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Sample records for chronic intermittent materno-fetal

  1. MATERNO-FETAL IMMUNOTOLERANCE: AN EVOLUTIONARY VIEW

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    Luana Paulesu

    2013-12-01

    Full Text Available Since Medawar (1953, much attention has been given to the immunological paradox of the survival and growth of the semi-allogeneic fetus in the maternal uterus. Numerous studies, mainly on the human placenta, have established fundamental mechanisms of this phenomenon; however, many aspects are still unclear and the complex process has yet to be completely defined. One of the accepted principles is that the secretion and action of mediators, i.e. cytokines, at the materno-fetal interface have a central role. Focusing on the cytokine Interleukin-1 (IL-1 the review highlights the importance of a physiological approach based on evolutionary studies in animals using similar or different reproductive strategies. Data on IL-1 in viviparity and oviparity, two reproductive strategies in which female reproductive tissues have to deal with paternal-derived antigens on sperm, fertilized eggs, and embryo, will be presented and discussed in the light of materno-fetal immuntolerance. Ovuliparity, a reproductive modality in which the eggs are released from the female reproductive tract and fertilization and embryonic development take place in the external environment will also be extensively reported as a negative control in the studies on materno-fetal immunotolerance. The evidence shown reveals that non-mammalian vertebrates with different reproductive strategies represent a good model to understand biological mechanisms allowing fetal acceptance and growth in the maternal tissues.

  2. Vinculação da gestante e apego materno fetal

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    Eluisa Bordin Schmidt

    2009-08-01

    Full Text Available Este trabalho verificou as relações existentes entre o tipo de vinculação da gestante, sintomas de ansiedade, depressão e nível de apego materno fetal. Participaram 136 gestantes entre 18 e 42 anos de idade, do 6º ao 9º mês de gestação com escolaridade mínima de 5ª série. Foi realizado um estudo quantitativo, transversal, correlacional. Os instrumentos utilizados foram: Ficha de Dados Sociodemográficos, Escala de Vinculação do Adulto (EVA, Escala de Apego Materno Fetal (MFAS, Inventário de Depressão de Beck (BDI e Inventário de Ansiedade de Beck (BAI. A análise dos dados foi realizada por meio de estatística descritiva, teste exato de Fischer, simulações de Monte Carlo e Correlação de Pearson. Os resultados indicaram que existe associação significativa entre o tipo de vinculação da gestante e o apego materno fetal, e sintomas depressivos. As gestantes que apresentaram uma vinculação segura evidenciaram apego materno fetal alto e sintomas depressivos e ansiosos mínimos.

  3. Efeitos da ingestão de glicose sobre a circulação materno-fetal Materno-fetal hemodynamic repercussion of glucose ingestion

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    Rose Mary de Castro Ranciaro

    2006-12-01

    Full Text Available OBJETIVOS: analisar o efeito da glicose na hemodinâmica materno-fetal pela avaliação doplervelocimétrica da circulação materno-fetal e fetoplacentária. MÉTODOS: trata-se de estudo realizado por único observador, no qual foram incluídas 31 gestantes clinicamente sadias entre a 28ª e a 36ª semana. Os parâmetros foram avaliados imediatamente antes e 60 minutos após a ingestão de 50 g de glicose. Foram utilizados como critérios de inclusão a avaliação clínica e laboratorial normal, a presença de feto único, a idade gestacional entre a 28ª e a 36ª semana de gestação confirmada por exame de ultra-sonografia e/ou a data da última menstruação, a glicemia de jejum menor ou igual a 110 mg/dL e o teste de sobrecarga após 50 g de glicose menor de 140 mg/dL. Como critérios de exclusão, adotaram-se a presença de malformação ou alterações de desenvolvimento fetal, o trabalho de parto, os antecedentes familiares de diabetes, as patologias próprias ou intercorrentes à gestação e o uso de fumo, álcool ou outras drogas. Foram avaliados os vasos maternos da artéria carótida comum e artérias uterinas, os vasos placentários da artéria umbilical e os vasos fetais da artéria cerebral média e aorta abdominal. Foram analisados os seguintes parâmetros em cada vaso: índice de resistência, índice de pulsatilidade, velocidade sistólica máxima, velocidade diastólica final e tempo de aceleração. A freqüência cardíaca fetal foi avaliada pelo modo M da ultra-sonografia. Para análise estatística foi utilizado o teste t de Student quando a variável diferença de antes e depois da ingestão de glicose apresentou distribuição normal no teste de Kolmogorov-Smirnov. Quando a normalidade foi rejeitada, utilizamos o teste não-paramétrico de Wilcoxon, com o nível de significância sempre estabelecido de pPURPOSE: to analyze the effect of glucose in the materno-fetal hemodynamics through dopplervelocimetric assessment of

  4. Análise morfológica dos fígados e rins no binômio materno-fetal após tratamento de ratas prenhes com Ritonavir durante toda a prenhez Morphological analysis of liver and kidneys of pregnant rats and their fetuses upon chronic Ritonavir administration

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    Adelino Moreira de Carvalho

    2007-07-01

    Full Text Available OBJETIVO: avaliar os efeitos da administração crônica de três diferentes doses de Ritonavir nos fígados e rins de ratas prenhes e seus conceptos do ponto de vista morfológico. MÉTODOS: Quarenta ratas albinas EPM-1 Wistar, prenhes, foram aleatoriamente divididas em quatro grupos: Contr (controle do veículo e três grupos experimentais, Exp20, Exp60 e Exp180, que receberam, respectivamente, 20, 60 e 180 mg/kg por dia de Ritonavir por via oral. A droga e o veículo (propilenoglicol foram administrados por gavagem, desde o primeiro até o 20º dia da prenhez. No último dia do experimento, todos os animais foram anestesiados e sacrificados. Em seguida, fragmentos dos fígados e rins maternos e fetais foram coletados e preparados para análise em microscopia de luz. RESULTADOS: não observamos nenhuma alteração morfológica nas vísceras estudadas nos Grupos Contr e Exp20. No Grupo Exp60, encontramos, no fígado materno, hepatócitos com sinais de atrofia e de apoptose (eosinofilia citoplasmática e núcleos picnóticos e vasodilatação marcante dos capilares sinusóides (congestão. No rim materno, encontramos áreas eosinofílicas e núcleos hipercromáticos na parede dos túbulos contorcidos proximais. O fígado e rins maternos do Grupo Exp180 tiveram alterações morfológicas mais intensas do que no Grupo Exp60. Não observamos alterações histomorfológicas nos fígados e rins fetais em todos os grupos, o que pode ser decorrente da ação protetora da glicoproteína P. CONCLUSÕES: nossos resultados mostram que a administração de Ritonavir a ratas prenhes causou alterações morfológicas nos fígados e rins maternos em doses mais altas que a convencional. Já a ausência de anormalidades nos órgãos fetais pode ser explicada pelo papel protetor da glicoproteína P.PURPOSE: to evaluate the effect of the chronic administration of three different doses of Ritonavir in the liver and kidneys of pregnant albino rats and their concepts

  5. Influência do Tabagismo no Sistema Vascular Materno-fetal: estudo com Dopplervelocimetria Effect of Cigarette Smoking on Maternal-fetal Blood Flow: Doppler Velocimetry Study

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    Gilberto Rodrigues Pinto

    2000-12-01

    Full Text Available Objetivo: avaliar a influência do tabagismo materno na dinâmica vascular materno-fetal, por meio da dopplervelocimetria obstétrica das artérias uterinas, umbilical e cerebral média. Métodos: estudo prospectivo em 42 gestantes saudáveis, sendo 20 fumantes e 22 não-fumantes. Foram realizadas ultra-sonografias para determinar o tempo de gestação e exame de dopplervelocimetria pulsátil das artérias uterinas, umbilical e cerebral média nas 24ª, 28ª, 32ª e 36ª semana para avaliar o fluxo vascular materno-fetal. As fumantes foram orientadas a não fumar por pelo menos 2 horas antes do exame. Resultados: o índice de resistência (IR médio das artérias uterinas D e E foi maior no grupo de fumantes na 36ª semana com média de 0,50 e desvio padrão de 0,034. O índice de pulsatilidade (IP da artéria umbilical foi maior no grupo de fumantes na 28ª semana [x (DP = 1,135 (0,182], p = 0,008; o IP da artéria cerebral média (ACM não se mostrou diferente entre os grupos, porém, a relação IP ACM/umbilical foi menor no grupo de fumantes, na 32ª semana [x (DP = 1,9 (0,291], p = 0,027 e na 36ª semana [x (DP = 1,850 (0,465], p = 0,014. Conclusões: os índices de dopplervelocimetria mostraram que no grupo de fumantes há aumento na resistência da circulação útero-placentária e feto-placentária, associado a concomitante diminuição na resistência da ACM, mimetizando uma tendência do tabagismo levar à hipóxia crônica do feto.Purpose: to evaluate the influence of cigarette smoking on uteroplacental, fetoplacental and fetal blood flow by obstetric Doppler velocimetry of the uterine, umbilical and middle cerebral arteries. Method: a prospective study with 42 healthy pregnant women, 20 of whom were smokers and 24 nonsmokers. Ultrasound was performed initially to determine the gestation time. The pregnant women next underwent pulsed and color Doppler velocimetry of the uterine, umbilical and middle cerebral arteries at the 24th, 28

  6. Apego materno-fetal e a percepção materna acerca da capacidade interativa do bebê no primeiro mês = Maternal-fetal attachment and maternal perception about infant interactive skills in the first month = Apego materno-fetal y la percepción materna sobre la capacidad interactiva del bebé en el primer mes

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    Alvarenga, Patrícia

    2015-01-01

    Full Text Available A percepção da mãe acerca das capacidades interativas do recém-nascido tem sido apontada como um fator crucial para o estabelecimento de padrões interativos de qualidade entre a díade mãe-filho. O objetivo deste estudo foi examinar as relações entre o apego materno-fetal e a percepção da mãe acerca das capacidades interativas do bebê. Participaram do estudo 64 mães de bebês do sexo masculino, que responderam a Escala de Apego Materno-fetal, no terceiro trimestre da gestação, e uma entrevista sobre a experiência da maternidade, no primeiro mês do bebê. Houve uma correlação positiva entre o apego materno-fetal e a percepção geral das capacidades interativas do bebê (r=0,23; p<0,05. A análise de regressão confirmou que a escolaridade materna e o apego materno-fetal explicaram 12% da variância na percepção da mãe acerca das capacidades interativas dos bebês. Discute-se a relevância da relação da mãe com o feto durante a gestação para a interação mãe-bebê no período pós-natal

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

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    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.

  8. Relações entre a saúde mental da gestante e o apego materno-fetal Relations between pregnant women's mental health and maternal-fetal attachment

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    Patrícia Alvarenga

    2012-12-01

    Full Text Available O estudo investigou as relações entre variáveis sociodemográficas, saúde mental da gestante e o apego materno-fetal no terceiro trimestre de gestação. Participaram do estudo 261 gestantes selecionadas através de amostragem por acessibilidade em quatro maternidades públicas. As gestantes responderam individualmente uma ficha de dados sociodemográficos, a Escala de Apego Materno-Fetal e o SRQ-20. A análise de regressão revelou que o número de filhos (4% e a saúde mental materna (4,2% explicaram parte da variância no apego materno-fetal. A escolaridade da mãe e do pai não esteve associada a essa variável. O modelo de regressão múltipla considerando os quatro fatores analisados, explicou 8,2% da variância nos escores de apego materno-fetal. Discutem-se as implicações dessas variáveis na formação do vínculo da mãe com o bebê durante a gestação.This study investigated the relations among sociodemographic variables, pregnant women mental health, and maternal-fetal attachment in the third trimester of pregnancy. Participants were 261 pregnant women recruited from public maternity wards using a convenience sampling technique. Each pregnant woman completed a sociodemographic data form, the Maternal-Fetal Attachment Scale, and the SRQ-20. Regression analysis revealed that the number of children (4% and mothers' mental health (4.2% accounted for part of the variance in maternal-fetal attachment scores. Father's and mother's schooling was not associated with this variable. Taking the four analyzed factors into account, a multiple regression model accounted for 8.2% of the variance in the maternal-fetal attachment scores. The implications of these variables for mother-infant bonding during pregnancy are discussed.

  9. Influencia de la diabetes mellitus gestacional en parámetros antropométricos y bioquímicos materno-fetales y en la transferencia placentaria de ácidos grasos

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    Prieto Sánchez, María Teresa

    2012-01-01

    El objetivo del estudio fue evaluar el perfil de ácidos grasos en plasma materno, fetal y placenta en pacientes con diabetes gestacional y controles, así como determinar modificaciones en parámetros antropométricos y bioquímicos maternos y fetales asociados a la diabetes gestacional. Los porcentajes de DHA y de ácidos grasos poliinsaturados de cadena larga, no se encuentran disminuidos en los lípidos totales del plasma materno ni del tejido placentario, sin embargo, en sangre de cordón, o...

  10. Asociación del intervalo intergenésico y la morbimortalidad materno fetal en el Hospital María Auxiliadora de San Juan de Miraflores, Lima. 2014

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    Huamaní Cueto, Silvia Constanza

    2015-01-01

    Determina la asociación del intervalo intergenésico sobre la morbilidad materno fetal en el Hospital María Auxiliadora, 2014. Material y métodos: estudio descriptivo correlacional y retrospectivo; la muestra estuvo conformada por 7631 historias clínicas de gestantes que dieron parto, y cuyo embarazo finalizó en un nacido vivo o muerto; se estudió 3138 historias clínicas de gestantes divididas en intervalos según criterios de inclusión. Los datos fueron obtenidos del Sistema Informático Perina...

  11. Chronic intermittent high altitude exposure, occupation, and body mass index in workers of mining industry.

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    Esenamanova, Marina K; Kochkorova, Firuza A; Tsivinskaya, Tatyana A; Vinnikov, Denis; Aikimbaev, Kairgeldy

    2014-09-01

    The obesity and overweight rates in population exposed to chronic intermittent exposure to high altitudes are not well studied. The aim of the retrospective study was to evaluate whether there are differences in body mass index in different occupation groups working in intermittent shifts at mining industry at high altitude: 3800-4500 meters above sea level. Our study demonstrated that obesity and overweight are common in workers of high altitude mining industry exposed to chronic intermittent hypoxia. The obesity rate was lowest among miners as compared to blue- and white-collar employees (9.5% vs. 15.6% and 14.7%, p=0.013). Obesity and overweight were associated with older age, higher rates of increased blood pressure (8.79% and 5.72% vs. 1.92%), cholesterol (45.8% and 45.6% vs. 32.8%) and glucose (4.3% and 1.26% vs. 0.57%) levels as compared to normal body mass index category (pmining industry exposed to intermittent high-altitude hypoxia. Therefore, assessment and monitoring of body mass index seems to be essential in those who live and work at high altitudes to supply the correct nutrition, modify risk factors, and prevent related disorders.

  12. Evaluation of anxiolytic effect and withdrawal anxiety in chronic intermittent diazepam treatment in rats.

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    Açikmeşe, Bariş; Haznedar, Seçil; Hatipoğlu, Iclal; Enginar, Nurhan

    2012-04-01

    This study evaluated the effect of intermittent administration in the development of dependence to diazepam in chronic use of the drug. Gabapentin was used to provide an anxiolytic effect on drug-free days. During a 28-day treatment schedule, rats were given diazepam (15 mg/kg) once daily continuously, or intermittently with saline or gabapentin (50 mg/kg) on days 5, 10, 15, 20, and 25. Anxiety-like behavior was assessed on days 10 and 30 using the elevated plus-maze test and novelty-induced grooming test. Contrary to continuous administration, intermittent diazepam did not provide anxiolytic-like activity on day 10; instead, it prevented withdrawal anxiety on day 30. Gabapentin produced anxiolytic-like effects during the withdrawal period, but not on day 10. These results suggest that intermittent administration of diazepam (given either alone or alternatively with a drug possessing anxiolytic activity) may be of value in preventing the development of physical dependence during the chronic use of the drug. However, further studies are needed to demonstrate that this protocol could effectively produce anxiolytic activity on diazepam-free days.

  13. Evolução e prognóstico materno-fetal da cirurgia cardíaca durante a gravidez Evolución y pronóstico materno-fetal de la cirugía cardiaca durante el embarazo Maternal-fetal outcome and prognosis of cardiac surgery during pregnancy

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    Walkiria Samuel Ávila

    2009-07-01

    Full Text Available FUNDAMENTO: A cirurgia cardíaca favorece o prognóstico materno em casos refratários à terapêutica clínica, contudo associa-se a riscos ao concepto quando realizada durante a gravidez. OBJETIVO: Analisar a evolução e o prognóstico materno-fetal de gestantes submetidas à cirurgia cardíaca no ciclo gravídico-puerperal. MÉTODOS: Estudou-se a evolução de 41 gestações de mulheres que tiveram indicação de cirurgia cardíaca no ciclo gravídico puerperal. A cardiotocografia fetal foi mantida durante o procedimento nas pacientes com idade gestacional acima de 20 semanas. RESULTADOS: A média da idade materna foi de 27,8 ± 7,6 anos, houve predomínio da valvopatia reumática (87,8%, e 15 dessas (41,6% foram submetidas à reoperação, devido à disfunção de prótese valvar. A média do tempo de circulação extracorpórea foi de 87,4 ± 43,6 min, e a hipotermia foi utilizada em 27 casos (67,5%. Treze mães (31,7% não apresentaram intercorrências e tiveram seus recém-nascidos vivos e saudáveis. A evolução pós-operatória das demais 28 gestações (68,3% mostrou: 17 complicações maternas (41,5%; três óbitos (7,3%; 12 perdas fetais (29,2% e quatro casos de malformação neurológica (10%, dois dos quais evoluíram para óbito tardio. Houve uma perda de seguimento após a cirurgia. Nove pacientes (21,9% foram operadas em caráter de emergência, situação que influenciou (p FUNDAMENTO: La cirugía cardiaca favorece el pronóstico materno en casos refractarios a la terapéutica clínica, sin embargo está asociada a riesgos cuando realizada durante el embarazo. OBJETIVO: Analizar la evolución y el pronóstico materno-fetal de gestantes sometidas a la cirugía cardiaca en el ciclo grávido puerperal. MÉTODOS: Se estudió la evolución de 41 gestaciones de mujeres que tuvieron indicación de cirugía cardiaca en el ciclo grávido puerperal. La cardiotocografía fetal se mantuvo durante el procedimiento en las pacientes con

  14. CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FAILS TO ALTER FLASH OR PATTERN REVERSAL EVOKED POTENTIALS IN RATS.

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    Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Visual disturbances are often reported following exposure to xenobiotics, and cholinesterase-inhibiting compounds have been reported to alter visual functi...

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

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    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

  16. Chronic intermittent hypoxia causes hepatitis in a mouse model of diet-induced fatty liver.

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    Savransky, Vladimir; Bevans, Shannon; Nanayakkara, Ashika; Li, Jianguo; Smith, Philip L; Torbenson, Michael S; Polotsky, Vsevolod Y

    2007-10-01

    Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (CIH) during sleep. OSA is associated with nonalcoholic steatohepatitis (NASH) in obese individuals and may contribute to progression of nonalcoholic fatty liver disease from steatosis to NASH. The purpose of this study was to examine whether CIH induces inflammatory changes in the liver in mice with diet-induced hepatic steatosis. C57BL/6J mice (n = 8) on a high-fat, high-cholesterol diet were exposed to CIH for 6 mo and were compared with mice on the same diet exposed to intermittent air (control; n = 8). CIH caused liver injury with an increase in serum ALT (461 +/- 58 U/l vs. 103 +/- 16 U/l in the control group; P diet.

  17. Effect of superoxide anion scavenger on rat hearts with chronic intermittent hypoxia.

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    Pai, Peiying; Lai, Ching Jung; Lin, Ching-Yuang; Liou, Yi-Fan; Huang, Chih-Yang; Lee, Shin-Da

    2016-04-15

    Only very limited information regarding the protective effects of the superoxide anion scavenger on chronic intermittent hypoxia-induced cardiac apoptosis is available. The purpose of this study is to evaluate the effects of the superoxide anion scavenger on cardiac apoptotic and prosurvival pathways in rats with sleep apnea. Forty-two Sprague-Dawley rats were divided into three groups, rats with normoxic exposure (Control, 21% O2, 1 mo), rats with chronic intermittent hypoxia exposure (Hypoxia, 3-7% O2vs. 21% O2per 40 s cycle, 8 h per day, 1 mo), and rats with pretreatment of the superoxide anion scavenger and chronic intermittent hypoxia exposure (Hypoxia-O2 (-)-Scavenger, MnTMPyP pentachloride, 1 mg/kg ip per day; 3-7% O2vs. 21% O2per 40 s cycle, 8 h per day, 1 mo) at 5-6 mo of age. After 1 mo, the protein levels and apoptotic cells of excised hearts from three groups were measured by Western blotting and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. The superoxide anion scavenger decreased hypoxia-induced myocardial architecture abnormalities, left ventricular hypertrophy, and TUNEL-positive apoptosis. The superoxide anion scavenger decreased hypoxia-induced Fas ligand, Fas death receptors, Fas-associated death domain (FADD), activated caspase-8, and activated caspase-3 (Fas-dependent apoptotic pathway) as well as Bad, activated caspase-9 and activated caspase-3 (mitochondria-dependent apoptotic pathway), endonuclease G (EndoG), apoptosis-inducing factor (AIF), and TUNEL-positive apoptosis. The superoxide anion scavenger increased IGF-1, IGF-1R, p-PI3k, p-Akt, p-Bad, Bcl-2, and Bcl-xL (survival pathway). Our findings imply that the superoxide anion scavenger might prevent cardiac Fas-mediated and mitochondrial-mediated apoptosis and enhance the IGF-1-related survival pathway in chronic intermittent hypoxia. The superoxide anion scavenger may prevent chronic sleep apnea-enhanced cardiac apoptotic pathways and enhances

  18. Intermittent targeted therapies and stochastic evolution in patients affected by chronic myeloid leukemia

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    Pizzolato, N.; Persano Adorno, D.; Valenti, D.; Spagnolo, B.

