation in the Janus kinase 2 (JAK2 gene, and both cell culture and mouse models have established a functional role for this mutation in the development of this disease. We describe the properties of MRLB-11055, a highly potent inhibitor of both the WT and V617F forms of JAK2, that has therapeutic efficacy in erythropoietin (EPO-driven and JAK2V617F-driven mouse models of PV. In cultured cells, MRLB-11055 blocked proliferation and induced apoptosis in a manner consistent with JAK2 pathway inhibition. MRLB-11055 effectively prevented EPO-induced STAT5 activation in the peripheral blood of acutely dosed mice, and could prevent EPO-induced splenomegaly and erythrocytosis in chronically dosed mice. In a bone marrow reconstituted JAK2V617F-luciferase murine PV model, MRLB-11055 rapidly reduced the burden of JAK2V617F-expressing cells from both the spleen and the bone marrow. Using real-time in vivo imaging, we examined the kinetics of disease regression and resurgence, enabling the development of an intermittent dosing schedule that achieved significant reductions in both erythroid and myeloid populations with minimal impact on lymphoid cells. Our studies provide a rationale for the use of non-continuous treatment to provide optimal therapy for PV patients.

  12. Intermittent positive-pressure hyperventilation with high inflation pressures produces pulmonary microvascular injury in rats.

    Science.gov (United States)

    Dreyfuss, D; Basset, G; Soler, P; Saumon, G

    1985-10-01

    The mechanisms by which intermittent positive-pressure ventilation with high inflation pressure (HIPPV) induces pulmonary edema remain uncertain. In this study we investigated the physiologic and anatomic changes related to HIPPV at 45 cmH2O peak inspiratory pressure in rats. Edema was quantified by the extravascular lung water obtained from postmortem weighing and by 22Na distribution space. Pulmonary microvascular permeability was assessed by dry lung weight and fractional albumin uptake. After only 5 min of HIPPV, there was a significant increase in Na space, dry lung weight, and fractional albumin uptake when compared with that in control rats mechanically ventilated at 7 cmH2O peak inspiratory pressure. These changes suggest that edema may be due at least in part to alterations in microvascular permeability. Moderate peribronchovascular edema was present. At the ultrastructural level, some endothelial cells were found detached from their basement membrane. This lesion has been previously described in other types of pulmonary microvascular injury. The above findings remained almost unchanged after 10 min of HIPPV. After 20 min of HIPPV, we observed the outpouring of a high protein content alveolar flooding accompanied by a further significant increase in fractional albumin uptake and dry lung weight. Additional anatomic damage appeared including epithelial lesions and hyaline membranes. Thus, HIPPV edema presents all the features of high permeability edema. These results may be of concern in the ventilatory management of patients with acute respiratory failure in order to avoid additional damages induced by local overinflation. PMID:3901844

  13. Intermittency in MHD turbulence and coronal nanoflares modelling

    Directory of Open Access Journals (Sweden)

    P. Veltri

    2005-01-01

    Full Text Available High resolution numerical simulations, solar wind data analysis, and measurements at the edges of laboratory plasma devices have allowed for a huge progress in our understanding of MHD turbulence. The high resolution of solar wind measurements has allowed to characterize the intermittency observed at small scales. We are now able to set up a consistent and convincing view of the main properties of MHD turbulence, which in turn constitutes an extremely efficient tool in understanding the behaviour of turbulent plasmas, like those in solar corona, where in situ observations are not available. Using this knowledge a model to describe injection, due to foot-point motions, storage and dissipation of MHD turbulence in coronal loops, is built where we assume strong longitudinal magnetic field, low beta and high aspect ratio, which allows us to use the set of reduced MHD equations (RMHD. The model is based on a shell technique in the wave vector space orthogonal to the strong magnetic field, while the dependence on the longitudinal coordinate is preserved. Numerical simulations show that injected energy is efficiently stored in the loop where a significant level of magnetic and velocity fluctuations is obtained. Nonlinear interactions give rise to an energy cascade towards smaller scales where energy is dissipated in an intermittent fashion. Due to the strong longitudinal magnetic field, dissipative structures propagate along the loop, with the typical speed of the Alfvén waves. The statistical analysis on the intermittent dissipative events compares well with all observed properties of nanoflare emission statistics. Moreover the recent observations of non thermal velocity measurements during flare occurrence are well described by the numerical results of the simulation model. All these results naturally emerge from the model dynamical evolution without any need of an ad-hoc hypothesis.

  14. Hybrid optimal scheduling for intermittent androgen suppression of prostate cancer

    Science.gov (United States)

    Hirata, Yoshito; di Bernardo, Mario; Bruchovsky, Nicholas; Aihara, Kazuyuki

    2010-12-01

    We propose a method for achieving an optimal protocol of intermittent androgen suppression for the treatment of prostate cancer. Since the model that reproduces the dynamical behavior of the surrogate tumor marker, prostate specific antigen, is piecewise linear, we can obtain an analytical solution for the model. Based on this, we derive conditions for either stopping or delaying recurrent disease. The solution also provides a design principle for the most favorable schedule of treatment that minimizes the rate of expansion of the malignant cell population.

  15. Intermittency in hadronic decays of the Z sup 0

    Energy Technology Data Exchange (ETDEWEB)

    Akrawy, M.Z.; Alexander, G.; Allison, J.; Allport, P.P.; Anderson, K.J.; Armitage, J.C.; Ashton, P.; Astbury, A.; Axen, D.; Azuelos, G.; Baines, J.T.M.; Ball, A.H.; Banks, J.; Barker, G.J.; Barlow, R.J.; Batley, J.R.; Beaudoin, G.; Beck, A.; Becker, J.; Behnke, T.; Bell, K.W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I.J.; Bock, P.; Bougerolle, S.; Brabson, B.B.; Breuker, H.; Brown, R.M.; Brun, R.; Buijs, A.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Chrin, J.T.M.; Clarke, P.E.L.; Cohen, I.; Collins, W.J.; Conboy, J.E.; Cooper, M.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G.M.; De Jong, S.; Debu, P.; Deninno, M.M.; Dieckmann, A.; Dittmar, M.; Dixit, M.S.; Duchovni, E.; Duerdoth, I.P.; Dumas, D.J.P.; Elcombe, P.A.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fincke-Keeler, M.; Fischer, H.M.; Fong, D.G.; Fukunaga, C.; Gaidot, A.; Ganel, O.; Gary, J.W.; Gascon, J.; Geddes, N.I; OPAL Collaboration

    1991-06-20

    A factorial moment analysis has been performed on the differential multiplicity distributions of hadronic final states of the Z{sup 0} recorded with the OPAL detector at LEP. The moments of the one-dimensional rapidity and the two-dimensional rapidity versus azimuthal angle distributions are found to exhibit 'intermittent' behaviour attributable to the jet structure of the events. The moments are reproduced by both parton shower and matrix element QCD based hadronisation models. No evidence for fluctuations beyond those attributable to jet structure is observed. (orig.).

  16. Intermittency induced long-range cross-correlations

    CERN Document Server

    Diakonos, Fotis K; Schmelcher, Peter

    2013-01-01

    Cross-correlations are usually considered to emerge through interaction between particles. Here we present a mechanism capable to generate power-law cross-correlations between non-interacting particles exposed to an external potential. This phenomenon can occur as an ensemble property when the external potential induces intermittent dynamics, providing laminar and stochastic phases of motion. We have strong indications that the divergence of the mean residence time in the laminar phase of the single particle motion - sporadic dynamics - is a sufficient condition for the emergence of long-range cross-correlations. We argue that this mechanism may be relevant for the occurrence of collective behaviour in critical systems.

  17. Intermittent versus Continuous Incremental Field Tests: Are Maximal Variables Interchangeable?

    Science.gov (United States)

    Carminatti, Lorival J; Possamai, Carlos A P; de Moraes, Marcelo; da Silva, Juliano F; de Lucas, Ricardo D; Dittrich, Naiandra; Guglielmo, Luiz G A

    2013-01-01

    The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR) and the Vameval test (T-VAM)), characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat), volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE) at peak test velocities (PV). No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h(-1)) and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm). During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm). However, there was a significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l(-1)). Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs. Key pointsT-CAR is an intermittent shuttle run test that predicts the maximal aerobic speed with accuracy, hence, test results could be interchangeable with continuous straight-line tests.T-CAR provides valid field data for evaluating aerobic fitness.In comparison with T-VAM, T-CAR may be a more favourable way to prescribe intermittent training using a shuttle-running protocol.

  18. Carbon-Carbon Turbocharger Housing Unit for Intermittent Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1998-01-01

    An improved, lightweight, turbine housing unit for an intermittent combustion reciprocating internal combustion engine turbocharger is prepared from a lay-up or molding of carbon-carbon composite materials in a single-piece or two-piece process. When compared to conventional steel or cast iron, the use of carbon-carbon composite materials in a turbine housing unit reduces the overall weight of the engine and reduces the heat energy loss used in the turbocharging process. This reduction in heat energy loss and weight reduction provides for more efficient engine operation.

  19. Percutaneous transluminal angioplasty of infrarenal arteries in intermittent claudication

    DEFF Research Database (Denmark)

    Henriksen, L O; Jørgensen, B; Holstein, P E;

    1988-01-01

    Percutaneous transluminal angioplasty was performed on 55 iliac and 31 femoropopliteal arteries in 71 patients with intermittent claudication (23 women, 48 men). The two-year patency rate was 80% after iliac and 41% after femoropopliteal angioplasty. In 17 femoropopliteal cases with lesions greater...... than or equal to 5 cm the 2-year patency rate was only 32%, but the corresponding figure for shorter lesions was 53%. Complicating haematoma appeared in 10% of the cases and the arterial state deteriorated in one patient. There was no distal embolization. Percutaneous transluminal angioplasty...

  20. Google matrix and Ulam networks of intermittency maps.

    Science.gov (United States)

    Ermann, L; Shepelyansky, D L

    2010-03-01

    We study the properties of the Google matrix of an Ulam network generated by intermittency maps. This network is created by the Ulam method which gives a matrix approximant for the Perron-Frobenius operator of dynamical map. The spectral properties of eigenvalues and eigenvectors of this matrix are analyzed. We show that the PageRank of the system is characterized by a power law decay with the exponent beta dependent on map parameters and the Google damping factor alpha . Under certain conditions the PageRank is completely delocalized so that the Google search in such a situation becomes inefficient.

  1. Intermittent duty solar refrigerator assisted by heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hindi, R.R.; Khalifa, A.M.A.; Akyurt, M.

    1988-01-01

    The design of a solar operated intermittent-duty aqua-ammonia type of absorption refrigerator is described. The generator is heated by an integral acetone heat pipe, the evaporator of which is in the form of a low-thermal-mass flat plate collector. The condenser is air cooled. The absorber is likewise cooled via a second R22 heat-pipe system by convection/radiation panels. Initial test results for the collector-generator loop are reported for a single-glazed collector. A discussion of overall performance is presented.

  2. Atomistic Model of Fluorescence Intermittency of Colloidal Quantum Dots

    KAUST Repository

    Voznyy, O.

    2014-04-16

    Optoelectronic applications of colloidal quantum dots demand a high emission efficiency, stability in time, and narrow spectral bandwidth. Electronic trap states interfere with the above properties but understanding of their origin remains lacking, inhibiting the development of robust passivation techniques. Here we show that surface vacancies improve the fluorescence yield compared to vacancy-free surfaces, while dynamic vacancy aggregation can temporarily turn fluorescence off. We find that infilling with foreign cations can stabilize the vacancies, inhibiting intermittency and improving quantum yield, providing an explanation of recent experimental observations. © 2014 American Physical Society.

  3. Monitoring antifolate resistance in intermittent preventive therapy for malaria

    DEFF Research Database (Denmark)

    Venkatesan, Meera; Alifrangis, Michael; Roper, Cally;

    2013-01-01

    Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps have rendered sulfadoxine-pyrimethamine (SP) ineffective for malaria treatment in most regions of the world. Yet, SP is efficacious as intermittent preventive therapy in pregnant women (IPTp) and infants (IPTi) and as seasonal malaria...... control in children (SMC). SP-IPTp is being widely implemented in sub-Saharan Africa. SP-IPTi is recommended where the prevalence of SP-resistant malaria parasites is low, whereas SMC is recommended for areas of intense seasonal malaria transmission. The continuing success of these interventions depends...

  4. Intermittent contact atomic force microscopy in electrochemical environment

    Energy Technology Data Exchange (ETDEWEB)

    Haering, P.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Siegenthaler, H. [Bern Univ., Bern (Switzerland)

    1997-06-01

    In situ measurements with Atomic Force Microscopy may cause surface modifications due to the tip-surface interactions. As an alternative and less destructive method, Intermittent Contact Atomic Force Microscopy (ICAFM) has been tested in an electrolytic environment. In the ICAFM mode the tip is not constantly in contact with the surface under investigation but is tapping onto the surface with a certain frequency. A commercial Park Scientific Instruments Microscopy has been modified to enable in situ experiment with ICAFM. It was possible to image iridium oxide films with ICAFM in the electrolytic environment without any noticeable surface modifications. (author) 3 figs., 4 refs.

  5. Influence of intermittency on the anisotropy of magnetic structure functions of solar wind turbulence

    Science.gov (United States)

    Pei, Zhongtian; He, Jiansen; Wang, Xin; Tu, Chuanyi; Marsch, Eckart; Wang, Linghua; Yan, Limei

    2016-02-01

    Intermittency appears to be connected with the spectral anisotropy of solar wind turbulence. We use the Local Intermittency Measure to identify and remove intermittency from the magnetic field data measured by the Ulysses spacecraft in fast solar wind. Structure functions are calculated based on the time sequences as obtained before and after removing intermittency and arranged by time scale (τ) and ΘRB (the angle between local mean magnetic field B0 and radial direction R). Thus, the scaling exponent (ξ(p, ΘRB)) of every structure function of order (p) is obtained for different angles. Before removing intermittency, ξ(p, ΘRB) shows a distinctive dependence on ΘRB: from monofractal scaling law at ΘRB ~0° to multifractal scaling law at ΘRB ~90°. In contrast after eliminating the intermittency, ξ(p, ΘRB) is found to be more monofractal for all ΘRB. The extended structure-function model is applied to ξ(p, ΘRB), revealing differences of its fitting parameters α (a proxy of the power spectral index) and P1 (fragmentation fraction) for the cases with and without intermittency. Parameter α shows an evident angular trend falling from 1.9 to 1.6 for the case with intermittency but has a relatively flat profile around 1.8 for the case without intermittency. Parameter P1 rises from around 0.5 to above 0.8 with increasing ΘRB for the intermittency case and is located between 0.5 and 0.8 for the case lacking intermittency. Therefore, we may infer that it is the anisotropy of intermittency that causes the scaling anisotropy of energy spectra and the unequal fragmentation of energy cascading.

  6. AMP: a new time-frequency feature extraction method for intermittent time-series data

    OpenAIRE

    Barrack, Duncan; Goulding, James; Hopcraft, Keith; Preston, Simon; Smith, Gavin

    2015-01-01

    The characterisation of time-series data via their most salient features is extremely important in a range of machine learning task, not least of all with regards to classification and clustering. While there exist many feature extraction techniques suitable for non-intermittent time-series data, these approaches are not always appropriate for intermittent time-series data, where intermittency is characterized by constant values for large periods of time punctuated by sharp and transient incr...

  7. Blood lactate level in Wistar rats after four and twelve week intermittent aerobic training

    OpenAIRE

    Dewi N. Sari; Sutjahjo Endardjo; Dewi I.S. Santoso

    2013-01-01

    Background: Aerobic training can be done not only continuously, but also intermittently. Intermittent aerobic training aimed to get blood lactate level lower than continuous aerobic training. Blood lactate concentration in one of the various factors that determine training performance. However, until recently, little studies about intermittent aerobic training and blood lactate levels have been done. Therefore, this study aimed to measure blood lactate levels in Wistar rats after 4 and 12 wee...

  8. Volcano-like intermittent bleeding activity for seven years from an arterio-enteric fistula on a kidney graft site after pancreas-kidney transplantation: a case report

    Science.gov (United States)

    2010-01-01

    Introduction We report the first case of a patient who underwent simultaneous kidney and pancreas transplantation and who then suffered from repeated episodes of severe gastrointestinal bleeding over a period of seven years. Locating the site of gastrointestinal bleeding is a challenging task. This case illustrates that detection of an arterio-enteric fistula can be very difficult, especially in technically-challenging situations such as cases of severe intra-abdominal adhesions. It is important to consider the possibility of arterio-enteric fistulas in cases of intermittent bleeding episodes, especially in transplant patients. Case presentation A 40-year-old Caucasian man received a combined pancreas-kidney transplantation as a result of complications from diabetes mellitus type I. Thereafter, he suffered from intermittent clinically-relevant episodes of gastrointestinal bleeding. Repeat endoscopic, surgical, scintigraphic, and angiographic investigations during his episodes of acute bleeding could not locate the bleeding site. He finally died in hemorrhagic shock due to arterio-enteric bleeding at the kidney graft site, which was diagnosed post-mortem. Conclusions In accordance with the literature, we suggest considering the removal of any rejected transplant organs in situations where arterio-enteric fistulas seem likely but cannot be excluded by repeat conventional or computed tomography-angiographic methods. Arterio-enteric fistulas may intermittently bleed over many years. PMID:21059222

  9. Volcano-like intermittent bleeding activity for seven years from an arterio-enteric fistula on a kidney graft site after pancreas-kidney transplantation: a case report

    Directory of Open Access Journals (Sweden)

    Schölmerich Jürgen

    2010-11-01

    Full Text Available Abstract Introduction We report the first case of a patient who underwent simultaneous kidney and pancreas transplantation and who then suffered from repeated episodes of severe gastrointestinal bleeding over a period of seven years. Locating the site of gastrointestinal bleeding is a challenging task. This case illustrates that detection of an arterio-enteric fistula can be very difficult, especially in technically-challenging situations such as cases of severe intra-abdominal adhesions. It is important to consider the possibility of arterio-enteric fistulas in cases of intermittent bleeding episodes, especially in transplant patients. Case presentation A 40-year-old Caucasian man received a combined pancreas-kidney transplantation as a result of complications from diabetes mellitus type I. Thereafter, he suffered from intermittent clinically-relevant episodes of gastrointestinal bleeding. Repeat endoscopic, surgical, scintigraphic, and angiographic investigations during his episodes of acute bleeding could not locate the bleeding site. He finally died in hemorrhagic shock due to arterio-enteric bleeding at the kidney graft site, which was diagnosed post-mortem. Conclusions In accordance with the literature, we suggest considering the removal of any rejected transplant organs in situations where arterio-enteric fistulas seem likely but cannot be excluded by repeat conventional or computed tomography-angiographic methods. Arterio-enteric fistulas may intermittently bleed over many years.

  10. Intermittent Demand Forecasting in a Tertiary Pediatric Intensive Care Unit.

    Science.gov (United States)

    Cheng, Chen-Yang; Chiang, Kuo-Liang; Chen, Meng-Yin

    2016-10-01

    Forecasts of the demand for medical supplies both directly and indirectly affect the operating costs and the quality of the care provided by health care institutions. Specifically, overestimating demand induces an inventory surplus, whereas underestimating demand possibly compromises patient safety. Uncertainty in forecasting the consumption of medical supplies generates intermittent demand events. The intermittent demand patterns for medical supplies are generally classified as lumpy, erratic, smooth, and slow-moving demand. This study was conducted with the purpose of advancing a tertiary pediatric intensive care unit's efforts to achieve a high level of accuracy in its forecasting of the demand for medical supplies. On this point, several demand forecasting methods were compared in terms of the forecast accuracy of each. The results confirm that applying Croston's method combined with a single exponential smoothing method yields the most accurate results for forecasting lumpy, erratic, and slow-moving demand, whereas the Simple Moving Average (SMA) method is the most suitable for forecasting smooth demand. In addition, when the classification of demand consumption patterns were combined with the demand forecasting models, the forecasting errors were minimized, indicating that this classification framework can play a role in improving patient safety and reducing inventory management costs in health care institutions. PMID:27562485

  11. Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2016-08-01

    Full Text Available Inorganic-organic halide organometal perovskites have demonstrated very promising performance for opto-electronic applications, such as solar cells, light-emitting diodes, lasers, single-photon sources, etc. However, the little knowledge on the underlying photophysics, especially on a microscopic scale, hampers the further improvement of devices based on this material. In this communication, correlated conventional photoluminescence (PL characterization and wide-field PL imaging as a function of time are employed to investigate the spatially- and temporally-resolved PL in CH3NH3PbI3−xClx perovskite films. Along with a continuous increase of the PL intensity during light soaking, we also observe PL blinking or PL intermittency behavior in individual grains of these films. Combined with significant suppression of PL blinking in perovskite films coated with a phenyl-C61-butyric acid methyl ester (PCBM layer, it suggests that this PL intermittency is attributed to Auger recombination induced by photoionized defects/traps or mobile ions within grains. These defects/traps are detrimental for light conversion and can be effectively passivated by the PCBM layer. This finding paves the way to provide a guideline on the further improvement of perovskite opto-electronic devices.

  12. Assessment of intermittent trace element pollution by moss bags

    Energy Technology Data Exchange (ETDEWEB)

    Cesa, M. [Dipartimento di Biologia, Universita di Trieste, Via Giorgieri 10, I-34127 Trieste (Italy)]. E-mail: mcesa@units.it; Bizzotto, A. [ARPAV Dipartimento di Vicenza, Servizio Territoriale di Bassano del Grappa, Via Cereria 15, I-36061 Bassano del Grappa (VI) (Italy); Ferraro, C. [ARPAV Dipartimento di Vicenza, Servizio Territoriale di Bassano del Grappa, Via Cereria 15, I-36061 Bassano del Grappa (VI) (Italy); Fumagalli, F. [Dipartimento di Biologia, Universita di Trieste, Via Giorgieri 10, I-34127 Trieste (Italy); Nimis, P.L. [Dipartimento di Biologia, Universita di Trieste, Via Giorgieri 10, I-34127 Trieste (Italy)

    2006-12-15

    Moss bags of the aquatic bryophyte Rhynchostegium riparioides (Hedw.) C. Jens. were transplanted into an irrigation ditch in the Province of Vicenza (NE Italy), affected by intermittent trace element contamination due to galvanics. The study aimed at: (a) testing the ability of mosses to detect different patterns of pollution (b) providing information about intensity and temporal extension of pollution events, and (c) localising the main sources. Moss bags were collected after 20, 34, 48 and 62 days of exposure. The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn in the desiccated apical shoots of mosses were determined by atomic absorption spectrophotometry. The mean concentrations measured in non-contaminated stations of a previous work were adopted as background values, to calculate the contamination factor (CF). Transplants were able to: (a) detect spatial patterns of bioaccumulation (b) reveal chronic contamination by Pb and Cu, intermittent contamination by Cr, Zn, and Ni, and a release of Cd by moss bags, and (c) localise the main emission sources. - Transplanted bryophytes are able to detect accidental trace element pollution in freshwaters of industrial areas.