    2016-05-01

    Front line therapy for the treatment of patients affected by chronic myeloid leukemia (CML) is based on the administration of tyrosine kinase inhibitors, namely imatinib or, more recently, axitinib. Although imatinib is highly effective and represents an example of a successful molecular targeted therapy, the appearance of resistance is observed in a proportion of patients, especially those in advanced stages. In this work, we investigate the appearance of resistance in patients affected by CML, by modeling the evolutionary dynamics of cancerous cell populations in a simulated patient treated by an intermittent targeted therapy. We simulate, with the Monte Carlo method, the stochastic evolution of initially healthy cells to leukemic clones, due to genetic mutations and changes in their reproductive behavior. We first present the model and its validation with experimental data by considering a continuous therapy. Then, we investigate how fluctuations in the number of leukemic cells affect patient response to the therapy when the drug is administered with an intermittent time scheduling. Here we show that an intermittent therapy (IT) represents a valid choice in patients with high risk of toxicity, despite an associated delay to the complete restoration of healthy cells. Moreover, a suitably tuned IT can reduce the probability of developing resistance.

  19. A novel adjustable automated system for inducing chronic intermittent hypoxia in mice

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    Polšek, Dora; Bago, Marcel; Živaljić, Marija; Rosenzweig, Ivana; Lacza, Zsombor

    2017-01-01

    Background Sleep apnea is a chronic, widely underdiagnosed condition characterized by disruption of sleep architecture and intermittent hypoxia due to short cessations of breathing. It is a major independent risk factor for myocardial infarction, congestive heart failure and stroke as well as one of the rare modifiable risk factors for Alzheimer’s Dementia. Reliable animal disease models are needed to understand the link between sleep apnea and the various clinically linked disorders. New method An automated system for inducing hypoxia was developed, in which the major improvement was the possibility to efficiently adjust the length and intensity of hypoxia in two different periods. The chamber used a small volume of gas allowing for fast exchanges of different oxygen levels. The mice were kept in their cages adapted with the system on the cage lid. As a proof of principle, they were exposed to a three week period of intermittent hypoxia for 8 hours a day, with 90 s intervals of 5, 7% and 21% oxygen to validate the model. Treated (n = 8) and control mice (no hypoxia, n = 7) were handled in the same manner and their hippocampal brain regions compared by histology. Results The chamber provided a fast, reliable and precise intermittent hypoxia, without inducing noticeable side effects to the animals. The validation experiment showed that apoptotic neurons in the hippocampus were more numerous in the mice exposed to intermittent hypoxia than in the control group, in all tested hippocampal regions (cornu ammonis 1 (CA1) P neurons in the DG compared to the CA1 and CA3 subfields (P neurons. PMID:28362813

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

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    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.

  1. 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.

  2. Chronic intermittent heroin produces locomotor sensitization and long-lasting enhancement of conditioned reinforcement.

    Science.gov (United States)

    Morrison, J; Thornton, V; Ranaldi, R

    2011-09-01

    In a previous study we showed that chronic intermittent heroin in rats enhanced responding with conditioned reinforcement and reversal learning of a conditioned magazine approach task when tested three days after the heroin treatment. Whether or not this enhanced appetitive learning persists after a protracted withdrawal period remains unknown and constitutes the aim of the present study. Forty-eight male Long Evans rats were each exposed to positive pairings of a light stimulus and food for 4 consecutive daily sessions. Then, two groups of rats received saline and two groups received heroin (2 mg/kg) injections before placement in activity monitors for 9 consecutive daily sessions. This was followed by testing in operant conditioning chambers where one lever produced the light stimulus previously paired with food and another no stimulus. For one saline and one heroin group this testing occurred after 2 days of withdrawal while for the other saline and heroin groups it occurred after 30 days of withdrawal. The results indicate that animals treated with heroin displayed progressively and significantly greater locomotor activity across sessions while animals treated with saline displayed locomotor activity that remained low and stable across sessions. In addition, the heroin groups in each withdrawal condition displayed significantly enhanced responding with conditioned reinforcement compared to their respective saline control groups. These results demonstrate that chronic intermittent heroin enhances appetitive learning for natural reinforcers and motivational processes and that this effect persists even after 30-days of withdrawal.

  3. Superficially, longer, intermittent ozone theraphy in the treatment of the chronic, infected wounds.

    Science.gov (United States)

    Białoszewski, Dariusz; Kowalewski, Michał

    2003-10-30

    Background. Ozone therapy - i.e. the treatment of patients by a mixture of oxygen and ozone - has been used for many years as a method ancillary to basic treatment, especially in those cases in which traditional treatment methods do not give satisfactory results, e.g. skin loss in non-healing wounds, ulcers, pressure sores, fistulae, etc. Material and methods. In the Department of Phisiotherapy of the Medical Faculty and the Department of the Orthopedics and Traumatology of the Locomotor System at the Medical University of Warsaw in the period from January 2001 until November 2002, 23 patients with heavy,chronic, antibiotic resistants septic complications after trauma, surgical procedures and secundary skin infetions were treated with ozone. The ozone therapy was administered using an authorial technique of superficially, longer, intermittent ozone application. Results. In the wounds of the all experienced patients the inhibition of septic processes and wound healing was much faster than normal. Conclusions. Our data confirm the advantages wich result from the technique of superficially, longer, intermittent ozone theraphy in combined treatment for septic complications in the soft tissue, especially in the locomotor system. These technique makes posttraumatic infections and promotes quicker healing of post-surgical and post-traumal complications - chronic septic infections. This method also lowers the cost of antibiotic therapy and is sometimes the only available auxiliary technique to support surgical procedures.

  4. 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.

  5. Influence of chronic intermittent hypoxia on growth associated protein 43 expression in the hippocampus of young rats

    Institute of Scientific and Technical Information of China (English)

    Yan Chen; Chunling Zhao; Chunlai Zhang; Lirong Luo; Guang Yu

    2012-01-01

    This study aimed to explore the pathological change to hippocampal neurons and the expression of growth associated protein 43 in 21-day-old young rats following chronic intermittent hypoxia. Hematoxylin-eosin staining results showed varying degrees of degeneration and necrosis in hippocampal neurons depending on the modeling time. Immunohistochemistry revealed that growth associated protein 43 expression in young rats following chronic intermittent hypoxia de-creased, but that levels were still higher than those of normal rats at each time point, especially 4 weeks after modeling. During 1-5 weeks after modeling, a slow growth in rat weight was ob-served. Experimental findings indicate that chronic intermittent hypoxia may induce growth dys-function and necrosis of hippocampal neurons, as well as increase the expression of growth as-sociated protein 43 in young rats.

  6. Influence of chronic intermittent hypoxia on growth associated protein 43 expression in the hippocampus of young rats.

    Science.gov (United States)

    Chen, Yan; Zhao, Chunling; Zhang, Chunlai; Luo, Lirong; Yu, Guang

    2012-06-05

    This study aimed to explore the pathological change to hippocampal neurons and the expression of growth associated protein 43 in 21-day-old young rats following chronic intermittent hypoxia. Hematoxylin-eosin staining results showed varying degrees of degeneration and necrosis in hippocampal neurons depending on the modeling time. Immunohistochemistry revealed that growth associated protein 43 expression in young rats following chronic intermittent hypoxia decreased, but that levels were still higher than those of normal rats at each time point, especially 4 weeks after modeling. During 1-5 weeks after modeling, a slow growth in rat weight was observed. Experimental findings indicate that chronic intermittent hypoxia may induce growth dysfunction and necrosis of hippocampal neurons, as well as increase the expression of growth associated protein 43 in young rats.

  7. Differential Effects of Chronic and Chronic-Intermittent Ethanol Treatment and Its Withdrawal on the Expression of miRNAs

    Directory of Open Access Journals (Sweden)

    Joanne M. Lewohl

    2013-05-01

    Full Text Available Chronic and excessive alcohol misuse results in changes in the expression of selected miRNAs and their mRNA targets in specific regions of the human brain. These expression changes likely underlie the cellular adaptations to long term alcohol misuse. In order to delineate the mechanism by which these expression changes occur, we have measured the expression of six miRNAs including miR-7, miR-153, miR-152, miR-15B, miR-203 and miR-144 in HEK293T, SH SY5Y and 1321 N1 cells following exposure to ethanol. These miRNAs are predicted to target key genes involved in the pathophysiology of alcoholism. Chronic and chronic-intermittent exposure to ethanol, and its removal, resulted in specific changes in miRNA expression in each cell line suggesting that different expression patterns can be elicited with different exposure paradigms and that the mechanism of ethanol’s effects is dependent on cell type. Specifically, chronic exposure to ethanol for five days followed by a five day withdrawal period resulted in up-regulation of several miRNAs in each of these cell lines similar to expression changes identified in post mortem human brain. Thus, this model can be used to elucidate the role of miRNAs in regulating gene expression changes that occur in response to ethanol exposure.

  8. Vortioxetine restores reversal learning impaired by 5-HT depletion or chronic intermittent cold stress in rats.

    Science.gov (United States)

    Wallace, Ashley; Pehrson, Alan L; Sánchez, Connie; Morilak, David A

    2014-10-01

    Current treatments for depression, including serotonin-specific reuptake inhibitors (SSRIs), are only partially effective, with a high incidence of residual symptoms, relapse, and treatment resistance. Loss of cognitive flexibility, a component of depression, is associated with dysregulation of the prefrontal cortex. Reversal learning, a form of cognitive flexibility, is impaired by chronic stress, a risk factor for depression, and the stress-induced impairment in reversal learning is sensitive to chronic SSRI treatment, and is mimicked by serotonin (5-HT) depletion. Vortioxetine, a novel, multimodal-acting antidepressant, is a 5-HT3, 5-HT7 and 5-HT1D receptor antagonist, a 5-HT1B receptor partial agonist, a 5-HT1A receptor agonist, and inhibits the 5-HT transporter. Using adult male rats, we first investigated the direct effects of vortioxetine, acting at post-synaptic 5-HT receptors, on reversal learning that was compromised by 5-HT depletion using 4-chloro-DL-phenylalanine methyl ester hydrochloride (PCPA), effectively eliminating any contribution of 5-HT reuptake blockade. PCPA induced a reversal learning impairment that was alleviated by acute or sub-chronic vortioxetine administration, suggesting that post-synaptic 5-HT receptor activation contributes to the effects of vortioxetine. We then investigated the effects of chronic dietary administration of vortioxetine on reversal learning that had been compromised in intact animals exposed to chronic intermittent cold (CIC) stress, to assess vortioxetine's total pharmacological effect. CIC stress impaired reversal learning, and chronic vortioxetine administration prevented the reversal-learning deficit. Together, these results suggest that the direct effect of vortioxetine at 5-HT receptors may contribute to positive effects on cognitive flexibility deficits, and may enhance the effect of 5-HT reuptake blockade.

  9. Intermittent acute angle closure glaucoma and chronic angle closure following topiramate use with plateau iris configuration

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    Rajjoub LZ

    2014-07-01

    Full Text Available Lamise Z Rajjoub, Nisha Chadha, David A Belyea Department of Ophthalmology, The George Washington University, Washington, DC, USA Abstract: This is a case report describing recurrent intermittent acute angle closure episodes in the setting of topiramate use in a female suffering from migraines. Despite laser peripheral iridotomy placement for the pupillary block component, and the discontinuation of topiramate, the acute angle closure did not resolve in the left eye with chronic angle closure and the patient required urgent trabeculectomy. The right eye responded to laser peripheral iridotomy immediately and further improved after the cessation of topiramate. While secondary angle closure glaucoma due to topiramate use has been widely reported, its effects in patients with underlying primary angle closure glaucoma have not been discussed. Our report highlights the importance of recognizing the often multifactorial etiology of angle closure glaucoma to help guide clinical management. Keywords: angle closure glaucoma, plateau iris, topiramate, secondary glaucoma, drug-induced glaucoma

  10. Chronic cervicogenic tinnitus rapidly resolved by intermittent use of cervical collar

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    Karl eBechter

    2016-03-01

    Full Text Available Introduction:Cervicogenic tinnitus is a not generally accepted pathogenetic subtype, which might be subsumed under the concept of somatosensory tinnitus. After the personal experience of therapy resistant tinnitus in context with a cervical pain syndrome (CS and successful add-on treatment with cervical collar (CC, the idea was persued in several individual treatments in patients.Patients and Methods:Reporting one particular case with chronic tinnitus considered untreatable, but rapidly improved with CC use. Thereafter tinnitus was experimentally replicated by head inclination, the respective neck-head angles and cerebral blood flow measured. Results:Chronic subjective tinnitus of a 20 years duration completely disappeared within 4 weeks with an intermittent short time application of CC. Thereafter, tinnitus was liberately again induced by head inclination, set on with anterior tilt of 14°, reaching maximum strength by 23°. Tinnitus stopped with return to neutral head position. Blood flow in the vertebral arteries on both sides was unchanged during head inclination with prevalent tinnitus, however blood flow was physiologically reduced with head rotation though not accompanied by tinnitus.Discussion:In a single case of chronic tinnitus, we found that treatment with CC rapidly led to full remission. Nevertheless, tinnitus could be resumed by constrained head postures. Experimental tinnitus replication by inclination points to an underscored role of upper posterior cervical muscle groups, matching with animal experiments, working in concert with other triggers including psychological factors. Blood flow reduction in vertebral arteries was unrelated to tinnitus.

  11. Gastric malpositioning and chronic, intermittent vomiting following prophylactic gastropexy in a 20-month-old great Dane dog

    OpenAIRE

    Sutton, Jessie S.; Steffey, Michele A.; Bonadio, Cecily M.; Marks, Stanley L

    2015-01-01

    A 20-month-old castrated male great Dane dog was presented for evaluation of chronic intermittent vomiting of 2 months’ duration. A prophylactic incisional gastropexy performed at 6 mo of age resulted in gastric malpositioning and subsequent partial gastric outflow tract obstruction.

  12. Chronic Intermittent Fasting Improves Cognitive Functions and Brain Structures in Mice

    OpenAIRE

    Liaoliao Li; Zhi Wang; Zhiyi Zuo

    2013-01-01

    Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day) fasting or high fat diet (45% caloric supplied by fat) for 11 months. Mice on intermittent fasting had better learning and me...

  13. Vagal cardiac efferent innervation in F344 rats: Effects of chronic intermittent hypoxia.

    Science.gov (United States)

    Cheng, Zixi Jack

    2017-03-01

    Chronic intermittent hypoxia (CIH), which is a physiological consequence of obstructive sleep apnea, reduces baroreflex control of heart rate (HR). Previously, we showed that the heart rate (HR) response to electrical stimulation of the vagal efferent nerve was significantly increased following CIH in F344 rats. Since vagal cardiac efferent from the nucleus ambiguus (NA) project to cardiac ganglia and regulate HR, we hypothesized that vagal cardiac efferent innervation of cardiac ganglia is reorganized. Young adult F344 rats were exposed either to room air (RA) or to intermittent hypoxia for 35-50days. Fluorescent tracer DiI was injected into the NA to label vagal efferent innervation of cardiac ganglia which had been counterstained by Fluoro-Gold (FG) injections (i.p). Confocal microscopy was used to examine vagal cardiac efferent axons and terminals in cardiac ganglia. NA axons entered cardiac ganglia and innervated principal neurons (PNs) with robust basket endings in both RA control and CIH animals. In addition, the percentage of PNs which were innervated by DiI-labeled fibers in ganglia was similar. In CIH rats, abnormally large swollen cardiac axon segments and disorganized terminals as well as leaky endings were observed. In general, vagal efferent terminal varicosities around PNs appeared larger and the number of varicosities was significantly increased. Interestingly, some cardiac axons had sprouting-like terminal structures in the cardiac ganglia as well as in cardiac muscle, which had not been found in RA control. Finally, CIH increased the size of PNs and reduced the ratio of nucleus to PN somata. Thus, CIH significantly remodeled the structure of vagal cardiac axons and terminals in cardiac ganglia as well as cardiac PNs.

  14. Chronic intermittent ethanol induced axon and myelin degeneration is attenuated by calpain inhibition.

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    Samantaray, Supriti; Knaryan, Varduhi H; Patel, Kaushal S; Mulholland, Patrick J; Becker, Howard C; Banik, Naren L

    2015-10-01

    Chronic alcohol consumption causes multifaceted damage to the central nervous system (CNS), underlying mechanisms of which are gradually being unraveled. In our previous studies, activation of calpain, a calcium-activated neutral protease has been found to cause detrimental alterations in spinal motor neurons following ethanol (EtOH) exposure in vitro. However, it is not known whether calpain plays a pivotal role in chronic EtOH exposure-induced structural damage to CNS in vivo. To test the possible involvement of calpain in EtOH-associated neurodegenerative mechanisms the present investigation was conducted in a well-established mouse model of alcohol dependence - chronic intermittent EtOH (CIE) exposure and withdrawal. Our studies indicated significant loss of axonal proteins (neurofilament light and heavy, 50-60%), myelin proteins (myelin basic protein, 20-40% proteolipid protein, 25%) and enzyme (2', 3'-cyclic-nucleotide 3'-phosphodiesterase, 21-55%) following CIE in multiple regions of brain including hippocampus, corpus callosum, cerebellum, and importantly in spinal cord. These CIE-induced deleterious effects escalated after withdrawal in each CNS region tested. Increased expression and activity of calpain along with enhanced ratio of active calpain to calpastatin (sole endogenous inhibitor) was observed after withdrawal compared to EtOH exposure. Pharmacological inhibition of calpain with calpeptin (25 μg/kg) prior to each EtOH vapor inhalation significantly attenuated damage to axons and myelin as demonstrated by immuno-profiles of axonal and myelin proteins, and Luxol Fast Blue staining. Calpain inhibition significantly protected the ultrastructural integrity of axons and myelin compared to control as confirmed by electron microscopy. Together, these findings confirm CIE exposure and withdrawal induced structural alterations in axons and myelin, predominantly after withdrawal and corroborate calpain inhibition as a potential protective strategy against

  15. Repeated episodes of chronic intermittent ethanol promote insensitivity to devaluation of the reinforcing effect of ethanol.

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    Lopez, M F; Becker, H C; Chandler, L J

    2014-11-01

    Studies in animal models have shown that repeated episodes of alcohol dependence and withdrawal promote escalation of drinking that is presumably associated with alterations in the addiction neurocircuitry. Using a lithium chloride-ethanol pairing procedure to devalue the reinforcing properties of ethanol, the present study determined whether multiple cycles of chronic intermittent ethanol (CIE) exposure by vapor inhalation also alters the sensitivity of drinking behavior to the devaluation of ethanol's reinforcing effects. The effect of devaluation on operant ethanol self-administration and extinction was examined in mice prior to initiation of CIE (short drinking history) and after repeated cycles of CIE or air control exposure (long drinking history). Devaluation significantly attenuated the recovery of baseline ethanol self-administration when tested either prior to CIE or in the air-exposed controls that had experienced repeated bouts of drinking but no CIE. In contrast, in mice that had undergone repeated cycles of CIE exposure that promoted escalation of ethanol drinking, self-administration was completely resistant to the effect of devaluation. Devaluation had no effect on the time course of extinction training in either pre-CIE or post-CIE mice. Taken together, these results are consistent with the suggestion that repeated cycles of ethanol dependence and withdrawal produce escalation of ethanol self-administration that is associated with a change in sensitivity to devaluation of the reinforcing properties of ethanol.

  16. Effect of chronic intermittent hypoxia on exercise adaptations in healthy subjects.

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    Tonini, Julia; Michallet, Anne-Sophie; Flore, Patrice; Nespoulet, Hugo; Pepin, Jean-Louis; Wuyam, Bernard; Levy, Patrick; Tamisier, Renaud

    2011-12-15

    Reduced exercise tolerance has been reported in obstructive sleep apnea syndrome (OSAS) patients, although the associated hypertension, obesity and/or metabolic disorder may underlie this reduction. Therefore, we evaluated the effects of chronic intermittent hypoxia (CIH) in 12 healthy subjects on exercise capacity, cardio-respiratory responses, and substrate oxidation during maximal and sub-maximal exercise. Subjects were exposed to 30 cycles of hypoxia-reoxygenation per hour for 14 nights. Although exercise capacity was unaltered PETCO(2) was reduced and V˙E/V˙CO(2) increased during both maximal and submaximal exercise tests, indicating a hyperventilatory response. Maximal heart rate was lower and diastolic arterial blood pressure (DBP) was higher in the 1st min of recovery after submaximal exercise. Subjects reached maximal lipid oxidation at a higher power output and had decreased blood lactate for a given power output. This suggests that although the metabolic adaptations to CIH in healthy subjects may improve exercise performance, the cardio-pulmonary modifications are similar to those observed in OSAS patients and could limit exercise capacity.

  17. Chronic intermittent hypoxia induces atherosclerosis by NF-κB-dependent mechanisms.

    Science.gov (United States)

    Song, D; Fang, G; Mao, S-Z; Ye, X; Liu, G; Gong, Y; Liu, S F

    2012-11-01

    Chronic intermittent hypoxia (CIH) causes atherosclerosis in mice fed a high cholesterol diet (HCD). The mechanisms by which CIH promotes atherosclerosis are incompletely understood. This study defined the mechanistic role of NF-κB pathway in CIH+HCD induced atherosclerosis. Wild type (WT) and mice deficient in the p50 subunit of NF-κB (p50-KO) were fed normal chow diet (ND) or HCD, and exposed to sham or CIH. Atherosclerotic lesions on the en face aortic preparation and cross-sections of aortic root were examined. In WT mice, neither CIH nor HCD exposure alone caused, but CIH+HCD caused evident atherosclerotic lesions on both preparations after 20weeks of exposure. WT mice on ND and exposed to CIH for 35.6weeks did not develop atherosclerotic lesions. P50 gene deletion diminished CIH+HCD induced NF-κB activation and abolished CIH+HCD induced atherosclerosis. P50 gene deletion inhibited vascular wall inflammation, reduced hepatic TNF-α level, attenuated the elevation in serum cholesterol level and diminished macrophage foam cell formation induced by CIH+HCD exposure. These results demonstrate that inhibition of NF-κB activation abrogates the activation of three major atherogenic mechanisms associated with an abolition of CIH+HCD induced atherosclerosis. NF-κB may be a central common pathway through which CIH+HCD exposure activates multiple atherogenic mechanisms, leading to atherosclerosis.

  18. CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FALLS TO ALTER SOMATOSENSORY EVOKED POTENTIALS, COMPOUND NERVE ACTION POTENTIALS, OR NERVE CONDUCTION VELOCITY IN RATS.

    Science.gov (United States)

    Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Cholinergic transmission is involved in sensory modulation in the cortex and cerebellum, and therefore may be altered following chlorpyrifos (CPF) exposure...

  19. Effect of chronic intermittent hypoxia on theophylline metabolism in mouse liver

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-yang; ZENG Yi-ming; ZHANG Yi-xiang; WANG Wan-yu; WU Run-hua

    2013-01-01

    Background Chronic intermittent hypoxia (CIH) has been associated with abnormalities in the liver,which is the most important organ for drug metabolism.This study aimed to investigate the effect of CIH on theophylline metabolism in mouse liver.Methods Eight C57BL/6J mice were exposed to CIH for 12 weeks.Eight C57BL/6J mice were exposed to room air as a control group.Serum levels of alanine aminotransferase and aspartate aminotransferase were measured.Liver histology was observed by light and electron microscopy.Total hepatic cytochrome P450 concentration was measured.Hepatocytes were isolated and incubated with 15 mg/ml theophylline for four hours.After incubation,the theophylline concentration in the supernatant was measured and the theophylline metabolism rate was calculated.Results CIH did not affect the serum transaminase levels.Livers from mice exposed to CIH showed hepatocellular edema,and liver cells had fuzzy rough endoplasmic reticulum under the electron microscope.The theophylline metabolism rate was significantly inhibited by CIH compared with controls; (16.60±2.43)% vs.(21.58±4.52)% (P=0.02).The total liver cytochrome P450 concentration in the CIH group was significantly lower than in the control group;(0.83±0.08) vs.(1.13±0.21) mol/mg microsomal protein (P=0.004).Conclusion CIH decreases theophylline metabolism by mouse hepatocytes,which may correlate with the downregulation of cytochrome P450 expression by CIH.

  20. The effect of oxidative stress in myocardial cell injury in mice exposed to chronic intermittent hypoxia

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-nan; ZHANG Jie-xin; LIU gan; QIU Yan; YANG Di; YIN Guo-yong; ZHANG Xi-long

    2010-01-01

    Background Obstructive sleep apnea syndrome (OSAS) is an important risk factor for cardiovascular diseases. Chronic intermittent hypoxia (CIH) is considered to be one of the most important causes of cardiovascular diseases in OSA patients. This repeated hypoxia and reoxygenation cycle is similar to hypoxia-reperfusion injury, which initiates oxidative stress. In this study, we observed cardiocytes injury induced by CIH and the effect of N-acetylcysteine (NAC). Methods Thirty ICR mice were randomly assigned to 3 groups: control, CIH and NAC (CIH+NAC) groups. Malondialdehyde (MDA) and superoxide dismutase (SOD) of cardiocyte homogenates were measured. Serum lipids were measured by an instrument method. Serum cardiac troponin I (cTnl) was detected by enzyme-linked immunosorbent assays (ELISA). Myocardium pathological sections were observed.Results (1) The SOD activity and MDA concentration of cardiocyte homogenates in the CIH group were significantly higher than in other groups (P <0.005). The MDA concentration of the NAC group was lower than that of the control group (P <0.01). (2) The serum cTnl concentration of the CIH and NAC groups was significantly higher than that of the control group (P<0.01). (3) Serum triglyceride levels in the NAC group were lower than in the other groups (P<0.01), while there were no significant differences in low density lipoprotein and high density lipoprotein among the three groups. (4) The degeneration of myocardium, transverse striation blurred, and fabric effusion were observed in tissue sections in the CIH and NAC groups. However, normal tissue was found in the control group.Conclusion The oxidative stress induced by CIH can injure cardiocytes and the injury effect can be partially inhibited by NAC.

  1. ERK signaling mediates enhanced angiotensin Ⅱ-induced rat aortic constriction following chronic intermittent hypoxia

    Institute of Scientific and Technical Information of China (English)

    GUO Xue-ling; DENG Yan; SHANG Jin; LIU Kui; XU Yong-jian; LIU Hui-guo

    2013-01-01

    Background Obstructive sleep apnea (OSA) has been recognized as an independent risk factor for systemic hypertension.The study investigated the functional consequences of chronic intermittent hypoxia (CIH) on aortic constriction induced by angiotensin Ⅱ (Ang Ⅱ) and the possible signaling involving ERK1/2 and contractile proteins such as myosin light chain kinase (MLCK),myosin phosphatase targeting subunit (MYPT1) and myosin light chain (MLC).Methods Male Wistar rats were randomly divided into CIH group and normoxia group and exposed to either CIH procedure or air-air cycles.Phosphorylation of ERK1/2,MYPT1 and MLC was assessed by Western blotting following constrictor studies in the presence or absence of PD98059 (10 μmol/L).Results CIH-exposure resulted in more body weight gain and elevated blood pressure,which could be attenuated by pretreatment with PD98059.Endothelium-removed aortic rings from CIH rats exhibited higher constrictor sensitivity to Ang Ⅱ (Emax:(138.56±5.78)% versus (98.45±5.31)% of KCI; pD2:7.98±0.14 versus 8.14±0.05,respectively).CIH procedure exerted complex effects on ERK expressions (total ERK1/2 decreased whereas the ratio of phosphorylated to total ERK1/2increased).CIH aortas had higher MLCK mRNA and basal phosphorylation of MYPT1 and MLC.In parallel to greater increases in phosphorylation of ERK1/2,MYPT1 and MLC,Ang Ⅱ-induced aortic constriction was significantly enhanced in CIH rats,which was largely reversed by PD98059.However vascular constriction of normoxia rats remained unchanged despite similar but smaller changing tendency of proteins phosphorylation.Conclusion These data suggest that CIH exposure results in aortic hyperresponsiveness to Ang Ⅱ,presumably owing to more activated ERK1/2 signaling pathway.

  2. Adiponectin alleviates contractile dysfunction of genioglossus in rats exposed to chronic intermittent hypoxia

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-jing; LU Gan; DING Ning; HUANG Han-peng; DING Wen-xiao; ZHANG Xi-long

    2013-01-01

    Background Genioglossal dysfuntion takes an important role in pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS) in which chronic intermittent hypoxia (CIH) is the major pathological origin.Recent studies have suggested genioglossal injury induced by CIH might be improved by adiponectin.The aim of this study was to investigate the effects of adiponectin on genioglossus contractile properties in rats exposed to CIH.Methods Thirty-nine healthy male Wistar rats were randomly divided into three groups:normal control (NC),CIH and adiponectin supplement (CIH+Ad) with 13 rats in each.Rats in NC were kept breathing normal air,while rats in CIH and CIH+Ad experienced the same CIH environment eight hours per day for 35 successive days.Rats in CIH+Ad were given intravenous adiponectin of 10 μg twice a week for 30 successive days.Rats in the NC and CIH were injected with normal saline as a control.After 35 days' CIH exposure,the levels of serum adiponectin and genioglossus contractile properties were compared.Results Serum adiponectin level was significantly lower in CIH than in NC (1210 ng/ml vs.2236 ng/ml).Serum adiponectin level in CIH+Ad (1844 ng/ml) was significantly higher than CIH but lower than NC.Twitch tension,time to peak tension,half relaxation time and tetanic tension were significantly lower in CIH than NC and improved in CIH+Ad.All mean tetanic fatigue indices decreased more rapidly in the first 20 seconds than during the subsequent 100 seconds.Tetanic fatigue indices in NC and CIH+Ad were significantly higher compared to CIH.Conclusions CIH could lead to hypoadiponectinaemia,impaired genioglossus contractile properties and decreased fatigue resistance in rats.Such changes could be partially offset by supplementation of adiponectin.

  3. Vulnerabilidade programática na prevenção da transmissão materno-fetal da AIDS Program deficiencies in the prevention of maternal-fetal transmission of AIDS

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    Katia V. de O. Feliciano

    2002-08-01

    Full Text Available OBJETIVOS: avaliar a operacionalidade das ações de prevenção da transmissão materno-fetal do HIV na assistência pré-natal. MÉTODOS: estudo descritivo realizado na cidade do Recife, Pernambuco, de maio a julho de 1998, em 27 unidades dos seis Distritos Sanitários: 19 Centros de Saúde, duas Maternidades e seis do Programas de Saúde da Família (PSF. A organização foi caracterizada por meio de observações e entrevistas com gerentes e equipes técnicas. Acompanhou-se o processo de trabalho durante, no mínimo, dois turnos, em dias da semana aleatoriamente selecionados, totalizando 214 horas. As 355 gestantes presentes responderam um questionário: idade, antecedentes obstétricos, número de consultas, acessibilidade e orientações recebidas. RESULTADOS: em 63,0% das unidades houve demanda reprimida. Somente 41,6% das gestantes em seguimento tiveram a consulta atual agendada pelo serviço após a anterior. Em relação às doenças sexualmente transmissíveis: todos solicitaram o teste luético e 67,0% convocaram os parceiros quando o exame é positivo; não houve oferta universal do teste anti-HIV, nenhum realizou aconselhamento, apenas 26,7% dos médicos que identificaram gestantes de risco para AIDS solicitaram o teste e 19,8% das gestantes receberam orientações sobre essas doenças. CONCLUSÕES: a vulnerabilidade institucional na execução das ações programáticas e o amplo conjunto de necessidades de saúde da mulher em idade reprodutiva reiteram a importância de organizar o pré-natal.OBJECTIVES: to assess the effectiveness of maternal-fetal HIV transmission prevention programs at the pre-natal care stage. METHODS:a descriptive study was held in the city of Recife, Pernambuco, from May to July 1998, in 27 locations of six Sanitary Districts: 19 Health Centers, two Maternity Clinics and six Family Health Programs (PSF. The study focused on observation and interviews of managers and technical teams. Their work was followed

  4. Association between maternal-fetal genetic histocompatibility and maternal undernutrition in mice: influence on intrauterine growth Associação entre histocompatibilidade genética materno-fetal e desnutrição materna em camundongos: influência no crescimento fetal

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    Celso M. Rebello

    2006-04-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the effects of maternal-fetal genetic histocompatibility and the association of that condition with maternal undernutrition regarding fetal growth and litter size. STUDY DESIGN: Fetuses that were either syngeneic or allogeneic with the mothers were bred, using mice of well-defined syngeneic strains (A/J and Balb/c. Pregnant mice were fed using either unrestricted normal diet with 22% protein, consumed ad libitum, or a diet containing 14% protein, with intake restricted to 70% of that consumed by the unrestricted group. At the end of gestation, the number of fetoplacental units and fetal losses, the fetal and placental weight, and the weights of fetal brain and liver were recorded. RESULTS: Fetuses from undernourished mothers showed a reduction in body, placental, and brain weight (P OBJETIVO: Avaliar os efeitos da histocompatibilidade genética materno-fetal e sua associação com a desnutrição materna em relação ao crescimento fetal e número de fetos. MÉTODOS: Fetos singênicos ou alogênicos em relação às respectivas mães foram obtidos através de cruzamentos de camundongos com linhagens genéticas bem definidas (A/J e Balb/c. As fêmeas grávidas foram alimentadas ad libitum com dieta normal contendo 22% de proteínas ou dieta com restrição, contendo 14% de proteína e aporte máximo de 70% do total consumido pelo grupo em dieta livre. No final da gestação, o número de unidades feto-placentárias e de perdas fetais, o peso da placenta e do feto, assim como o peso do cérebro e do fígado foram anotados. RESULTADOS: Os fetos das mães submetidas à desnutrição mostraram redução no peso corpóreo, placentário e cerebral (p<0.01, sendo que a associação entre a compatibilidade genética materno-fetal resultou em maior restrição ao crescimento fetal (p<0.01. Foi observada uma redução no número de fetos viáveis por fêmea entre os animais do grupo de restri

  5. Chronic intermittent fasting improves cognitive functions and brain structures in mice.

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    Liaoliao Li

    Full Text Available Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day fasting or high fat diet (45% caloric supplied by fat for 11 months. Mice on intermittent fasting had better learning and memory assessed by the Barnes maze and fear conditioning, thicker CA1 pyramidal cell layer, higher expression of drebrin, a dendritic protein, and lower oxidative stress than mice that had free access to regular diet (control mice. Mice fed with high fat diet was obese and with hyperlipidemia. They also had poorer exercise tolerance. However, these obese mice did not present significant learning and memory impairment or changes in brain structures or oxidative stress compared with control mice. These results suggest that intermittent fasting improves brain functions and structures and that high fat diet feeding started early in life does not cause significant changes in brain functions and structures in obese middle-aged animals.

  6. Chronic intermittent fasting improves cognitive functions and brain structures in mice.

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    Li, Liaoliao; Wang, Zhi; Zuo, Zhiyi

    2013-01-01

    Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day) fasting or high fat diet (45% caloric supplied by fat) for 11 months. Mice on intermittent fasting had better learning and memory assessed by the Barnes maze and fear conditioning, thicker CA1 pyramidal cell layer, higher expression of drebrin, a dendritic protein, and lower oxidative stress than mice that had free access to regular diet (control mice). Mice fed with high fat diet was obese and with hyperlipidemia. They also had poorer exercise tolerance. However, these obese mice did not present significant learning and memory impairment or changes in brain structures or oxidative stress compared with control mice. These results suggest that intermittent fasting improves brain functions and structures and that high fat diet feeding started early in life does not cause significant changes in brain functions and structures in obese middle-aged animals.

  7. Impairment of cognitive function and reduced hippocampal cholinergic activity in a rat model of chronic intermittent hypoxia

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    Chunling Zhao; Yan Chen; Chunlai Zhang; Linya Lü; Qian Xu

    2011-01-01

    The present study established a rat model of chronic intermittent hypoxia (CIH) to simulate obstructive sleep apnea syndrome. CIH rats were evaluated for cognitive function using the Morris water maze, and neuronal pathology in the hippocampus was observed using hematoxylin-eosin staining. In addition, hippocampal choline acetyl transferase (ChAT) and nicotinic acetylcholine receptor (nAChR) expression was determined by immunohistochemistry. Our results revealed necrotic hippocampal neurons, decreased ChAT and nAChR expression, as well as cognitive impairment in CIH rats. These results suggest that hippocampal neuronal necrosis and decreased cholinergic activity may be involved in CIH-induced cognitive impairment in rats.

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

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    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.

  9. Chronic Elevation of Liver Enzymes in Acute Intermittent Porphyria Initially Misdiagnosed as Autoimmune Hepatitis

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    A. González Estrada

    2011-01-01

    Full Text Available Autoimmune hepatitis is a disease characterized by an elevation of liver enzymes, as well as specific autoantibodies. It is more common in women than men. We describe a 32-year-old woman with elevated transaminases, autoantibodies, and a liver biopsy result suggestive of autoimmune hepatitis. The indicated treatment was administered without showing a satisfactory response. The patient had a family history of acute intermittent porphyria (AIP so we decided to begin treatment with hematin, achieving a complete remission of the symptoms. Acute intermittent porphyria is a rare condition characterized by neurovisceral symptoms, abdominal pain being the most common of them. The disease has a higher prevalence among young women and certain European countries such as Sweden, Great Britain, and Spain. A correct diagnosis and prompt treatment are essential because patients affected by AIP must have a strict followup due to the fatal outcome of the outbreaks.

  10. Validation of housekeeping genes in the brains of rats submitted to chronic intermittent hypoxia, a sleep apnea model.

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    Julian, Guilherme Silva; de Oliveira, Renato Watanabe; Perry, Juliana Cini; Tufik, Sergio; Chagas, Jair Ribeiro

    2014-01-01

    Obstructive sleep apnea (OSA) is a syndrome characterized by intermittent nocturnal hypoxia, sleep fragmentation, hypercapnia and respiratory effort, and it has been associated with several complications, such as diabetes, hypertension and obesity. Quantitative real-time PCR has been performed in previous OSA-related studies; however, these studies were not validated using proper reference genes. We have examined the effects of chronic intermittent hypoxia (CIH), which is an experimental model mainly of cardiovascular consequences of OSA, on reference genes, including beta-actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and eukaryotic 18S rRNA, in different areas of the brain. All stability analyses were performed using the geNorm, Normfinder and BestKeeper software programs. With exception of the 18S rRNA, all of the evaluated genes were shown to be stable following CIH exposure. However, gene stability rankings were dependent on the area of the brain that was analyzed and varied according to the software that was used. This study demonstrated that CIH affects various brain structures differently. With the exception of the 18S rRNA, all of the tested genes are suitable for use as housekeeping genes in expression analyses.

  11. Validation of housekeeping genes in the brains of rats submitted to chronic intermittent hypoxia, a sleep apnea model.

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    Guilherme Silva Julian

    Full Text Available Obstructive sleep apnea (OSA is a syndrome characterized by intermittent nocturnal hypoxia, sleep fragmentation, hypercapnia and respiratory effort, and it has been associated with several complications, such as diabetes, hypertension and obesity. Quantitative real-time PCR has been performed in previous OSA-related studies; however, these studies were not validated using proper reference genes. We have examined the effects of chronic intermittent hypoxia (CIH, which is an experimental model mainly of cardiovascular consequences of OSA, on reference genes, including beta-actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and eukaryotic 18S rRNA, in different areas of the brain. All stability analyses were performed using the geNorm, Normfinder and BestKeeper software programs. With exception of the 18S rRNA, all of the evaluated genes were shown to be stable following CIH exposure. However, gene stability rankings were dependent on the area of the brain that was analyzed and varied according to the software that was used. This study demonstrated that CIH affects various brain structures differently. With the exception of the 18S rRNA, all of the tested genes are suitable for use as housekeeping genes in expression analyses.

  12. Validation of Housekeeping Genes in the Brains of Rats Submitted to Chronic Intermittent Hypoxia, a Sleep Apnea Model

    Science.gov (United States)

    Julian, Guilherme Silva; de Oliveira, Renato Watanabe; Perry, Juliana Cini; Tufik, Sergio; Chagas, Jair Ribeiro

    2014-01-01

    Obstructive sleep apnea (OSA) is a syndrome characterized by intermittent nocturnal hypoxia, sleep fragmentation, hypercapnia and respiratory effort, and it has been associated with several complications, such as diabetes, hypertension and obesity. Quantitative real-time PCR has been performed in previous OSA-related studies; however, these studies were not validated using proper reference genes. We have examined the effects of chronic intermittent hypoxia (CIH), which is an experimental model mainly of cardiovascular consequences of OSA, on reference genes, including beta-actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and eukaryotic 18S rRNA, in different areas of the brain. All stability analyses were performed using the geNorm, Normfinder and BestKeeper software programs. With exception of the 18S rRNA, all of the evaluated genes were shown to be stable following CIH exposure. However, gene stability rankings were dependent on the area of the brain that was analyzed and varied according to the software that was used. This study demonstrated that CIH affects various brain structures differently. With the exception of the 18S rRNA, all of the tested genes are suitable for use as housekeeping genes in expression analyses. PMID:25289636

  13. High intensity aerobic exercise training improves chronic intermittent hypoxia-induced insulin resistance without basal autophagy modulation

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    Pauly, Marion; Assense, Allan; Rondon, Aurélie; Thomas, Amandine; Dubouchaud, Hervé; Freyssenet, Damien; Benoit, Henri; Castells, Josiane; Flore, Patrice

    2017-01-01

    Chronic intermittent hypoxia (IH) associated with obstructive sleep apnea (OSA) is a major risk factor for cardiovascular and metabolic diseases (insulin resistance: IR). Autophagy is involved in the pathophysiology of IR and high intensity training (HIT) has recently emerged as a potential therapy. We aimed to confirm IH-induced IR in a tissue-dependent way and to explore the preventive effect of HIT on IR-induced by IH. Thirty Swiss 129 male mice were randomly assigned to Normoxia (N), Intermittent Hypoxia (IH: 21–5% FiO2, 30 s cycle, 8 h/day) or IH associated with high intensity training (IH HIT). After 8 days of HIT (2*24 min, 50 to 90% of Maximal Aerobic Speed or MAS on a treadmill) mice underwent 14 days IH or N. We found that IH induced IR, characterized by a greater glycemia, an impaired insulin sensitivity and lower AKT phosphorylation in adipose tissue and liver. Nevertheless, MAS and AKT phosphorylation were greater in muscle after IH. IH associated with HIT induced better systemic insulin sensitivity and AKT phosphorylation in liver. Autophagy markers were not altered in both conditions. These findings suggest that HIT could represent a preventive strategy to limit IH-induced IR without change of basal autophagy. PMID:28255159

  14. Melatonin reduces microvascular damage and insulin resistance in hamsters due to chronic intermittent hypoxia.

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    Bertuglia, Silvia; Reiter, Russel J

    2009-04-01

    Obstructive sleep apnea (OSA) causes intermittent hypoxia (IH) associated with hypertension, insulin resistance and a systemic inflammatory response. We evaluated the effects of melatonin on vasodilation, capillary perfusion in hamster cheek pouch and insulin resistance, hypertension, and reactive oxygen species (ROS) and nitrate/nitrite levels after IH for 4 wk. Syrian hamsters were divided into four groups: control group (CON), IH group, and melatonin (10 mg/kg) intraperitoneally administered daily for 4 wk/30 min before intermittent air (MEL) or IH (IH + MEL) exposure. IH alone caused elevated blood pressure, increased hematocrit, fasting hyperglycemia, elevated ROS and nitrite/nitrate levels, and vasoconstriction and reduced microvascular perfusion. Melatonin treatment of IH-exposed animals decreased blood pressure, blood glucose, and ROS and nitrite/nitrate levels, and increased vasodilation and capillary perfusion. An oral glucose tolerance test was performed after 4 wk of IH. During the last 30 min of the hyperinsulinemic euglycemic clamp, blood glucose, and insulin levels were identically matched between groups, but the glucose infusion rate was significantly reduced in IH (29.9 +/- 1.9 mg/kg/min) versus IH + MEL group (45.4 +/- 1.5 mg/kg/min, P melatonin. In conclusion, protection induced by melatonin against functional and metabolic impairment in IH is related to the regulation of ROS and nitrite/nitrate levels in the microcirculation. These observations may have importance to OSA pathological changes.