  13. Intermittent Water Supply: Prevalence, Practice, and Microbial Water Quality.

    Science.gov (United States)

    Kumpel, Emily; Nelson, Kara L

    2016-01-19

    Intermittent water supplies (IWS), in which water is provided through pipes for only limited durations, serve at least 300 million people around the world. However, providing water intermittently can compromise water quality in the distribution system. In IWS systems, the pipes do not supply water for periods of time, supply periods are shortened, and pipes experience regular flow restarting and draining. These unique behaviors affect distribution system water quality in ways that are different than during normal operations in continuous water supplies (CWS). A better understanding of the influence of IWS on mechanisms causing contamination can help lead to incremental steps that protect water quality and minimize health risks. This review examines the status and nature of IWS practices throughout the world, the evidence of the effect of IWS on water quality, and how the typical contexts in which IWS systems often exist-low-income countries with under-resourced utilities and inadequate sanitation infrastructure-can exacerbate mechanisms causing contamination. We then highlight knowledge gaps for further research to improve our understanding of water quality in IWS.

  14. Horizontal visibility graphs generated by type-I intermittency

    Science.gov (United States)

    Núñez, Ángel M.; Luque, Bartolo; Lacasa, Lucas; Gómez, Jose Patricio; Robledo, Alberto

    2013-05-01

    The type-I intermittency route to (or out of) chaos is investigated within the horizontal visibility (HV) graph theory. For that purpose, we address the trajectories generated by unimodal maps close to an inverse tangent bifurcation and construct their associated HV graphs. We show how the alternation of laminar episodes and chaotic bursts imprints a fingerprint in the resulting graph structure. Accordingly, we derive a phenomenological theory that predicts quantitative values for several network parameters. In particular, we predict that the characteristic power-law scaling of the mean length of laminar trend sizes is fully inherited by the variance of the graph degree distribution, in good agreement with the numerics. We also report numerical evidence on how the characteristic power-law scaling of the Lyapunov exponent as a function of the distance to the tangent bifurcation is inherited in the graph by an analogous scaling of block entropy functionals defined on the graph. Furthermore, we are able to recast the full set of HV graphs generated by intermittent dynamics into a renormalization-group framework, where the fixed points of its graph-theoretical renormalization-group flow account for the different types of dynamics. We also establish that the nontrivial fixed point of this flow coincides with the tangency condition and that the corresponding invariant graph exhibits extremal entropic properties.

  15. Intermittent Demand Forecasting in a Tertiary Pediatric Intensive Care Unit.

    Science.gov (United States)

    Cheng, Chen-Yang; Chiang, Kuo-Liang; Chen, Meng-Yin

    2016-10-01

    Forecasts of the demand for medical supplies both directly and indirectly affect the operating costs and the quality of the care provided by health care institutions. Specifically, overestimating demand induces an inventory surplus, whereas underestimating demand possibly compromises patient safety. Uncertainty in forecasting the consumption of medical supplies generates intermittent demand events. The intermittent demand patterns for medical supplies are generally classified as lumpy, erratic, smooth, and slow-moving demand. This study was conducted with the purpose of advancing a tertiary pediatric intensive care unit's efforts to achieve a high level of accuracy in its forecasting of the demand for medical supplies. On this point, several demand forecasting methods were compared in terms of the forecast accuracy of each. The results confirm that applying Croston's method combined with a single exponential smoothing method yields the most accurate results for forecasting lumpy, erratic, and slow-moving demand, whereas the Simple Moving Average (SMA) method is the most suitable for forecasting smooth demand. In addition, when the classification of demand consumption patterns were combined with the demand forecasting models, the forecasting errors were minimized, indicating that this classification framework can play a role in improving patient safety and reducing inventory management costs in health care institutions.

  16. [Denitrification water treatment with zeolite composite filter by intermittent operation].

    Science.gov (United States)

    Qing, Cheng-Song; Bao, Tao; Chen, Tian-Hu; Chen, Dong; Xie, Jing-Jing

    2012-12-01

    The zeolite composite filters (ZCF) with the size of4-8 mm were prepared using raw zeolite (0.15-0.18 mm) as the main material and the cement as binder. After a combination of material characterizations, such as the void fraction, apparent density, compression strength and surface area, the optimal prepared conditions of composite filters were obtained as follow: weight ratio of m (zeolite): m (cement) = 7 : 3, curing for 15 d under the moisture condition and ambient temperature. Through upflow low-concentration ammonia nitrogen wastewater, ZCF filled in the experimental column was hung with the biological membrane. Thus, intermittent dynamic experiments were conducted, the intermittent operation cycle included adsorption, biological regeneration and drip washing. Until concentration of ammonia nitrogen was more than 2 mg x L(-1) of effluent standards, water in experiment column was firstly emptied, and then blast biological regeneration was conducted. After the filters were bathed with water, the zeolite adsorption-biological regeneration cycle was performed repeatedly. The experimental results show that under conditions of 24 h blast and 5 d of continuous operation period, ammonia nitrogen removal rate is up to 87.6% on average, total nitrogen removal rate reaches 51.2% on average. PMID:23379168

  17. Twist-induced Magnetosphere Reconfiguration for Intermittent Pulsars

    CERN Document Server

    Huang, Lei; Tong, Hao

    2016-01-01

    We propose that the magnetosphere reconfiguration induced by magnetic twists in the closed field line region can account for the mode-switching of intermittent pulsars. We carefully investigate the properties of axisymmetric force-free pulsar magnetospheres with magnetic twists in closed field line region around the polar caps. The magnetosphere with twisted closed lines leads to enhanced spin-down rates. The enhancement in spin-down rate depends on the size of region with twisted closed lines. Typically, it is increased by a factor of $\\sim2$, which is consistent with the intermittent pulsars' spin down behavior during the `off' and `on' states. We find there is a threshold of maximal twist angle $\\Delta\\phi_{\\rm thres}\\sim1$. The magnetosphere is stable only if the closed line twist angle is less than $\\Delta\\phi_{\\rm thres}$. Beyond this value, the magnetosphere becomes unstable and gets untwisted. The spin-down rate would reduce to its off-state value. The quasi-periodicity in spin-down rate change can be...

  18. Antral hyperplastic polyp causing intermittent gastric outlet obstruction: Case report

    Directory of Open Access Journals (Sweden)

    Kurtkaya-Yapicier Ozlem

    2003-06-01

    Full Text Available Abstract Background Hyperplastic polyps are the most common polypoid lesions of the stomach. Rarely, they cause gastric outlet obstruction by prolapsing through the pyloric channel, when they arise in the prepyloric antrum. Case presentation A 62-year-old woman presented with intermittent nausea and vomiting of 4 months duration. Upper gastrointestinal endoscopy revealed a 30 mm prepyloric sessile polyp causing intermittent gastric outlet obstruction. Following submucosal injection of diluted adrenaline solution, the polyp was removed with a snare. Multiple biopsies were taken from the greater curvature of the antrum and the corpus. Rapid urease test for Helicobacter pylori yielded a negative result. Histopathologic examination showed a hyperplastic polyp without any evidence of malignancy. Biopsies of the antrum and the corpus revealed gastritis with neither atrophic changes nor Helicobacter pylori infection. Follow-up endoscopy after a 12-week course of proton pomp inhibitor therapy showed a complete healing without any remnant tissue at the polypectomy site. The patient has been symptom-free during 8 months of follow-up. Conclusions Symptomatic gastric polyps should be removed preferentially when they are detected at the initial diagnostic endoscopy. Polypectomy not only provides tissue to determine the exact histopathologic type of the polyp, but also achieves radical treatment.

  19. INTERMITTENT CLONAZEPAM IN THE PREVENTION OF RECURRENT FEBRILE SEIZURES

    Directory of Open Access Journals (Sweden)

    BAJOGHLI Shirin MD

    2010-09-01

    Full Text Available ObjectiveTo evaluate the efficacy and common side effects of intermittent clonazepamin febrile seizures.Materials & MethodsThis study was an experimental trial designed to determine the efficacy ofintermittent clonazepam in febrile seizures .Thirty patients with an age rangeof 6 months to 5 years (60% male, 40% female were studied. Children with ahistory of psychomotor delay, abnormal neurological examination, a history ofantiepileptic drug consumption, and afebrile seizures were excluded from thestudy. Patients received a single dose of prophylactic Clonazepam (0.05 mg/kg/day on the first day of febrile illness and twice daily during the course of fever.An antipyretic medication (Acetaminophen was advised if fever exceeded38oC. Patients were followed up for one year after the study inclusion date.ResultsThree patients were excluded from study since they didnot follow the tritmentand three patients experienced afebrile seizures. Twenty four patients had 162febrile episodes during the course of the study and all patients were seizure-freeafter 1 year.ConclusionClonazepam was 100% effective but lethargy and ataxia were common sideeffects in patients. Fortunately, their parents continued treatment because theyhad prior awareness of the possible side effects of clonazepam. Clonazepam isefficacious as an intermittent therapy for febrile seizures if parents are informedof its side effects.

  20. Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films.

    Science.gov (United States)

    Li, Cheng; Zhong, Yu; Luna, Carlos Andres Melo; Unger, Thomas; Deichsel, Konstantin; Gräser, Anna; Köhler, Jürgen; Köhler, Anna; Hildner, Richard; Huettner, Sven

    2016-01-01

    Inorganic-organic halide organometal perovskites have demonstrated very promising performance for opto-electronic applications, such as solar cells, light-emitting diodes, lasers, single-photon sources, etc. However, the little knowledge on the underlying photophysics, especially on a microscopic scale, hampers the further improvement of devices based on this material. In this communication, correlated conventional photoluminescence (PL) characterization and wide-field PL imaging as a function of time are employed to investigate the spatially- and temporally-resolved PL in CH₃NH₃PbI3-xClx perovskite films. Along with a continuous increase of the PL intensity during light soaking, we also observe PL blinking or PL intermittency behavior in individual grains of these films. Combined with significant suppression of PL blinking in perovskite films coated with a phenyl-C61-butyric acid methyl ester (PCBM) layer, it suggests that this PL intermittency is attributed to Auger recombination induced by photoionized defects/traps or mobile ions within grains. These defects/traps are detrimental for light conversion and can be effectively passivated by the PCBM layer. This finding paves the way to provide a guideline on the further improvement of perovskite opto-electronic devices. PMID:27548128

  1. Reconstructing the intermittent dynamics of the torque in wind turbines

    CERN Document Server

    Lind, Pedro G; Peinke, Joachim

    2014-01-01

    We apply a framework introduced in the late nineties to analyze load measurements in off-shore wind energy converters (WEC). The framework is borrowed from statistical physics and properly adapted to the analysis of multivariate data comprising wind velocity, power production and torque measurements, taken at one single WEC. In particular, we assume that wind statistics drives the fluctuations of the torque produced in the wind turbine and show how to extract an evolution equation of the Langevin type for the torque driven by the wind velocity. It is known that the intermittent nature of the atmosphere, i.e. of the wind field, is transferred to the power production of a wind energy converter and consequently to the shaft torque. We show that the derived stochastic differential equation quantifies the dynamical coupling of the measured fluctuating properties as well as it reproduces the intermittency observed in the data. Finally, we discuss our approach in the light of turbine monitoring, a particular importa...

  2. Mechanisms affecting water quality in an intermittent piped water supply.

    Science.gov (United States)

    Kumpel, Emily; Nelson, Kara L

    2014-01-01

    Drinking water distribution systems throughout the world supply water intermittently, leaving pipes without pressure between supply cycles. Understanding the multiple mechanisms that affect contamination in these intermittent water supplies (IWS) can be used to develop strategies to improve water quality. To study these effects, we tested water quality in an IWS system with infrequent and short water delivery periods in Hubli-Dharwad, India. We continuously measured pressure and physicochemical parameters and periodically collected grab samples to test for total coliform and E. coli throughout supply cycles at 11 sites. When the supply was first turned on, water with elevated turbidity and high concentrations of indicator bacteria was flushed out of pipes. At low pressures (pressures between 10 and 17 psi, evidence of periodic contamination suggested that transient intrusion, backflow, release of particulates, or sloughing of biofilms from pipe walls had occurred. Few total coliform and no E. coli were detected when water was delivered with a chlorine residual and at pressures >17 psi. PMID:24459990

  3. Bubble shape in horizontal and near horizontal intermittent flow

    International Nuclear Information System (INIS)

    Highlights: • The bubble shapes in intermittent flows are presented experimentally. • The nose-tail inversion phenomenon appears at a low Froude number in downward pipe. • Transition from plug to slug flow occurs when the bubble tail changes from staircase pattern to hydraulic jump. - Abstract: This paper presents an experimental study of the shape of isolated bubbles in horizontal and near horizontal intermittent flows. It is found that the shapes of the nose and body of bubble depend on the Froude number defined by gas/liquid mixture velocity in a pipe, whereas the shape of the back of bubble region depends on both the Froude number and bubble length. The photographic studies show that the transition from plug to slug flow occurs when the back of the bubble changes from staircase pattern to hydraulic jump with the increase of the Froude number and bubble length. The effect of pipe inclination on characteristics of bubble is significant: The bubble is inversely located in a downwardly inclined pipe when the Froude number is low, and the transition from plug flow to slug flow in an upward inclined pipe is more ready to occur compared with that in a downwardly inclined pipe

  4. Intermittent cathodic protection for steel reinforced concrete bridges

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Ziomek-Moroz, Margaret; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Soltesz, S.M. (ODOT)

    2002-01-01

    Thermal-sprayed zinc anodes are used for impressed current cathodic protection (ICCP) systems on Oregon's reinforced concrete coastal bridges to prevent chloride-induced corrosion damage. Thermal-sprayed zinc performs well as an ICCP anode but the service life of the zinc anode is directly related to the average current density used to operate the systems. After a ICCP system is turned off, the rebar in the concrete remains passive and protected for a period of time. Intermittent operation of CP systems is possible when continuous corrosion rate monitoring is used to identify conditions when the CP system needs to be turned on to reestablish protection conditions for the rebar. This approach applies CP protection only when needed and reflects the fact that external protection may not be needed for a range of environmental conditions. In doing so, intermittent CP would lower the average current necessary to protect rebar, increase the anode service life, and reduce the lifetime costs for protecting reinforced concrete bridges.

  5. Tracking Intermittently Speaking Multiple Speakers Using a Particle Filter

    Directory of Open Access Journals (Sweden)

    Quinlan Angela

    2009-01-01

    Full Text Available The problem of tracking multiple intermittently speaking speakers is difficult as some distinct problems must be addressed. The number of active speakers must be estimated, these active speakers must be identified, and the locations of all speakers including inactive speakers must be tracked. In this paper we propose a method for tracking intermittently speaking multiple speakers using a particle filter. In the proposed algorithm the number of active speakers is firstly estimated based on the Exponential Fitting Test (EFT, a source number estimation technique which we have proposed. The locations of the speakers are then tracked using a particle filtering framework within which the decomposed likelihood is used in order to decouple the observed audio signal and associate each element of the decomposed signal with an active speaker. The tracking accuracy is then further improved by the inclusion of a silence region detection step and estimation of the noise-only covariance matrix. The method was evaluated using live recordings of 3 speakers and the results show that the method produces highly accurate tracking results.

  6. Timing of synchronization in intermittent irradiation synchronized with respiratory motion

    International Nuclear Information System (INIS)

    In order to reduce the increase in the irradiated volume caused by respiratory motion, a system which intermittently emits radiation synchronized with respiration was developed. A phantom of oscillating motion was made, and the effect of the motion on the penumbra of the dose profile was investigated by changing the distance of the motion and the timing of the synchronization. Irradiation was carried out by a 10-MV linear accelerator. Decreasing the irradiated time per motion cycle reduced the width of the penumbra. With a synchronized irradiation gated at end-of-inspiration or end-of-expiration, an intermittent irradiation ratio 47% kept the extension of the penumbra width to 2.2 times of the value measured in the phantom without motion when the motion distance was 4 cm. Investigation of the patients' diaphragmatic motion was done by reading the IBS (Image Brightness Stabilizer) circuit during fluoroscopic examination. A quiescent period was often observed at end-of-expiration. Synchronized irradiation gated at end-of-expiration was considered suitable for clinical application. (author)

  7. Distinct mechanisms underlying tolerance to intermittent and constant hypoxia in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Priti Azad

    Full Text Available BACKGROUND: Constant hypoxia (CH and intermittent hypoxia (IH occur during several pathological conditions such as asthma and obstructive sleep apnea. Our research is focused on understanding the molecular mechanisms that lead to injury or adaptation to hypoxic stress using Drosophila as a model system. Our current genome-wide study is designed to investigate gene expression changes and identify protective mechanism(s in D. melanogaster after exposure to severe (1% O(2 intermittent or constant hypoxia. METHODOLOGY/PRINCIPAL FINDINGS: Our microarray analysis has identified multiple gene families that are up- or down-regulated in response to acute CH or IH. We observed distinct responses to IH and CH in gene expression that varied in the number of genes and type of gene families. We then studied the role of candidate genes (up-or down-regulated in hypoxia tolerance (adult survival for longer periods (CH-7 days, IH-10 days under severe CH or IH. Heat shock proteins up-regulation (specifically Hsp23 and Hsp70 led to a significant increase in adult survival (as compared to controls of P-element lines during CH. In contrast, during IH treatment the up-regulation of Mdr49 and l(208717 genes (P-element lines provided survival advantage over controls. This suggests that the increased transcript levels following treatment with either paradigm play an important role in tolerance to severe hypoxia. Furthermore, by over-expressing Hsp70 in specific tissues, we found that up-regulation of Hsp70 in heart and brain play critical role in tolerance to CH in flies. CONCLUSIONS/SIGNIFICANCE: We observed that the gene expression response to IH or CH is specific and paradigm-dependent. We have identified several genes Hsp23, Hsp70, CG1600, l(208717 and Mdr49 that play an important role in hypoxia tolerance whether it is in CH or IH. These data provide further clues about the mechanisms by which IH or CH lead to cell injury and morbidity or adaptation and survival.

  8. Hippocampal impairments are associated with intermittent hypoxia of obstructive sleep apnea

    Institute of Scientific and Technical Information of China (English)

    FENG Jing; WU Qi; ZHANG Dan; CHEN Bao-yuan

    2012-01-01

    Obstructive sleep apnea (OSA),which is the most common sleep-related breathing disorder,is characterized as frequent upper airway collapse and obstruction.It is a treatable disorder but if left untreated is associated with complications in several organ systems.The health risk to OSA patients shows a strong association with acute cardiovascular events,and with chronic conditions.To the central nervous system,OSA causes behavioral and neuropsychologic deficits including daytime sleepiness,depression,impaired memory,mood disorders,cognition deficiencies,language comprehension and expression deficiencies,all of which are compatible with impaired hippocampal function.Furthermore,there exists a significant correlation between disease severity and cognitive deficits in OSA.Children with severe OSA have significantly lower intelligence quotient (IQ) and executive control functions compared to normal children matched for age,gender and ethnicity.This corroborates the findings of several pediatric studies of cognition in childhood OSA,where deficits are reported in general intelligence and some measures of executive function.In studies of OSA,it is difficult to differentiate the effects of its two main pathologic traits,intermittent hypoxia (IH) and sleep fragmentation.Many OSA studies,utilize IH as the only exposure factor in OSA studies.These approaches simplify research process and attain most of the academic goals.IH,continuous hypoxia and intermittent continuous hypoxia can all result in decreases in arterial O2.There are striking differences to them in the response of physiological systems.There are multiple studies showing that IH treatment in a rodent model of OSA can impair performance of standard water maze tests associated with deficits in spatial learning and memory which most likely are hippocampal-dependent.Cellular damage to the hippocampal cornuammonis 1 (CA1) region likely contributes to neuropsychological impairment among OSA patients,since neural circuits

  9. Changes in the Adult GluN2B Associated Proteome following Adolescent Intermittent Ethanol Exposure.

    Directory of Open Access Journals (Sweden)

    H Scott Swartzwelder

    Full Text Available Adolescent alcohol use is the strongest predictor for alcohol use disorders. In rodents, adolescents have distinct responses to acute ethanol, and prolonged alcohol exposure during adolescence can maintain these phenotypes into adulthood. One brain region that is particularly sensitive to the effects of both acute and chronic ethanol exposure is the hippocampus. Adolescent intermittent ethanol exposure (AIE produces long lasting changes in hippocampal synaptic plasticity and dendritic morphology, as well as in the susceptibility to acute ethanol-induced spatial memory impairment. Given the pattern of changes in hippocampal structure and function, one potential target for these effects is the ethanol sensitive GluN2B subunit of the NMDA receptor, which is known to be involved in synaptic plasticity and dendritic morphology. Thus we sought to determine if there were persistent changes in hippocampal GluN2B signaling cascades following AIE. We employed a previously validated GluN2B-targeted proteomic strategy that was used to identify novel signaling mechanisms altered by chronic ethanol exposure in the adult hippocampus. We collected adult hippocampal tissue (P70 from rats that had been given 2 weeks of AIE from P30-45. Tissue extracts were fractionated into synaptic and non-synaptic pools, immuno-precipitated for GluN2B, and then analyzed using proteomic methods. We detected a large number of proteins associated with GluN2B. AIE produced significant changes in the association of many proteins with GluN2B in both synaptic and non-synaptic fractions. Intriguingly the number of proteins changed in the non-synaptic fraction was double that found in the synaptic fraction. Some of these proteins include those involved in glutamate signaling cytoskeleton rearrangement, calcium signaling, and plasticity. Disruptions in these pathways may contribute to the persistent cellular and behavioral changes found in the adult hippocampus following AIE. Further

  10. Changes in the Adult GluN2B Associated Proteome following Adolescent Intermittent Ethanol Exposure

    Science.gov (United States)

    Swartzwelder, H. Scott; Risher, Mary-Louise; Miller, Kelsey M.; Colbran, Roger J.; Winder, Danny G.; Wills, Tiffany A.