  15. Interactions of chronic lead exposure and intermittent stress: consequences for brain catecholamine systems and associated behaviors and HPA axis function.

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    Virgolini, Miriam B; Chen, Kevin; Weston, Doug D; Bauter, Mark R; Cory-Slechta, Deborah A

    2005-10-01

    Elevated lead (Pb) burden and high stress levels are co-occurring risk factors in low socioeconomic status (SES) children. Our previous work demonstrated that maternal Pb exposure can permanently alter hypothalamic-pituitary-adrenal (HPA) axis function and responsivity to stress challenges in offspring. The current study sought to determine the consequences of chronic Pb exposures initiated later in development combined with variable intermittent stress challenges. Male rats were exposed chronically from weaning to 0, 50, or 150 ppm Pb acetate drinking solutions (producing blood Pb levels of challenges including novelty, cold, and restraint, was measured as changes in Fixed Interval (FI) schedule-controlled behavior in a subset of rats within each group. FI performance was modified by novelty stress only in Pb-treated rats, whereas cold and restraint stress effects were comparable across groups. Novelty elevated corticosterone equivalently across groups, but cold stress markedly increased corticosterone only in Pb-treated groups. The pattern of Pb-induced changes in serotonin (5-HT) or its metabolite 5-HIAA in frontal cortex, nucleus accumbens, striatum, and hypothalamus resembled that observed for basal corticosterone levels indicating a relationship between these variables. In addition to suggesting the potential for HPA axis-mediated effects of Pb on the central nervous system, these findings also raise questions about whether single chemicals studied in isolation from other relevant risk factors can adequately identify neurotoxic hazards.

  16. Moléculas que participan en el transporte de hierro materno-fetal: importancia del receptor 1 de transferrina y de la ferroportina en la placenta humana = Molecules implicated in maternal-fetal iron transport across the placental barrier: Role of Transferrin Receptor 1 and Ferroportin

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    Corrales Agudelo, Lady Vanessa

    2011-03-01

    Full Text Available La adecuada transferencia placentaria de hierro es crucial para satisfacer los altos requerimientos del feto y promover su adecuado crecimiento y desarrollo intrauterino; de otra parte, contribuye a prevenir la ferropenia y la anemia, entidades altamente prevalentes en los lactantes durante los primeros dos años de edad, que se asocian con mayor morbilidad y mortalidad en la infancia. La placenta es un órgano capaz de realizar diferentes adaptaciones en la producción de moléculas que participan en el transporte de hierro materno-fetal en respuesta al estado de hierro celular, para proveer la mayor disponibilidad de este mineral al feto. Esta revisión, pretende acercar al lector a los mecanismos metabólicos y moleculares relacionados con la captación, el transporte y la salida de hierro por la placenta hacia el feto, así como su regulación, para proporcionar elementos que le permitan comprender en forma integrada, la importancia de un adecuado estado de hierro materno antes y durante la gestación.

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

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    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.

  18. Cardiac Response to Chronic Intermittent Hypoxia with a Transition from Adaptation to Maladaptation: The Role of Hydrogen Peroxide

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    Xia Yin

    2012-01-01

    Full Text Available Obstructive sleep apnea (OSA is a highly prevalent respiratory disorder of sleep, and associated with chronic intermittent hypoxia (CIH. Experimental evidence indicates that CIH is a unique physiological state with potentially “adaptive” and “maladaptive” consequences for cardio-respiratory homeostasis. CIH is also a critical element accounting for most of cardiovascular complications of OSA. Cardiac response to CIH is time-dependent, showing a transition from cardiac compensative (such as hypertrophy to decompensating changes (such as failure. CIH-provoked mild and transient oxidative stress can induce adaptation, but severe and persistent oxidative stress may provoke maladaptation. Hydrogen peroxide as one of major reactive oxygen species plays an important role in the transition of adaptive to maladaptive response to OSA-associated CIH. This may account for the fact that although oxidative stress has been recognized as a driver of cardiac disease progression, clinical interventions with antioxidants have had little or no impact on heart disease and progression. Here we focus on the role of hydrogen peroxide in CIH and OSA, trying to outline the potential of antioxidative therapy in preventing CIH-induced cardiac damage.

  19. Effects of Gestational and Postnatal Exposure to Chronic Intermittent Hypoxia on Diaphragm Muscle Contractile Function in the Rat

    Science.gov (United States)

    McDonald, Fiona B.; Dempsey, Eugene M.; O'Halloran, Ken D.

    2016-01-01

    Alterations to the supply of oxygen during early life presents a profound stressor to physiological systems with aberrant remodeling that is often long-lasting. Chronic intermittent hypoxia (CIH) is a feature of apnea of prematurity, chronic lung disease, and sleep apnea. CIH affects respiratory control but there is a dearth of information concerning the effects of CIH on respiratory muscles, including the diaphragm—the major pump muscle of breathing. We investigated the effects of exposure to gestational CIH (gCIH) and postnatal CIH (pCIH) on diaphragm muscle function in male and female rats. CIH consisted of exposure in environmental chambers to 90 s of hypoxia reaching 5% O2 at nadir, once every 5 min, 8 h a day. Exposure to gCIH started within 24 h of identification of a copulation plug and continued until day 20 of gestation; animals were studied on postnatal day 22 or 42. For pCIH, pups were born in normoxia and within 24 h of delivery were exposed with dams to CIH for 3 weeks; animals were studied on postnatal day 22 or 42. Sham groups were exposed to normoxia in parallel. Following gas exposures, diaphragm muscle contractile, and endurance properties were examined ex vivo. Neither gCIH nor pCIH exposure had effects on diaphragm muscle force-generating capacity or endurance in either sex. Similarly, early life exposure to CIH did not affect muscle tolerance of severe hypoxic stress determined ex vivo. The findings contrast with our recent observation of upper airway dilator muscle weakness following exposure to pCIH. Thus, the present study suggests a relative resilience to hypoxic stress in diaphragm muscle. Co-ordinated activity of thoracic pump and upper airway dilator muscles is required for optimal control of upper airway caliber. A mismatch in the force-generating capacity of the complementary muscle groups could have adverse consequences for the control of airway patency and respiratory homeostasis. PMID:27462274

  20. Prevalence and severity of pain in adult end-stage renal disease patients on chronic intermittent hemodialysis: a systematic review

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    Brkovic T

    2016-06-01

    Full Text Available Tonci Brkovic,1 Eliana Burilovic,2 Livia Puljak3 1Department of Internal Medicine, Division of Nephrology, 2Department of Psychiatry, University Hospital Split, 3Department of Anatomy, Histology and Embryology, Laboratory for Pain Research, University of Split School of Medicine, Split, Croatia Objectives: Understanding the epidemiology of pain in patients on hemodialysis (HD is crucial for further improvement in managing pain. The aim of this study was to systematically review available evidence on the prevalence and severity of pain in adult end-stage renal disease patients on chronic intermittent HD. Materials and methods: We carried out a systematic review of the literature and developed a comprehensive search strategy based on search terms on pain and HD. We searched the databases MEDLINE, Scopus, PsycINFO, and CINAHL from the earliest date of each database to July 24, 2014. Manuscripts in all languages were taken into consideration. Two authors performed each step independently, and all disagreements were resolved after discussion with the third author. The quality of studies was estimated using the STROBE checklist and Cochrane risk-of-bias tool.Results: We included 52 studies with 6,917 participants. The prevalence of acute and chronic pain in HD patients was up to 82% and 92%, respectively. A considerable number of patients suffered from severe pain. Various locations and causes of pain were described, with most of the studies reporting pain in general, pain related to arteriovenous access, headache, and musculoskeletal pain.Conclusion: The findings of this systematic review indicate high prevalence of pain in HD patients and considerable gaps and limitations in the available evidence. Pain in this population should be recognized as a considerable health concern, and the nephrology community should promote pain management in HD patients as a clinical and research priority to improve patients’ quality of life and pain

  1. A two-phase model for chronic disease processes under intermittent inspection.

    Science.gov (United States)

    Wu, Ying; Cook, Richard J

    2017-02-26

    A model is developed for chronic diseases with an indolent phase that is followed by a phase with more active disease resulting in progression and damage. The time scales for the intensity functions for the active phase are more naturally based on the time since the start of the active phase, corresponding to a semi-Markov formulation. This two-phase model enables one to fit a separate regression model for the duration of the indolent phase and intensity-based models for the more active second phase. In cohort studies for which the disease status is only known at a series of clinical assessment times, transition times are interval-censored, which means the time origin for phase II is interval-censored. Weakly parametric models with piecewise constant baseline hazard and rate functions are specified, and an expectation-maximization algorithm is described for model fitting. Simulation studies examining the performance of the proposed model show good performance under maximum likelihood and two-stage estimation. An application to data from the motivating study of disease progression in psoriatic arthritis illustrates the procedure and identifies new human leukocyte antigens associated with the duration of the indolent phase. Copyright © 2017 John Wiley & Sons, Ltd.

  2. The efficacy of intermittent cervical traction in patents with chronic neck pain.

    Science.gov (United States)

    Borman, Pinar; Keskin, Dilek; Ekici, Betul; Bodur, Hatice

    2008-10-01

    Previous studies about the usefulness of traction therapy have concluded with conflicting results. The aim of this study was to examine its efficacy in chronic neck pain. Forty-two patients with at least 6 weeks of nonspecific neck pain were selected for the study. Data about demographic characteristics including age, sex, body mass index, duration of cervical pain, working status, smoking status, and regular exercise were recorded. Each patient was randomly assigned to Group 1-receiving only standard physical therapy including hot pack, ultrasound therapy and exercise program and Group 2-treated with traction therapy in addition to standard physical therapy. The patients were reevaluated at the end of the therapy. The main outcome measures of the treatment were pain intensity by visual analog scale (VAS), disability by neck disability index (NDI), and quality of life assessed by Nottingham Health Profile (NHP). Twenty-four female and 18 male patients with mean age of 48.2+/-11.5 years and a mean disease duration of 4.3+/-2.9 years were included to the study. There were no differences between the groups in terms of age, sex, pain intensity, and scores of NHP and NDI at entry. There were 21 patients in both groups. Both groups improved significantly in pain intensity and the scores of NDI and physical subscles of NHP at the end of the therapies (ppain scores in both groups (pneck pain. We suggest the clinicians to consider this condition and to focus on exercise therapy in the management of patients suffering from this condition.

  3. Mother-to-child transmission of different HIV-1 subtypes among ARV Naïve infected pregnant women in Nigeria Transmissão materno-fetal de diferentes subtipos de HIV-1 entre gestantes infectadas na Nigéria

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    G.N. Odaibo

    2006-04-01

    Full Text Available The rate of mother-to-child transmission (MTCT of HIV as well as the implications of the circulating multiple subtypes to MTCT in Nigeria are not known. This study was therefore undertaken to determine the differential rates of MTCT of HIV-1 subtypes detected among infected pregnant women before ARV intervention therapy became available in Nigeria. Twenty of the HIV-positive women who signed the informed consent form during pregnancy brought their babies for follow-up testing at age 18-24 months. Plasma samples from both mother and baby were tested for HIV antibody at the Department of Virology, UCH, Ibadan, Nigeria. All positive samples (plasma and peripheral blood mononuclear cells - PBMCs were shipped to the Institute of Tropical Medicine, Antwerp, Belgium, where the subtype of the infecting virus was determined using the HMA technique. Overall, a mother-to-child HIV transmission rate of 45% was found in this cohort. Specifically, 36.4%, 66.7% and 100% of the women infected with HIV-1 CRF02 (IbNg, G and B, respectively, transmitted the virus to their babies. As far as it can be ascertained, this is the first report on the rate of MTCT of HIV in Nigeria. The findings reported in this paper will form a useful reference for assessment of currently available therapeutic intervention of MTCT in the country.A taxa de transmissão materno-fetal (MTCT do HIV bem como as implicações dos múltiplos subtipos circulantes para MTCT na Nigéria não são conhecidos. Este estudo foi realizado para determinar as diferentes taxas de MTCT dos subtipos de HIV-1 detectados entre gestantes infectadas antes que a administração da terapia ARV estivesse disponível na Nigéria. Vinte das mulheres HIV positivas que assinaram o consentimento durante a gravidez trouxeram seus filhos para seguimento na idade de 18-24 meses. Amostras de plasma de ambos, mãe e filho foram testadas para anticorpos HIV no Departamento de Virologia, UCH, Ibadan, Nigéria. Todas as

  4. Analysis of the stability of housekeeping gene expression in the left cardiac ventricle of rats submitted to chronic intermittent hypoxia.

    Science.gov (United States)

    Julian, Guilherme Silva; Oliveira, Renato Watanabe de; Tufik, Sergio; Chagas, Jair Ribeiro

    2016-01-01

    Obstructive sleep apnea (OSA) has been associated with oxidative stress and various cardiovascular consequences, such as increased cardiovascular disease risk. Quantitative real-time PCR is frequently employed to assess changes in gene expression in experimental models. In this study, we analyzed the effects of chronic intermittent hypoxia (an experimental model of OSA) on housekeeping gene expression in the left cardiac ventricle of rats. Analyses via four different approaches-use of the geNorm, BestKeeper, and NormFinder algorithms; and 2-ΔCt (threshold cycle) data analysis-produced similar results: all genes were found to be suitable for use, glyceraldehyde-3-phosphate dehydrogenase and 18S being classified as the most and the least stable, respectively. The use of more than one housekeeping gene is strongly advised. RESUMO A apneia obstrutiva do sono (AOS) tem sido associada ao estresse oxidativo e a várias consequências cardiovasculares, tais como risco aumentado de doença cardiovascular. A PCR quantitativa em tempo real é frequentemente empregada para avaliar alterações na expressão gênica em modelos experimentais. Neste estudo, analisamos os efeitos da hipóxia intermitente crônica (um modelo experimental de AOS) na expressão de genes de referência no ventrículo cardíaco esquerdo de ratos. Análises a partir de quatro abordagens - uso dos algoritmos geNorm, BestKeeper e NormFinder e análise de dados 2-ΔCt (ciclo limiar) - produziram resultados semelhantes: todos os genes mostraram-se adequados para uso, sendo que gliceraldeído-3-fosfato desidrogenase e 18S foram classificados como o mais e o menos estável, respectivamente. A utilização de mais de um gene de referência é altamente recomendada.

  5. Repeated Cycles of Chronic Intermittent Ethanol Exposure Increases Basal Glutamate in the Nucleus Accumbens of Mice without affecting glutamate transport

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    William C. Griffin

    2015-02-01

    Full Text Available Repeated cycles of chronic intermittent ethanol (CIE exposure increase voluntary consumption of ethanol in mice. Previous work has shown that extracellular glutamate in the nucleus accumbens (NAc is significantly elevated in ethanol dependent mice and that pharmacologically manipulating glutamate concentrations in the NAc will alter ethanol drinking, indicating that glutamate homeostasis plays a crucial role in ethanol drinking in this model. The present studies were designed to measure extracellular glutamate at a time point in which mice would ordinarily be allowed voluntary access to ethanol in the CIE model and, additionally, to measure glutamate transport capacity in the NAc at the same time point. Extracellular glutamate was measured using quantitative microdialysis procedures. Glutamate transport capacity was measured under Na+ dependent and Na+ independent conditions to determine whether the function of excitatory amino acid transporters (EAATs; also known as system XAG or of system Xc- (Glial cysteine-glutamate exchanger was influenced by CIE exposure. The results of the quantitative microdialysis experiment confirm increased extracellular glutamate (~2 –fold in the NAc of CIE exposed mice (i.e. ethanol-dependent compared to non-dependent mice in the NAc, consistent with earlier work. However, the increase in extracellular glutamate was not due to altered transporter function in the NAc of ethanol-dependent mice, because neither Na+ dependent nor Na+ independent glutamate transport was significantly altered by CIE exposure. These findings point to the possibility that hyperexcitability of cortical-striatal pathways underlies the increases in extracellular glutamate found in the nucleus accumbens of ethanol-dependent mice.

  6. Withdrawal from chronic, intermittent access to a highly palatable food induces depressive-like behavior in compulsive eating rats.

    Science.gov (United States)

    Iemolo, Attilio; Valenza, Marta; Tozier, Lisa; Knapp, Clifford M; Kornetsky, Conan; Steardo, Luca; Sabino, Valentina; Cottone, Pietro

    2012-09-01

    The increased availability of highly palatable foods is a major contributing factor toward the development of compulsive eating in obesity and eating disorders. It has been proposed that compulsive eating may develop as a form of self-medication to alleviate the negative emotional state associated with withdrawal from highly palatable foods. This study was aimed at determining whether withdrawal from chronic, intermittent access to a highly palatable food was responsible for the emergence of depressive-like behavior. For this purpose, a group of male Wistar rats was provided a regular chow diet 7 days a week (Chow/Chow), whereas a second group of rats was provided chow for 5 days a week, followed by a 2-day access to a highly palatable sucrose diet (Chow/Palatable). Following 7 weeks of diet alternation, depressive-like behavior was assessed during withdrawal from the highly palatable diet and following renewed access to it, using the forced swim test, the sucrose consumption test, and the intracranial self-stimulation threshold procedure. It was found that Chow/Palatable rats withdrawn from the highly palatable diet showed increased immobility time in the forced swim test and decreased sucrose intake in the sucrose consumption test compared with the control Chow/Chow rats. Interestingly, the increased immobility in the forced swim test was abolished by renewing access to the highly palatable diet. No changes were observed in the intracranial self-stimulation threshold procedure. These results validate the hypothesis that withdrawal from highly palatable food is responsible for the emergence of depressive-like behavior, and they also show that compulsive eating relieves the withdrawal-induced negative emotional state.

  7. Chronic intermittent hypoxia depresses afferent neurotransmission in NTS neurons by a reduction in the number of active synapses.

    Science.gov (United States)

    Almado, Carlos Eduardo L; Machado, Benedito H; Leão, Ricardo M

    2012-11-21

    Long-term synaptic plasticity has been recently described in brainstem areas associated to visceral afferent sensory integration. Chronic intermittent hypoxia (CIH), an animal model for studying obstructive sleep apnea in humans, depresses the afferent neurotransmission in nucleus tractus solitarii (NTS) neurons, which affect respiratory and autonomic regulation. Here we identified the synaptic mechanisms of CIH-induced depression of the afferent neurotransmission in NTS neurons in juvenile rats. We verified that CIH reduced the amplitude of both NMDA and non-NMDA glutamatergic excitatory currents (eEPSCs) evoked by tractus solitarii stimulation (TS-eEPSC) of second-order neurons in the NTS. No changes were observed in release probability, evidenced by absence of any CIH-elicited effects on short-term depression and failures in EPSCs evoked in low calcium. CIH also produced no changes in TS-eEPSC quantal size, since the amplitudes of both low calcium-evoked EPSCs and asynchronous TS-eEPSCs (evoked in the presence of Sr(2+)) were unchanged. Using single TS afferent fiber stimulation in slices from control and CIH rats we clearly show that CIH reduced the quantal content of the TS-eEPSCs without affecting the quantal size or release probability, suggesting a reduction in the number of active synapses as the mechanism of CIH induced TS-eEPSC depression. In accordance with this concept, the input-output relationship of stimulus intensity and TS-eEPSC amplitude shows an early saturation in CIH animals. These findings open new perspectives for a better understanding of the mechanisms underlying the synaptic plasticity in the brainstem sensory neurons under challenges such as those produced by CIH in experimental and pathological conditions.

  8. Mice Exposed to Chronic Intermittent Hypoxia Simulate Clinical Features of Deficiency of both Qi and Yin Syndrome in Traditional Chinese Medicine

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    Chengzhi Chai

    2011-01-01

    Full Text Available Deficiency of both Qi and Yin Syndrome (DQYS is one of the common syndromes in traditional Chinese medicine (TCM, mainly characterized by tiredness, emaciation, anorexia, fidget, palpitation and rapid pulse, and so forth. Currently, there is no available animal model which can reflect the clinical features of this syndrome. In the present paper, we observed the time-course changes of whole behavior, body weight, food intake, locomotive activity and electrocardiogram in mice exposed to chronic intermittent hypoxia for 6 weeks, and measured bleeding time at last according to the clinical features of DQYS and one key pathological factor. The results showed that the mice exposed to intermittent hypoxia for certain time presented lackluster hair, dull looking hair, resistance, attacking, body weight loss, food intake decline, locomotive activity decrease, heart rate quickening and T wave elevating, which were similar to the major clinical features of DQYS. Meanwhile, bleeding time shortening was also found, which was consistent with the clinical fact that DQYS often accompanied with blood stasis. The possible explanation was also outlined according to the available literature. Such findings suggested chronic intermittent hypoxia could induce similar symptoms and signs in mice accorded with the clinical features of DQYS, which provided a suitable animal model for evaluation of drugs for the treatment of this syndrome and further exploration of pathological process or correlation of the syndrome and related diseases.

  9. Mice Exposed to Chronic Intermittent Hypoxia Simulate Clinical Features of Deficiency of both Qi and Yin Syndrome in Traditional Chinese Medicine.

    Science.gov (United States)

    Chai, Chengzhi; Kou, Junping; Zhu, Danni; Yan, Yongqing; Yu, Boyang

    2011-01-01

    Deficiency of both Qi and Yin Syndrome (DQYS) is one of the common syndromes in traditional Chinese medicine (TCM), mainly characterized by tiredness, emaciation, anorexia, fidget, palpitation and rapid pulse, and so forth. Currently, there is no available animal model which can reflect the clinical features of this syndrome. In the present paper, we observed the time-course changes of whole behavior, body weight, food intake, locomotive activity and electrocardiogram in mice exposed to chronic intermittent hypoxia for 6 weeks, and measured bleeding time at last according to the clinical features of DQYS and one key pathological factor. The results showed that the mice exposed to intermittent hypoxia for certain time presented lackluster hair, dull looking hair, resistance, attacking, body weight loss, food intake decline, locomotive activity decrease, heart rate quickening and T wave elevating, which were similar to the major clinical features of DQYS. Meanwhile, bleeding time shortening was also found, which was consistent with the clinical fact that DQYS often accompanied with blood stasis. The possible explanation was also outlined according to the available literature. Such findings suggested chronic intermittent hypoxia could induce similar symptoms and signs in mice accorded with the clinical features of DQYS, which provided a suitable animal model for evaluation of drugs for the treatment of this syndrome and further exploration of pathological process or correlation of the syndrome and related diseases.