    2016-01-01

    Adolescent alcohol use is the strongest predictor for alcohol use disorders. In rodents, adolescents have distinct responses to acute ethanol, and prolonged alcohol exposure during adolescence can maintain these phenotypes into adulthood. One brain region that is particularly sensitive to the effects of both acute and chronic ethanol exposure is the hippocampus. Adolescent intermittent ethanol exposure (AIE) produces long lasting changes in hippocampal synaptic plasticity and dendritic morphology, as well as in the susceptibility to acute ethanol-induced spatial memory impairment. Given the pattern of changes in hippocampal structure and function, one potential target for these effects is the ethanol sensitive GluN2B subunit of the NMDA receptor, which is known to be involved in synaptic plasticity and dendritic morphology. Thus we sought to determine if there were persistent changes in hippocampal GluN2B signaling cascades following AIE. We employed a previously validated GluN2B-targeted proteomic strategy that was used to identify novel signaling mechanisms altered by chronic ethanol exposure in the adult hippocampus. We collected adult hippocampal tissue (P70) from rats that had been given 2 weeks of AIE from P30-45. Tissue extracts were fractionated into synaptic and non-synaptic pools, immuno-precipitated for GluN2B, and then analyzed using proteomic methods. We detected a large number of proteins associated with GluN2B. AIE produced significant changes in the association of many proteins with GluN2B in both synaptic and non-synaptic fractions. Intriguingly the number of proteins changed in the non-synaptic fraction was double that found in the synaptic fraction. Some of these proteins include those involved in glutamate signaling cytoskeleton rearrangement, calcium signaling, and plasticity. Disruptions in these pathways may contribute to the persistent cellular and behavioral changes found in the adult hippocampus following AIE. Further, the robust change in

  11. Acute abdomen

    Directory of Open Access Journals (Sweden)

    Wig J

    1978-01-01

    Full Text Available 550 cases of acute abdomen have been analysed in detail includ-ing their clinical presentation and operative findings. Males are more frequently affected than females in a ratio of 3: 1. More than 45% of patients presented after 48 hours of onset of symptoms. Intestinal obstruction was the commonest cause of acute abdomen (47.6%. External hernia was responsible for 26% of cases of intestinal obstruction. Perforated peptic ulcer was the commonest cause of peritonitis in the present series (31.7% while incidence of biliary peritonitis was only 2.4%.. The clinical accuracy rate was 87%. The mortality in operated cases was high (10% while the over-all mortality rate was 7.5%.

  12. Continuous versus intermittent tamoxifen versus intermittent/alternated tamoxifen and medroxyprogesterone acetate as first line endocrine treatment in advanced breast cancer : An EORTC phase III study (10863)

    NARCIS (Netherlands)

    Beex, L.; Rose, C.; Mouridsen, H.; Jassem, J.; Nooij, M.; Estape, J.; Paridaens, R.; Piccart, M.; Gorlia, T.; Lardenoije, S.; Baila, L.

    2006-01-01

    Background: Continuous ligand depletion of endocrine responsive tumours may enhance resistance to therapy. Intermittent treatment with tamoxifen (T) was considered to mimic (incomplete) ligand depletion and reintroduction. Furthermore it was postulated that alternating tamoxifen with a non-cross res

  13. Continuous versus intermittent tamoxifen versus intermittent/alternated tamoxifen and medroxyprogesterone acetate as first line endocrine treatment in advanced breast cancer: an EORTC phase III study (10863).

    NARCIS (Netherlands)

    Beex, L.V.A.M.; Rose, C.; Mouridsen, H.; Jassem, J.; Nooij, M.; Estape, J.; Paridaens, R.; Piccart, M.; Gorlia, T.; Lardenoije, S.; Baila, L.

    2006-01-01

    BACKGROUND: Continuous ligand depletion of endocrine responsive tumours may enhance resistance to therapy. Intermittent treatment with tamoxifen (T) was considered to mimic (incomplete) ligand depletion and reintroduction. Furthermore it was postulated that alternating tamoxifen with a non-cross res

  14. An investigation of apparent, intermittent fuel failure in TRIGA fuel

    International Nuclear Information System (INIS)

    Full text: The 1 Mw TRIGA Reactor is cooled by natural convection and 16N and 41Ar which were released from the pool caused an undesirably high background in the gas detector used for fission product monitorings. It was necessary to convert the gas detector which was very sensitive to 16N and 41Ar to a particulate monitor. The monitor chosen was a commercially available moving tape continuous air monitor. It was placed adjacent to the pool wall where air under the reactor bridge could be sampled at the surface of the pool water. This monitoring system proved to be adequate under normal conditions. However, on several occasions, sharp increases in activity of short, duration were noted on the monitor recorder. These brief high levels of activity were similar to those described by other facilities which had experienced intermittent fuel element leakage and the integrity of the reactor fuel was suspected. The filter paper from the monitor was removed and its gamma spectrum obtained using a 30 cc Ge(Li) detector. This analysis revealed only the naturally occurring airborne isotopes, and it was concluded that the recorder increases in activity were not from fuel leakage. It was suspected that the activity increases were due to the intermittent release of radioactive gases from the pool water at higher temperatures. A series of experiments was performed which demonstrated the following: 1. At pool temperatures up to 80oF, the reading of the CAM remained constant. From 80 to 95oF, the reading increased by nearly a factor of 3 and became more erratic. 2. With the air pump off, the CAM response did not change. 3. A gas monitor set up in series with the CAM exhibited nearly an identical response and its spectrum showed only the existence of 41Ar and 16N. 4. After reactor shutdown, the CAM reading decayed with a half-life of 1.4 hr. It was concluded that at the higher pool temperatures large bubbles containing 41Ar escaped to the pool surface and the 41Ar was seen through the

  15. Simultaneous Infrared Dry-Blanching and Dehydration of apple slices Controlled by Intermittent Heating Mode

    Science.gov (United States)

    Infrared heating controlled by intermittent heating mode was found to be able to achieve simultaneous dry-blanching and dehydration of apple slices with a desirable quality. In order to better understand the performance of intermittent heating for simultaneous dry-blanching and dehydration (SIDBD),...

  16. Intermittent turbulence and oscillations in the stable boundary layer over land

    NARCIS (Netherlands)

    Wiel, van de B.J.H.

    2002-01-01

    As the title of this thesis indicates, our main subject of interest is: "Intermittent turbulence and oscillation in the stable boundary layer over land". As such, this theme connects the different chapters. Here, intermittent turbulence is defined as a sequence of events were 'burst' of increased tu

  17. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Scheduling of intermittent or reduced schedule leave. 825.203 Section 825.203 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT... Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave....

  18. Persistence during Extinction: Examining the Effects of Continuous and Intermittent Reinforcement on Problem Behavior

    OpenAIRE

    MacDonald, Jacquelyn M.; Ahearn, William H; Parry-Cruwys, Diana; Bancroft, Stacie; Dube, William V.

    2013-01-01

    This study examined behavioral persistence during extinction following continuous or intermittent reinforcement in the context of an analogue functional analysis of problem behavior. Participants were four children diagnosed with an autism spectrum disorder who engaged in problem behavior; and for whom functional analyses indicated sensitivity to social reinforcers. Experimental sessions included four successive 5-min components: No social interaction, continuous or intermittent reinforcement...

  19. The influence of basketball dribbling on repeated high-intensity intermittent runs

    Directory of Open Access Journals (Sweden)

    Zhaowei Kong

    2015-12-01

    Conclusion: The results suggest that the Yo-Yo IE2 test could reflect the repeatability of high-intensity intermittent basketball dribbling performance, while dribbling skills may have different influences on high-intensity intermittent exercise capacity in adolescent players at different ages.

  20. Robust, low-cost data loggers for stream temperature, flow intermittency, and relative conductivity monitoring

    Science.gov (United States)

    Chapin, Thomas; Todd, Andrew S.; Zeigler, Matthew P.

    2014-01-01

    Water temperature and streamflow intermittency are critical parameters influencing aquatic ecosystem health. Low-cost temperature loggers have made continuous water temperature monitoring relatively simple but determining streamflow timing and intermittency using temperature data alone requires significant and subjective data interpretation. Electrical resistance (ER) sensors have recently been developed to overcome the major limitations of temperature-based methods for the assessment of streamflow intermittency. This technical note introduces the STIC (Stream Temperature, Intermittency, and Conductivity logger); a robust, low-cost, simple to build instrument that provides long-duration, high-resolution monitoring of both relative conductivity (RC) and temperature. Simultaneously collected temperature and RC data provide unambiguous water temperature and streamflow intermittency information that is crucial for monitoring aquatic ecosystem health and assessing regulatory compliance. With proper calibration, the STIC relative conductivity data can be used to monitor specific conductivity.

  1. Coexistence of intermittencies in the neuronal network of the epileptic brain

    Science.gov (United States)

    Koronovskii, Alexey A.; Hramov, Alexander E.; Grubov, Vadim V.; Moskalenko, Olga I.; Sitnikova, Evgenia; Pavlov, Alexey N.

    2016-03-01

    Intermittent behavior occurs widely in nature. At present, several types of intermittencies are known and well-studied. However, consideration of intermittency has usually been limited to the analysis of cases when only one certain type of intermittency takes place. In this paper, we report on the temporal behavior of the complex neuronal network in the epileptic brain, when two types of intermittent behavior coexist and alternate with each other. We prove the presence of this phenomenon in physiological experiments with WAG/Rij rats being the model living system of absence epilepsy. In our paper, the deduced theoretical law for distributions of the lengths of laminar phases prescribing the power law with a degree of -2 agrees well with the experimental neurophysiological data.

  2. Intermittent Fasting Modulation of the Diabetic Syndrome in Streptozotocin-Injected Rats

    Directory of Open Access Journals (Sweden)

    Louiza Belkacemi

    2012-01-01

    Full Text Available This study investigates the effects of intermittent overnight fasting in streptozotocin-induced diabetic rats (STZ rats. Over 30 days, groups of 5-6 control or STZ rats were allowed free food access, starved overnight, or exposed to a restricted food supply comparable to that ingested by the intermittently fasting animals. Intermittent fasting improved glucose tolerance, increased plasma insulin, and lowered Homeostatis Model Assessment index. Caloric restriction failed to cause such beneficial effects. The β-cell mass, as well as individual β-cell and islet area, was higher in intermittently fasting than in nonfasting STZ rats, whilst the percentage of apoptotic β-cells appeared lower in the former than latter STZ rats. In the calorie-restricted STZ rats, comparable findings were restricted to individual islet area and percentage of apoptotic cells. Hence, it is proposed that intermittent fasting could represent a possible approach to prevent or minimize disturbances of glucose homeostasis in human subjects.

  3. Effects of intermittent aeration on pollutants removal in subsurface wastewater infiltration system.

    Science.gov (United States)

    Pan, Jing; Fei, Hexin; Song, Siyu; Yuan, Fang; Yu, Long

    2015-09-01

    In this study, the pollutant removal performances in two pilot-scale subsurface wastewater infiltration systems (SWISs) with and without intermittent aeration were investigated. Matrix oxidation reduction potential (ORP) results showed that intermittent aeration well developed aerobic conditions in upper matrix and anoxic or anaerobic conditions in the subsequent sections, which resulted in high NH4(+)-N and TN removal. Moreover, intermittent aeration increased removal rates of COD and TP. Microbial populations and enzyme activities analysis proved that intermittent aeration not only obviously boosted the growth and reproduction of bacteria, fungus, actinomyces, nitrifying bacteria and denitrifying bacteria, but also successfully increased nitrate reductase (NR) and nitrite reductase (NIR) in the depth of 80 and 110 cm. The results suggest that the intermittent aeration could be a widespread research and application strategy for achieving the high removal performance in SWISs.

  4. Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas.

    Science.gov (United States)

    Matthaeus, W H; Wan, Minping; Servidio, S; Greco, A; Osman, K T; Oughton, S; Dmitruk, P

    2015-05-13

    An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

  5. Intermittency and chaos in intracavity doubled lasers. II

    Energy Technology Data Exchange (ETDEWEB)

    James, G.E.; Harrell, E.M. II (School of Mathematics, Georgia Institute of Technology, Atlanta, Georgia 30332 (USA)); Roy, R. (School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (USA))

    1990-03-01

    We describe the nonlinear dynamics of intracavity doubled multimode lasers. Baer (J. Opt. Soc. Am. B 3, 1175 (1986)) observed irregular amplitude fluctuations in a multimode yttrium aluminum garnet laser with an intracavity potassium titanyl phosphate frequency-doubling crystal; we identify type-III intermittency as the route to chaos. Subsequently, Oka and Kubota (Opt. Lett. 13, 805 (1988)) demonstrated the stabilization of such a laser by the introduction of a quarter wave plate into the cavity. A generalized model of rate equations for this case is introduced. It is shown that a second route to chaos through a Hopf bifurcation, synchronization, and period-doubling sequence occurs on rotation of the quarter wave plate within the cavity. In addition, we predict that the laser output may be stable for particular lengths of the doubling crystal.

  6. A conditional simulation model of intermittent rain fields

    Directory of Open Access Journals (Sweden)

    L. G. Lanza

    2000-01-01

    Full Text Available The synthetic generation of random fields with specified probability distribution, correlation structure and probability of no-rain areas is used as the basis for the formulation of a stochastic space-time rainfall model conditional on rain gauge observations. A new procedure for conditioning while preserving intermittence is developed to provide constraints to Monte Carlo realisations of possible rainfall scenarios. The method addresses the properties of the convolution operator involved in generating random field realisations and is actually independent of the numerical algorithm used for unconditional simulation. It requires only the solution of a linear system of algebraic equations the order of which is given by the number of the conditioning nodes. Applications of the methodology are expected in rainfall field reconstruction from sparse rain gauge data and in rainfall downscaling from the large scale information that may be provided by remote sensing devices or numerical weather prediction models. Keywords: Space-time rainfall; Conditioning; Stochastic models

  7. Detecting the temporal structure of intermittent phase locking

    CERN Document Server

    Ahn, Sungwoo; Rubchinsky, Leonid L

    2011-01-01

    This study explores a method to characterize temporal structure of intermittent phase locking in oscillatory systems. When an oscillatory system is in a weakly synchronized regime away from a synchronization threshold, it spends most of the time in parts of its phase space away from synchronization state. Therefore characteristics of dynamics near this state (such as its stability properties/Lyapunov exponents or distributions of the durations of synchronized episodes) do not describe system's dynamics for most of the time. We consider an approach to characterize the system dynamics in this case, by exploring the relationship between the phases on each cycle of oscillations. If some overall level of phase locking is present, one can quantify when and for how long phase locking is lost, and how the system returns back to the phase-locked state. We consider several examples to illustrate this approach: coupled skewed tent maps, which stability can be evaluated analytically, coupled R\\"{o}ssler and Lorenz oscill...

  8. Hyperchaotic Intermittent Convection in a Magnetized Viscous Fluid

    CERN Document Server

    Macek, Wieslaw M

    2014-01-01

    We consider a low-dimensional model of convection in a horizontally magnetized layer of a viscous fluid heated from below. We analyze in detail the stability of hydromagnetic convection for a wide range of two control parameters. Namely, when changing the initially applied temperature difference or magnetic field strength, one can see transitions from regular to irregular long-term behavior of the system, switching between chaotic, periodic, and equilibrium asymptotic solutions. It is worth noting that owing to the induced magnetic field a transition to hyperchaotic dynamics is possible for some parameters of the model. We also reveal new features of the generalized Lorenz model, including both type I and III intermittency.

  9. Turbulent energy dissipation and intermittency in ambipolar diffusion magnetohydrodynamics

    CERN Document Server

    Momferratos, Georgios; Falgarone, Edith; Forêts, Guillaume Pineau des

    2015-01-01

    The dissipation of kinetic and magnetic energy in the interstellar medium (ISM) can proceed through viscous, Ohmic or ambipolar diffusion (AD). It occurs at very small scales compared to the scales at which energy is presumed to be injected. This localized heating may impact the ISM evolution but also its chemistry, thus providing observable features. Here, we perform 3D spectral simulations of decaying magnetohydrodynamic turbulence including the effects of AD. We find that the AD heating power spectrum peaks at scales in the inertial range, due to a strong alignment of the magnetic and current vectors in the dissipative range. AD affects much greater scales than the AD scale predicted by dimensional analysis. We find that energy dissipation is highly concentrated on thin sheets. Its probability density function follows a lognormal law with a power-law tail which hints at intermittency, a property which we quantify by use of structure function exponents. Finally, we extract structures of high dissipation, de...

  10. Fractal clusters and intermittency in relativistic heavy ion collisions

    CERN Document Server

    Antoniou, Nikos G; Diakonos, F K

    2000-01-01

    We investigate the formation of particle clusters (pions) associated with the chiral QCD phase transition in thermodynamic equilibrium. The geometry of these clusters at the critical point (T=T/sub c/) turns out to be fractal reflecting the self similar structure of the density fluctuations of the produced pions. The fractal dimension of the "critical" clusters is related to the critical exponents characterizing the phase transition. We examine the possibility to observe such pion clusters in relativistic heavy ion collisions. A Monte Carlo simulation of the critical system in 3D is performed leading to a typical set of "critical" events. Factorial moment analysis of the rapidity and transverse momentum distribution for these events shows a characteristic intermittency pattern. Mini-jet like structures arise in a azimuth angle rapidity lego plot. These features allow for a unique identification of the class of "critical events" in an event by event analysis in current and future experiments with relativistic ...

  11. Modeling Integrated Water-User Decisions with Intermittent Supplies

    Science.gov (United States)

    Lund, J. R.; Rosenberg, D.

    2006-12-01

    We present an economic-engineering method to estimate urban water use demands with intermittent water supplies. A two-stage, probabilistic optimization formulation includes a wide variety of water supply enhancement and conservation actions that individual households can adopt to meet multiple water quality uses with uncertain water availability. We embed the optimization in Monte-Carlo simulations to show aggregate effects at a utility (citywide) scale for a population of user conditions and decisions. Parametric analysis provides derivations of supply curves to subsidize conservation, demand responses to alternative pricing, and customer willingness-to-pay to avoid shortages. Results show a good empirical fit for the average and distribution of billed residential water use in Amman, Jordan. Additional outputs give likely market penetration rates for household conservation actions, associated water savings, and subsidies required to entice further adoption. We discuss new insights to size, target, market, and finance conservation programs and interpret a demand curve with block pricing.

  12. Suppression of spiral waves using intermittent local electric shock

    Institute of Scientific and Technical Information of China (English)

    Ma Jun; Ying He-Ping; Li Yan-Long

    2007-01-01

    In this paper, an intermittent local electric shock scheme is proposed to suppress stable spiral waves in the Barkley model by a weak electric shock (about 0.4 to 0.7) imposed on a random selected n × n grids (n = 1-5, compared with the original 256×256 lattice) and monitored synchronically the evolutions of the activator on the grids as the sampled signal of the activator steps out a given threshold (i.e., the electric shock works on the n × n grids if the activator u (≤) 0.4 or u (≥) 0.8). The numerical simulations show that a breakup of spiral is observed in the media state evolution to finally obtain homogeneous states if the electric shock with appropriate intensity is imposed.

  13. Wind and Current Intermittency in Coastal and Atmospheric Environments

    Science.gov (United States)

    Sekula, Emil; Martinez-Benjamin, Juan Jose; Redondo, Jose M.; Jorge, Juan; Mahjoub, Otman B.

    2015-04-01

    We study at several non-homogeneous sites, such as the coastal Mediterranean Area (Ebro Delta, Blanes) and in the iberian Plateau the wind intermittency as well as the fractal structure of the induced cloud and wave fronts. Weather data from 10 and 100m hight masts are used to calculate Local Richardson number, Monin-Obukhov length, eddy transfer coefficients, turbulent kinetic energy, turbulent intensities, friction velocities and sensible heat flux at three levels (5, 17 and 32 m) were considered. The results show how the stability at 17 and 32 m influences the turbulent transfer near the ground. The shear of wind or convection are the main mechanism to produce mixing in the surface, which is often detected in satellite images of nearby clouds or coastal features. The influence of internal gravity-waves on the atmospheric boundary-layer during strong stable stratification is quantified. atmospheric and oceanic circulation involve non-linear intermittency that account for unresolved turbulent mixing and diffusion. The most sophisticated turbulent closure models involve using structure functions of higher order [1,2]. The relationship between the intermittency of turbulence and the type of stratification for different atmospheric situations during the SABLES98 field campaign. We first show that the scaling behaviour of the velocity structure function in events such as GABLS (GEWEX Atmospheric Boundary-Layer Study)and in combined ESA SAR measurements [3-6] near the coast exhibit fractal and intermittent scaling. Near the Gulf of Lyons, vortical scaling show coupling between synoptic and rossby deformation scales [7]. [1]Mahjoub O., Redondo J.M. and Babiano A. (1998) Structure Functions in Complex Flows, Applied Scientific Research 59, 299-313. [2]Fraunie P., Berreba S. Chashechkin Y., Velasco D. and Redondo J.M. (2008)LES and laboratory experiments on the decay of grid wakes in strongly stratified flows. Il Nuovo Cimento C 31, 909-930. [3]Diez M., Bezerra M

  14. Intermittent Jolts of Galactic UV Radiation Mutagenetic Effects

    CERN Document Server

    Scalo, J M; Williams, P; Scalo, John M.; Williams, Peter

    2001-01-01

    We estimate the frequency of intermittent hypermutation events and disruptions of planetary/satellite photochemistry due to ultraviolet radiation from core collapse supernova explosions. Calculations are presented for planetary systems in the local Milky Way, including the important moderating effects of vertical Galactic structure and UV absorption by interstellar dust. The events are particularly frequent for satellites of giant gas planets at \\gtrsim 5-10 AU distance from solar-type parent stars, or in the conventional habitable zones for planets orbiting spectral type K and M parent stars, with rates of significant jolts about 10^3 - 10^4 per Gyr. The steep source spectra and existing data on UVA and longer-wavelength radiation damage in terrestrial organisms suggest that the mutational effects may operate even on planets with ozone shields. We argue that the mutation doubling dose for UV radiation should be much smaller than the mean lethal dose, using terrestrial prokaryotic organisms as our model, and ...

  15. Caustics and Intermittency in Turbulent Suspensions of Heavy Particles

    CERN Document Server

    Bec, J; Cencini, M; Lanotte, A S; Toschi, F

    2009-01-01

    The statistics of velocity differences between very heavy inertial particles suspended in an incompressible turbulent flow is found to be extremely intermittent. When particles are separated by distances within the viscous subrange, the competition between quiet regular regions and multi-valued caustics leads to a quasi bi-fractal behavior of the particle velocity structure functions, with high-order moments bringing the statistical signature of caustics. Contrastingly, for particles separated by inertial-range distances, the velocity-difference statistics is characterized in terms of a local H\\"{o}lder exponent, which is a function of the scale-dependent particle Stokes number only. Results are supported by high-resolution direct numerical simulations. It is argued that these findings might have implications in the early stage of rain droplets formation in warm clouds.