  10. Chronic intermittent hypoxia from pedo-stage decreases glucose transporter 4 expression in adipose tissue and causes insulin resistance

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin; CAO Zhao-long; HAN Fang; GAO Zhan-cheng; HE Quan-ying

    2010-01-01

    Background The persistence of sleep disordered breathing (SDB) symptoms after tonsil and/or adenoid (T&A) surgery are common in children with obstructive sleep apnea (OSA). We tested the hypothesis that disturbances of glucose transporters (GLUTs) in intraabdominal adipose tissue caused by chronic intermittent hypoxia (CIH) from the pedo-period could facilitate the appearance of periphery insulin resistance in Sprague-Dawley (SD) rats. We tested the hypothesis that the changes of GLUTs in adipose tissue may be one of the reasons for persistent SDB among clinical OSA children after T&A surgery.Methods Thirty 21-day-old SD rats were randomly divided into a CIH group, a chronic continuous hypoxia (CCH) group, and a normal oxygen group (control group) and exposed for 40 days. The changes of weight, fasting blood glucose and fasting blood insulin levels were measured. Hyperinsulinemic-euglycemic clamp techniques were used to measure insulin resistance in each animal. Real-time quantitative PCR and Westem blotting were used to measure GLUT Mrna and proteins in intraabdominal adipose tissue. Additional intraabdomial white adipose tissue (WAT) was also processed into paraffin sections and directly observed for GLUTs1-4 expression.Results When compared with control group, CIH increased blood fasting insulin levels, (245.07±53.89) pg/ml vs. (168.63±38.70) pg/ml, p=0.038, and decreased the mean glucose infusion rate (GIR), (7.25±1.29) mg·kg~(-1)·min~(-1) vs. (13.34±1.54) mg·kg~(-1)·min~(-1), P<0.001. GLUT-4 Mrna and protein expression was significantly reduced after CIH compared with CCH or normal oxygen rats, 0.002±0.002 vs. 0.039±0.009, P <0.001; 0.642±0.073 vs. 1.000±0.103, P=0.035.Conclusions CIH in young rats could induce insulin resistance via adverse effects on glycometabolism. These findings emphasize the importance of early detection and treatment of insulin insensitivity in obese childhood OSA.

  11. Energy intermittency

    CERN Document Server

    Sorensen, Bent

    2014-01-01

    The first book to consider intermittency as a key point of an energy system, Energy Intermittency describes different levels of variability for traditional and renewable energy sources, presenting detailed solutions for handling energy intermittency through trade, collaboration, demand management, and active energy storage. Addressing energy supply intermittency systematically, this practical text:Analyzes typical time-distributions and intervals between episodes of demand-supply mismatch and explores their dependence on system layouts and energy source characteristicsSimulates scenarios regar

  12. Adiponectin protects rat myocardium against chronic intermittent hypoxia-induced injury via inhibition of endoplasmic reticulum stress.

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    Wenxiao Ding

    Full Text Available Obstructive sleep apnea syndrome (OSAS is associated with many cardiovascular disorders such as heart failure, hypertension, atherosclerosis, and arrhythmia and so on. Of the many associated factors, chronic intermittent hypoxia (CIH in particular is the primary player in OSAS. To assess the effects of CIH on cardiac function secondary to OSAS, we established a model to study the effects of CIH on Wistar rats. Specifically, we examined the possible underlying cellular mechanisms of hypoxic tissue damage and the possible protective role of adiponectin against hypoxic insults. In the first treatment group, rats were exposed to CIH conditions (nadir O2, 5-6% for 8 hours/day, for 5 weeks. Subsequent CIH-induced cardiac dysfunction was measured by echocardiograph. Compared with the normal control (NC group, rats in the CIH-exposed group experienced elevated levels of left ventricular end-systolic dimension and left ventricular end-systolic volume and depressed levels of left ventricular ejection fraction and left ventricular fractional shortening (p<0.05. However, when adiponectin (Ad was added in CIH + Ad group, we saw a rescue in the elevations of the aforementioned left ventricular function (p<0.05. To assess critical cardiac injury, we detected myocardial apoptosis by Terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL analysis. It was showed that the apoptosis percentage in CIH group (2.948% was significantly higher than that in NC group (0.4167% and CIH + Ad group (1.219% (p<0.05. Protein expressions of cleaved caspase-3, cleaved caspase-9, and cleaved-caspase-12 validated our TUNEL results (p<0.05. Mechanistically, our results demonstrated that the proteins expressed with endoplasmic reticulum stress and the expression of reactive oxygen species (ROS were significantly elevated under CIH conditions, whereas Ad supplementation partially decreased them. Overall, our results suggested that Ad augmentation could improve CIH

  13. Adiponectin protects the genioglossus of rats against chronic intermittent hypoxia-induced injury via inhibition of endoplasmic reticulum stress

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-feng; HUANG Han-peng; DING Wen-xiao; DING Ning; LU Gan; LIU Jian-nan; ZHANG Xi-long

    2013-01-01

    Background Obstructive sleep apnea hypopnea syndrome,characterized by chronic intermittent hypoxia (CIH),is closely correlated with genioglossus dysfunction.CIH has been identified to mediate mitochondrial damage in genioglossus.It has been reported that endoplasmic reticulum stress (ERS) could be induced by mitochondrial dysfunction.This study aimed to investigate the role of ERS in CIH-induced genioglossus injury,as well as the possible intervention effect of adiponectin (Ad) supplement in rats.Methods Forty-five male Wistar rats were randomly divided into three groups and submitted to room air (group A,n=15) as a control or CIH (groups B and C,n=15,respectively).Throughout the exposure period,intravenous Ad was given in group C; while intravenous normal saline was simultaneously given in groups A and B.After 35-day exposure,genioglossus samples were obtained from the pentobarbital-anaesthetized rats via surgical dissection,following blood sampling.Western blotting was applied to detect expressions of ERS signals and associated apoptotic pathways in genioglossus.Serum adiponectin levels were assessed via enzyme-linked immunosorbent assay (ELISA).Results Significant hypoadiponectinemia was revealed in group B only (P <0.05).Compared to those in groups A and C,expressions of markers involved in ERS,such as glucose regulated protein 78 (GRP78),p-PERK,phosphorylated eukaryotic initiation factor 2α (p-elF2α),phosphorylated inositol-requiring transmembrane kinase/endoribonuclease 1α (p-IRE1α),spliced X-Box binding protein 1 (XBP1s) and activating transcription factor 6 (ATF6),were significantly enhanced in group B (all P <0.01); while no significant difference was shown between groups A and C (all P >0.05).ERS-associated apoptotic pathways were remarkably activated in group B.The involved markers detected as the expression of CCAAT/enhancer binding protein homologous protein (CHOP),B-cell lymphoma/leukemia associatied X protein (BAX)and caspase-12 were

  14. Early Life Exposure to Chronic Intermittent Hypoxia Primes Increased Susceptibility to Hypoxia-Induced Weakness in Rat Sternohyoid Muscle During Adulthood

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    Fiona B Mcdonald

    2016-03-01

    Full Text Available Intermittent hypoxia is a feature of apnea of prematurity, chronic lung disease and sleep apnea. Despite the clinical relevance, the long-term effects of hypoxic exposure in early life on respiratory control are not well defined. We recently reported that exposure to chronic intermittent hypoxia (CIH during postnatal development (pCIH causes upper airway muscle weakness in both sexes, which persists for several weeks. We sought to examine if there are persistent sex-dependent effects of pCIH on respiratory muscle function into adulthood and/or increased susceptibility to re-exposure to CIH in adulthood in animals previously exposed to CIH during postnatal development. We hypothesized that pCIH would cause long-lasting muscle impairment and increased susceptibility to subsequent hypoxia. Within 24 hours of delivery, pups and their respective dams were exposed to CIH: 90s of hypoxia reaching 5% O2 at nadir; once every 5 min, 8 hrs per day for 3 weeks. Sham groups were exposed to normoxia in parallel. Three groups were studied: sham; pCIH; and pCIH combined with adult CIH (p+aCIH, where a subset of the pCIH-exposed pups were re-exposed to the same CIH paradigm beginning at 13 weeks. Following gas exposures, sternohyoid and diaphragm muscle isometric contractile and endurance properties were examined ex vivo. There was no apparent lasting effect of pCIH on respiratory muscle function in adults. However, in both males and females, re-exposure to CIH in adulthood in pCIH-exposed animals caused sternohyoid (but not diaphragm weakness. Exposure to this paradigm of CIH in adulthood alone had no effect on muscle function. Persistent susceptibility in pCIH-exposed airway dilator muscle to subsequent hypoxic insult may have implications for the control of airway patency in adult humans exposed to intermittent hypoxic stress during early life.

  15. Early life exposure to chronic intermittent Hypoxia Primes Increased Susceptibility to Hypoxia-Induced Weakness in Rat Sternohyoid Muscle during adulthood.

    LENUS (Irish Health Repository)

    McDonald, Fiona B

    2016-03-01

    Intermittent hypoxia is a feature of apnea of prematurity (AOP), chronic lung disease, and sleep apnea. Despite the clinical relevance, the long-term effects of hypoxic exposure in early life on respiratory control are not well defined. We recently reported that exposure to chronic intermittent hypoxia (CIH) during postnatal development (pCIH) causes upper airway muscle weakness in both sexes, which persists for several weeks. We sought to examine if there are persistent sex-dependent effects of pCIH on respiratory muscle function into adulthood and\\/or increased susceptibility to re-exposure to CIH in adulthood in animals previously exposed to CIH during postnatal development. We hypothesized that pCIH would cause long-lasting muscle impairment and increased susceptibility to subsequent hypoxia. Within 24 h of delivery, pups and their respective dams were exposed to CIH: 90 s of hypoxia reaching 5% O2 at nadir; once every 5 min, 8 h per day for 3 weeks. Sham groups were exposed to normoxia in parallel. Three groups were studied: sham; pCIH; and pCIH combined with adult CIH (p+aCIH), where a subset of the pCIH-exposed pups were re-exposed to the same CIH paradigm beginning at 13 weeks. Following gas exposures, sternohyoid and diaphragm muscle isometric contractile and endurance properties were examined ex vivo. There was no apparent lasting effect of pCIH on respiratory muscle function in adults. However, in both males and females, re-exposure to CIH in adulthood in pCIH-exposed animals caused sternohyoid (but not diaphragm) weakness. Exposure to this paradigm of CIH in adulthood alone had no effect on muscle function. Persistent susceptibility in pCIH-exposed airway dilator muscle to subsequent hypoxic insult may have implications for the control of airway patency in adult humans exposed to intermittent hypoxic stress during early life.

  16. Angiotensin II type 1a receptors in subfornical organ contribute towards chronic intermittent hypoxia-associated sustained increase in mean arterial pressure.

    Science.gov (United States)

    Saxena, Ashwini; Little, Joel T; Nedungadi, T Prashant; Cunningham, J Thomas

    2015-03-01

    Sleep apnea is associated with hypertension. The mechanisms contributing to a sustained increase in mean arterial pressure (MAP) even during normoxic awake-state remain unknown. Rats exposed to chronic intermittent hypoxia for 7 days, a model of the hypoxemia associated with sleep apnea, exhibit sustained increases in MAP even during the normoxic dark phase. Activation of the renin-angiotensin system (RAS) has been implicated in chronic intermittent hypoxia (CIH) hypertension. Since the subfornical organ (SFO) serves as a primary target for the central actions of circulating ANG II, we tested the effects of ANG II type 1a receptor (AT1aR) knockdown in the SFO on the sustained increase in MAP in this CIH model. Adeno-associated virus carrying green fluorescent protein (GFP) and small-hairpin RNA against either AT1aR or a scrambled control sequence (SCM) was stereotaxically injected in the SFO of rats. After recovery, MAP, heart rate, respiratory rate, and activity were continuously recorded using radiotelemetry. In the normoxic groups, the recorded variables did not deviate from the baseline values. Both CIH groups exhibited significant increases in MAP during CIH exposures (P SCM-injected group exhibited a sustained increase in MAP (P SCM-CIH group. Our data indicate that AT1aRs in the SFO are critical for the sustained elevation in MAP and increased FosB/ΔFosB expression in forebrain autonomic nuclei associated with CIH.

  17. Soluble Receptor for Advanced Glycation End Product Ameliorates Chronic Intermittent Hypoxia Induced Renal Injury, Inflammation, and Apoptosis via P38/JNK Signaling Pathways

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    Xu Wu

    2016-01-01

    Full Text Available Obstructive sleep apnea (OSA associated chronic kidney disease is mainly caused by chronic intermittent hypoxia (CIH triggered tissue damage. Receptor for advanced glycation end product (RAGE and its ligand high mobility group box 1 (HMGB1 are expressed on renal cells and mediate inflammatory responses in OSA-related diseases. To determine their roles in CIH-induced renal injury, soluble RAGE (sRAGE, the RAGE neutralizing antibody, was intravenously administered in a CIH model. We also evaluated the effect of sRAGE on inflammation and apoptosis. Rats were divided into four groups: (1 normal air (NA, (2 CIH, (3 CIH+sRAGE, and (4 NA+sRAGE. Our results showed that CIH accelerated renal histological injury and upregulated RAGE-HMGB1 levels involving inflammatory (NF-κB, TNF-α, and IL-6, apoptotic (Bcl-2/Bax, and mitogen-activated protein kinases (phosphorylation of P38, ERK, and JNK signal transduction pathways, which were abolished by sRAGE but p-ERK. Furthermore, sRAGE ameliorated renal dysfunction by attenuating tubular endothelial apoptosis determined by immunofluorescence staining of CD31 and TUNEL. These findings suggested that RAGE-HMGB1 activated chronic inflammatory transduction cascades that contributed to the pathogenesis of the CIH-induced renal injury. Inhibition of RAGE ligand interaction by sRAGE provided a therapeutic potential for CIH-induced renal injury, inflammation, and apoptosis through P38 and JNK pathways.

  18. Intermittent and graded exercise effects on NK cell degranulation markers LAMP-1/LAMP-2 and CD8(+)CD38(+) in chronic fatigue syndrome/myalgic encephalomyelitis.

    Science.gov (United States)

    Broadbent, Suzanne; Coutts, Rosanne

    2017-03-01

    There is substantial evidence of immune system dysfunction in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) but little is understood of exercise training effects on lymphocyte function in this illness. This study investigated whether graded and intermittent exercise improved CD8(+) lymphocyte activation and natural killer cell degranulation markers compared to no exercise. Twenty-four chronic fatigue syndrome (CFS) patients (50.2 ± 10 year) were randomized to graded exercise (GE), intermittent exercise (IE) or usual care (UC) groups; a control group (CTL) of 18 matched sedentary non-CFS/ME participants were included for immunological variable comparisons. Main outcome measures were pre- and postintervention expression of CD3(+)CD8(+)CD38(+) and CD3(-)CD16(+)56(+)CD107a(+) (LAMP-1) CD107b(+) (LAMP-2) and aerobic exercise capacity. The postintervention percentage of NK cells expressing LAMP-1 and -2 was significantly higher in IE compared to UC, and higher in GE compared to UC and CTL LAMP-1 and LAMP-2 expression (absolute numbers and percent positive) increased significantly pre-to-postintervention for both GE and IE Preintervention, the absolute number of CD8(+)CD38(+) cells was significantly lower in CTL compared to UC and IE There were no significant pre- to postintervention changes in CD8(+)CD38(+) expression for any group. Aerobic exercise capacity was significantly improved by GE and IE Twelve weeks of GE and IE increased the expression of NK cell activation and degranulation markers, suggesting enhanced immunosurveillance. Low-intensity exercise may also reduce CD8(+)CD38(+) expression, a marker of inflammation. Both GE and IE improved exercise capacity without worsening CFS/ME symptoms, and more robust trials of these exercise modalities are warranted.

  19. The materno-fetal interface in llama (Lama guanicoe glama A interface materno-fetal em lhamas (Lama guanicoe glama

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    David M. Iturrizaga

    2007-06-01

    Full Text Available Samples from 9 llamas (28 through 36 weeks of gestation were collected and fixed in 4% buffered paraformaldehyde (light microscopy and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy. The material was processed in paraplast and slides (5mm were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.Fragmentos da placenta de 9 animais (28-36 semanas de gestação, provenientes do Instituto Veterinario de Investigaciones Tropicales y de Altura (IVITA, Cusco-Peru, e da Universidad del Altiplano (UNA, Puno-Peru, foram colhidos e fixados em paraformoldeído 4% em PBS para microscopia de luz e em glutaraldeido em 2,5% PBS para microscopia eletrônica de transmissão e de varredura. O material incluido em paraplast cortado com 5 mm foi processado para HE, PAS, Tricrômio de Masson, fosfatase ácida e Perl's e para imuno-histoquimica da uteroferrina. Os resultados mostraram que a placenta da lhama é corialantóide, difusa, pregueada e epiteliocorial e o feto está recoberto pela membrana epidermal. O trofoblasto possui morfologia variada: células cúbicas, arredondadas ou triangulares, com citoplasma contendo grânulos PAS+. Células binucleadas com citoplasma aumentado e núcleo arredondado e células trofoblásticas aumentados com múltiplos núcleos, também foram observadas. Grande quantidade de vasos sanguíneos foi observada entre as células do epitélio uterino e ao redor das projeções coriônicas, as quais estavam subdivididas. A atividade glandular foi demonstrada pelas reações de PAS, Perl's e fosfatase ácida positivas e pela imunolocalização da uteroferrina na luz e epitélio glandular. As glândulas uterinas abrem-se nos espaços formados pelas aréolas, as quais estavam preenchidas por material PAS+. Os fetos das lhamas estavam recobertos pela membrana epidermal, constituída por um epitélio estratificado composto por mais de 7 camadas de células mono, bi ou trinucleadas. A alta vascularização das superfícies materna e fetais indica intensa capacidade de trocas de substâncias entre as duas superfícies, e a atividade metabólica mostrada pelas glândulas uterinas sugere adaptação da gestação às altitudes elevadas do habitat natural desta espécie.

  20. Immunoreactivity for neuronal NOS and fluorescent indication of NO formation in the NTS of juvenile rats submitted to chronic intermittent hypoxia.

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    Pajolla, Gisela P; Accorsi-Mendonça, Daniela; Lunardi, Claure N; Bendhack, Lusiane M; Machado, Benedito H; Llewellyn-Smith, Ida J

    2009-06-15

    Exposure to chronic intermittent hypoxia (CIH) leads to significant autonomic and respiratory changes, similar to those observed in obstructive sleep apnea. The hypertension associated with CIH is due to sympathoexcitation triggered by long-term exposure to intermittent hypoxia. However, the mechanisms underlying these effects are unknown. Changes in central regulation of sympathetic activity may underlie CIH-induced hypertension. Since NO appears to be mainly sympathoinhibitory in the nucleus of the solitary tract (NTS), we hypothesized that CIH augments sympathetic activity, in part by reducing neuronal nitric oxide synthase (nNOS) expression and consequently nitric oxide (NO) production in this brain region. To test our hypothesis, juvenile male Wistar rats were exposed to CIH for 8 h/day for 10 days and sections of perfused brainstem were either stained to reveal nNOS-immunoreactivity or loaded with DAF 2-DA to label neurons containing NO. CIH rats showed a significant increase in mean arterial pressure and heart rate compared to controls. However, there was no significant difference in the distribution, staining intensity or numbers of nNOS-immunoreactive neurons in the NTS between experimental and control rats. We also found no significant change in NO content in the DAF 2-DA-loaded sections of NTS from CIH rats. Our data show that NO is not altered in the NTS of juvenile CIH rats, suggesting that nitrergic mechanisms, at least in the NTS, are unlikely to be involved in the sympathetic excitation that generates the hypertension observed after 10 days of CIH.

  1. Efficacy of lovastatin on learning and memory deficits caused by chronic intermittent hypoxia-hypercapnia: through regulation of NR2B-containing NMDA receptor-ERK pathway.

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    Xin-long Huo

    Full Text Available BACKGROUND: Chronic intermittent hypoxia-hypercapnia (CIHH exposure leads to learnning and memory deficits in rats. Overactivation of N-methyl-D-aspartate receptors(NMDARs can lead to the death of neurons through a process termed excitotoxicity, which is involved in CIHH-induced cognitive deficits. Excessively activated NR2B (GluN2B-containing NMDARs was reported as the main cause of excitotoxicity. The ERK1/2 (extracellular signal-regulated kinase 1/2 signaling cascade acts as a key component in NMDARs-dependent neuronal plasticity and survival. Ca2+/calmodulin-dependent protein kinase II (CaMKII, synapse-associated protein 102 (SAP102 and Ras GTPase-activating protein (SynGAP have been shown to be involved in the regulation of NMDAR-ERK signalling cascade. Recent studies revealed statins (the HMG-CoA reductase inhibitor have effect on the expression of NMDARs. The present study intends to explore the potential effect of lovastatin on CIHH-induced cognitive deficits and the NR2B-ERK signaling pathway. METHODS AND FINDINGS: Eighty male Sprague Dawley rats were randomly divided into five groups. Except for those in the control group, the rats were exposed to chronic intermittent hypoxia-hypercapnia (CIHH (9 ∼ 11%O2, 5.5 ∼ 6.5%CO2 for 4 weeks. After lovastatin administration, the rats performed better in the Morris water maze test. Electron microscopy showed alleviated hippocampal neuronal synaptic damage. Further observation suggested that either lovastatin or ifenprodil (a selective NR2B antagonist administration similarly downregulated NR2B subunit expression leading to a suppression of CaMKII/SAP102/SynGAP signaling cascade, which in turn enhanced the phosphorylation of ERK1/2. The phosphorylated ERK1/2 induced signaling cascade involving cAMP-response element-binding protein (CREB phosphorylation and brain-derived neurotrophic factor (BDNF activation, which is responsible for neuroprotection. CONCLUSIONS: These findings suggest that the

  2. Distinct Effects of Nalmefene on Dopamine Uptake Rates and Kappa Opioid Receptor Activity in the Nucleus Accumbens Following Chronic Intermittent Ethanol Exposure

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    Jamie H. Rose

    2016-07-01

    Full Text Available The development of pharmacotherapeutics that reduce relapse to alcohol drinking in patients with alcohol dependence is of considerable research interest. Preclinical data support a role for nucleus accumbens (NAc κ opioid receptors (KOR in chronic intermittent ethanol (CIE exposure-induced increases in ethanol intake. Nalmefene, a high-affinity KOR partial agonist, reduces drinking in at-risk patients and relapse drinking in rodents, potentially due to its effects on NAc KORs. However, the effects of nalmefene on accumbal dopamine transmission and KOR function are poorly understood. We investigated the effects of nalmefene on dopamine transmission and KORs using fast scan cyclic voltammetry in NAc brain slices from male C57BL/6J mice following five weeks of CIE or air exposure. Nalmefene concentration-dependently reduced dopamine release similarly in air and CIE groups, suggesting that dynorphin tone may not be present in brain slices. Further, nalmefene attenuated dopamine uptake rates to a greater extent in brain slices from CIE-exposed mice, suggesting that dopamine transporter-KOR interactions may be fundamentally altered following CIE. Additionally, nalmefene reversed the dopamine-decreasing effects of a maximal concentration of a KOR agonist selectively in brain slices of CIE-exposed mice. It is possible that nalmefene may attenuate withdrawal-induced increases in ethanol consumption by modulation of dopamine transmission through KORs.