  16. Intermittency and transient chaos from simple frequency-dependent selection.

    Science.gov (United States)

    Gavrilets, S; Hastings, A

    1995-08-22

    Frequency-dependent selection is an important determinant of the evolution of gametophytic self-incompatibility systems in plants, aposematic (warning) and cryptic coloration, systems of mimicry, competitive interactions among members of a population, mating preferences, predator-prey and host-parasite interactions, aggression and other behavioural traits. Past theoretical studies of frequency-dependent selection have shown it to be a plausible mechanism for the maintenance of genetic variability in natural populations. Here, through an analysis of a simple deterministic model for frequency-dependent selection, we demonstrate that complex dynamic behaviour is possible under a broad range of parameter values. In particular we show that the model exhibits not only cycles and chaos but also, for a more restricted set of parameters, transient chaos and intermittency: alterations between an apparently deterministic behaviour and apparently chaotic fluctuations. This behaviour, which has not been stressed within the population genetics literature, provides an explanation for erratic dynamics of gene frequencies.

  17. Intermittent Flow of Granular Matter in an Annular Geometry

    Science.gov (United States)

    Brzinski, Ted; Daniels, Karen E.

    Granular solids can be subjected to a finite stress below which the response is elastic. Above this yield stress, however, the material fails catastrophically, undergoing a rapid plastic deformation. In the case of a monotonically increasing stress the material exhibits a characteristic stick-slip response. We investigate the statistics of this intermittent failure in an annular shear geometry, driven with a linear-ramp torque in order to generate the stick-slip behavior. The apparatus is designed to allow visual access to particle trajectories and inter-particle forces (through the use of photoelastic materials). Additionally, twelve piezoelectric sensors at the outer wall measure acoustic emissions due to the plastic deformation of the material. We vary volume fraction, and use both fixed and deformable boundaries. We measure how the distribution of slip size and duration are related to the bulk properties of the packing, and compare to systems with similar governing statistics.

  18. Optimizing intermittent water supply in urban pipe distribution networks

    CERN Document Server

    Lieb, Anna M; Wilkening, Jon

    2015-01-01

    In many urban areas of the developing world, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. Here, we develop a computational model of transition, transient pipe flow in a network, accounting for a wide variety of realistic boundary conditions. We validate the model against several published data sets, and demonstrate its use on a real pipe network. The model is extended to consider several optimization problems motivated by realistic scenarios. We demonstrate how to infer water flow in a small pipe network from a single pressure sensor, and show how to control water inflow to minimize damaging pressure gradients.

  19. Optimal control system of the intermittent bus-only approach

    Institute of Scientific and Technical Information of China (English)

    Jie Jiang; Yulin Chang

    2014-01-01

    To guarantee bus priority with a minimum impact on car traffic at intersections, an optimal control system of the intermittent bus-only approach (IBA) was proposed. The problems of the existing system are first solved through optimization: the judgment time of the IBA system was advanced to allow a bus to jump car queues if the bus was detected to arrive at the intersection, and the instant that the IBA lane became available to cars was controlled dynamically to increase the capacity of the IBA lane. The total car delay in one cycle was then analyzed quantitatively when implementing the optimal control system. The results show that in comparison with the existing system of the IBA, the car delay is greatly reduced and the probability of a car stopping twice is low after optimizing the IBA system.

  20. BCR Routing for Intermittently Connected Mobile Ad hoc Networks

    Directory of Open Access Journals (Sweden)

    S. RAMESH

    2014-03-01

    Full Text Available The Wireless and the Mobile Networks appear to provide a wide range of applications. Following these, the Mobile Ad hoc Networks (MANET aid in wide development of many applications. The achievement of the real world applications are attained through effective routing. The Intermittently Connected Mobile Ad hoc Network (ICMANET is a sparse network where a full connectivity is never possible. ICMANET is a disconnected MANET and is also a Delay Tolerant Network (DTN that sustains for higher delays. The routing in a disseminated network is a difficult task. A new routing scheme called Bee Colony Routing (BCR is been proposed with a motto of achieving optimal result in delivering the data packet towards the destined node. BCR is proposed with the basis of Bee Colony Optimization technique (BCO. The routing in ICMNAET is done by means of Bee routing protocol. This paper enchants a novel routing methodology for data transmission in ICMANET.

  1. Distributed Particle Filter Implementation with Intermittent/Irregular Consensus Convergence

    CERN Document Server

    Mohammadi, Arash

    2011-01-01

    Motivated by non-linear, non-Gaussian, distributed multi-sensor/agent navigation and tracking applications, we propose a multi-rate consensus/fusion based framework for distributed implementation of the particle filter (CF/DPF). The CF/DPF framework is based on running localized particle filters to estimate the overall state vector at each observation node. Separate fusion filters are designed to consistently assimilate the local filtering distributions into the global posterior by compensating for the common past information between neighbouring nodes. The CF/DPF offers two distinct advantages over its counterparts. First, the CF/DPF framework is suitable for scenarios where network connectivity is intermittent and consensus can not be reached between two consecutive observations. Second, the CF/DPF is not limited to the Gaussian approximation for the global posterior density. A third contribution of the paper is the derivation of the optimal posterior Cram\\'er-Rao lower bound (PCRLB) for the distributed arc...

  2. Intermittent criticality on a regional scale in Bhuj

    Science.gov (United States)

    Padhy, Simanchal

    2004-08-01

    The statistics of the Bhuj earthquake population are examined to investigate the proximity of the system to the critical state, defined through an entropy-energy relationship based on the tools of statistical mechanics. The results are compared with a theoretical model corresponding to a Boltzmann probability density distribution of degenerate microscopic energy states of the form p(E) ~E-B-1 e-E/θ. The data exhibit fluctuations in characteristic energy θ at a constant B-value of the form S~B. Features such as (1) time-dependent variations in seismicity during the period of presumably uncorrelated stress field following a major event, and (2) +/-12 per cent fluctuations in the macroscopic thermodynamic variable (entropy) support the intermittent criticality of Bhuj crust.

  3. Intermittent Testing and Training for High-Level Football Players

    DEFF Research Database (Denmark)

    Ingebrigtsen, Jørgen

    Football is the most popular sport in the world, played by over 400 million men and women. In addition to the wide range of sport-specific technical and tactical skills needed, several physical components have been shown to be necessary to perform at a high level. The present PhD thesis is based...... on four articles that focus on physical testing and training for elite and sub-elite football players.The first article (Study I) aims to identify and establish aerobic capacities and anthropometric characteristics of elite female football players with the use of laboratory tests, and to examine whether...... systematic differences between the playing positions can be detected. Lately, field tests have become more frequently used in football than the laboratory tests used in Study I. Study II therefore aims to assess the validity of one of them, the Yo-Yo Intermittent Recovery test level 2 (Yo-Yo IR2). Along...

  4. ImOSM: intermittent evolution and robustness of phylogenetic methods.

    Science.gov (United States)

    Thi Nguyen, Minh Anh; Gesell, Tanja; von Haeseler, Arndt

    2012-02-01

    Among the criteria to evaluate the performance of a phylogenetic method, robustness to model violation is of particular practical importance as complete a priori knowledge of evolutionary processes is typically unavailable. For studies of robustness in phylogenetic inference, a utility to add well-defined model violations to the simulated data would be helpful. We therefore introduce ImOSM, a tool to imbed intermittent evolution as model violation into an alignment. Intermittent evolution refers to extra substitutions occurring randomly on branches of a tree, thus changing alignment site patterns. This means that the extra substitutions are placed on the tree after the typical process of sequence evolution is completed. We then study the robustness of widely used phylogenetic methods: maximum likelihood (ML), maximum parsimony (MP), and a distance-based method (BIONJ) to various scenarios of model violation. Violation of rates across sites (RaS) heterogeneity and simultaneous violation of RaS and the transition/transversion ratio on two nonadjacent external branches hinder all the methods recovery of the true topology for a four-taxon tree. For an eight-taxon balanced tree, the violations cause each of the three methods to infer a different topology. Both ML and MP fail, whereas BIONJ, which calculates the distances based on the ML estimated parameters, reconstructs the true tree. Finally, we report that a test of model homogeneity and goodness of fit tests have enough power to detect such model violations. The outcome of the tests can help to actually gain confidence in the inferred trees. Therefore, we recommend using these tests in practical phylogenetic analyses.

  5. Respiratory plasticity in the behaving rat following chronic intermittent hypoxia.

    Science.gov (United States)

    Edge, Deirdre; Skelly, J Richard; Bradford, Aidan; O'Halloran, Ken D

    2010-01-01

    Chronic intermittent hypoxia (CIH), a feature of obstructive sleep apnoea (OSA) has been shown to have myriad effects on the respiratory control system. The effects on breathing are of great clinical significance for the sleep apnoea patient. We sought to determine the effect of CIH on normoxic ventilation. Both male and female adult Wistar rats were studied due to the evident sex difference in the prevalence of OSA. A role for oxidative stress in respiratory modifications was also explored. Adult male (n = 30) and female (n = 16) rats were exposed to alternating periods of N(2) and O(2) for 90 s each, bringing the ambient oxygen concentration to 5% at nadir (CIH) group. Sham groups were subject to cycles of air/air under identical experimental conditions. A subset of male rats (8 controls, 8 CIH) had free access to water containing 1 mM Tempol (SOD-mimetic) at all times. Treatments were carried out for 8 hours a day for 9 days. Following treatment, normoxic ventilation was assessed by whole body plethysmography in sleeping animals. Baseline normoxic ventilation was increased in both male and female treated rats but this did not achieve statistical significance. However, ventilatory drive (V(T)/Ti) was significantly increased in male rats. Chronic treatment with Tempol abolished this effect. Conversely, CIH had no significant effect on VT/Ti in female rats. Our results indicate subtle effects of intermittent hypoxia on breathing in conscious behaving rats. We speculate the increased ventilatory drive following CIH represents a form a neural plasticity - a ROS dependent phenomenon - with sexual dimorphism. PMID:20217363

  6. INTERMITTENT VERSUS CONTINUOUS INCREMENTAL FIELD TESTS: ARE MAXIMAL VARIABLES INTERCHANGEABLE?

    Directory of Open Access Journals (Sweden)

    Lorival J. Carminatti

    2013-03-01

    Full Text Available The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR and the Vameval test (T-VAM, characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat, volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE at peak test velocities (PV. No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h-1 and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm. During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm. However, there was a significant difference in TTE (p = 0.04 (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s with a low correlation (r = 0.41. The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l-1. Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs.

  7. Comparison Between the Continuous and Intermittent Heating Methods for Simultaneous Infrared Dry-Blanching and Dehydration of Apple Slices

    Science.gov (United States)

    Simultaneous infrared dry-blanching and dehydration (SIRDBD) can be operated in two heating modes, continuous and intermittent heating. Under continuous heating, infrared radiation intensity was kept constant while the product temperature remained constant under intermittent heating in this study. ...

  8. Hiatus Hernia: A Rare Cause of Acute Pancreatitis.

    Science.gov (United States)

    Patel, Shruti; Shahzad, Ghulamullah; Jawairia, Mahreema; Subramani, Krishnaiyer; Viswanathan, Prakash; Mustacchia, Paul

    2016-01-01

    Hiatal hernia (HH) is the herniation of elements of the abdominal cavity through the esophageal hiatus of the diaphragm. A giant HH with pancreatic prolapse is very rare and its causing pancreatitis is an even more extraordinary condition. We describe a case of a 65-year-old man diagnosed with acute pancreatitis secondary to pancreatic herniation. In these cases, acute pancreatitis may be caused by the diaphragmatic crura impinging upon the pancreas and leading to repetitive trauma as it crosses the hernia; intermittent folding of the main pancreatic duct; ischemia associated with stretching at its vascular pedicle; or total pancreatic incarceration. Asymptomatic hernia may not require any treatment, while multiple studies have supported the recommendation of early elective repair as a safer route in symptomatic patients. In summary, though rare, pancreatic herniation should be considered as a cause of acute pancreatitis. A high index of suspicion for complications is warranted in cases like these. PMID:27066077

  9. Hiatus Hernia: A Rare Cause of Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Shruti Patel

    2016-01-01

    Full Text Available Hiatal hernia (HH is the herniation of elements of the abdominal cavity through the esophageal hiatus of the diaphragm. A giant HH with pancreatic prolapse is very rare and its causing pancreatitis is an even more extraordinary condition. We describe a case of a 65-year-old man diagnosed with acute pancreatitis secondary to pancreatic herniation. In these cases, acute pancreatitis may be caused by the diaphragmatic crura impinging upon the pancreas and leading to repetitive trauma as it crosses the hernia; intermittent folding of the main pancreatic duct; ischemia associated with stretching at its vascular pedicle; or total pancreatic incarceration. Asymptomatic hernia may not require any treatment, while multiple studies have supported the recommendation of early elective repair as a safer route in symptomatic patients. In summary, though rare, pancreatic herniation should be considered as a cause of acute pancreatitis. A high index of suspicion for complications is warranted in cases like these.

  10. [Acute myocarditis].

    Science.gov (United States)

    Combes, Alain

    2013-05-01

    Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackievirus and adenovirus being the most frequently viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. In this setting, ECMO should be the first-line mechanical assistance. For highly unstable patients, a Mobile Cardiac Assistance Unit, that rapidly travels to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure takes hold, is the preferred option. PMID:23789482

  11. COMPARISON OF LIVE HIGH: TRAIN LOW ALTITUDE AND INTERMITTENT HYPOXIC EXPOSURE

    Directory of Open Access Journals (Sweden)

    Clare E. Humberstone-Gough

    2013-09-01

    Full Text Available Live High:Train Low (LHTL altitude training is a popular ergogenic aid amongst athletes. An alternative hypoxia protocol, acute (60-90 min daily Intermittent Hypoxic Exposure (IHE, has shown potential for improving athletic performance. The aim of this study was to compare directly the effects of LHTL and IHE on the running and blood characteristics of elite triathletes. Changes in total haemoglobin mass (Hbmass, maximal oxygen consumption (VO2max, velocity at VO2max (vVO2max, time to exhaustion (TTE, running economy, maximal blood lactate concentration ([La] and 3 mM [La] running speed were compared following 17 days of LHTL (240 h of hypoxia, IHE (10.2 h of hypoxia or Placebo treatment in 24 Australian National Team triathletes (7 female, 17 male. There was a clear 3.2 ± 4.8% (mean ± 90% confidence limits increase in Hbmass following LHTL compared with Placebo, whereas the corresponding change of -1.4 ± 4.5% in IHE was unclear. Following LHTL, running economy was 2.8 ± 4.4% improved compared to IHE and 3mM [La] running speed was 4.4 ± 4.5% improved compared to Placebo. After IHE, there were no beneficial changes in running economy or 3mM [La] running speed compared to Placebo. There were no clear changes in VO2max, vVO2max and TTE following either method of hypoxia. The clear difference in Hbmass response between LHTL and IHE indicated that the dose of hypoxia in IHE was insufficient to induce accelerated erythropoiesis. Improved running economy and 3mM [La] running speed following LHTL suggested that this method of hypoxic exposure may enhance performance at submaximal running speeds. Overall, there was no evidence to support the use of IHE in elite triathletes

  12. Modelling the epidemiological impact of intermittent preventive treatment against malaria in infants.

    Directory of Open Access Journals (Sweden)

    Amanda Ross

    Full Text Available BACKGROUND: Trials of intermittent preventive treatment against malaria in infants (IPTi using sulphadoxine-pyrimethamine (SP have shown a positive, albeit variable, protective efficacy against clinical malaria episodes. The impact of IPTi in different epidemiological settings and over time is unknown and predictions are hampered by the lack of knowledge about how IPTi works. We investigated mechanisms proposed for the action of IPTi and made predictions of the likely impact on morbidity and mortality. METHODS/PRINCIPAL FINDINGS: We used a comprehensive, individual-based, stochastic model of malaria epidemiology to simulate recently published trials of IPTi using SP with site-specific characteristics as inputs. This baseline model was then modified to represent hypotheses concerning the duration of action of SP, the temporal pattern of fevers caused by individual infections, potential benefits of avoiding fevers on immunity and the effect of sub-therapeutic levels of SP on parasite dynamics. The baseline model reproduced the pattern of results reasonably well. None of the models based on alternative hypotheses improved the fit between the model predictions and observed data. Predictions suggest that IPTi would have a beneficial effect across a range of transmission intensities. IPTi was predicted to avert a greater number of episodes where IPTi coverage was higher, the health system treatment coverage lower, and for drugs which were more efficacious and had longer prophylactic periods. The predicted cumulative benefits were proportionately slightly greater for severe malaria episodes and malaria-attributable mortality than for acute episodes in the settings modelled. Modest increased susceptibility was predicted between doses and following the last dose, but these were outweighed by the cumulative benefits. The impact on transmission intensity was negligible. CONCLUSIONS: The pattern of trial results can be accounted for by differences between

  13. Intermittent Hypoxia-Induced Carotid Body Chemosensory Potentiation and Hypertension Are Critically Dependent on Peroxynitrite Formation

    Directory of Open Access Journals (Sweden)

    Esteban A. Moya

    2016-01-01

    Full Text Available Oxidative stress is involved in the development of carotid body (CB chemosensory potentiation and systemic hypertension induced by chronic intermittent hypoxia (CIH, the main feature of obstructive sleep apnea. We tested whether peroxynitrite (ONOO−, a highly reactive nitrogen species, is involved in the enhanced CB oxygen chemosensitivity and the hypertension during CIH. Accordingly, we studied effects of Ebselen, an ONOO− scavenger, on 3-nitrotyrosine immunoreactivity (3-NT-ir in the CB, the CB chemosensory discharge, and arterial blood pressure (BP in rats exposed to CIH. Male Sprague-Dawley rats were exposed to CIH (5% O2, 12 times/h, 8 h/day for 7 days. Ebselen (10 mg/kg/day was administrated using osmotic minipumps and BP measured with radiotelemetry. Compared to the sham animals, CIH-treated rats showed increased 3-NT-ir within the CB, enhanced CB chemosensory responses to hypoxia, increased BP response to acute hypoxia, and hypertension. Rats treated with Ebselen and exposed to CIH displayed a significant reduction in 3-NT-ir levels (60.8 ± 14.9 versus 22.9 ± 4.2 a.u., reduced CB chemosensory response to 5% O2 (266.5 ± 13.4 versus 168.6 ± 16.8 Hz, and decreased mean BP (116.9 ± 13.2 versus 82.1 ± 5.1 mmHg. Our results suggest that CIH-induced CB chemosensory potentiation and hypertension are critically dependent on ONOO− formation.

  14. Maximal intermittent handgrip strategy: design and evaluation of an exercise protocol and a grip tool.

    Science.gov (United States)

    Bentley, Danielle Christine; Thomas, Scott Gordon

    2016-01-01

    Handgrip (HG) exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP) among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT) HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets) and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex) of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm) that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep research is a novel HG exercise strategy with enhanced accessibility by being easy to understand and simple to execute. The long-term training effectiveness of MINT as an exercise

  15. Activity and immunohistochemical localization of porphobilinogen deaminase in rat tissues

    DEFF Research Database (Denmark)

    Jørgensen, P E; Erlandsen, E J; Poulsen, Steen Seier;

    2000-01-01

    Porphobilinogen deaminase (PBGD) is an enzyme involved in the synthesis of heme. Acute intermittent porphyria (AIP) is an inherited disease resulting from a reduced activity of PBGD. The symptoms seem to be due to a neurological dysfunction. Attacks of AIP are often provoked by conditions where...... the activity and the immunohistochemical localization of PBGD in the following tissues of wistar female rats: brain, heart, submandibular gland, liver, kidney, pancreas, ovary, stomach, duodenum, jejunum, ileum, colon and musculature. The PBGD activity varied considerably among the tissues. It was highest...

  16. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    Directory of Open Access Journals (Sweden)

    Line A.

    2006-11-01

    Full Text Available Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au culot de la poche, une loi de glissement du gaz dans les bouchons et par une loi de la vitesse moyenne de propagation des fronts de poches. Le calibrage et la qualification du modèle s'appuient sur deux banques de données, dont l'une a été obtenue avec des fluides pétroliers dans des conditions proches des situations industrielles (boucle diphasique de Boussens. The model described here can be used to predetermine the pressure gradient, the overall gas rate and the characteristic intermittence magnitudes in pocket and slug flow in a vertical pipe. The way governing equations in the conditional phase average are written defines an equivalent average cell. The model is closed by film/wall, film/pocket and slug/wall shear-stress laws, by a pulloff law for the gas at the bottom of the pocket, a slippage law for the gas in the slugs, and a mean propagation velocity law for the pocket fronts. The calibration and qualification of the model are based on two data banks, one of which contains data on petroleum fluids under conditions close to industrial situations (two-phase loop at Boussens.

  17. RECURRENT SEASONAL ACUTE PSYCHOSIS

    OpenAIRE

    Agarwal, Vivek

    1999-01-01

    Acute psychoses have been reported to occur more frequently in summer. This is a report of seasonal recurrence of acute psychosis in a patient. This case report emphasizes towards the biological etiology of acute psychoses.

  18. Acute kidney failure

    Science.gov (United States)

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... To prevent acute kidney failure: Health problems such as high blood pressure or diabetes should be well controlled. Avoid drugs and medicines that can cause kidney injury.

  19. Acute cerebellar ataxia

    Science.gov (United States)

    Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Post-varicella acute cerebellar ataxia; PVACA ... Acute cerebellar ataxia in children, especially younger than age 3, may occur several weeks after an illness caused by a virus. ...

  20. Human adipocytes are highly sensitive to intermittent hypoxia induced NF-kappaB activity and subsequent inflammatory gene expression

    International Nuclear Information System (INIS)

    Highlights: • Intermittent hypoxia (IH) leads to NF-κB activation in human primary adipocytes. • Adipocytes bear higher pro-inflammatory potential than other human primary cells. • IH leads to upregulation of multiple pro-inflammatory genes in human adipocytes. - Abstract: Introduction: Intermittent hypoxia (IH)-induced activation of pro-inflammatory pathways is a major contributing factor to the cardiovascular pathophysiology associated with obstructive sleep apnea (OSA). Obesity is commonly associated with OSA although it remains unknown whether adipose tissue is a major source of inflammatory mediators in response to IH. The aim of this study was to test the hypothesis that IH leads to augmented inflammatory responses in human adipocytes when compared to cells of non-adipocyte lineages. Methods and results: Human primary subcutaneous and visceral adipocytes, human primary microvascular pulmonary endothelial cells (HUMEC-L) and human primary small airway epithelial cells (SAEC) were exposed to 0, 6 or 12 cycles of IH or stimulated with tumor necrosis factor (TNF)-α. IH led to a robust increase in NF-κB DNA-binding activity in adipocytes compared with normoxic controls regardless of whether the source of adipocytes was visceral or subcutaneous. Notably, the NF-κB response of adipocytes to both IH and TNF-α was significantly greater than that in HUMEC-L and SAEC. Western blotting confirmed enhanced nuclear translocation of p65 in adipocytes in response to IH, accompanied by phosphorylation of I-κB. Parallel to p65 activation, we observed a significant increase in secretion of the adipokines interleukin (IL)-8, IL-6 and TNF-α with IH in adipocytes accompanied by significant upregulation of mRNA expression. PCR-array suggested profound influence of IH on pro-inflammatory gene expression in adipocytes. Conclusion: Human adipocytes demonstrate strong sensitivity to inflammatory gene expression in response to acute IH and hence, adipose tissue may be a key

  1. Human adipocytes are highly sensitive to intermittent hypoxia induced NF-kappaB activity and subsequent inflammatory gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Cormac T. [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Kent, Brian D.; Crinion, Sophie J.; McNicholas, Walter T. [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Pulmonary and Sleep Disorders Unit, St. Vincent’s University Hospital, Dublin (Ireland); Ryan, Silke, E-mail: silke.ryan@ucd.ie [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Pulmonary and Sleep Disorders Unit, St. Vincent’s University Hospital, Dublin (Ireland)

    2014-05-16

    Highlights: • Intermittent hypoxia (IH) leads to NF-κB activation in human primary adipocytes. • Adipocytes bear higher pro-inflammatory potential than other human primary cells. • IH leads to upregulation of multiple pro-inflammatory genes in human adipocytes. - Abstract: Introduction: Intermittent hypoxia (IH)-induced activation of pro-inflammatory pathways is a major contributing factor to the cardiovascular pathophysiology associated with obstructive sleep apnea (OSA). Obesity is commonly associated with OSA although it remains unknown whether adipose tissue is a major source of inflammatory mediators in response to IH. The aim of this study was to test the hypothesis that IH leads to augmented inflammatory responses in human adipocytes when compared to cells of non-adipocyte lineages. Methods and results: Human primary subcutaneous and visceral adipocytes, human primary microvascular pulmonary endothelial cells (HUMEC-L) and human primary small airway epithelial cells (SAEC) were exposed to 0, 6 or 12 cycles of IH or stimulated with tumor necrosis factor (TNF)-α. IH led to a robust increase in NF-κB DNA-binding activity in adipocytes compared with normoxic controls regardless of whether the source of adipocytes was visceral or subcutaneous. Notably, the NF-κB response of adipocytes to both IH and TNF-α was significantly greater than that in HUMEC-L and SAEC. Western blotting confirmed enhanced nuclear translocation of p65 in adipocytes in response to IH, accompanied by phosphorylation of I-κB. Parallel to p65 activation, we observed a significant increase in secretion of the adipokines interleukin (IL)-8, IL-6 and TNF-α with IH in adipocytes accompanied by significant upregulation of mRNA expression. PCR-array suggested profound influence of IH on pro-inflammatory gene expression in adipocytes. Conclusion: Human adipocytes demonstrate strong sensitivity to inflammatory gene expression in response to acute IH and hence, adipose tissue may be a key

  2. Cardiometabolic complications after androgen deprivation therapy in a man with prostate cancer: effects of three years intermittent testosterone supplementation

    Directory of Open Access Journals (Sweden)

    Antonio eAversa

    2012-02-01

    Full Text Available Androgen deprivation therapy (ADT for prostate carcinoma (PCa may cause cardiometabolic complications unless intermittent androgen blockade (IAB is instituted. An 80-year-old man was diagnosed intermediate grade (Gleason 4+3 PCa and was treated with continuous ADT with triptorelin plus bicalutamide. After 6 months of treatment, he experienced an acute myocardial infarction and one month after hospitalization he came to our outpatient clinic for fatigue, weight gain and hyperglycemia. Due to iatrogenic hypogonadism, we decided to proceed with IAB, but after three months ADT withdrawal his serum testosterone (T was still 0.5 ng/mL. Due to very low concomitant PSA levels (0.1 ng/mL he was then proposed intermittent T-gel supplementation (Tostrex® which was initiated according to the following scheme: 6 months on and three months off. T-gel dose was titrated tri-weekly in order to achieve T plasma levels below 3.49 ng/mL. After six months on, his serum T raised to a mean value of 2.0 ng/mL without increments in PSA. After overall twelve months on, his serum T peaked to a mean value of 3.0 ng/mL while a delay in PSA rise was seen after 24 mo (0.6 ng/mL but remained stable until the last observation carried forward (LOCF, at 45 months. No clinical and biochemical PCa progression were observed at LOCF. Reversion of iatrogenic metabolic syndrome started after six mo of T supplementation without using any add-on treatment. This case provides support that once regression of PCa growth is attained, T supplementation may be administered in well differentiated PCa, especially if IAB is not successful in reverting iatrogenic hypogonadism and its associated cardiac and metabolic complications.

  3. EVOLUTION OF INTERMITTENCY IN THE SLOW AND FAST SOLAR WIND BEYOND THE ECLIPTIC PLANE

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzaszek, A.; Macek, W. M. [Space Research Centre, Polish Academy of Sciences, Warsaw (Poland); Echim, M. [The Belgian Institute for Space Aeronomy, Brussels (Belgium); Bruno, R., E-mail: anna.wawrzaszek@cbk.waw.pl, E-mail: marius.echim@oma.be, E-mail: macek@cbk.waw.pl, E-mail: roberto.bruno@iaps.inaf.it [Institute for Space Astrophysics and Planetology, Roma (Italy)

    2015-12-01

    We study intermittency as a departure from self-similarity of the solar wind magnetic turbulence and investigate the evolution with the heliocentric distance and latitude. We use data from the Ulysses spacecraft measured during two solar minima (1997–1998 and 2007–2008) and one solar maximum (1999–2001). In particular, by modeling a multifractal spectrum, we revealed the intermittent character of turbulence in the small-scale fluctuations of the magnetic field embedded in the slow and fast solar wind. Generally, at small distances from the Sun, in both the slow and fast solar wind, we observe the high degree of multifractality (intermittency) that decreases somewhat slowly with distance and slowly with latitude. The obtained results seem to suggest that generally intermittency in the solar wind has a solar origin. However, the fast and slow streams, shocks, and other nonlinear interactions can only be considered as the drivers of the intermittent turbulence. It seems that analysis shows that turbulence beyond the ecliptic plane evolves too slowly to maintain the intermittency with the distance and latitude. Moreover, we confirm that the multifractality and intermittency are at a lower level than in the ecliptic, as well as the existence of symmetry with respect to the ecliptic plane, suggesting that there are similar turbulent properties observed in the two hemispheres.

  4. Intermittent aeration to improve wastewater treatment efficiency in pilot-scale constructed wetland.

    Science.gov (United States)

    Uggetti, Enrica; Hughes-Riley, Theodore; Morris, Robert H; Newton, Michael I; Trabi, Christophe L; Hawes, Patrick; Puigagut, Jaume; García, Joan

    2016-07-15

    Forced aeration of horizontal subsurface flow constructed wetlands (HSSF CWs) is nowadays a recognized method to improve treatment efficiency, mainly in terms of ammonium removal. While numerous investigations have been reported testing constant aeration, scarce information can be found about the efficiency of intermittent aeration. This study aims at comparing continuous and intermittent aeration, establishing if there is an optimal regime that will increase treatment efficiency of HSSF CWs whilst minimizing the energy requirement. Full and intermittent aeration were tested in a pilot plant of three HSSF CWs (2.64m(2) each) fed with primary treated wastewater. One unit was fully aerated; one intermittently aerated (i.e. by setting a limit of 0.5mg/L dissolved oxygen within the bed) with the remaining unit not aerated as a control. Results indicated that intermittent aeration was the most successful operating method. Indeed, the coexistence of aerobic and anoxic conditions promoted by the intermittent aeration resulted in the highest COD (66%), ammonium (99%) and total nitrogen (79%) removals. On the other hand, continuous aeration promotes ammonium removal (99%), but resulted in nitrate concentrations in the effluent of up to 27mg/L. This study demonstrates the high potential of the intermittent aeration to increase wastewater treatment efficiency of CWs providing an extreme benefit in terms of the energy consumption. PMID:27062558

  5. Intermittent aeration to improve wastewater treatment efficiency in pilot-scale constructed wetland.

    Science.gov (United States)

    Uggetti, Enrica; Hughes-Riley, Theodore; Morris, Robert H; Newton, Michael I; Trabi, Christophe L; Hawes, Patrick; Puigagut, Jaume; García, Joan

    2016-07-15

    Forced aeration of horizontal subsurface flow constructed wetlands (HSSF CWs) is nowadays a recognized method to improve treatment efficiency, mainly in terms of ammonium removal. While numerous investigations have been reported testing constant aeration, scarce information can be found about the efficiency of intermittent aeration. This study aims at comparing continuous and intermittent aeration, establishing if there is an optimal regime that will increase treatment efficiency of HSSF CWs whilst minimizing the energy requirement. Full and intermittent aeration were tested in a pilot plant of three HSSF CWs (2.64m(2) each) fed with primary treated wastewater. One unit was fully aerated; one intermittently aerated (i.e. by setting a limit of 0.5mg/L dissolved oxygen within the bed) with the remaining unit not aerated as a control. Results indicated that intermittent aeration was the most successful operating method. Indeed, the coexistence of aerobic and anoxic conditions promoted by the intermittent aeration resulted in the highest COD (66%), ammonium (99%) and total nitrogen (79%) removals. On the other hand, continuous aeration promotes ammonium removal (99%), but resulted in nitrate concentrations in the effluent of up to 27mg/L. This study demonstrates the high potential of the intermittent aeration to increase wastewater treatment efficiency of CWs providing an extreme benefit in terms of the energy consumption.

  6. In-out intermittency in partial differential equation and ordinary differential equation models.

    Science.gov (United States)

    Covas, Eurico; Tavakol, Reza; Ashwin, Peter; Tworkowski, Andrew; Brooke, John M.

    2001-06-01

    We find concrete evidence for a recently discovered form of intermittency, referred to as in-out intermittency, in both partial differential equation (PDE) and ordinary differential equation (ODE) models of mean field dynamos. This type of intermittency [introduced in P. Ashwin, E. Covas, and R. Tavakol, Nonlinearity 9, 563 (1999)] occurs in systems with invariant submanifolds and, as opposed to on-off intermittency which can also occur in skew product systems, it requires an absence of skew product structure. By this we mean that the dynamics on the attractor intermittent to the invariant manifold cannot be expressed simply as the dynamics on the invariant subspace forcing the transverse dynamics; the transverse dynamics will alter that tangential to the invariant subspace when one is far enough away from the invariant manifold. Since general systems with invariant submanifolds are not likely to have skew product structure, this type of behavior may be of physical relevance in a variety of dynamical settings. The models employed here to demonstrate in-out intermittency are axisymmetric mean-field dynamo models which are often used to study the observed large-scale magnetic variability in the Sun and solar-type stars. The occurrence of this type of intermittency in such models may be of interest in understanding some aspects of such variabilities. (c) 2001 American Institute of Physics.

  7. Phosphodiesterase-5 inhibition mimics intermittent reoxygenation and improves cardioprotection in the hypoxic myocardium.

    Directory of Open Access Journals (Sweden)

    Giuseppina Milano

    Full Text Available UNLABELLED: Although chronic hypoxia is a claimed myocardial risk factor reducing tolerance to ischemia/reperfusion (I/R, intermittent reoxygenation has beneficial effects and enhances heart tolerance to I/R. AIM OF THE STUDY: To test the hypothesis that, by mimicking intermittent reoxygenation, selective inhibition of phosphodiesterase-5 activity improves ischemia tolerance during hypoxia. Adult male Sprague-Dawley rats were exposed to hypoxia for 15 days (10% O₂ and treated with placebo, sildenafil (1.4 mg/kg/day, i. p., intermittent reoxygenation (1 h/day exposure to room air or both. Controls were normoxic hearts. To assess tolerance to I/R all hearts were subjected to 30-min regional ischemia by left anterior descending coronary artery ligation followed by 3 h-reperfusion. Whereas hypoxia depressed tolerance to I/R, both sildenafil and intermittent reoxygenation reduced the infarct size without exhibiting cumulative effects. The changes in myocardial cGMP, apoptosis (DNA fragmentation, caspase-3 activity (alternative marker for cardiomyocyte apoptosis, eNOS phosphorylation and Akt activity paralleled the changes in cardioprotection. However, the level of plasma nitrates and nitrites was higher in the sildenafil+intermittent reoxygenation than sildenafil and intermittent reoxygenation groups, whereas total eNOS and Akt proteins were unchanged throughout. CONCLUSIONS: Sildenafil administration has the potential to mimic the cardioprotective effects led by intermittent reoxygenation, thereby opening the possibility to treat patients unable to be reoxygenated through a pharmacological modulation of NO-dependent mechanisms.

  8. Acute Myopericarditis Mimicking Acute Myocardial Infarction

    OpenAIRE

    Seval İzdeş; Neriman Defne Altıntaş; Gülin Karaaslan; Recep Uygun; Abdulkadir But

    2011-01-01

    Acute coronary syndromes among young adults are relatively low when compared with older population in the intensive care unit. Electrocardiographic abnormalities mimicking acute coronary syndromes may be caused by non-coronary syndromes and the differential diagnosis requires a detailed evaluation. We are reporting a case of myopericarditis presenting with acute ST elevation and elevated cardiac enzymes simulating acute coronary syndrome. In this case report, the literature is reviewed to dis...

  9. Intermittent hypoxia can aggravate motor neuronal loss and cognitive dysfunction in ALS mice.

    Directory of Open Access Journals (Sweden)

    Sung-Min Kim

    Full Text Available BACKGROUND: Patients with ALS may be exposed to variable degrees of chronic intermittent hypoxia. However, all previous experimental studies on the effects of hypoxia in ALS have only used a sustained hypoxia model and it is possible that chronic intermittent hypoxia exerts effects via a different molecular mechanism from that of sustained hypoxia. No study has yet shown that hypoxia (either chronic intermittent or sustained can affect the loss of motor neurons or cognitive function in an in vivo model of ALS. OBJECTIVE: To evaluate the effects of chronic intermittent hypoxia on motor and cognitive function in ALS mice. METHODS: Sixteen ALS mice and 16 wild-type mice were divided into 2 groups and subjected to either chronic intermittent hypoxia or normoxia for 2 weeks. The effects of chronic intermittent hypoxia on ALS mice were evaluated using the rotarod, Y-maze, and wire-hanging tests. In addition, numbers of motor neurons in the ventral horn of the spinal cord were counted and western blot analyses were performed for markers of oxidative stress and inflammatory pathway activation. RESULTS: Compared to ALS mice kept in normoxic conditions, ALS mice that experienced chronic intermittent hypoxia had poorer motor learning on the rotarod test, poorer spatial memory on the Y-maze test, shorter wire hanging time, and fewer motor neurons in the ventral spinal cord. Compared to ALS-normoxic and wild-type mice, ALS mice that experienced chronic intermittent hypoxia had higher levels of oxidative stress and inflammation. CONCLUSIONS: Chronic intermittent hypoxia can aggravate motor neuronal death, neuromuscular weakness, and probably cognitive dysfunction in ALS mice. The generation of oxidative stress with activation of inflammatory pathways may be associated with this mechanism. Our study will provide insight into the association of hypoxia with disease progression, and in turn, the rationale for an early non-invasive ventilation treatment in

  10. Intermittent hypoxia and isoniazid plus rifampicin affect hepatic ultrastructure in mice

    Institute of Scientific and Technical Information of China (English)

    WU Run-hua; ZENG Yi-ming; CHEN Xiao-yang

    2011-01-01

    Background Chronic intermittent hypoxia is the most important pathophysiologic feature of sleep apnea syndrome.The present study aimed to determine whether chronic intermittent hypoxia,which is associated with sleep apnea syndrome,can cause or increase damage to liver cell ultrastructure induced by isoniazid and rifampicin in mice.Methods Based on a 2x2 full factorial design consisting of two factors of chronic intermittent hypoxia and isoniazid plus rifampicin,32 male C57B6J mice were randomized into the control group,the chronic intermittent hypoxia group,the isoniazid plus rifampicin group,and the chronic intermittent hypoxia + isoniazid plus rifampicin group.Twelve weeks after treatment,we examined the ultrastructure of liver cells and quantitatively analyzed mitochondrial morphology in C57B6J mice.Results Chronic intermittent hypoxia did not significantly affect the ultrastructure of liver cells.The main effect of chronic intermittent hypoxia did not lead to an increase of mean profile area or mean perimeter of mitochondria,and a decrease of numerical density on area of mitochondria (all P >0.05).Isoniazid plus rifampicin significantly affected liver cell ultrastructure.The main effect of isoniazid plus rifampicin resulted in an increase of mean profile area and mean perimeter of mitochondria,and a decrease of numerical density on area of mitochondria (all P <0.05).Moreover,there was a positive interaction among the chronic intermittent hypoxia and the isoniazid plus rifampicin groups for mean profile area,mean perimeter,and numerical density on area of mitochondria (all P<0.05).Conclusion Chronic intermittent hypoxia and isoniazid plus rifampicin treatment lead to synergistic liver cell ultrastructural injury.

  11. Study of intermittent dynamics in the terrestrial foreshock using the Cluster spacecraft records

    Science.gov (United States)

    Kovács, Péter; Vadász, Gergely; Koppán, András; Vörös, Zoltán

    2014-05-01

    The paper concerns with the statistical investigation of the intermittent dynamics in the terrestrial foreshock. We use the 22.5 Hz FGM magnetic data of the four spacecraft of the Cluster mission from periods when the mission orbit traversed the solar wind (January-April in the years of 2001-2010). Intermittency is studied in terms of space and time through a sliding-window probability density function (PDF) analysis of the records. The spatial dependence of the appearance of intermittent fluctuations is monitored according to the distance from the bow shock (BS) and the angle measured between the BS normal and the IMF direction (quasi parallel and perpendicular conditions). Beside the intermittent turbulent fluctuations, the foreshock dynamics is dominated by various wave phenomena, that are, in most cases, more energetic than the turbulent activity. For this reason, a high-pass wavelet filtering is carried out on the time-series for extracting the small-amplitude intermittent fluctuations at high-frequencies. The level of intermittent fluctuations is measured through the deviation of the fourth statistical moments of the time-series increments (i.e. the flatness) from the Gaussian value, 3. Instead of temporal increments, the PDF analysis is also carried out with spatial differences among the records of the four Cluster spacecraft. In this case the Taylor hypothesis has not to be invoked in the interpretation of the obtained results. It is shown that the intermittency level measured by spatial differences decreases logarithmically with the inter-spacecraft distance. The level of intermittent fluctuations in the foreshock is studied in terms of different solar wind conditions. The strongest correlation turns out to be between the intensity of intermittent foreshock dynamics and the solar wind bulk velocity and Alfvén Mach number. The research leading to these results has received funding from the European Community's Seventh Framework Programme ([FP7

  12. Clinical study of intermittent lock of the temporomandibular joint. Relation to frequency of intermittent lock on clinical examination and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ide, Takashi; Nagai, Itaru; Miyazaki, Akihiro; Yamaguchi, Akira; Kohama, Geniku [Sapporo Medical Univ. (Japan). School of Medicine

    2002-03-01

    To examine the occurrence of intermittent lock, we investigated the correlation between the frequency of intermittent lock of the temporomandibular joint and magnetic resonance imaging (MRI) findings. The subjects consisted of 25 patients (25 joints) with unilateral intermittent lock who were treated from April 1994 through March 2000 at our department. MRI examination of the joint was performed on the affected side. We divided the patients into two groups: a high-frequency group consisting of 15 patients who had symptoms of intermittent lock every day and a low-frequency group consisting of 10 patients who did not have symptoms every day. The results showed no statistical difference between the two groups in clinical findings such as age, sex, clicking side of the joint, duration of intermittent lock, method of unlocking, muscle pain on palpation, degree of maximal mouth opening, distance between the maxillary and mandibular tooth midline, or the degree of overbite and overjet. However, the two groups differed significantly in the degree of anterior disc displacement as assessed by MRI. (author)

  13. Solar system plasma Turbulence: Observations, inteRmittency and Multifractals

    Science.gov (United States)

    Echim, Marius M.

    2016-04-01

    The FP7 project STORM is funded by the European Commission to "add value to existing data bases through a more comprehensive interpretation". STORM targets plasma and magnetic field databases collected in the solar wind (Ulysses and also some planetary missions), planetary magnetospheres (Venus Express, Cluster, a few orbits from Cassini), cometary magnetosheaths (e.g. Haley from Giotto observations). The project applies the same package of analysis methods on geomagnetic field observations from ground and on derived indices (e.g. AE, AL, AU, SYM-H). The analysis strategy adopted in STORM is built on the principle of increasing complexity, from lower (like, e.g., the Power Spectral Density - PSD) to higher order analyses (the Probability Distribution Functions - PDFs, Structure Functions - SFs, Fractals and Multifractals - MFs). Therefore STORM targets not only the spectral behavior of turbulent fluctuations but also their topology and scale behavior inferred from advanced mathematical algorithms and geometrical-like analogs. STORM started in January 2013 and ended in December 2015. We will report on a selection of scientific and technical achievements and will highlight: (1) the radial evolution of solar wind turbulence and intermittency based on Ulysses data with some contributions from Venus Express and Cluster; (2) comparative study of fast and slow wind turbulence and intermittency at solar minimum; (3) comparative study of the planetary response (Venus and Earth magnetosheaths) to turbulent solar wind; (4) the critical behavior of geomagnetic fluctuations and indices; (5) an integrated library for non-linear analysis of time series that includes all the approaches adopted in STORM to investigate solar system plasma turbulence. STORM delivers an unprecedented volume of analysed data for turbulence. The project made indeed a systematic survey, orbit by orbit, of data available from ESA repositories and Principal Investigators and provides results ordered as a

  14. Diffusion, intermittency and scaling in wave breaking turbulence

    Science.gov (United States)

    Redondo, J. M.; Mosso, C.; Marino, R.