  3. Angiotensin-(1-7 relieved renal injury induced by chronic intermittent hypoxia in rats by reducing inflammation, oxidative stress and fibrosis

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    W. Lu

    Full Text Available We aimed to study the renal injury and hypertension induced by chronic intermittent hypoxia (CIH and the protective effects mediated by angiotensin 1-7 [Ang(1-7]. We randomly assigned 32 male Sprague-Dawley rats (body weight 180-200 g to normoxia control, CIH, Ang(1-7-treated normoxia, and Ang(1-7-treated CIH groups. Systolic blood pressure (SBP was monitored at the start and end of each week. Renal sympathetic nerve activity (RSNA was recorded. CTGF and TGF-β were detected by immunohistochemistry and western blotting. Tissue parameters of oxidative stress were also determined. In addition, renal levels of interleukin-6, tumor necrosis factor-α, nitrotyrosine, and hypoxia-inducible factor-1α were determined by immunohistochemistry, immunoblotting, and ELISA. TUNEL assay results and cleaved caspase 3 and 12 were also determined. Ang(1-7 induced a reduction in SBP together with a restoration of RSNA in the rat model of CIH. Ang(1-7 treatment also suppressed the production of reactive oxygen species, reduced renal tissue inflammation, ameliorated mesangial expansion, and decreased renal fibrosis. Thus, Ang(1-7 treatment exerted renoprotective effects on CIH-induced renal injury and was associated with a reduction of oxidative stress, inflammation and fibrosis. Ang(1-7 might therefore represent a promising therapy for obstructive sleep apnea-related hypertension and renal injury.

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

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    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.

  5. Time-Course Analysis of Brain Regional Expression Network Responses to Chronic Intermittent Ethanol and Withdrawal: Implications for Mechanisms Underlying Excessive Ethanol Consumption.

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    Smith, Maren L; Lopez, Marcelo F; Archer, Kellie J; Wolen, Aaron R; Becker, Howard C; Miles, Michael F

    2016-01-01

    Long lasting abusive consumption, dependence, and withdrawal are characteristic features of alcohol use disorders (AUD). Mechanistically, persistent changes in gene expression are hypothesized to contribute to brain adaptations leading to ethanol toxicity and AUD. We employed repeated chronic intermittent ethanol (CIE) exposure by vapor chamber as a mouse model to simulate the cycles of ethanol exposure and withdrawal commonly seen with AUD. This model has been shown to induce progressive ethanol consumption in rodents. Brain CIE-responsive expression networks were identified by microarray analysis across five regions of the mesolimbic dopamine system and extended amygdala with tissue harvested from 0-hours to 7-days following CIE. Weighted Gene Correlated Network Analysis (WGCNA) was used to identify gene networks over-represented for CIE-induced temporal expression changes across brain regions. Differential gene expression analysis showed that long-lasting gene regulation occurred 7-days after the final cycle of ethanol exposure only in prefrontal cortex (PFC) and hippocampus. Across all brain regions, however, ethanol-responsive expression changes occurred mainly within the first 8-hours after removal from ethanol. Bioinformatics analysis showed that neuroinflammatory responses were seen across multiple brain regions at early time-points, whereas co-expression modules related to neuroplasticity, chromatin remodeling, and neurodevelopment were seen at later time-points and in specific brain regions (PFC or HPC). In PFC a module containing Bdnf was identified as highly CIE responsive in a biphasic manner, with peak changes at 0 hours and 5 days following CIE, suggesting a possible role in mechanisms underlying long-term molecular and behavioral response to CIE. Bioinformatics analysis of this network and several other modules identified Let-7 family microRNAs as potential regulators of gene expression changes induced by CIE. Our results suggest a complex temporal

  6. Time-Course Analysis of Brain Regional Expression Network Responses to Chronic Intermittent Ethanol and Withdrawal: Implications for Mechanisms Underlying Excessive Ethanol Consumption.

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    Maren L Smith

    Full Text Available Long lasting abusive consumption, dependence, and withdrawal are characteristic features of alcohol use disorders (AUD. Mechanistically, persistent changes in gene expression are hypothesized to contribute to brain adaptations leading to ethanol toxicity and AUD. We employed repeated chronic intermittent ethanol (CIE exposure by vapor chamber as a mouse model to simulate the cycles of ethanol exposure and withdrawal commonly seen with AUD. This model has been shown to induce progressive ethanol consumption in rodents. Brain CIE-responsive expression networks were identified by microarray analysis across five regions of the mesolimbic dopamine system and extended amygdala with tissue harvested from 0-hours to 7-days following CIE. Weighted Gene Correlated Network Analysis (WGCNA was used to identify gene networks over-represented for CIE-induced temporal expression changes across brain regions. Differential gene expression analysis showed that long-lasting gene regulation occurred 7-days after the final cycle of ethanol exposure only in prefrontal cortex (PFC and hippocampus. Across all brain regions, however, ethanol-responsive expression changes occurred mainly within the first 8-hours after removal from ethanol. Bioinformatics analysis showed that neuroinflammatory responses were seen across multiple brain regions at early time-points, whereas co-expression modules related to neuroplasticity, chromatin remodeling, and neurodevelopment were seen at later time-points and in specific brain regions (PFC or HPC. In PFC a module containing Bdnf was identified as highly CIE responsive in a biphasic manner, with peak changes at 0 hours and 5 days following CIE, suggesting a possible role in mechanisms underlying long-term molecular and behavioral response to CIE. Bioinformatics analysis of this network and several other modules identified Let-7 family microRNAs as potential regulators of gene expression changes induced by CIE. Our results suggest a

  7. Effect of chronic intermittent hypoxia on the expression of Nip3, cell apoptosis, β-amyloid protein deposit in mice brain cortex

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    ZENG Yi-ming; CAI Kai-jin; CHEN Xiao-yong; WU Minx-ia; LIN Xi

    2009-01-01

    Background Chronic intermittent hypoxia (CIH) is the most important pathophysiologic feature of sleep apnea syndrome (SAS). To explore the relationship between SAS and dementia, the effects of CIH on the expression of Nip3, neuron apoptosis andβ-amyloid protein deposit in the brain cortex of the frontal lobe of mice were evaluated in this study. Methods Thirty male ICR mice were divided into four groups: control group (A, n=-10, sham hypoxia/reoxygenation), 2 weeks CIH group (B, n=-5), 4 weeks CIH group (C, n=-5), and 8 weeks CIH group (D, n=10). The ICR mice were placed in a chamber and exposed to intermittent hypoxia (oxygen concentration changed periodically from (21.72±0.55)% to (6.84±0.47)% every two minutes, eight hours per day). Neuron apoptosis of the cortex of the frontal lobe was detected by means of terminal deoxy-nucleotidyl transferase-mediated in situ end labeling (TUNEL). Immunohistochemical staining was performed for measuring expression of Nip3 and β-amyloid protein. The ultrastructure of neurons was observed under a transmission electron microscope. Results TUNEL positive neurons in each square millimeter in the cortex of the frontal lobe were categorized by median or Ri into group A (1,5.5), group B (133, 13), group C (252, 21), and group D (318, 24). There were significant differences among the above four groups (P=0.000). The significance test was performed between the control group and each CIH group respectively: group A and B (P>0.05); group A and C (P 0.05); groups A and C (P<0.005); and groups A and D (P<0.005). There was no significant difference between groups B and C, groups B and D, and groups C and D. The expression of Nip3 was closely correlated with neuron apoptosis in the brain (P <0.05). The expression ofβ-amyloid protein in the brain of mice was negative in all CIH groups and the control group. Ultrastructure observation showed karyopyknosis of nucleus, swelling of chondriosomes, deposit of lipofuscins and degeneration of

  8. Ang Ⅱ type 1 receptor expression in rat aorta exposed to chronic intermittent hypoxia: effects of p38MAPK and ERK1/2 signaling

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    SHANG Jin; YANG Yuan-yuan; GUO Xue-ling; LIU Hui-guo

    2013-01-01

    Background Obstructive sleep apnea is a frequent medical condition consisting of repetitive sleep-related episodes of upper air ways obstruction and can lead to hypertension.Ang Ⅱ type 1 receptor (AT1R) played important roles in hypertension since it binds with Ang Ⅱ,controlling salt-water and blood pressure homeostasis.This study explores rat aorta AT1R expression during intermittent hypoxia (IH) and the signaling pathways involved.Methods A rat model and a cell model used a BioSpherix-OxyCycler A84 system and a ProOx C21 system respectively.The arterial blood pressure was recorded by a Nihon Kohden Polygraph System.Immunohistochemic was used to focus and analyze the expression of AT1R in rat aorta.Real-time PCR and Western blotting were used to explore the signaling pathways that participated in AT1R expression.Results In this study,we found that chronic intermittent hypoxia (CIH) induced AT1R transcription which increased the blood pressure in rat aorta compared to normoxia and to sustained hypoxia.The AT1R protein expression in the aorta was similar to the real-time PCR results.We explored the signaling mechanisms involved in the AT1R induction in both rat aorta and the aortic endothelial cells by real-time PCR and Western blotting.Compared to normoxia,CIH increased ERK1 mRNA transcription but not ERK2 or p38MAPK in the aorta; whereas sustained hypoxia (SH) upregulated ERK2 but not ERK1 or p38MAPK mRNA.In cells,IH induced AT1R expression with ERK1/2 phosphorylation but reduced p38MAPKs phosphorylation,whereas SH induced only ERK1/2 phosphorylation.The ERK1/2 inhibitor PD98059 attenuated the IHinduced AT1R increase but the p38MAPK inhibitor SB203580 did not.Conclusions Our results indicate that CIH induced the elevation of rat blood pressure and aorta AT1R expression.Moreover,AT1R expression in IH and sustained hypoxia might be regulated by different signal transduction pathways,highlighting a novel regulatory function through ERK1/2 signaling in IH.

  9. Chronic intermittent hypobaric hypoxia protects the heart against ischemia/reperfusion injury through upregulation of antioxidant enzymes in adult guinea pigs

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    Hui-cai GUO; Zhe ZHANG; Li-nan ZHANG; Chen XIONG; Chen FENG; Qian LIU; Xu LIU; Xiao-lu SHI; Yong-li WANG

    2009-01-01

    Aim:To investigate the protection and the anti-oxidative mechanism afforded by chronic intermittent hypobaric hypoxia (CIHH) against ischemia/reperfusion (I/R) injury in guinea pig hearts.Methods:Adult male guinea pigs were exposed to CIHH by mimicking a 5000 m high altitude (pB=404 mmHg,p02=84 mmHg) in a hypobaric chamber for 6 h/day for 28 days.Langendorff-perfused isolated guinea pig hearts were used to measure variables of left ventricular function during baseline perfusion,ischemia and the reperfusion period.The activity and protein expression of antioxidant enzymes in the left myocardium were evaluated using biochemical methods and Western blotting.respectively.Intracellular reactive oxygen species (ROS) were assessed using ROS-sensitive fluorescence.Results:After 30 min of global no-flow ischemia followed by 60 min of reperfusion,myocardial function had better recovery rates in CIHH guinea pig hearts than in control hearts.The activity and protein expression of superoxide dismutase (SOD) and catalase (CAT) were significantly increased in the myocardium of CIHH guinea pigs.Pretreatment of control hearts with an antioxidant mixture containing SOD and CAT exerted cardioprotective effects similar to CIHH.The irreversible CAT inhibitor aminotriazole (ATZ) abolished the cardioprotection of CIHH.Cardiac contractile dysfunction and oxidative stress induced by exogenous hydrogen peroxide (H2O2) were attenuated by CIHH and CAT.Conclusions:These data suggest that CIHH protects the heart against I/R injury through upregulation of antioxidant enzymes in guinea pig.

  10. Chronic intermittent hypoxia increases encoding pigment epithelium-derived factor gene expression, although not that of the protein itself, in the temporal cortex of rats,

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    Guilherme Silva Julian

    2015-02-01

    Full Text Available Objective: Obstructive sleep apnea syndrome is mainly characterized by intermittent hypoxia (IH during sleep, being associated with several complications. Exposure to IH is the most widely used animal model of sleep apnea, short-term IH exposure resulting in cognitive and neuronal impairment. Pigment epithelium-derived factor (PEDF is a hypoxia-sensitive factor acting as a neurotrophic, neuroprotective, and antiangiogenic agent. Our study analyzed performance on learning and cognitive tasks, as well as PEDF gene expression and PEDF protein expression in specific brain structures, in rats exposed to long-term IH. Methods: Male Wistar rats were exposed to IH (oxygen concentrations of 21-5% for 6 weeks-the chronic IH (CIH group-or normoxia for 6 weeks-the control group. After CIH exposure, a group of rats were allowed to recover under normoxic conditions for 2 weeks (the CIH+N group. All rats underwent the Morris water maze test for learning and memory, PEDF gene expression and PEDF protein expression in the hippocampus, frontal cortex, and temporal cortex being subsequently assessed. Results: The CIH and CIH+N groups showed increased PEDF gene expression in the temporal cortex, PEDF protein expression remaining unaltered. PEDF gene expression and PEDF protein expression remained unaltered in the frontal cortex and hippocampus. Long-term exposure to IH did not affect cognitive function. Conclusions: Long-term exposure to IH selectively increases PEDF gene expression at the transcriptional level, although only in the temporal cortex. This increase is probably a protective mechanism against IH-induced injury.

  11. Ethanol withdrawal is required to produce persisting N-methyl-D-aspartate receptor-dependent hippocampal cytotoxicity during chronic intermittent ethanol exposure

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    Reynolds, Anna R.; Berry, B. Jennifer N.; Sharrett-Field, Lynda; Prendergast, Mark A.

    2015-01-01

    Chronic intermittent ethanol consumption is associated with neurodegeneration and cognitive deficits in preclinical laboratory animals and in the clinical population. While previous work suggests a role for neuroadaptations in the N-methyl-D-aspartate (NMDA) receptor in the development of ethanol dependence and manifestation of withdrawal, the relative roles of ethanol exposure and ethanol withdrawal in producing these effects have not been fully characterized. To examine underlying cytotoxic mechanisms associated with CIE exposure, organotypic hippocampal slices were exposed to 1–3 cycles of ethanol (50 mM) in cell culture medium for 5 days, followed by 24-hours of ethanol withdrawal in which a portion of slices were exposed to competitive NMDA receptor antagonist (2R)-amino-5-phosphonovaleric acid (APV; 40 µM). Cytotoxicity was assessed using immunohistochemical labeling of neuron specific nuclear protein (NeuN; Fox-3), a marker of mature neurons, and thionine (2%) staining of Nissl bodies. Multiple cycles of CIE produced neurotoxicity, as reflected in persisting losses of neuron NeuN immunoreactivity and thionine staining in each of the primary cell layers of the hippocampal formation. Hippocampi aged in vitro were significantly more sensitive to the toxic effects of multiple CIEs than were non-aged hippocampi. This effect was not demonstrated in slices exposed to continuous ethanol, in the absence of withdrawal, or to a single exposure/withdrawal regimen. Exposure to APV significantly attenuated the cytotoxicity observed in the primary cell layers of the hippocampus. The present findings suggest that ethanol withdrawal is required to produce NMDA receptor-dependent hippocampal cytotoxicity, particularly in the aging hippocampus in vitro. PMID:25746220

  12. Studies on effect of chronic intermittent starvation on neuroendocrinous function in rats%慢性间歇饥饿对大鼠神经内分泌功能的影响

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    宋世一; 马宏

    2001-01-01

    探讨了慢性间歇饥饿及重饲过程中神经内分泌功能的动态变化并与急性饥饿进行比较.研究发现慢性间歇饥饿每100克体重垂体重量升高,附性器官无显著变化,重饲后恢复较快,与急性饥饿明显不同;慢性间歇饥饿时血液及垂体催乳素(PRL)无显著变化,PRL诱发反应减弱,与急性饥饿时PRL释放障碍较重,PRL诱发分泌增强有明显不同.结果表明:尽管体重下降程度完全一致,不同的饥饿方式和时程也可能对神经内分泌功能造成不同的影响.%This paper studies the dynamic changes of neuroendcrinous function during chronic intermittent starvation in rats and compares it with the result of acute starvation. The data shows that chronic intermittent starvation causes an elevation in pituitary weight per 100g body weight and no significant changes are found in accessory sex organs ,the changes can return to normal rapidly after refeeding. In chronic intermittent starvation, pituitary PRL and blood PRL show no significant changes, induced PRL serection is attenuated. A significant difference is revealed between chronic starvation and acute starvation. Although the body weight drops in the same degree during the above two kinds of starvation, various ways and periods of starvation can cause different changes in neuroendocrinous function.

  13. Complete healing of chronic wounds of a lower leg with haemoglobin spray and regeneration of an accompanying severe dermatoliposclerosis with intermittent normobaric oxygen inhalation (INBOI: a case report

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    Pötzschke, Harald

    2011-01-01

    Full Text Available A new healing procedure has been developed on the basis of the successful treatment of therapy-resistant hypoxic (and practically anoxic leg ulcerations located within a heavy dermatoliposclerosis. The procedure involves an initial intra-ulceral application of haemoglobin followed by the intermittent administration of normobaric oxygen via inhalation. Haemoglobin is capable of externally supplying the granulating wound bed with oxygen at low partial pressure in a physiological manner, like a micro lung, so that oxidative stress can be avoided. A long-term daily administration of oxygen from within – including the peri-ulceral skin – is achieved by intermittent normobaric oxygen inhalation (INBOI regularly throughout the day in the form of 1-hour sessions. Using this combined healing treatment during haemoglobin applications the ulcerations healed within about 1 month, and subsequently with INBOI therapy within further approx. 4 months the peri-ulceral skin regenerated as far as the oxygenation status was concerned: The peri-ulceral transcutaneous oxygen partial pressure (tcPO2 of zero (measured during breathing of normal air rose to a satisfactory value of approx. 35 mmHg. After 28 months of treatment, the completely hypoxic and degenerated skin on the leg had practically returned to normal with a PO2 of 45 mmHg. Furthermore, the skin dermatoliposclerosis regressed. The skin regeneration was long-lasting, which was probably related to cellular tissue regeneration with an increase in the capillary density, whereby it had to be maintained by regular oxygen inhalation (INBOI maintaining treatment. By unintended intra-individual therapy variations it is evidenced that local hypoxia was the reason for skin degeneration: 3 x 1 h oxygen inhalation were sufficient for the healing treatment; 2 x 1 h sufficed for maintenance, whereas 2 x 0.5 h did not. The new procedure carries practically no risks, is simple, cheap and effective. Whereas the

  14. CaV3.2 T-type Ca2+ channels mediate the augmented calcium influx in carotid body glomus cells by chronic intermittent hypoxia.

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    Makarenko, Vladislav V; Ahmmed, Gias U; Peng, Ying-Jie; Khan, Shakil A; Nanduri, Jayasri; Kumar, Ganesh K; Fox, Aaron P; Prabhakar, Nanduri R

    2016-01-01

    Chronic intermittent hypoxia (CIH) is a hallmark manifestation of sleep apnea. A heightened carotid body activity and the resulting chemosensory reflex mediate increased sympathetic nerve activity by CIH. However, the mechanisms underlying heightened carotid body activity by CIH are not known. An elevation of intracellular calcium ion concentration ([Ca(2+)]i) in glomus cells, the primary oxygen-sensing cells, is an essential step for carotid body activation by hypoxia. In the present study, we examined the effects of CIH on the glomus cell [Ca(2+)]i response to hypoxia and assessed the underlying mechanisms. Glomus cells were harvested from adult rats or wild-type mice treated with 10 days of either room air (control) or CIH (alternating cycles of 15 s of hypoxia and 5 min of room air; 9 episodes/h; 8 h/day). CIH-treated glomus cells exhibited an enhanced [Ca(2+)]i response to hypoxia, and this effect was absent in the presence of 2-(4-cyclopropylphenyl)-N-((1R)-1-[5-[(2,2,2-trifluoroethyl)oxo]-pyridin-2-yl]ethyl)acetamide (TTA-A2), a specific inhibitor of T-type Ca(2+) channels, and in voltage-gated calcium channel, type 3.2 (CaV3.2), null glomus cells. CaV3.2 knockout mice exhibited an absence of CIH-induced hypersensitivity of the carotid body. CIH increased reactive oxygen species (ROS) levels in glomus cells. A ROS scavenger prevented the exaggerated TTA-A2-sensitive [Ca(2+)]i response to hypoxia. CIH had no effect on CaV3.2 mRNA levels. CIH augmented Ca(2+) currents and increased CaV3.2 protein in plasma membrane fractions of human embryonic kidney-293 cells stably expressing CaV3.2, and either a ROS scavenger or brefeldin-A, an inhibitor of protein trafficking, prevented these effects. These findings suggest that CIH leads to an augmented Ca(2+) influx via ROS-dependent facilitation of CaV3.2 protein trafficking to the plasma membrane.