    2009-04-01

    Measurements of 3D turbulent velocity have been made near the coast for a variety of weather conditions in the wave breaking zone, and these values have been compared with flume measurements at a 100m long wave tank. There is a strong dependence of the integral lenthscales with the Wave Reynolds number as well as with the position and the wind, quantified through the friction velocity from wind profiles measured at the coastline. Earlier results have been published in Bezerra et al. (1998) and Rodriguez et al(1999). Several effects are important and give several decades of variation of eddy diffusivities measured near the coastline (between 0.0001 and 2 m2s-1)Inman et al.(1971), Zeitler(1976). Measurements of electromagnetic and ADV velocity measurements of the Coastal wave generated turbulence are compared in order to invest the scaling and intermittency of the turbulence produced by wave breaking. The velocity measurements were performed with an array of electromagnetic sensors that could be placed along the coastline in a stainless steel sledge. Rodriguez et al.(1994,1999) showed a parabolic shape of cross-shore diffusivity values but present analysis also shows the crosshore dependence of the intermittency as well as changes in the spectral slopes. Bezerra M.O., Diez M., Medeiros C., Rodriguez A., Bahia E. Sanchez-Arcilla A. y Redondo J.M. (1998) Study on the influence of waves on coastal diffusion using image analysis Applied Scientific Research. 59, 191-204. Rodriguez A., Sanchez-Arcilla A., Redondo J.M and C. Mosso (1999) Macroturbulence measurements with electromagnetic and ultrasonic sensors: a comparison under high-turbulent flows. Experiments in Fluids, 27, 31-42. Inman, D. L.; Tait, R.J.; Nordstrom, C.E. (1971). Mixing in the surf zone. Journal of Geophysical Research, vol 76, n° 15, 3493 - 3514. Zeidler, R. B. (1976) Coastal dispersion of pollutants, Journal of the Waterways Harbors and Coastal Engineering Division, 235 - 254 p. Rodriguez, A.; Bahia

  15. Synchronization analysis of coloured delayed networks under decentralized pinning intermittent control

    Indian Academy of Sciences (India)

    JIANG SHENGQIN; LU XIAOBO

    2016-06-01

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that most of pinning intermittent controls are only appliedto the nodes from 1 to l or centralized nodes. Moreover, sufficient conditions are derived to guarantee the synchronization of coloured delayed networks based on Lyapunov stability theorem. Finally, numerical simulations are provided to verify the validity of the obtained results.

  16. Intermittent magnetic field excitation by a turbulent flow of liquid sodium

    CERN Document Server

    Nornber, M D; Kendrick, R D; Jacobson, C M; Forest, C B

    2006-01-01

    The magnetic field measured in the Madison Dynamo Experiment shows intermittent periods of growth when an axial magnetic field is applied. The geometry of the intermittent field is consistent with the fastest growing magnetic eigenmode predicted by kinematic dynamo theory using a laminar model of the mean flow. Though the eigenmodes of the mean flow are decaying, it is postulated that turbulent fluctuations of the velocity field change the flow geometry such that the eigenmode growth rate is temporarily positive. Therefore, it is expected that a characteristic of the onset of a turbulent dynamo is magnetic intermittency.

  17. Probabilistic signatures of spatiotemporal intermittency in the coupled sine circle map lattice

    Indian Academy of Sciences (India)

    Zahera Jabeen; Neelima Gupta

    2008-06-01

    The phase diagram of the coupled sine circle map system exhibits a variety of interesting phenomena including spreading regions with spatiotemporal intermittency, non-spreading regions with spatial intermittency, and coherent structures termed solitons. A spreading to non-spreading transition is seen in the system. A cellular automaton version of the coupled system maps the spreading to non-spreading transition to a transition from a probabilistic to a deterministic cellular automaton. The solitonic sector of the system shows spatiotemporal intermittency with soliton creation, propagation and absorption. A probabilistic cellular automaton mapping is set up for this sector which can identify each one of these phenomena.

  18. Measurement and mathematical model of a driver's intermittent compensatory steering control

    Science.gov (United States)

    Johns, Tim A.; Cole, David J.

    2015-12-01

    The compensatory (feedback) component of a human driver's steering control is examined. In particular, the effect of the cognitive process is studied. Model predictive control theory is used to implement models of intermittency in cognitive processing. Experiments using a fixed-base driving simulator with periodic occlusion of the visual display are used to reveal the nature of the driver's steering behaviour. An intermittent serial-ballistic control strategy is found to match the measured behaviour better than intermittent zero-order hold or continuous control. The findings may enable some insight to driver-vehicle interaction and vehicle handling qualities.

  19. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

    2015-01-01

    Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test perfor......-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion....

  20. A Prospective, Randomized, Crossover, Multicenter Study Comparing Quality of Life Using Compact versus Standard Catheters for Intermittent Self-Catheterization

    DEFF Research Database (Denmark)

    Chartier-Kastler, Emmanuel; Amarenco, Gérard; Lindbo, Lena;

    2013-01-01

    Intermittent catheterization is the recommended standard treatment for neurogenic bladder dysfunction. However, standard intermittent catheters can be unwieldy, difficult to use and carry discreetly. This can influence patient ability to perform catheterization efficiently, discreetly and private......, therefore, affecting patient quality of life. We evaluated whether the discreet design of the compact catheter would improve quality of life in intermittent catheterization users compared with standard catheters.......Intermittent catheterization is the recommended standard treatment for neurogenic bladder dysfunction. However, standard intermittent catheters can be unwieldy, difficult to use and carry discreetly. This can influence patient ability to perform catheterization efficiently, discreetly and privately...

  1. Efficient pricing and investment in electricity markets with intermittent resources

    International Nuclear Information System (INIS)

    Facing growing technological and environmental challenges, the electricity industry needs effective pricing mechanism to promote efficient risk management and investment decisions. In a restructured electricity market with competitive wholesale prices and traditionally regulated retail rates, however, there are technical and institutional barriers that prevent dynamic pricing with price responsive demand. In regions with limited energy storage capacity, intermittent renewable resources present special challenges. This could adversely affect the effectiveness of public policies causing inefficient investments in energy technologies. In this paper, we present an updated economic model of pricing and investment in restructured electricity market and use the model in a simulation study for an initial assessment of renewable energy strategy and alternative pricing mechanisms. A key objective of the study is to shed light on the policy issues so that effective decisions can be made to improve efficiency. - Highlights: → Renewable resources present special challenges in regions with limited energy storage capacity. → This paper presents an updated economic model of pricing and investment in restructured electricity market. → A simulation study assesses renewable energy strategy and alternative pricing mechanisms. → The study results inform policy decisions to improve efficient investments in energy technologies.

  2. Intermittent Oral Versus Intravenous Alfacalcidol in Dialysis Patients

    Directory of Open Access Journals (Sweden)

    Mitwalli Ahmed

    2000-01-01

    Full Text Available Patients with end-stage renal failure (ESRF on maintenance dialysis, commonly develop secondary hyperparathyroidism and renal osteodystrophy (ROD. Alfacalcidol, taken orally or administered intravenously, is known to reverse these complications. In this study, 19 ESRF patients, who were on dialysis (13 on hemodialysis and six on peritoneal dialysis for longer than six months and having serum parathormone levels at least four times normal and serum calcium less than 2.1 mmol/L, were randomly allocated to treatment with oral or intravenous (i.v. alfacalcidol for a period of 12 months. There were six patients on hemodialysis (HD and three on peritoneal dialysis (PD in the oral treatment group while in the i.v. group there were seven patients on HD and three on PD. Clinical and serial biochemical assessments showed no statistically significant difference between the orally- and i.v.-treated patients in terms of suppressing secondary hyperparathyroidism and osteodystrophy. However, patients with features of mild ROD on bone histology, had more satisfactory changes in biochemistry when compared to others. Our results further support the use of intermittent oral alfacalcidol in ESRF patients because of its cost effectiveness, ease of administration and convenience, especially for peritoneal dialysis patients.

  3. Optimal Intermittent Dose Schedules for Chemotherapy Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Nadia ALAM

    2013-08-01

    Full Text Available In this paper, a design method for optimal cancer chemotherapy schedules via genetic algorithm (GA is presented. The design targets the key objective of chemotherapy to minimize the size of cancer tumor after a predefined time with keeping toxic side effects in limit. This is a difficult target to achieve using conventional clinical methods due to poor therapeutic indices of existing anti-cancer drugs. Moreover, there are clinical limitations in treatment administration to maintain continuous treatment. Besides, carefully decided rest periods are recommended to for patient’s comfort. Three intermittent drug scheduling schemes are presented in this paper where GA is used to optimize the dose quantities and timings by satisfying several treatment constraints. All three schemes are found to be effective in total elimination of cancer tumor after an agreed treatment length. The number of cancer cells is found zero at the end of the treatment for all three cases with tolerable toxicity. Finally, two of the schemes, “Fixed interval variable dose (FIVD and “Periodic dose” that are periodic in characteristic have been emphasized due to their additional simplicity in administration along with friendliness to patients. responses to the designed treatment schedules. Therefore the proposed design method is capable of planning effective, simple, patient friendly and acceptable chemotherapy schedules.

  4. Forage production of elephant grass under intermittent stocking

    Directory of Open Access Journals (Sweden)

    Carla Silva Chaves

    2013-02-01

    Full Text Available The objective of this work was to evaluate the dry matter production of elephant grass (Pennisetum purpureum genotypes, managed under intermittent stocking. A completely randomized design was used, with two genotypes and three replicates. The treatments consisted of factorial combinations (2x2x2 of genotypes ('BRS Kurumi' and the clone CNPGL 00‑1‑3, two light interception levels (LI at the onset of grazing (90 and 95%, and two post‑grazing canopy heights (30 and 50 cm. A total of 24 Holstein x Zebu crossbred heifers were used. The stocking density varied in order to finish the grazing periods in two days. The interval between the defoliation, based on 95% LI, resulted in a higher leaf mass per grazing cycle. The post‑grazing height of 30 cm did not affect the number of grazing cycles but provided a greater herbage accumulation rate. The cultivar BRS Kurumi has higher pasture growth, lower rest period, and greater number of grazing cycles, which results in increased forage production in the growing season.

  5. A Mathematical Model of Intermittent Androgen Suppression for Prostate Cancer

    Science.gov (United States)

    Ideta, Aiko Miyamura; Tanaka, Gouhei; Takeuchi, Takumi; Aihara, Kazuyuki

    2008-12-01

    For several decades, androgen suppression has been the principal modality for treatment of advanced prostate cancer. Although the androgen deprivation is initially effective, most patients experience a relapse within several years due to the proliferation of so-called androgen-independent tumor cells. Bruchovsky et al. suggested in animal models that intermittent androgen suppression (IAS) can prolong the time to relapse when compared with continuous androgen suppression (CAS). Therefore, IAS has been expected to enhance clinical efficacy in conjunction with reduction in adverse effects and improvement in quality of life of patients during off-treatment periods. This paper presents a mathematical model that describes the growth of a prostate tumor under IAS therapy based on monitoring of the serum prostate-specific antigen (PSA). By treating the cancer tumor as a mixed assembly of androgen-dependent and androgen-independent cells, we investigate the difference between CAS and IAS with respect to factors affecting an androgen-independent relapse. Numerical and bifurcation analyses show how the tumor growth and the relapse time are influenced by the net growth rate of the androgen-independent cells, a protocol of the IAS therapy, and the mutation rate from androgen-dependent cells to androgen-independent ones.

  6. Intermittent control models of human standing: similarities and differences.

    Science.gov (United States)

    Gawthrop, Peter; Loram, Ian; Gollee, Henrik; Lakie, Martin

    2014-04-01

    Two architectures of intermittent control are compared and contrasted in the context of the single inverted pendulum model often used for describing standing in humans. The architectures are similar insofar as they use periods of open-loop control punctuated by switching events when crossing a switching surface to keep the system state trajectories close to trajectories leading to equilibrium. The architectures differ in two significant ways. Firstly, in one case, the open-loop control trajectory is generated by a system-matched hold, and in the other case, the open-loop control signal is zero. Secondly, prediction is used in one case but not the other. The former difference is examined in this paper. The zero control alternative leads to periodic oscillations associated with limit cycles; whereas the system-matched control alternative gives trajectories (including homoclinic orbits) which contain the equilibrium point and do not have oscillatory behaviour. Despite this difference in behaviour, it is further shown that behaviour can appear similar when either the system is perturbed by additive noise or the system-matched trajectory generation is perturbed. The purpose of the research is to come to a common approach for understanding the theoretical properties of the two alternatives with the twin aims of choosing which provides the best explanation of current experimental data (which may not, by itself, distinguish between the two alternatives) and suggesting future experiments to distinguish between the two alternatives. PMID:24500616

  7. Intravesical oxybutinin chloride in children with intermittent catheterization: sonographic findings.

    Science.gov (United States)

    Zerin, J M; DiPietro, M A; Ritchey, M L; Bloom, D A

    1994-01-01

    The sonographic findings in the bladder are presented in four children with myelomeningocele and neurogenic dysfunction of the bladder, who were treated with intermittent self-catheterization and intravesical oxybutinin chloride. All were referred for routine sonography of the urinary tract. Each had infused a crushed tablet of oxybutinin chloride intravesically 30-120 min before the examination. In two children, brightly echogenic, non-shadowing particles were suspended in the bladder urine. In one of these, the particles swirled giving the impression of a "snowstorm"; in the other, most of the particles gradually settled forming an irregular clump on the bladder base. In the remaining two children, the urine appeared diffusely hazy with innumerable tiny particles giving the impression of a fine mist filling the bladder. The sonographic appearance of the urine in the bladder after intravesical instillation of crushed tablets can be dramatic and can simulate pus, blood, fungus, or other debris in the bladder lumen. In the absence of clinical symptoms or hematuria, a history of recent infusion of medication into the bladder should be sought.

  8. Intermittent Brugada Syndrome Presenting with Syncope in an Adult Female

    Directory of Open Access Journals (Sweden)

    Patricia Chavez

    2014-01-01

    Full Text Available Background. Brugada syndrome accounts for 4–12% of all sudden deaths worldwide and at least 20% of sudden deaths in patients with structurally normal hearts. Case Report. A 48-year-old female presented to the emergency department after two witnessed syncopal episodes. While awaiting discharge had a third collapse followed by cardiac arrest with shockable rhythm. Initial electrocardiogram showed wide QRS complex with left axis deviation, ST-segment elevation of 2 mm followed by a negative T wave with no isoelectric separation, suggestive of spontaneous intermittent Brugada type 1 pattern. Cardiac magnetic resonance imaging demonstrated neither structural heart disease nor abnormal myocardium. After placement of an implantable cardioverter defibrillator the patient was discharged. Why should an emergency physician be aware of this? Brugada syndrome is an infrequently encountered clinical entity which may have a fatal outcome. This syndrome primarily presents with syncope. It should be considered as a component of differential diagnosis in patients with family history of syncope and sudden cardiac death.

  9. Beneficial effects of intermittent hypobaric hypoxia on the body

    Institute of Scientific and Technical Information of China (English)

    Yi ZHANG; Zhao-nian ZHOU

    2012-01-01

    Myocardial ischemia and reperfusion (I/R) is a common problem in clinic and there is no satisfactory method for prevention or treatment of I/R injury so far.Chronic intermittent hypobaric hypoxia (CIHH),similar to the concept of ischemia preconditioning(IPC)or altitude hypoxia adaptation (AHA),has been recognized to confer a protective effect on heart against I/R injury with a longer protective effect than IPC and a less adverse effect than AHA.It has been proved that CIHH increases myocardial tolerance to ischemia or hypoxia,reserving cardiac function and preventing arrhythmia during I/R.Multiple mechanisms or pathway underlying the cardiac protection of ClHH have been proposed,such as induction of heatshock protein,enhancement of myocardial antioxidation capacity,increase of coronary flow and myocardial capillary angiogenesis,activation of adenosine triphosphate (ATP)-sensitive potassium channels,inhibition of mitochondrial permeability transition pores,and activation of protein kinase C (PKC) and induced nitric oxide synthase (iNOS).In addition,CIHH has been found having many beneficial effects on the body,such as promotion of health,increase of oxygen utilization,and prevention or treatment for some diseases.The beneficial effects of ClHH and potential mechanisms are reviewed mainly based on the researches performed by our group.

  10. Movement mechanisms of gross solids in intermittent flow.

    Science.gov (United States)

    Littlewood, K; Butler, D

    2003-01-01

    Gross solids, such as used tampons, sanitary towels and faecal stools, are introduced into the sewer network via the WC. Although small diameter pipes (diameter) make up a large proportion of most sewer networks, the transport behaviour of gross solids in these smaller pipes is not fully established. In particular, there are concerns about the effect of water conservation measures on the transport of gross solids in the intermittent flow regime prevalent in small pipes. This paper introduces a study carried out on the movement of solids in this flow regime. An extensive series of experiments has been carried out to investigate the movement mechanisms and behaviour in detail. It was found that there are three different mechanisms of movement, and photographic evidence is provided in the paper. The concept and implications of the "limiting solid transport distance" is also introduced. It is argued that solid movement is dependent on factors other than just WC flush volume and that increased blockage potential is not inevitable. PMID:12666800

  11. Commercial and Industrial Base Intermittent Resource Management Pilot

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila; Sporborg, Pamela; Sheik, Imran; Huffaker, Erich; Piette, Mary Ann

    2010-11-30

    This scoping study summarizes the challenges with integrating wind and solar generation into the California's electricity grid. These challenges include: Smoothing intra-hour variability; - Absorbing excess renewable energy during over-generation periods; - Addressing morning and evening ramping periods. In addition, there are technical challenges to integrating retail demand response (DR) triggered by the wholesale conditions into the CAISO markets. The study describes the DR programs available to the consumers through the utilities in California and CAISO's ancillary services market because an integration of the wholesale and retail DR requires an understanding of these different offerings and the costs associated with acquiring them. Demand-side active and passive storage systems are proposed as technologies that may be used to mitigate the effects of intermittence due to renewable generation. Commercial building technologies as well as industrial facilities with storage capability are identified as targets for the field tests. Two systems used for ancillary services communications are identified as providing the triggers for DR enablement. Through the field tests, issues related to communication, automation and flexibility of demand-side resources will be explored and the performance of technologies that participate in the field tests will be evaluated. The major outcome of this research is identifying and defining flexibility of DR resources and optimized use of these resources to respond to grid conditions.

  12. Role of orthoptic treatment in the management of intermittent exotropia

    Directory of Open Access Journals (Sweden)

    Singh Vinita

    1992-01-01

    Full Text Available 30 patients of intermittent ACDS were studied prospectively for a period of 8 weeks to 1 year to evaluate the role of orthoptics in the management of these cases. In patients with convergence insufficiency and a maximum deviation of 25 PD or less the orthoptic treatment was found to be effective in offering symptomatic relief and improving binocular functional status. A reduction in the maximum angle of deviation by 4 PD to 8 PD was observed in 4 patients. Even though the basic angle of deviation remained unchanged in most of the patients, significant functional and symptomatic improvement was obtained in 64% to 85.7% of these cases. The long term stability of these results remains to be studied. In patients with a deviation of more than 25 PD there was no significant improvement in symptoms or reduction in maximum angle of deviation. In 6(37.5% of these patients some improvement in the fusional range could be demonstrated on the synoptophore without any symptomatic relief.

  13. A stochastic space-time model for intermittent precipitation occurrences

    KAUST Repository

    Sun, Ying

    2016-01-28

    Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

  14. Tensor-Based Link Prediction in Intermittently Connected Wireless Networks

    CERN Document Server

    Zayani, Mohamed-Haykel; Slama, Ines; Zeghlache, Djamal

    2011-01-01

    Through several studies, it has been highlighted that mobility patterns in mobile networks are driven by human behaviors. This effect has been particularly observed in intermittently connected networks like DTN (Delay Tolerant Networks). Given that common social intentions generate similar human behavior, it is relevant to exploit this knowledge in the network protocols design, e.g. to identify the closeness degree between two nodes. In this paper, we propose a temporal link prediction technique for DTN which quantifies the behavior similarity between each pair of nodes and makes use of it to predict future links. Our prediction method keeps track of the spatio-temporal aspects of nodes behaviors organized as a third-order tensor that aims to records the evolution of the network topology. After collapsing the tensor information, we compute the degree of similarity for each pair of nodes using the Katz measure. This metric gives us an indication on the link occurrence between two nodes relying on their closene...

  15. Aerodynamic surface stress intermittency and conditionally averaged turbulence statistics

    Science.gov (United States)

    Anderson, William; Lanigan, David

    2015-11-01

    Aeolian erosion is induced by aerodynamic stress imposed by atmospheric winds. Erosion models prescribe that sediment flux, Q, scales with aerodynamic stress raised to exponent, n, where n > 1 . Since stress (in fully rough, inertia-dominated flows) scales with incoming velocity squared, u2, it follows that q ~u2n (where u is some relevant component of the flow). Thus, even small (turbulent) deviations of u from its time-mean may be important for aeolian activity. This rationale is augmented given that surface layer turbulence exhibits maximum Reynolds stresses in the fluid immediately above the landscape. To illustrate the importance of stress intermittency, we have used conditional averaging predicated on stress during large-eddy simulation of atmospheric boundary layer flow over an arid, bare landscape. Conditional averaging provides an ensemble-mean visualization of flow structures responsible for erosion `events'. Preliminary evidence indicates that surface stress peaks are associated with the passage of inclined, high-momentum regions flanked by adjacent low-momentum regions. We characterize geometric attributes of such structures and explore streamwise and vertical vorticity distribution within the conditionally averaged flow field. This work was supported by the National Sci. Foundation, Phys. and Dynamic Meteorology Program (PM: Drs. N. Anderson, C. Lu, and E. Bensman) under Grant # 1500224. Computational resources were provided by the Texas Adv. Comp. Center at the Univ. of Texas.

  16. Assimilating uncertain, dynamic and intermittent streamflow observations in hydrological models

    Science.gov (United States)

    Mazzoleni, Maurizio; Alfonso, Leonardo; Chacon-Hurtado, Juan; Solomatine, Dimitri

    2015-09-01

    Catastrophic floods cause significant socio-economical losses. Non-structural measures, such as real-time flood forecasting, can potentially reduce flood risk. To this end, data assimilation methods have been used to improve flood forecasts by integrating static ground observations, and in some cases also remote sensing observations, within water models. Current hydrologic and hydraulic research works consider assimilation of observations coming from traditional, static sensors. At the same time, low-cost, mobile sensors and mobile communication devices are becoming also increasingly available. The main goal and innovation of this study is to demonstrate the usefulness of assimilating uncertain streamflow observations that are dynamic in space and intermittent in time in the context of two different semi-distributed hydrological model structures. The developed method is applied to the Brue basin, where the dynamic observations are imitated by the synthetic observations of discharge. The results of this study show how model structures and sensors locations affect in different ways the assimilation of streamflow observations. In addition, it proves how assimilation of such uncertain observations from dynamic sensors can provide model improvements similar to those of streamflow observations coming from a non-optimal network of static physical sensors. This can be a potential application of recent efforts to build citizen observatories of water, which can make the citizens an active part in information capturing, evaluation and communication, helping simultaneously to improvement of model-based flood forecasting.

  17. Intravesical oxybutinin chloride in children with intermittent catheterization: sonographic findings.

    Science.gov (United States)

    Zerin, J M; DiPietro, M A; Ritchey, M L; Bloom, D A

    1994-01-01

    The sonographic findings in the bladder are presented in four children with myelomeningocele and neurogenic dysfunction of the bladder, who were treated with intermittent self-catheterization and intravesical oxybutinin chloride. All were referred for routine sonography of the urinary tract. Each had infused a crushed tablet of oxybutinin chloride intravesically 30-120 min before the examination. In two children, brightly echogenic, non-shadowing particles were suspended in the bladder urine. In one of these, the particles swirled giving the impression of a "snowstorm"; in the other, most of the particles gradually settled forming an irregular clump on the bladder base. In the remaining two children, the urine appeared diffusely hazy with innumerable tiny particles giving the impression of a fine mist filling the bladder. The sonographic appearance of the urine in the bladder after intravesical instillation of crushed tablets can be dramatic and can simulate pus, blood, fungus, or other debris in the bladder lumen. In the absence of clinical symptoms or hematuria, a history of recent infusion of medication into the bladder should be sought. PMID:7824373

  18. Nonlinear random optical waves: Integrable turbulence, rogue waves and intermittency

    Science.gov (United States)

    Randoux, Stéphane; Walczak, Pierre; Onorato, Miguel; Suret, Pierre

    2016-10-01

    We examine the general question of statistical changes experienced by ensembles of nonlinear random waves propagating in systems ruled by integrable equations. In our study that enters within the framework of integrable turbulence, we specifically focus on optical fiber systems accurately described by the integrable one-dimensional nonlinear Schrödinger equation. We consider random complex fields having a Gaussian statistics and an infinite extension at initial stage. We use numerical simulations with periodic boundary conditions and optical fiber experiments to investigate spectral and statistical changes experienced by nonlinear waves in focusing and in defocusing propagation regimes. As a result of nonlinear propagation, the power spectrum of the random wave broadens and takes exponential wings both in focusing and in defocusing regimes. Heavy-tailed deviations from Gaussian statistics are observed in focusing regime while low-tailed deviations from Gaussian statistics are observed in defocusing regime. After some transient evolution, the wave system is found to exhibit a statistically stationary state in which neither the probability density function of the wave field nor the spectrum changes with the evolution variable. Separating fluctuations of small scale from fluctuations of large scale both in focusing and defocusing regimes, we reveal the phenomenon of intermittency; i.e., small scales are characterized by large heavy-tailed deviations from Gaussian statistics, while the large ones are almost Gaussian.

  19. SP Monitoring of Intermittent Flow Through Covered-Karst Sinkholes

    Science.gov (United States)

    Bumpus, P. B.; Kruse, S. E.

    2010-12-01

    A year of continuous SP (self-potential) monitoring was combined with high-resolution 3-D GPR surveys and intermittent water table monitoring over two small covered-karst conduits in Tampa, Florida. SP readings were logged over ~30 electrodes at 2-minute intervals. Positive and negative SP anomalies episodically manifested over conduits, suggesting that conduit flow is dynamic, not static. Three distinct SP flow regimes in the conduits are postulated: fast flow through the conduit to the underlying aquifer, slow flow to the confining layer through the collapse conduit walls, and a conduit plugged high enough to behave like the rest of the confining layer. SP responses after rain events appear to measure the effects of two wetting front curves, one striking the monitoring electrode, one the reference. By comparing curve shapes for all possible pairs of electrodes, it may be possible to establish surficial infiltration and flow patterns. SP is also strongly affected by soil conductivity, rainfall history, and cultural noise. Further concurrent study of moisture content and SP with a suite of reference electrodes placed in various topographic, vegetative, geologic, and climatic settings will help distinguish groundwater flow from other sources affecting SP measurements.

  20. Unilateral Hydronephrosis and Renal Damage after Acute Leukemia

    Directory of Open Access Journals (Sweden)

    Egle Simanauskiene

    2012-01-01

    Full Text Available A 14-year-old boy presented with asymptomatic right hydronephrosis detected on routine yearly ultrasound examination. Previously, he had at least two normal renal ultrasonograms, 4 years after remission of acute myeloblastic leukemia, treated by AML-BFM-93 protocol. A function of the right kidney and no damage on the left was confirmed by a DMSA scan. Right retroperitoneoscopic nephrectomy revealed 3 renal arteries with the lower pole artery lying on the pelviureteric junction. Histologically chronic tubulointerstitial nephritis was detected. In the pathogenesis of this severe unilateral renal damage, we suspect the exacerbation of deleterious effects of cytostatic therapy on kidneys with intermittent hydronephrosis.

  1. Intermittent observer-based consensus control for multi-agent systems with switching topologies

    Science.gov (United States)

    Xu, Xiaole; Gao, Lixin

    2016-06-01

    In this paper, we focus on the consensus problem for leaderless and leader-followers multi-agent systems with periodically intermittent control. The dynamics of each agent in the system is a linear system, and the interconnection topology among the agents is assumed to be switching. We assume that each agent can only share the outputs with its neighbours. Therefore, a class of distributed intermittent observer-based consensus protocols are proposed for each agent. First, in order to solve this problem, a parameter-dependent common Lyapunov function is constructed. Using this function, we prove that all agents can access a prescribed value, under the designed intermittent controller and observer, if there are suitable conditions on communication. Second, based on the investigation of the leader-following consensus problem, we design a new distributed intermittent observer-based protocol for each following agent. Finally, we provide an illustrative example to verify the effectiveness of the proposed approach.

  2. Maintenance immunosuppression with intermittent intravenous IL-2 receptor antibody therapy in renal transplant recipients.

    LENUS (Irish Health Repository)

    Gabardi, Steven

    2011-09-01

    To report what we believe to be the first 2 cases of long-term (>24 months) intermittent intravenous interleukin-2 receptor antibody (IL-2RA) therapy for maintenance immunosuppression following renal transplantation.

  3. Critical behavior of the Lyapunov exponent in type-III intermittency

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Llamoza, O. [Departamento de Fisica, FACYT, Universidad de Carabobo, Valencia (Venezuela); Centro de Fisica Fundamental, Grupo de Caos y Sistemas Complejos, Universidad de Los Andes, Merida 5251, Merida (Venezuela)], E-mail: llamoza@ula.ve; Cosenza, M.G. [Centro de Fisica Fundamental, Grupo de Caos y Sistemas Complejos, Universidad de Los Andes, Merida 5251, Merida (Venezuela); Ponce, G.A. [Departamento de Fisica, Universidad Nacional Autonoma de Honduras (Honduras); Departamento de Ciencias Naturales, Universidad Pedagogica Nacional Francisco Morazan, Tegucigalpa (Honduras)

    2008-04-15

    The critical behavior of the Lyapunov exponent near the transition to robust chaos via type-III intermittency is determined for a family of one-dimensional singular maps. Critical boundaries separating the region of robust chaos from the region where stable fixed points exist are calculated on the parameter space of the system. A critical exponent {beta} expressing the scaling of the Lyapunov exponent is calculated along the critical curve corresponding to the type-III intermittent transition to chaos. It is found that {beta} varies on the interval 0 {<=} {beta} < 1/2 as a function of the order of the singularity of the map. This contrasts with earlier predictions for the scaling behavior of the Lyapunov exponent in type-III intermittency. The variation of the critical exponent {beta} implies a continuous change in the nature of the transition to chaos via type-III intermittency, from a second-order, continuous transition to a first-order, discontinuous transition.

  4. Changes in pulmonary blood flow do not affect gas exchange during intermittent ventilation in resting turtles

    DEFF Research Database (Denmark)

    Wang, Tobias; Hicks, James W.

    2008-01-01

    The breathing pattern of many different air-breathing vertebrates, including lungfish, anuran amphibians, turtles, crocodiles and snakes, is characterized by brief periods of lung ventilation interspersed among apnoeas of variable duration. These intermittent ventilatory cycles are associated...

  5. Analysis of residual chlorine in simple drinking water distribution system with intermittent water supply

    Science.gov (United States)

    Goyal, Roopali V.; Patel, H. M.

    2015-09-01

    Knowledge of residual chlorine concentration at various locations in drinking water distribution system is essential final check to the quality of water supplied to the consumers. This paper presents a methodology to find out the residual chlorine concentration at various locations in simple branch network by integrating the hydraulic and water quality model using first-order chlorine decay equation with booster chlorination nodes for intermittent water supply. The explicit equations are developed to compute the residual chlorine in network with a long distribution pipe line at critical nodes. These equations are applicable to Indian conditions where intermittent water supply is the most common system of water supply. It is observed that in intermittent water supply, the residual chlorine at farthest node is sensitive to water supply hours and travelling time of chlorine. Thus, the travelling time of chlorine can be considered to justify the requirement of booster chlorination for intermittent water supply.

  6. Antibiotic Prophylaxis for Urinary Tract Infections in Children With Spina Bifida on Intermittent Catheterization

    NARCIS (Netherlands)

    Zegers, Bas; Uiterwaal, Cuno; Kimpen, Jan; van Gool, Jan; de Jong, Tom; Winkler-Seinstra, Pauline; Houterman, Saskia; Verpoorten, Carla; van Steenwijk, Catharine de Jong-de Vos

    2011-01-01

    Purpose: Antibiotic prophylaxis (low dose chemoprophylaxis) has been prescribed since the introduction of clean intermittent catheterization in children with spina bifida. We hypothesized that stopping low dose chemoprophylaxis does not increase the number of urinary tract infections in these patien

  7. Muscle involvement during intermittent contraction patterns with different target force feedback modes

    DEFF Research Database (Denmark)

    Sjøgaard, G; Jørgensen, L V; Ekner, D;

    2000-01-01

    OBJECTIVE: Assess the effect of different feedback modes during intermittent contractions on primary and assessory muscle activity. BACKGROUND: Intermittent contractions and physiological responses have been studied in laboratory settings. However, the feedback given to the subjects regarding...... the two different feedback modes. In line with this, EMG recorded from four shoulder/arm muscles analyzed for amplitude and frequency showed similar activity initially; but later, during the 30 min contraction larger amplitudes were attained during proprioceptive feedback than visual feedback. CONCLUSIONS......: Feedback mode significantly effects the muscle involvement and fatigue during intermittent contractions. RelevanceIntermittent contractions are common in many work places and various feedback modes are being given regarding work requirements. The choice of feedback may significantly affect the muscle load...

  8. Assessment of Cortical Dysfunction in Patients with Intermittent Exotropia: An fMRI Study.

    Science.gov (United States)

    Li, Qian; Bai, Junxing; Zhang, Junran; Gong, Qiyong; Liu, Longqian

    2016-01-01

    Neural imaging studies have found the connection between strabismus and brain cortex. However, the pathological mechanisms of intermittent exotropia are still not fully understood. In the present study, changes of binocular fusion related cortices in intermittent exotropia were investigated with blood oxygen level dependent functional magnetic resonance imaging. Activated cortices induced by fusion stimulus were found to be distributed in several regions such as bilateral middle occipital gyrus, bilateral middle temporal gyrus, left superior parietal lobule and so on. Compared with normal subjects, the increased activation intensity was observed in bilateral superior parietal lobule and inferior parietal lobule in subjects with intermittent exotropia. These findings indicate that binocular fusion involves a complicated brain network including several regions. And cortical activities of bilateral superior parietal lobule and inferior parietal lobule compensate for the binocular fusion dysfunction in intermittent exotropia. PMID:27501391

  9. Cardiovascular disease in obstructive sleep apnoea syndrome: the role of intermittent hypoxia and inflammation.

    LENUS (Irish Health Repository)

    Garvey, J F

    2012-02-01

    There is increasing evidence that intermittent hypoxia plays a role in the development of cardiovascular risk in obstructive sleep apnoea syndrome (OSAS) through the activation of inflammatory pathways. The development of translational models of intermittent hypoxia has allowed investigation of its role in the activation of inflammatory mechanisms and promotion of cardiovascular disease in OSAS. There are noticeable differences in the response to intermittent hypoxia between body tissues but the hypoxia-sensitive transcription factors hypoxia-inducible factor-1 and nuclear factor-kappaB appear to play a key role in mediating the inflammatory and cardiovascular consequences of OSAS. Expanding our understanding of these pathways, the cross-talk between them and the activation of inflammatory mechanisms by intermittent hypoxia in OSAS will provide new avenues of therapeutic opportunity for the disease.

  10. Exact occupation probabilities for intermittent transport and application to image correlation spectroscopy

    International Nuclear Information System (INIS)

    Intermittent transport is frequently observed in nature and has been proven to accelerate search processes at both the macroscopic (e.g., animals looking for food) and microscopic scale (e.g., protein-DNA interactions). In living cells, active transport of membrane proteins (e.g., membrane receptors) or intracellular vesicles (organelles) has been extensively studied as an example of intermittent behavior. The intermittent stochastic process is commonly analyzed in terms of first-passage probabilities. Here we derive exact occupation probabilities of intermittent active transport, making such analysis available for image correlation spectroscopy techniques. The power of this new theoretical framework is demonstrated on intracellular trafficking of lipid/DNA nanoparticles in living cells for which we were allowed to quantify switching time scales. (paper)

  11. Intermittent Transcription Dynamics for the Rapid Production of Long Transcripts of High Fidelity

    Directory of Open Access Journals (Sweden)

    Martin Depken

    2013-10-01

    Full Text Available Normal cellular function relies on the efficient and accurate readout of the genetic code. Single-molecule experiments show that transcription and replication are highly intermittent processes that are frequently interrupted by polymerases pausing and reversing directions. Although intermittent dynamics in replication are known to result from proofreading, their origin and significance during transcription remain controversial. Here, we theoretically investigate transcriptional fidelity and show that the kinetic scheme provided by the RNA-polymerase backtracking and transcript-cleavage pathway can account for measured error rates. Importantly, we find that intermittent dynamics provide an enormous increase in the rate of producing long transcripts of high fidelity. Our results imply that intermittent dynamics during transcription may have evolved as a way to mitigate the competing demands of speed and fidelity in the transcription of extended sequences.

  12. Acute plasmodium vivax malaria presenting with pancytopenia secondary to hemophagocytic syndrome: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Waleed Albaker

    2009-01-01

    Full Text Available Pancytopeni,a as an initial manifestation of acute plasmodium vivax malaria is extremely rare and mainly reported with plasmodium falciparum. We report a 37- year old Nepali patient who recently came to Saudi Arabia and presented with a three-week history of intermittent fever, chills and rigor. She was found to have spleenomegaly, pancytopenia, hyperferrtinemia, and hypofibronogenemia with positive peripheral blood smear for plasmodium vivax. The patient had a full recovery from pancytopenia with oral chloroquine.

  13. The Unpredictable Effect of Changing Cardiac Output on Hypoxemia after Acute Pulmonary Thromboembolism

    OpenAIRE

    Tsang, John Y.C.; Wayne J E Lamm; Blazej Neradilek; Polissar, Nayak L.; Michael P. Hlastala

    2008-01-01

    Previous studies reported that the degree of hypoxemia following acute pulmonary thromboembolism (APTE) was highly variable and that its mechanism was mainly due to the creation of many high and low ventilation/perfusion (V/Q) units, as a result of the heterogeneous regional blood flow (Q) caused by embolic obstruction. We studied the effect of changing cardiac output (Qt) on gas exchange after APTE in 5 embolized piglets (23 ± 3 Kg), using Dobutamine intermittently at approximately 20 µg/kg/...

  14. Quality of life and functional status after revascularization or conservative treatment in patients with intermittent claudication

    DEFF Research Database (Denmark)

    Hedeager Momsen, Anne-Mette; Bach Jensen, Martin; Norager, Charlotte Buchard;

    2011-01-01

    Revascularization of patients with intermittent claudication (IC) is recommended only for selected patients who have chronic pain or disabling disease. However, improvement in the quality of life (QoL) could justify more widespread use.......Revascularization of patients with intermittent claudication (IC) is recommended only for selected patients who have chronic pain or disabling disease. However, improvement in the quality of life (QoL) could justify more widespread use....

  15. Mean Field Theory of Sandpile Avalanches: from the Intermittent to the Continuous Flow Regime

    OpenAIRE

    Benza, V. G.; Nori, Franco; Pla, Oscar

    1993-01-01

    We model the dynamics of avalanches in granular assemblies in partly filled rotating cylinders using a mean-field approach. We show that, upon varying the cylinder angular velocity $\\omega$, the system undergoes a hysteresis cycle between an intermittent and a continuous flow regimes. In the intermittent flow regime, and approaching the transition, the avalanche duration exhibits critical slowing down with a temporal power-law divergence. Upon adding a white noise term, and close to the trans...

  16. Intermittent Cocaine Self-Administration Produces Sensitization of Stimulant Effects at the Dopamine Transporter

    OpenAIRE

    Calipari, Erin S.; Ferris, Mark J.; Siciliano, Cody A.; Zimmer, Benjamin A.; JONES, SARA R.

    2014-01-01

    Previous literature investigating neurobiological adaptations following cocaine self-administration has shown that high, continuous levels of cocaine intake (long access; LgA) results in reduced potency of cocaine at the dopamine transporter (DAT), whereas an intermittent pattern of cocaine administration (intermittent access; IntA) results in sensitization of cocaine potency at the DAT. Here, we aimed to determine whether these changes are specific to cocaine or translate to other psychostim...

  17. Trajectory Adjustments Underlying Task-Specific Intermittent Force Behaviors and Muscular Rhythms

    OpenAIRE

    Yi-Ching Chen; Yen-Ting Lin; Chien-Ting Huang; Chia-Li Shih; Zong-Ru Yang; Ing-Shiou Hwang

    2013-01-01

    Force intermittency is one of the major causes of motor variability. Focusing on the dynamics of force intermittency, this study was undertaken to investigate how force trajectory is fine-tuned for static and dynamic force-tracking of a comparable physical load. Twenty-two healthy adults performed two unilateral resistance protocols (static force-tracking at 75% maximal effort and dynamic force-tracking in the range of 50%-100% maximal effort) using the left hand. The electromyographic activi...

  18. Intermittent short ECG recording is more effective than 24-hour Holter ECG in detection of arrhythmias

    OpenAIRE

    Hendrikx, Tijn; Rosenqvist, Mårten; Wester, Per; Sandström, Herbert; Hörnsten, Rolf

    2014-01-01

    Background: Many patients report symptoms of palpitations or dizziness/presyncope. These patients are often referred for 24-hour Holter ECG, although the sensitivity for detecting relevant arrhythmias is comparatively low. Intermittent short ECG recording over a longer time period might be a convenient and more sensitive alternative. The objective of this study is to compare the efficacy of 24-hour Holter ECG with intermittent short ECG recording over four weeks to detect relevant arrhythmias...

  19. Distribution patterns of fish assemblages in an Eastern Mediterranean intermittent river

    OpenAIRE

    Vardakas L.; Kalogianni E.; Zogaris S.; Koutsikos N.; Vavalidis T.; Koutsoubas D.; Skoulikidis N. Th.

    2015-01-01

    The distribution patterns of fish assemblages within streams can provide insights for river type classifications and may warrant specific conservation actions. However, there is limited knowledge of how fish assemblages assort along a longitudinal axis in Mediterranean intermittent streams. Patterns in spatial and temporal distribution of fish communities were analysed in a Mediterranean intermittent river (Evrotas River) located in Southern Greece, hosting three endemic range restricted spec...

  20. Intermittent Water Supplies: Challenges and Opportunities for Residential Water Users in Jordan

    OpenAIRE

    Rosenberg, David E.; Talozi, Samer; Lund, Jay

    2008-01-01

    Intermittent access to improved urban water supplies is a large and expanding global problem. This paper describes 16 supply enhancement and 23 demand management actions available to urban residential water users in Jordan to cope with intermittent supplies. We characterize actions by implementation, costs, and water quantities and qualities acquired or conserved. This effort systematically identifies potential options prior to detailed study and shows that water users have significant capaci...

  1. Maternal and Cord Serum Cytokine Changes with Continuous and Intermittent Labor Epidural Analgesia: A Randomized Study

    OpenAIRE

    Mantha, Venkat R.; Vallejo, Manuel C.; Vimala Ramesh; Jones, Bobby L; Sivam Ramanathan

    2012-01-01

    Background. Maternal fever during labor epidural analgesia (LEA) may cause increased maternal and cord serum inflammatory cytokines. We report the effects of intermittent and continuous LEA on these cytokines. Methods. Ninety-two women were randomly assigned to continuous (CLEA) or intermittent (ILEA) groups, 46 in each. Maternal temperature was checked and blood drawn at epidural insertion (baseline) and four-hourly until 4 h postpartum (4 PP). Cord blood was drawn after placental delivery. ...

  2. Creatine supplementation spares muscle glycogen during high intensity intermittent exercise in rats

    OpenAIRE

    Costa André; Marquezi Marcelo; Gualano Bruno; Roschel Hamilton; Lancha Antonio H

    2010-01-01

    Abstract Background The effects of creatine (CR) supplementation on glycogen content are still debatable. Thus, due to the current lack of clarity, we investigated the effects of CR supplementation on muscle glycogen content after high intensity intermittent exercise in rats. Methods First, the animals were submitted to a high intensity intermittent maximal swimming exercise protocol to ensure that CR-supplementation was able to delay fatigue (experiment 1). Then, the CR-mediated glycogen spa...

  3. Intermittent hypoxia in childhood: the harmful consequences versus potential benefits of therapeutic uses

    Directory of Open Access Journals (Sweden)

    Tatiana V. Serebrovskaya

    2015-05-01

    Full Text Available Intermittent hypoxia often occurs in early infancy in both preterm and term infants and especially at 36 to 44 weeks postmenstrual age. These episodes of intermittent hypoxia could result from sleep-disordered breathing or may be temporally unrelated to apnea or bradycardia events. There are numerous reports indicating adverse effects of intermittent hypoxia on development, behavior, academic achievement and cognition in children with sleep apnea syndrome. It remains uncertain the exact causative relationship between the neurocognitive and behavioral morbidities and intermittent hypoxia and/or its associated sleep fragmentation. On the other hand, well-controlled and moderate intermittent hypoxia conditioning/training has been used in sick children for treating their various forms of bronchial asthma, allergic dermatoses, autoimmune thyroiditis, cerebral palsy, and obesity. This review article provides an updated and impartial analysis on the currently available evidence in supporting either side of the seemingly contradictory scenarios. We wish to stimulate a comprehensive understanding of such a complex physiological phenomenon as intermittent hypoxia, which may be accompanied by other confounding factors (e.g. hypercapnia, polycythemia, in order to prevent or reduce its harmful consequences, while maximize its potential utility as an effective therapeutic tool in pediatric patients.