  15. Intermittent Oxygen Inhalation with Proper Frequency Improves Overall Health Conditions and Alleviates Symptoms in a Population at High Risk of Chronic Mountain Sickness with Severe Symptoms

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    Bin Feng; Wei-Hao Xu; Yu-Qi Gao; Fu-Yu Liu; Peng Li; Shan-Jun Zheng; Lu-Yue Gai

    2016-01-01

    Background:Oxygen inhalation therapy is essential for the treatment of patients with chronic mountain sickness (CMS),but the efficacy of oxygen inhalation for populations at high risk of CMS remains unknown.This research investigated whether oxygen inhalation therapy benefits populations at high risk of CMS.Methods:A total of 296 local residents living at an altitude of 3658 m were included;of which these were 25 diagnosed cases of CMS,8 cases dropped out of the study,and 263 cases were included in the analysis.The subjects were divided into high-risk (180 ≤ hemoglobin (Hb) <210 g/L,n =161) and low-risk (Hb <180 g/L,n =102) groups,and the cases in each group were divided into severe symptom (CMS score ≥6) and mild symptom (CMS score 0-5) subgroups.Severe symptomatic population of either high-or low-risk CMS was randomly assigned to no oxygen intake group (A group) or oxygen intake 7 times/week group (D group);mild symptomatic population of either high-or low-risk CMS was randomly assigned to no oxygen intake group (A group),oxygen intake 2 times/week group (B group),and 4 times/week group (C group).The courses for oxygen intake were all 30 days.The CMS symptoms,sleep quality,physiological biomarkers,biochemical markers,etc.,were recorded on the day before oxygen intake,on the 15th and 30th days of oxygen intake,and on the 15th day after terminating oxygen intake therapy.Results:A total of 263 residents were finally included in the analysis.Among these high-altitude residents,CMS symptom scores decreased for oxygen inhalation methods B,C,and D at 15 and 30 days after oxygen intake and 15 days after termination,including dyspnea,palpitation,and headache index,compared to those before oxygen intake (B group:Z =5.604,5.092,5.741;C group:Z =4.155,4.068,4.809;D group:Z =6.021,6.196,5.331,at the 3 time points respectively;all P < 0.05/3 vs.before intake).However,dyspnea/palpitation (A group:Z =5.003,5.428,5.493,both P < 0.05/3 vs.before intake) and headache (A

  16. Does the thrifty phenotype result from chronic glutamate intoxication? A hypothesis.

    Science.gov (United States)

    Hermanussen, Michael; Tresguerres, Jesus A F

    2003-01-01

    The thrifty phenotype hypothesis proposes that the epidemiological associations between poor fetal and infant growth and the subsequent development of the metabolic syndrome, result from the effects of poor nutrition in early life. The present review however, considers an opposite explanation. We hypothesize that fetal over-nutrition plays a major role in the development of the metabolic syndrome. We found evidence that the thrifty phenotype may be the consequence of fetal hyperglutamatemia. Maternal glutamate (GLU) reaches the fetal circulation, as part of the materno-fetal glutamine-glutamate exchange. Glutamine is absorbed from the maternal circulation, and deaminated for nitrogen utilization, resulting in a fetal production of GLU. GLU is extracted as it returns to the placenta. When the umbilical plasma flow is low, GLU may be trapped in the fetal circulation, and reaches neurotoxic levels. Administering GLU to newborn rodents completely destructs arcuate nucleus neurons, and results in permanently elevated plasma leptin levels that fail to adequately counter-regulate food intake. Chronic fetal exposure to elevated levels of GLU may be caused by chronic maternal over-nutrition or by reduced umbilical plasma flow. We strongly suggest abandoing the flavoring agent monosodium glutamate and reconsidering the recommended daily allowances of protein and amino acids during pregnancy.

  17. 慢性间断性缺氧伴二氧化碳潴留小鼠模型的建立%A Mice Mode of Chronic Intermittent Hypoxia with Carbon Dioxide Retention

    Institute of Scientific and Technical Information of China (English)

    刘海林; 张子彦; 郭云云; 李景春; 宋永斌; 徐江涛

    2012-01-01

    目的 建立慢性间断性缺氧伴二氧化碳潴留(chronic intermittent hypoxia with carbon dioxide retention,CIH-CR)小鼠模型.方法 选取雄性昆明小鼠22只,随机分为常氧组(normal control group,NC)和CIH-CR组,每组11只.CIH-CR组小鼠每天CIH-CR处理8h,共4周,实验期间监测箱内O2和CO2浓度及小鼠尾部末端血氧饱和度( SO2).实验终点测定右室肥厚指数并观察心、肺、肾、脑组织病理改变.结果 CIH-CR组箱内O2浓度、CO2浓度和小鼠尾部末端SO2随实验仓的关闭和开启出现周期性的变化;与NC组相比CIH-CR组右心室明显肥大(P<0.01);小鼠心、肺、肾和脑组织均出现明显缺氧改变.结论 成功建立了CIH-CR小鼠模型.%Objective To establish a chronic intermittent hypoxia with carbon dioxide retention (CIH-CR)model in mice. Methods 22 male Kun Ming mice were divided into the normal control (NC) group and CIH-CR group. The mice of CIH-CR group suffered 8 hours intermittent hypoxia everyday for 4 weeks. The concentration of O2 and CO2 in the cabin was detected by oxygen analyzer and Carbon dioxide detector, meanwhile, the blood oxygen saturation were detected by blood oximeter. At the end of the experiment, weight of right and left ventricles was measured. The general pathological changes of myocardium, pulmonary, kidney and brain were observed by HE staining. Result The concentration of O2 and CO2 in the cabin and the SO2in the empennage of mouse accord with the cyclical change process. Compared with the NC group, the right ventricular hypertrophy were increased in the CIH-CR groups ( P < 0. 01 ). The tissue of myocardium, pulmonary, kidney and brain were showen obvious hypoxic change in CIH-CR group. Conclusion A CIH-CR animal model were be established successfully.

  18. Intermittent degradation and schizotypy

    Directory of Open Access Journals (Sweden)

    Matthew W. Roché

    2015-06-01

    Full Text Available 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-report questionnaires assessing schizotypy and psychological state variables (e.g., anxiety, depression, and their reaction times were recorded as they did so. Intermittent degradation was defined as the number of times a subject’s reaction time for questionnaire items met or exceeded three standard deviations from his or her mean reaction time after controlling for each item’s information processing load. Intermittent degradation scores were correlated with questionnaire scores. Our results indicate that intermittent degradation is associated with total scores on measures of positive and disorganized schizotypy, but unrelated to total scores on measures of negative schizotypy and psychological state variables. Intermittent degradation is interpreted as potentially derivative of schizotypy and a candidate endophenotypic marker worthy of continued research.

  19. Defining "intermittent UVR exposure"

    DEFF Research Database (Denmark)

    Bodekær, Mette; Philipsen, Peter Alshede; Petersen, Bibi Øager;

    2016-01-01

    to define and quantify “intermittent UVR exposure” by an objective measure. Methods: A broad study population of adults and children had data collected during a summer period. Data were personal UVR dosimetry measurements, from which the number of “intermittent days” was derived, sun behaviour diaries.......001). The corresponding numbers for prediction of nevi and lentigo density by retrospective questionnaire data was lower (R2 = 0.11, R2 = 0.26, p defined objective measure of intermittent UVR exposure. This measure may provide a better prediction of solar skin damage and CMM...

  20. 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.

  1. 低压氧舱慢性间断性缺氧诱导大鼠膈神经长时程易化%Phrenic long-term facilitation induced by hypobaric chronic intermittent hypoxia in rats

    Institute of Scientific and Technical Information of China (English)

    陈阳; 刘津平; 魏晓燕; 赵彩红; 李柱一; 刘莹莹

    2011-01-01

    Objective: Long-term facilitation (LTF) is an important electrophysiological characteristic indicative of respiratory neuroplasticity, and is tightly related to sleep disorders. Phrenic LTF can be induced by acute intermittent hypoxia (AIH, 3-5 episodic hypoxia), whereas chronic intermittent hypoxia (CIH) lasting for over one week leads to a large enhanced phrenic LTF. CIH rat models is usually prepared with alternately 5 min of 10% O2 + 90% N2, and 5 min of normoxia for 12 h/d for at least 7 d, a process that needs large amount of mixed gases, and is expensive. We aimed to establish an enhanced phrenic LTF model in intact rats in precondition with hypobaric chronic episodic hypoxia. Methods: Adult Sprague-Dawley rats were housed in a chamber and maintained with alternately 5 min of hypobaric hypoxia and 5 min of normoxia for 12 h/d for 7 consecutive days. Hypobaric hypoxia was achieved by air evacuation to gradually reach a pressure of 210-220 mmHg, corresponding to an altitude of around 9000 m. On the eighth day, both CIH and control animals were treated with AIH, to induce phrenic LTF expression. The control animals received AIH challenge only. Alterations of phrenic LIF expressions between two groups were then statistically analysed. Results: Phrenic nerve activity was more sensitive in response to hypoxia in CIH rats than that in control, showing rapid increases in frequency and amplitude during hypoxic period. The integrated amplitudes at 30 min and 60 min after episodic hypoxia were ( 116.3 ±6.5 ) % and ( 106.1 ± 19.2) %, respectively, from baseline in CIH animals, which were significantly different from those (60.4 ± 7.8 ) % and (48.2 ± 11.0) % in control ( P < 0.01 ), indicating a much larger LTF induced by CIH, the enhanced phrenic LTF. Conclusion: We establish an enhanced phrenic LTF model induced by chronic intermittent hypobaric hypoxia in intact rats, which will provide a useful platform for understanding the mechanism of LTF

  2. Chronic intermittent hypoxia increases β cell mass and activates the mammalian target of rapamycin/hypoxia inducible factor 1/vascular endothelial growth factor A pathway in mice pancreatic islet

    Institute of Scientific and Technical Information of China (English)

    GU Chen-juan; LI Min; LI Qing-yun; LI Ning

    2013-01-01

    Background Growing evidence from population and clinic based studies showed that obstructive sleep apnea (OSA) and its characterizing chronic intermittent hypoxia (IH) were independently associated with the development of type 2 diabetes mellitus.However,the pathogenesis by which OSA induces glucose metabolic disorders is not clear.We determined changes in pancreatic β cell mass and the mammalian target of rapamycin (mTOR)/hypoxia inducible factor 1 (HIF-1)/ vascular endothelial growth factor A (VEGF-A) pathway following IH exposure.Methods A controlled gas delivery system regulated the flow of nitrogen and oxygen into a customized cage housing mice during the experiment.Twenty-four male wild C57BL/6J mice were either exposed to IH (n=12) or intermittent air as a control (n=12) for 56 days.Mice were anaesthetized and sacrificed after exposure,pancreas samples were dissected for immunofluorescent staining.Insulin and DAPI staining labelled islet β cells.Insulin positive area and β cell number per islet were measured.P-S6,HIF-1α and VEGF-A staining were performed to detect the activation of mTOR/HIF-1NEGF-A pathway.Results After eight weeks of IH exposure,insulin positive area increased by an average of 18.5% (P <0.05).The β cell number per islet increased (92 vs.55,respectively for IH and the control groups,P <0.05) with no change in the size of individual β cells.Islet expression of HIF-1α and VEGF-A were higher in IH group than control group,and percentage of p-S6 positive β cell also increased after IH exposure (16.8% vs.4.6% respectively for IH and the control groups,P <0.05).Conclusion The number of pancreatic β cells increased as did the activity of the mTOR/HIF-1NEGF-A pathway after exposure to IH.

  3. The role of Foxp3+T cells in chronic intermittent hypoxia induced liver injury%Foxp3+Tregs在慢性间歇低氧所致肝损伤中的作用

    Institute of Scientific and Technical Information of China (English)

    白晓纯; 王琳; 赵忺; 田建立

    2016-01-01

    Objective To explore the role of Foxp3+ T cells (Tregs) in liver injury induced by chronic intermittent hypoxia. Methods Thirty-two male Wister rats were divided into four groups:control group (A), high-fat diet group (B), intermittent hypoxia group (C), and high-fat diet and intermittent hypoxia group (D). After 4 weeks, blood samples were collected and livers were surgically removed. Using the standard automatic clinical analyzer to test serum levels of total cholesterol (TC), low density lipoprotein cholesterol (LDL- C), alanina aminotransferase (ALT) and aspartato aminotransferase (AST). The MDA content of liver tissue was measured by colorimetrc method. The levels of TNF-αand IL-1βwere measured by radiommunoassay, and the expression of Foxp3 protein was measured by Western blotting technique. Results Serum levels of TC and LDL-C were significantly higher in B group than those of A, C and D groups, and which were higher in D group than those of A and C groups (P<0.05). There were no significant differences in serum levels of TC and LDL-C between A group and C group. Serum levels of ALT, AST, MDA, TNF-αand IL-1βwere significantly higher in C group than those of A group, and which were significantly higher in D group than those of A, B and C groups (P<0.05). There were no significant differences in these indicators between A group and B group, and between B group and C group. Foxp3 protein expression in liver was significantly lower in D group than that of other groups (P<0.05). Conclusion Foxp3+T regulatory cells involve in the regulation of hepatic injury induced by chronic intermittent hypoxia on the basis of a high-fat diet, and which may play an important role in this process of protective immune response.%目的:探讨叉头样转录因子P3(Foxp3)阳性调节性T细胞(Tregs)在慢性间歇低氧诱导的肝损伤中的作用。方法32只雄性Wistar大鼠随机均分为空白对照组(A组)、高脂饮食组(B组)、间歇低氧组

  4. Intermittency and exotic channels

    CERN Document Server

    Bialas, A

    1994-01-01

    It is pointed out that accurate measurements of short-range two-particle correlations in like-charge K\\pi and in \\pi^ 0\\pi^ 0 channels should be very helpful in determining the origin of the \\lq\\lq intermittency\\rq\\rq\\ phenomenon observed recently for the like-charge pion pairs.

  5. Chronic intermittent ethanol exposure alters stress effects on (3α,5α-3-hydroxy-pregnan-20-one (3α,5α-THP immunolabeling of amygdala neurons in C57BL/6J mice

    Directory of Open Access Journals (Sweden)

    Antoniette M Maldonado-Devincci

    2016-03-01

    Full Text Available The GABAergic neuroactive steroid (3α,5α-3-hydroxy-pregnan-20-one (3α,5α-THP, allopregnanolone is decreased in various brain regions of C57BL/6J mice following exposure to an acute stressor or chronic intermittent ethanol (CIE exposure and withdrawal. It is well established that there are complex interactions between stress and ethanol drinking, with mixed literature regarding the effects of stress on ethanol intake. However, there is little research examining how chronic ethanol exposure alters stress responses. The present work examined the impact of CIE exposure and withdrawal on changes in brain levels of 3α,5α-THP, hormonal, and behavioral responses to forced swim stress (FSS. Adult male C57BL/6J mice were exposed to four cycles of CIE to induce ethanol dependence. Following 8 or 72 hr withdrawal, mice were subjected to FSS for 10 min, and 50 min later brains were collected for immunohistochemical analysis of cellular 3α,5α-THP. Behavioral and circulating corticosterone responses to the FSS were quantified. Following 8 hr withdrawal, ethanol exposure potentiated the corticosterone response to FSS. Following 72 hr withdrawal, this difference was no longer observed. Following 8 hr withdrawal, stress-exposed mice showed no differences in immobility, swimming or struggling behavior. However, following 72 hr withdrawal, ethanol-exposed mice showed less immobility and greater swimming behavior compared to air-exposed mice. Interestingly, cellular 3α,5α-THP levels were increased in the lateral amygdala 8 hr and 72 hr post-withdrawal in stressed ethanol-exposed mice compared to ethanol-exposed/non-stressed mice. In the paraventricular nucleus of the hypothalamus, stress exposure decreased 3α,5α-THP levels compared to controls following 72 hr withdrawal, but no differences were observed 8 hr post-withdrawal. There were no differences in cellular 3α,5α-THP levels in the nucleus accumbens shell at either withdrawal time point. These data

  6. Infección por chikunguña materno-fetal asociada con miocarditis neonatal

    OpenAIRE

    Corrales Martínez, Silvia Catalina; Facultad de Salud, Universidad Surcolombiana-Hospital Universitario Hernando Moncaliano, Neiva, Colombia.; Fonseca, Carlos; Unidad de Cuidado Intensivo Neonatal-Hospital Universitario Hernando Moncaliano, Neiva, Colombia; Salgado, Doris; Departamento Infectología Pediátrica, Facultad de Salud, Universidad Surcolombiana-Hospital Universitario Hernando Moncaliano, Neiva, Colombia.

    2016-01-01

     El virus de chikunguña es un arbovirus de la familia Togaviridae y fue aislado por primera vez en Tanzania y Uganda, en 1953. Esta infección se ha desarrollado de manera endémica y es transmitida por el mosquito del género Aedes. El mecanismo exacto de la transmisión de madre a hijo aún no se tiene claro, pero se han identificado potenciales complicaciones de la transmisión vertical, como malformaciones congénitas, mortinatos, restricción del crecimiento intrauterino y partos pretérmino. En ...

  7. Competition for Materno-Fetal Resource Partitioning in a Rabbit Model of Undernourished Pregnancy

    Science.gov (United States)

    Lopez-Tello, Jorge; Arias-Alvarez, Maria; Jimenez-Martinez, Maria Angeles; Garcia-Garcia, Rosa Maria; Rodriguez, Maria; Lorenzo Gonzalez, Pedro Luis; Bermejo-Poza, Ruben; Garcia Rebollar, Pilar

    2017-01-01

    The major goal of animal production is to obtain abundant and healthy meat for consumers. Maternal food restriction (MFR) is often applied in farms to reduce production costs. However, the suitability of MFR in livestock animals is questionable, as this management may compromise maternal fitness due to a severe negative energetic balance and can induce Intrauterine Growth Restriction (IUGR) and prenatal programming in the offspring. Here, we sought to determine, using pregnant rabbits, the consequences of MFR on maternal endocrine and metabolic status and conceptus development. Pregnant dams were distributed into three groups: CONTROL (ad libitum feeding throughout the entire pregnancy; mean pregnancy length being around 31 days), UNDERFED (50% MFR during the entire pregnancy) and EARLY-UNDERFED (50% MFR only during the preimplantation period, Days 0–7). Maternal leptin concentrations and glycemic and lipid profiles were determined throughout pregnancy, whilst conceptus development was assessed ex-vivo at Day 28. Placental parameters were determined by macroscopic and histological evaluations and apoptotic assessments (TUNEL and Caspase-3). The main results of the study showed that, despite MFR altered maternal plasma lipid concentration (P<0.05), there were no effects on maternal bodyweight, plasma leptin concentration or glycemic profile. Fetal crown-rump lengths were reduced in both undernourished groups (P<0.001), but a significant reduction in fetal weight was only observed in the UNDERFED group (P<0.001). Growth in both undernourished groups was asymmetrical, with reduced liver weight (P<0.001) and significantly increased brain: fetal weight-ratio (P<0.001) and brain: liver weight-ratio (P<0.001) when compared to the CONTROL group. A significant reduction in placental weight was only observed in the UNDERFED group (P<0.001), despite both undernourished groups showing higher apoptotic rates at decidua and labyrinth zone (P<0.05) than the CONTROL group. Thus, these groups evidenced signs of placental degeneration, necrosis and stromal collapse. In summary, MFR may encourage the mother to make strategic decisions to safeguard her metabolic status and fitness at the expense of growth reduction in the litter, resulting in enhanced apoptotic and pathological processes at placental level and IUGR. PMID:28046002

  8. 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.

  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. Fate in intermittent claudication

    DEFF Research Database (Denmark)

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

    1986-01-01

    The fate of 257 consecutive patients (100 women) aged 36-85 years (mean 65) first seen with intermittent claudication in 1977 was analysed after a mean of 6.5 (SD 0.5) years. When first seen none of the patients complained of rest pain or had ulcers or gangrenous lesions on the feet. At follow up....... The rate of clinical progression of the arteriosclerotic disease (that is, rest pain or gangrene) of the worst affected leg was 7.5% in the first year after referral. Thereafter the rate was 2.2% a year. An ankle systolic blood pressure below 70 mm Hg, a toe systolic blood pressure below 40 mm Hg......, 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....

  11. The effect of chronic intermittent hypoxia and hyperlipidemia on the heart in rat model%慢性间歇性低氧与高脂血症对大鼠心脏的影响

    Institute of Scientific and Technical Information of China (English)

    韩茜; 杨思俊; 叶秀文; 麦翠和; 张挪富

    2015-01-01

    Objective Obstructive sleep apnea syndrome (OSAS),with intermittent hypoxia during sleep,is increasingly recognized as an independent risk factor of cardiovascular diseases (CVD).Oxidative stress and inflammation are pathogenic mechanisms in CVD,but majority of studies have focused on the systemic status.The aim of this study was to use an animal model to evaluate oxidative stress and inflammation in response to chronic intermittent hypoxia (CIH) with or without diet-induced hyperlipidemia,with special reference to any difference in the systemic and cardiac response,and the mechanistic pathways involved.Methods Male Sprague-Dawley rats were divided into four groups:regular chow diet or high fat high cholesterol (HFHC) diet plus intermittent air (IA) or IH treatment,and rats were sacrificed at 2 or 4 weeks.Serum and cardiac levels of oxidative and pro-inflammatory markers were assayed with ELISA,the expression of HO-1 was examined by immunohistochemistry and activation of signaling pathways in the heart were analyzed by Western blot.Results IH and HFHC diet alone or together caused time-dependent elevation in serum CINC-1 levels.In contrast,suppression of the cardiac levels of pro-inflammatory markers were seen,accompanied by upregulation of expression of cardiac heam-oxygenase,HO 1,a cytoprotective protein at 4 weeks,when cardiac activations of ERK and Akt were also observed.Conclusions Inflammation resulted from CIH and hyperlipidemia may serve as a potential mechanism underlying OSAS-related CVD.However,the upregulation of HO-1 expression via ERK and Akt activation in cardiac tissues may help to protect the heart from inflammatory insults.%目的 观察慢性间歇性低氧(CIH)及高脂高胆固醇(HFHC)饮食诱导的高脂血症对大鼠全身及心脏局部炎症反应的影响.方法 Sprague-Dawley雄性大鼠64只,随机分为对照组,慢性间歇低氧组+常规饲料喂养组(CIH组),常氧+HFHC饲料喂养组(IA/HFHC组)和慢性间歇低

  12. 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....