  4. Nitrogen removal in the bioreactor landfill system with intermittent aeration at the top of landfilled waste

    Energy Technology Data Exchange (ETDEWEB)

    He Ruo [College of Environment and Resource, Zhejiang University, Hangzhou 310029 (China)]. E-mail: heruo@zju.edu.cn; Shen Dongsheng [College of Environment and Resource, Zhejiang University, Hangzhou 310029 (China)

    2006-08-25

    High ammonia concentration of recycled landfill leachate makes it very difficult to treat. In this work, a vertical aerobic/anoxic/anaerobic lab-scale bioreactor landfill system, which was constructed by intermittent aeration at the top of landfilled waste, as a bioreactor for in situ nitrogen removal was investigated during waste stabilization. Intermittent aeration at the top of landfilled waste might stimulate the growth of nitrifying bacteria and denitrifying bacteria in the top and middle layers of waste. The nitrifying bacteria population for the landfill bioreactor with intermittent aeration system reached between10{sup 6} and 10{sup 8} cells/dry g waste, although it decreased 2 orders of magnitude on day 30, due to the inhibitory effect of the acid environment and high organic matter in the landfilled waste. The denitrifying bacteria population increased by between 4 and 13 orders of magnitude compared with conventional anaerobic landfilled waste layers. Leachate NO{sub 3} {sup -}-N concentration was very low in both two experimental landfill reactors. After 105 days operation, leachate NH{sub 4} {sup +}-N and TN concentrations for the landfill reactor with intermittent aeration system dropped to 186 and 289 mg/l, respectively, while they were still kept above 1000 mg/l for the landfill reactor without intermittent aerobic system. In addition, there is an increase in the rate of waste stabilization as well as an increase of 12% in the total waste settlement for the landfill reactor with intermittent aeration system.

  5. Statistical randomization test for QCD intermittency in a single-event distribution

    CERN Document Server

    Peterson, L E

    2004-01-01

    A randomization test was developed to determine the statistical significance of QCD intermittency in single-event distributions. A total of 96 simulated intermittent distributions based on standard normal Gaussian distributions of size N=500, 1000, 1500, 2000, 4000, 8000, 16000, and 32000 containing induced holes and spikes were tested for intermittency. Non-intermittent null distributions were also simulated as part of the test. A log-linear model was developed to simultaneously test the significance of fit coefficients for the y-intercept and slope contribution to ln(F_2) vs. ln(M) from both the intermittent and null distributions. Statistical power was also assessed for each fit coefficient to reflect the proportion of times out of 1000 tests each coefficient was statistically significant, given the induced effect size and sample size of the Gaussians. Results indicate that the slope of ln(F_2) vs. ln(M) for intermittent distributions increased with decreasing sample size, due to artificially-induced holes...

  6. Intermittent hypoxia training protects cerebrovascular function in Alzheimer's disease.

    Science.gov (United States)

    Manukhina, Eugenia B; Downey, H Fred; Shi, Xiangrong; Mallet, Robert T

    2016-06-01

    Alzheimer's disease (AD) is a leading cause of death and disability among older adults. Modifiable vascular risk factors for AD (VRF) include obesity, hypertension, type 2 diabetes mellitus, sleep apnea, and metabolic syndrome. Here, interactions between cerebrovascular function and development of AD are reviewed, as are interventions to improve cerebral blood flow and reduce VRF. Atherosclerosis and small vessel cerebral disease impair metabolic regulation of cerebral blood flow and, along with microvascular rarefaction and altered trans-capillary exchange, create conditions favoring AD development. Although currently there are no definitive therapies for treatment or prevention of AD, reduction of VRFs lowers the risk for cognitive decline. There is increasing evidence that brief repeated exposures to moderate hypoxia, i.e. intermittent hypoxic training (IHT), improve cerebral vascular function and reduce VRFs including systemic hypertension, cardiac arrhythmias, and mental stress. In experimental AD, IHT nearly prevented endothelial dysfunction of both cerebral and extra-cerebral blood vessels, rarefaction of the brain vascular network, and the loss of neurons in the brain cortex. Associated with these vasoprotective effects, IHT improved memory and lessened AD pathology. IHT increases endothelial production of nitric oxide (NO), thereby increasing regional cerebral blood flow and augmenting the vaso- and neuroprotective effects of endothelial NO. On the other hand, in AD excessive production of NO in microglia, astrocytes, and cortical neurons generates neurotoxic peroxynitrite. IHT enhances storage of excessive NO in the form of S-nitrosothiols and dinitrosyl iron complexes. Oxidative stress plays a pivotal role in the pathogenesis of AD, and IHT reduces oxidative stress in a number of experimental pathologies. Beneficial effects of IHT in experimental neuropathologies other than AD, including dyscirculatory encephalopathy, ischemic stroke injury, audiogenic

  7. Recommendations for Refinement and Validation of Intermittent Artificial Gravity

    Science.gov (United States)

    Young, Lauren R.; Paloski, William H.

    2007-01-01

    The IMAG Pilot Study, recently completed at the University of Texas Medical Branch, filled in the second major gap in knowledge standing in the way of development of a practical Short Radius Centrifuge (SRC) and the use of Artificial Gravity (AG) as a multi-system countermeasure to combat the deconditioning associated with extended weightlessness. (The first challenge, to adapt rapidly rotating subjects to permit unlimited head movements without excessive motion sickness, was achieved in a series of studies at MIT involving incremental increases in head and centrifuge velocity.) It remained to be demonstrated that intermittent exposure to AG, at only one hour per day for 21 days, would have any positive effect on slowing or eliminating of deconditioning. Bed-rested normal subjects were used as a ground analog for astronauts in weightlessness. The results are clearly positive for the key physiological systems of interest: cardiovascular, muscle, and bone. No functionally relevant changes were observed in immune, cognitive, or sensory-motor function. Furthermore, we found that our initial concerns about the inability of deconditioned subjects to withstand daily centrifugation without syncope were misplaced. These encouraging initial results clearly support the further development of AG protocols. We recommend, as the next steps, the integration of a controlled exercise device on the SRC to determine the synergy between AG and exercise. Coupled with appropriate exercise device(s) the AG protocol will be tuned to-ward an optimal prescription for minimum exposure duration and frequency, maximum AG level and SRC speed.. Performance of these next steps will require extensive use of bed-rest/centrifuge facilities and eventually validation using an SRC in space. A space SRC could be placed in the ISS or on a planetary surface.

  8. Characterizing the Drivers of Intermittent Flow in Arctic Alaska Streams

    Science.gov (United States)

    Betts, E.; Kane, D. L.; Stephan, N.

    2012-12-01

    Fish and wildlife species in the Arctic have developed life history strategies to deal with the extreme climate of the North. In the case of Arctic grayling, these strategies include long life, yearly spawning and migration.. In order to understand how such a species will be affected by a changing climate, we must first determine how these adaptive strategies may be at odds with the changing Arctic landscape. Arctic grayling migrate to spawning grounds just after spring break-up; then they migrate to feeding sites in early summer and finally in the fall migrate back to their overwintering sites. Low precipitation and high evapotranspiration rates during the summer can lead to low water levels and a fragmentation of the hydrologic landscape. This fragmentation creates a barrier to fish migration. The Kuparuk River is a perennial stream originating in the foothills of the Brooks Range on the North Slope of Alaska. The basin is underlain by continuous permafrost which essentially blocks the surface system from interacting with the subpermafrost groundwater system. Shallow subsurface flow occurs in the active layer, that area above permafrost which undergoes seasonal thawing in the summer. Sections of the Kuparuk are intermittent in that during low flows in the system these reaches appear dry (no flow in channel). Water reappears in the channel, downstream of these dry reaches, and it is believed that water continues to flow below the surface through the unfrozen thaw bulb beneath these reaches. These dry reaches act as summer barriers to fish migration within the Kuparuk River system. Previous research of this phenomenon sought to understand the location and timing of these dry events. The current research to be presented here attempts to determine the drivers of these dry channel events. Dye tracers and discharge measurements are used to determine the amount of hyporheic flow along these dry reaches and a statistical model incorporating soil moisture, precipitation

  9. The efficacy of antihypertensive drugs in chronic intermittent hypoxia conditions.

    Science.gov (United States)

    Diogo, Lucilia N; Monteiro, Emília C

    2014-01-01

    Sleep apnea/hypopnea disorders include centrally originated diseases and obstructive sleep apnea (OSA). This last condition is renowned as a frequent secondary cause of hypertension (HT). The mechanisms involved in the pathogenesis of HT can be summarized in relation to two main pathways: sympathetic nervous system stimulation mediated mainly by activation of carotid body (CB) chemoreflexes and/or asphyxia, and, by no means the least important, the systemic effects of chronic intermittent hypoxia (CIH). The use of animal models has revealed that CIH is the critical stimulus underlying sympathetic activity and hypertension, and that this effect requires the presence of functional arterial chemoreceptors, which are hyperactive in CIH. These models of CIH mimic the HT observed in humans and allow the study of CIH independently without the mechanical obstruction component. The effect of continuous positive airway pressure (CPAP), the gold standard treatment for OSA patients, to reduce blood pressure seems to be modest and concomitant antihypertensive therapy is still required. We focus this review on the efficacy of pharmacological interventions to revert HT associated with CIH conditions in both animal models and humans. First, we explore the experimental animal models, developed to mimic HT related to CIH, which have been used to investigate the effect of antihypertensive drugs (AHDs). Second, we review what is known about drug efficacy to reverse HT induced by CIH in animals. Moreover, findings in humans with OSA are cited to demonstrate the lack of strong evidence for the establishment of a first-line antihypertensive regimen for these patients. Indeed, specific therapeutic guidelines for the pharmacological treatment of HT in these patients are still lacking. Finally, we discuss the future perspectives concerning the non-pharmacological and pharmacological management of this particular type of HT. PMID:25295010

  10. The efficacy of antihypertensive drugs in chronic intermittent hypoxia conditions

    Directory of Open Access Journals (Sweden)

    Lucilia Neves Diogo

    2014-09-01

    Full Text Available Sleep apnea/hypopnea disorders include centrally originated diseases and obstructive sleep apnea (OSA. This last condition is renowned as a frequent secondary cause of hypertension (HT. The mechanisms involved in the pathogenesis of HT can be summarized in relation to two main pathways: sympathetic nervous system stimulation mediated mainly by activation of carotid body (CB chemoreflexes and/or asphyxia, and, by no means the least important, the systemic effects of chronic intermittent hypoxia (CIH. The use of animal models has revealed that CIH is the critical stimulus underlying sympathetic activity and hypertension, and that this effect requires the presence of functional arterial chemoreceptors, which are hyperactive in CIH. These models of CIH mimic the HT observed in humans and allow the study of CIH independently without the mechanical obstruction component. The effect of continuous positive airway pressure, the gold standard treatment for OSA patients, to reduce blood pressure seems to be modest and concomitant antihypertensive therapy is still required. We focus this review on the efficacy of pharmacological interventions to revert HT associated with CIH conditions in both animal models and humans. First, we explore the experimental animal models, developed to mimic HT related to CIH, which have been used to investigate the effect of antihypertensive drugs (AHDs. Second, we review what is known about drug efficacy to reverse HT induced by CIH in animals. Moreover, findings in humans with OSA are cited to demonstrate the lack of strong evidence for the establishment of a first-line antihypertensive regimen for these patients. Indeed, specific therapeutic guidelines for the pharmacological treatment of HT in these patients are still lacking. Finally, we discuss the future perspectives concerning the non-pharmacological and pharmacological management of this particular type of HT.

  11. Acute sensorineural hearing loss and severe otalgia due to scrub typhus

    Directory of Open Access Journals (Sweden)

    Kim Dong-Min

    2009-10-01

    Full Text Available Abstract Background Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. Case presentations We encountered a patient with sensorineural hearing loss complicating scrub typhus, and three patients with scrub typhus who complained of otalgia, which was sudden onset, severe, paroxysmal, intermittent yet persistent pain lasting for several seconds, appeared within 1 week after the onset of fever and rash. The acute sensorineural hearing loss and otalgia were resolved after antibiotic administration. Conclusion When patients in endemic areas present with fever and rash and have sensorineural hearing loss or otalgia without otoscopic abnormalities, clinicians should suspect scrub typhus and consider empirical antibiotic therapy.

  12. Acute chylous peritonitis due to acute pancreatitis

    OpenAIRE

    2012-01-01

    We report a case of acute chylous ascites formation presenting as peritonitis (acute chylous peritonitis) in a patient suffering from acute pancreatitis due to hypertriglyceridemia and alcohol abuse. The development of chylous ascites is usually a chronic process mostly involving malignancy, trauma or surgery, and symptoms arise as a result of progressive abdominal distention. However, when accumulation of “chyle” occurs rapidly, the patient may present with signs of peritonitis. Preoperative...

  13. Intermittent Hypoxia Affects the Spontaneous Differentiation In Vitro of Human Neutrophils into Long-Lived Giant Phagocytes

    Directory of Open Access Journals (Sweden)

    Larissa Dyugovskaya

    2016-01-01

    Full Text Available Previously we identified, for the first time, a new small-size subset of neutrophil-derived giant phagocytes (Gϕ which spontaneously develop in vitro without additional growth factors or cytokines. Gϕ are CD66b+/CD63+/MPO+/LC3B+ and are characterized by extended lifespan, large phagolysosomes, active phagocytosis, and reactive oxygen species (ROS production, and autophagy largely controls their formation. Hypoxia, and particularly hypoxia/reoxygenation, is a prominent feature of many pathological processes. Herein we investigated Gϕ formation by applying various hypoxic conditions. Chronic intermittent hypoxia (IH (29 cycles/day for 5 days completely abolished Gϕ formation, while acute IH had dose-dependent effects. Exposure to 24 h (56 IH cycles decreased their size, yield, phagocytic ability, autophagy, mitophagy, and gp91-phox/p22-phox expression, whereas under 24 h sustained hypoxia (SH the size and expression of LC3B and gp91-phox/p22-phox resembled Gϕ formed in normoxia. Diphenyl iodide (DPI, a NADPH oxidase inhibitor, as well as the PI3K/Akt and autophagy inhibitor LY294002 abolished Gϕ formation at all oxygen conditions. However, the potent antioxidant, N-acetylcysteine (NAC abrogated the effects of IH by inducing large CD66b+/LC3B+ Gϕ and increased both NADPH oxidase expression and phagocytosis. These findings suggest that NADPH oxidase, autophagy, and the PI3K/Akt pathway are involved in Gϕ development.

  14. High-flow priapism in acute lymphatic leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Mentzel, Hans-Joachim; Vogt, Susanna; Kaiser, Werner A. [Institute of Diagnostic and Interventional Radiology, Department of Pediatric Radiology, Friedrich-Schiller-Universitaet Jena, Bachstrasse 18, 07740, Jena (Germany); Kentouche, Karim; Doerfel, Claus; Zintl, Felix [Department of Paediatrics, University of Jena (Germany)

    2004-07-01

    Priapism is defined as prolonged and persistent erection of the penis without sexual stimulation. It is associated with excessive hyperleukocytosis (e.g. in acute or chronic leukaemia); however, this complication is rarely seen in the pediatric population. We report a 12-year-old boy suffering from acute leukaemia presenting with, at first intermittent, but increasingly persistent erection. Doppler US revealed signs of high-flow priapism. MRI excluded intrapelvic tumour masses, and three-dimensional contrast-enhanced MR angiography could not demonstrate an arteriovenous fistula or thrombosis. Cavernosal blood-gas measurement was in agreement with high-flow priapism. On the basis of the imaging findings, invasive therapeutic management was avoided in our patient with a successful outcome. (orig.)

  15. Renal replacement therapy in sepsis-induced acute renal failure

    Directory of Open Access Journals (Sweden)

    Rajapakse Senaka

    2009-01-01

    Full Text Available Acute renal failure (ARF is a common complication of sepsis and carries a high mortality. Renal replacement therapy (RRT during the acute stage is the mainstay of therapy. Va-rious modalities of RRT are available. Continuous RRT using convective methods are preferred in sepsis-induced ARF, especially in hemodynamically unstable patients, although clear evidence of benefit over intermittent hemodialysis is still not available. Peritoneal dialysis is clearly inferior, and is not recommended. Early initiation of RRT is probably advantageous, although the optimal timing of dialysis is yet unknown. Higher doses of RRT are more likely to be beneficial. Use of bio-compatible membranes and bicarbonate buffer in the dialysate are preferred. Anticoagulation during dialysis must be carefully adjusted and monitored.

  16. Pentoxifylline Treatment in Acute Pancreatitis (AP)

    Science.gov (United States)

    2016-09-14

    Acute Pancreatitis (AP); Gallstone Pancreatitis; Alcoholic Pancreatitis; Post-ERCP/Post-procedural Pancreatitis; Trauma Acute Pancreatitis; Hypertriglyceridemia Acute Pancreatitis; Idiopathic (Unknown) Acute Pancreatitis; Medication Induced Acute Pancreatitis; Cancer Acute Pancreatitis; Miscellaneous (i.e. Acute on Chronic Pancreatitis)

  17. Maximal intermittent handgrip strategy: design and evaluation of an exercise protocol and a grip tool

    Directory of Open Access Journals (Sweden)

    Bentley DC

    2016-05-01

    Full Text Available Danielle Christine Bentley, Scott Gordon Thomas Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada Abstract: Handgrip (HG exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep

  18. Intermittent ethanol consumption depresses endocannabinoid-signaling in the dorsolateral striatum of rat.

    Science.gov (United States)

    Adermark, Louise; Jonsson, Susanne; Ericson, Mia; Söderpalm, Bo

    2011-12-01

    Recent research suggests that adaptations elicited by drugs of abuse share common features with traditional learning models, and that drugs of abuse cause long-term changes in behavior by altering synaptic function and plasticity. In this study, endocannabinoid (eCB) signaling in the dorsolateral striatum, a brain region vital for habit formation, was evaluated in acutely isolated brain slices from ethanol (EtOH)-consuming rats and control rats. EtOH-consuming rats had free access to a 20% EtOH solution for three 24 hour sessions a week during seven weeks and consumed an average of 3.4 g/kg per session. eCB-mediated long-lasting disinhibition (DLL) of population spike (PS) amplitude induced by moderate frequency stimulation was impaired in EtOH-consuming rats, and was not restored by the muscarinic receptor antagonist scopolamine (10 μM). The lack of DLL could be linked to a reduced GABA(A) receptor tone, since bicuculline-mediated disinhibition of striatal output was significantly reduced in slices from EtOH-consuming rats. However, eCB signaling induced by high frequency stimulation (HFS) was also impaired in slices from EtOH-consuming rats and isolated control rats. Activation of presynaptic cannabinoid 1 receptors (CB1R) with WIN55,212-2 (250 nM, 1 μM) significantly modulated PS amplitude in slices from age-matched control rats while slices from EtOH-consuming rats remained unaffected, indicating that eCB signaling is inhibited at a level that is downstream from CB1R activation. Intermittent alcohol intake for seven weeks might thus be sufficient to modulate a presynaptic mechanism that needs to be synergized with CB1R activation for induction of long-term depression (LTD). In conclusion, alcohol consumption inhibits striatal eCB signaling in a way that could be of importance for understanding the neurological underpinnings of addictive behavior. PMID:21251919

  19. Challenges of treating a 466-kilogram man with acute kidney injury.

    Science.gov (United States)

    Friedman, Allon N; Decker, Brian; Seele, Louis; Hellman, Richard N

    2008-07-01

    Caring for super obese patients (body mass index > 50 kg/m(2)) presents a number of complex and unique clinical challenges, particularly when acute kidney injury is present. We describe our experience treating the heaviest individual with acute kidney injury requiring renal replacement therapy reported to date. A 24-year-old black man was admitted to our hospital with fever, vomiting, progressive weakness, shortness of breath, and hemoptysis. Admission weight was 1,024 lbs (466 kg), height was 6 ft 4 in (1.9 m), and body mass index was 125 kg/m(2). During hospitalization, the patient experienced oligoanuric acute kidney injury and required initiation of continuous and subsequently intermittent renal replacement therapy. This clinical scenario identifies the many challenges involved in caring for super obese patients with acute kidney injury and may be a harbinger of what awaits the nephrology community in the obesity pandemic era.

  20. Intermittent selective clamping improves rat liver regeneration by attenuating oxidative and endoplasmic reticulum stress.

    Science.gov (United States)

    Ben Mosbah, I; Duval, H; Mbatchi, S-F; Ribault, C; Grandadam, S; Pajaud, J; Morel, F; Boudjema, K; Compagnon, P; Corlu, A

    2014-01-01

    Intermittent clamping of the portal trial is an effective method to avoid excessive blood loss during hepatic resection, but this procedure may cause ischemic damage to liver. Intermittent selective clamping of the lobes to be resected may represent a good alternative as it exposes the remnant liver only to the reperfusion stress. We compared the effect of intermittent total or selective clamping on hepatocellular injury and liver regeneration. Entire hepatic lobes or only lobes to be resected were subjected twice to 10 min of ischemia followed by 5 min of reperfusion before hepatectomy. We provided evidence that the effect of intermittent clamping can be damaging or beneficial depending to its mode of application. Although transaminase levels were similar in all groups, intermittent total clamping impaired liver regeneration and increased apoptosis. In contrast, intermittent selective clamping improved liver protein secretion and hepatocyte proliferation when compared with standard hepatectomy. This beneficial effect was linked to better adenosine-5'-triphosphate (ATP) recovery, nitric oxide production, antioxidant activities and endoplasmic reticulum adaptation leading to limit mitochondrial damage and apoptosis. Interestingly, transient and early chaperone inductions resulted in a controlled activation of the unfolded protein response concomitantly to endothelial nitric oxide synthase, extracellular signal-regulated kinase-1/2 (ERK1/2) and p38 MAPK activation that favors liver regeneration. Endoplasmic reticulum stress is a central target through which intermittent selective clamping exerts its cytoprotective effect and improves liver regeneration. This procedure could be applied as a powerful protective modality in the field of living donor liver transplantation and liver surgery. PMID:24603335