  13. Uncoupling of Vascular Nitric Oxide Synthase Caused by Intermittent Hypoxia

    Directory of Open Access Journals (Sweden)

    Mohammad Badran

    2016-01-01

    Full Text Available Objective. Obstructive sleep apnea (OSA, characterized by chronic intermittent hypoxia (CIH, is often present in diabetic (DB patients. Both conditions are associated with endothelial dysfunction and cardiovascular disease. We hypothesized that diabetic endothelial dysfunction is further compromised by CIH. Methods. Adult male diabetic (BKS.Cg-Dock7m +/+ Leprdb/J (db/db mice (10 weeks old and their heterozygote littermates were subjected to CIH or intermittent air (IA for 8 weeks. Mice were separated into 4 groups: IA (intermittent air nondiabetic, IH (intermittent hypoxia nondiabetic, IADB (intermittent air diabetic, and IHDB (intermittent hypoxia diabetic groups. Endothelium-dependent and endothelium-independent relaxation and modulation by basal nitric oxide (NO were analyzed using wire myograph. Plasma 8-isoprostane, interleukin-6 (IL-6, and asymmetric dimethylarginine (ADMA were measured using ELISA. Uncoupling of eNOS was measured using dihydroethidium (DHE staining. Results. Endothelium-dependent vasodilation and basal NO production were significantly impaired in the IH and IADB group compared to IA group but was more pronounced in IHDB group. Levels of 8-isoprostane, IL-6, ADMA, and eNOS uncoupling were ≈2-fold higher in IH and IADB groups and were further increased in the IHDB group. Conclusion. Endothelial dysfunction is more pronounced in diabetic mice subjected to CIH compared to diabetic or CIH mice alone. Oxidative stress, ADMA, and eNOS uncoupling were exacerbated by CIH in diabetic mice.

  14. 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.

  15. Acute Intermittent Porphyria (AIP)

    Science.gov (United States)

    ... attacks, but are usually not chronic. Wearing a Medic Alert bracelet is advisable for patients who have ... Week is ONE Month Away! Mar 17, 2017 Access to Care Toolkit for the Acute Porphyrias is ...

  16. Acute intermittent porphyria.

    Science.gov (United States)

    Herrick, Ariane L; McColl, Kenneth E L

    2005-04-01

    Acute intermittent porphyria (AIP) is characterised by neurovisceral crises the most common clinical presentation of which is abdominal pain. It is an autosomal dominant condition with incomplete penetrance and is potentially life-threatening. The key point in management is to suspect and confirm the diagnosis as early as possible in order to treat the attack and to avoid inappropriate treatments which may exacerbate the crisis. In this chapter we briefly outline the haem biosynthetic pathway and how deficiencies in individual enzymes give rise to the different porphyrias. We then describe the clinical features and diagnosis of AIP, followed by a discussion of pathogenesis, highlighting advances in the molecular biology of AIP and introducing the debate as to whether neurovisceral crises might result from porphyrin precursor neurotoxicity or from haem deficiency. Finally we discuss management, including family screening, avoidance of triggering factors, analgesia, maintenance of a high calorie intake, and administration of haem derivatives.

  17. 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.

  18. 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.

  19. Intermittency in spiral Poiseuille flow

    Energy Technology Data Exchange (ETDEWEB)

    Heise, M; Abshagen, J; Menck, A; Pflster, G [Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel (Germany)

    2005-01-01

    The results of an experimental study on intermittent spiral vortices observed in a counter-rotating Taylor-Couette system with an additional axial through flow, i.e. Spiral-Poiseuille flow, are presented. Convectively unstable upstream propagating spiral vortices appear in the laminar basic flow from an oscillatory instability and in general become absolutely unstable at higher inner cylinder Reynolds number. It is found that at Reynolds numbers above the absolute stability border the spiral vortices become unstable and a complex flow state showing intermittent bursts appears. The intermittent flow state is characterised by an irregular alternation between clearly distinguishable 'laminar' phases corresponding to up-and downstream propagating spiral vortices as well as propagating Taylor vortices. For a sufficiently high rate of axial through flow it is found that intermittency can occur directly from the convectively unstable regime of the upstream propagating spiral vortices.

  20. Mechanism of endocannabinoids system in glucose metabolism of rats with chronic intermittent hypoxia%内源性大麻素系统对慢性间歇低氧大鼠糖代谢的影响机制

    Institute of Scientific and Technical Information of China (English)

    肖玲; 陈彦; 张晋源; 王蓓

    2014-01-01

    目的 探讨内源性大麻素系统(ECS)对慢性间歇低氧(CIH)大鼠糖代谢的影响机制.方法 将48只Wistar大鼠采用随机排列表法及实验结束时间分为4、6周正常对照组(充入压缩空气氧浓度为21%),4、6周CIH组(每日CIH暴露8h)及4、6周CIH+利莫那班组[CIH暴露前给予肝脏CB1受体拮抗剂利莫那班腹腔注射(1 mg·kg-1·d-1)]各8只.第4周及第6周结束实验,检测各组大鼠空腹血糖、血清胰岛素、血清C肽水平及肝脏CB1受体表达的变化,评价CIH对糖代谢指标的影响.结果 4、6周CIH组下列指标均显著高于4、6周正常对照组:空腹血糖(8.91±0.40)、(10.61 ±0.36)比(6.48±0.23)、(6.51 ±0.25) mmol/L,血清胰岛素(16.72 ±3.76)、(20.25 ±3.64)比(9.02±2.05)、(9.19 ±2.35) U/L,血清C肽水平(3.53±0.26)、(5.23±0.29)比(1.37±0.26)、(1.41 ±0.41) μg/L,肝脏CB1受体表达(0.290±0.026)、(0.342±0.030)比(0.214±0.023)、(0.221 ±0.026)(均P<0.05);且6周CIH组均显著高于4周CIH组(均P<0.05);而4、6周CIH+利莫那班组上述指标明显降低(均P<0.05).CB1水平与空腹血糖、血清胰岛素、血清C肽水平呈正相关(r=0.856、0.758、0.827,均P<0.05).结论 ECS在CIH引发的糖代谢异常中发挥一定的促进作用.%Objective To explore the mechanism of endocannabinoids system (ECS) in glucose metabolism of rats with chronic intermittent hypoxia (CIH).Methods According to random permutation table and experiment time,a total of 48 Wistar rats were randomly divided into 6 groups of 4/6-week control (filling with compressed air with 21% oxygen),4/6-week CIH (CIH exposure for 8 hours per day) and 4/ 6-week CIH plus rimonabant group [an intraperitoneal injection of CB1 receptor antagonist rimonabant into liver (1 mg · kg-1 · d-1) before CIH exposure] (n =8 each).The levels of fasting plasma glucose,serum insulin,serum C-peptide and the expression of CB1 receptor in liver were detected after 4/6 weeks to evaluate the

  1. 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.

  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. 2种慢性间歇性缺氧小鼠模型模拟气阴两虚证临床指征的比较研究%Comparison of Clinical Indications Simulating Deficiency of Both Qi and Yin Syndrome Induced by Two Types of Chronic Intermittent Hypoxia in Mice

    Institute of Scientific and Technical Information of China (English)

    王文萍; 柴程芝; 寇俊萍; 余伯阳

    2011-01-01

    目的:比较钠石灰和低压氧仪2种不同缺氧方式诱导的慢性间歇性缺氧小鼠模型的整体行为变化,为进一步构建气阴两虚证动物模型奠定基础.方法:分别采用氧分压从21%逐渐降至6%,平均下降速度为0.5%/min ~ 1%/min的钠石灰缺氧法和氧分压在短时间内骤降后维持在7% ~8%的低压氧仪缺氧法,考察2种缺氧模式对小鼠体重,摄食量,自发活动以及心率、T波等气阴两虚临床相关指标变化的影响.结果:钠石灰和低压氧仪2种不同的缺氧方式均能够导致小鼠体重下降;摄食量减少;行走格数减少,直立次数增加等自发活动改变;心率加快,T波持续抬高等心电图变化,二者对各项指标的影响呈基本一致的趋势,其结果具有显著相关性.结论:钠石灰和低压氧仪2种缺氧方式诱导的慢性间歇性缺氧小鼠模型均能够模拟形体消瘦,食欲不振,体倦乏力,烦躁,心悸,脉细数等气阴两虚证的主要临床特征.%Objective: To establish foundation for constructing a suitable animal model of deficiency of both Qi and Yin syndrome (DQYS) induced by two types of chronic intermittent hypoxia (soda lime and low-pressureoxygen controller) by comparison the whole behavior in mice. Method: The two modes of oxygen scarcity,including oxygen pressure declining continuously from 21% to 7%-8% with the average speed of 0. 5%/min-l% per minute in airtight wide-mouthed bottle and oxygen pressure falling abruptly within short period and then keeping in the level of 7% -8% ,were adopted respectively to observe the time-course changes in body weight, food intake, locomotive activity and electrocardiogram respectively. The experiments were designed for mimicing clinical features of DQYS. Result; The mice exposed to two different modes of chronic intermittent hypoxia for certain duration showed body weight loss, food intake decline, locomotive activity change of ambulation decrease and rearing increase

  4. Intermittent exotropia: Surgical treatment strategies

    Directory of Open Access Journals (Sweden)

    Jai Aditya Kelkar

    2015-01-01

    Full Text Available Surgical management of intermittent exotropias (IXTs is ambiguous, with techniques of management varying widely between institutions. This review aims to examine available literature on the surgical management of IXT. A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database. All English-language papers published between 1958 and the present day were considered.

  5. Power-constrained intermittent control

    OpenAIRE

    Gawthrop, P.; Wagg, D.; Neild, S.; Wang, L

    2013-01-01

    In this article, input power, as opposed to the usual input amplitude, constraints are introduced in the context of intermittent control. They are shown to result in a combination of quadratic optimisation and quadratic constraints. The main motivation for considering input power constraints is its similarity with semi-active control. Such methods are commonly used to provide damping in mechanical systems and structures. It is shown that semi-active control can be re-expressed and generalised...

  6. Low and high dietary protein:carbohydrate ratios during pregnancy affect materno-fetal glucose metabolism in pigs.

    Science.gov (United States)

    Metges, Cornelia C; Görs, Solvig; Lang, Iris S; Hammon, Harald M; Brüssow, Klaus-Peter; Weitzel, Joachim M; Nürnberg, Gerd; Rehfeldt, Charlotte; Otten, Winfried

    2014-02-01

    Inadequate dietary protein during pregnancy causes intrauterine growth retardation. Whether this is related to altered maternal and fetal glucose metabolism was examined in pregnant sows comparing a high-protein:low-carbohydrate diet (HP-LC; 30% protein, 39% carbohydrates) with a moderately low-protein:high-carbohydrate diet (LP-HC; 6.5% protein, 68% carbohydrates) and the isoenergetic standard diet (ST; 12.1% protein, 60% carbohydrates). During late pregnancy, maternal and umbilical glucose metabolism and fetal hepatic mRNA expression of gluconeogenic enzymes were examined. During an i.v. glucose tolerance test (IVGTT), the LP-HC-fed sows had lower insulin concentrations and area under the curve (AUC), and higher glucose:insulin ratios than the ST- and the HP-LC-fed sows (P < 0.05). Insulin sensitivity and glucose clearance were higher in the LP-HC sows compared with ST sows (P < 0.05). Glucagon concentrations during postabsorptive conditions and IVGTT, and glucose AUC during IVGTT, were higher in the HP-LC group compared with the other groups (P < 0.001). (13)C glucose oxidation was lower in the HP-LC sows than in the ST and LP-HC sows (P < 0.05). The HP-LC fetuses were lighter and had a higher brain:liver ratio than the ST group (P < 0.05). The umbilical arterial inositol concentration was greater in the HP-LC group (P < 0.05) and overall small fetuses (230-572 g) had higher values than medium and heavy fetuses (≥573 g) (P < 0.05). Placental lactate release was lower in the LP-HC group than in the ST group (P < 0.05). Fetal glucose extraction tended to be lower in the LP-HC group than in the ST group (P = 0.07). In the HP-LC and LP-HC fetuses, hepatic mRNA expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1) and glucose-6-phosphatase (G6PC) was higher than in the ST fetuses (P < 0.05). In conclusion, the HP-LC and LP-HC sows adapted by reducing glucose turnover and oxidation and having higher glucose utilization, respectively. The HP-LC and LP-HC fetuses adapted via prematurely expressed hepatic gluconeogenic enzymes.

  7. 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.

  8. 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...

  9. 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.

  10. Optical diagnostics of intermittent flows

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...... 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...... is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal...

  11. Lattice splitting under intermittent flows

    CERN Document Server

    Schläpfer, Markus

    2010-01-01

    We study the splitting of regular square lattices subject to stochastic intermittent flows. By extensive Monte Carlo simulations we reveal how the time span until the occurence of a splitting depends on various flow patterns imposed on the lattices. Increasing the flow fluctuation frequencies shortens this time span which reaches a minimum before rising again due to inertia effects incorporated in the model. The size of the largest connected component after the splitting is rather independent of the flow fluctuations but sligthly decreases with the link capacities. Our results are relevant for assessing the robustness of real-life systems, such as electric power grids with a large share of renewable energy sources including wind turbines and photovoltaic systems.

  12. 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)

  13. Cooperative controls with intermittent communication

    Science.gov (United States)

    Shen, Dan; Chen, Genshe; Cruz, Jose B., Jr.; Pham, Khanh; Blasch, Erik; Lynch, Robert

    2010-04-01

    In this paper, we propose a solution to the cooperative path planning with limited communication problem in two phases. In the first (offline) phase, a Pareto-optimal path problem is formulated to find a reference path and the graph cuts minimization method is used to speedily calculate the optimal solution. In the second (online) phase, a foraging algorithm is used to dynamically refine the reference path to meet the dynamic constraints of unmanned aerial vehicle (UAVs), during which an open-loop feedback optimal (OLFO) controller is used to estimate the states which may be unavailable due to infrequent battlefield information updates. Furthermore, an adaptive Markov decision process is proposed to deal with intermittent asynchronous information flow. The method is demonstrated in a simulation for a swarm of Unmanned Air Vehicle (UAV) teams with various communication ranges.

  14. Viral and host factors related with histopathologyc activity in patients with chronic hepatitis B and moderate or intermittently elevated alanine aminotransferase levels Influencia de factores virales y del huésped en la actividad histológica en pacientes con hepatitis crónica por virus de la hepatitis B y elevación moderada o intermitente de alanina aminotransferasa

    Directory of Open Access Journals (Sweden)

    E. Molina Pérez

    2010-09-01

    Full Text Available Objective: viral and host factors are related with progression of pathological lesion in chronic hepatitis B. We analyzed these factors in patients with moderate or intermittently elevated ALT levels, and its threshold that determinate significant histological activity. Patients and methods: retrospective analyses of viral and host parameters in 89 consecutive chronic hepatitis B patients biopsied because of moderate or intermittently elevated ALT levels [1-2 x ULN (ULN = 39 IU/mL] and/or DNA-HBV > 2 x 10³ IU/mL in AntiHBe+ patients. It was analyzed age, gender, ALT levels, HBeAg, viral load and genotype. It was considered advanced histological lesion a Knodell Score (KS > 7 and histological lesion indicating treatment, lobular inflammation ≥ 2 or fibrosis ≥ 2 according to Scheuer Classification. Results: KS > 7 and histological lesion indicating treatment was found in 47.8 and 60.7% respectively. It was observed relationship between age, male gender, ALT levels and viral load with histological damage (p ULN (69.1 vs. 47.1%, p = 0.04. There were not significant upper frequencies of advanced lesion when a cut-off of 40 years or DNA-HBV > 2 x 10³ IU/mL viral load or serological status HBeAg was considerate. Histological activity was lesser in genotype D patients than those infected with others genotypes (p Objetivo: analizar factores virales y del huésped relacionados con actividad histológica en un subgrupo de pacientes con hepatitis crónica B y elevación intermitente o moderada de alanina aminotransferasa (ALT, y el umbral que determine daño histológico indicativo de tratamiento. Pacientes y métodos: análisis retrospectivo de parámetros virales y del huésped en 89 pacientes con hepatitis crónica B biopsiados consecutivamente por elevación intermitente o moderada de ALT [1-2 x USN (USN = 39 UI/mL]. Fueron analizados edad, sexo, ALT, HBeAg, carga viral y genotipo. Se consideró como lesion histologica avanzada un Índice de

  15. 慢性间歇性低压低氧抑制线粒体途径介导的代谢综合征大鼠心肌组织细胞凋亡%Chronic intermittent hypobaric hypoxia ameliorates myocardial apoptosis through inhibiting mitochondrial pathway in rats with metabolism syndrome

    Institute of Scientific and Technical Information of China (English)

    袁芳; 李艳青; 滕旭; 周京京; 郭赞; 王昕; 张自伟; 张翼

    2015-01-01

    Aim To confirm the inhibitory effect of chronic intermittent hypobaric hypoxia ( CIHH) on my-ocardial apoptosis induced by metabolism syndrome ( MS) , and to investigate its mechanism. Methods A rat model of MS induced by fructose was used. The blood pressure and the plasma content of glucose, tri-glyceride, cholesterol, and insulin after 12 h fasting were detected. HE stain were used to detect the cardi-ac structure. The TUNEL staining and activity of caspase-3 were used to detect the apoptosis of myocar-dium. The protein expression of Bcl-2 and Bax was detected by Western blot . Results Compared with the control rats, the blood pressure and the plasma content of glucose, triglyceride, cholesterol, and insu-lin were all increased in rats with MS. In rats with MS, the impairment of cardiac structure and the increase of apoptosis were also observed. The protein expression of Bcl-2 was significantly down-regulated, and that of Bax was significantly up-regulated in MS rats. The ratio of Bcl-2/Bax was also significantly decreased. Interest-ingly, CIHH could ameliorate all of the above issues. There was no significant difference between control group and CIHH group. Conclusion CIHH may im-prove the increased apoptosis in rats with MS via inhib-iting the mitochondrial pathway of apoptosis. This stud-y might provide new targets for therapy and the preven-tion of MS patients.%目的:证实CIHH( chronic intermittent hypobaric hypoxi-a, CIHH)具有改善代谢综合征( metabolism syndrome, MS)大鼠心肌细胞凋亡的作用,并探讨其机制。方法10%果糖水喂养SD大鼠(250~300) g 42 d制备MS模型,检测动脉血压以及空腹血糖、胆固醇、甘油三酯和胰岛素含量,HE染色观察心肌结构,TUNEL染色和caspase-3活性测定检测心肌细胞凋亡, Western blot 检测 Bcl-2和 Bax 的蛋白表达水平。结果与正常大鼠比较,果糖喂养大鼠表现出明显的高血压、高血糖、高甘油三脂血症、高胆固醇血症和高胰

  16. 慢性间断性低氧大鼠认知功能和脑胆碱能神经元的进行性变化%The progressive effects of chronic intermittent hypoxia on cognitive function and the cholinergic neuron in rats

    Institute of Scientific and Technical Information of China (English)

    陈燕; 赵春玲; 张春来; 徐倩

    2011-01-01

    Objective: To investigate the relation between the progressive effects of chronic intermittent hypoxia(CIH) on cognitive function and the change of cholinergic neuron. Methods: Forty adult male Sprague-Dawley rats were randomly averagely divided into four groups: control group, CIH 1 week group, CIH 3 week group and CIH 5 week group. The cognitive function was assessed by the Morris Water Maze. The necrosis neurons in prefrontal cortex and hippocampus were observed and counted. The cholin aeetyltransferase(ChAT) immunostained cells in prefrontal cortex and hippocampus were identified and quantitated. Results: The spatial learning and memory impairments progressed from 1 to 5weeks in rats. Compared with the control group, the cognitive impairments in CIH5w group were significant( P < 0.05). The degeneration or necrosis neurons in prefrontal cortex and hippocampus were significantly increased in CIH rats, and worsen gradually along with the hypoxia. The ChAT immunostained cells in prefrontal cortex and hippocampus were gradually reduced. The ChAT immunostained cells of prefrontal cortex and hippocampus in CIH3w group and CIH5w group were less than that in control group ( P <0.05). Conclusion: Chronic intermittent hypoxia induced slowly progressive spatial learning and memory impairments in rats, which maybe associated with the damage of neurons and the reduction of ChAT in prefrontal cortex and hippocampus.%目的:探讨慢性间断性低氧(CIH)大鼠认知功能的进行性变化及其与脑胆碱能神经元变化的关系.方法:成年雄性SD大鼠40只,随机均分为对照组、慢性间断性低氧1,3,5周组.应用Morris水迷宫检测认知功能的变化:利用HE染色在光镜下计数前额叶皮层和海马坏死神经元数;利用免疫组化方法检测前额叶皮层和海马胆碱乙酰转移酶(ChAT)阳性表达.结果:CIH各组大鼠学习记忆能力呈进行性下降趋势;与对照组比较,CIH5w组出现明显学习记忆功能障碍(P<0

  17. 内源性大麻素系统在慢性间歇低氧大鼠心肌肥厚病理过程中的作用%The Pathological Processing of Endocannabinoid System on Cardiac Hypertrophy in a Experimental Rats With Chronic Intermittent Hypoxia

    Institute of Scientific and Technical Information of China (English)

    张晋源; 陈彦; 肖玲; 唐茜; 王蓓; 范艳锋

    2014-01-01

    Objective: To investigate the effect of endocannabinoid system on cardiac hypertrophy in experimental rats with chronic intermittent hypoxia and to study the impact of endocannabinoid antagonist, rimonabant in such pathological processing. Methods: A total of 48 male Wistar rats were divided into 6 groups. 4 and 6 weeks of Normal control group, 4 and 6 weeks of Hypoxia group, 4 and 6 weeks of Hypoxia with rimonabant intervention group. n=8 in each group. The rats were sacrificed to measure left ventricular mass index (LVMI), the myocardial cell morphological changes were observed by optical microscope, the expression of cardiac calcium/calmodulin-dependent protein kinase II (CaMKII) and cardiotrophin-1 (CT-1) were detected by immunohistochemistry at 4 and 6 weeks respectively. Results: Compared with 4 and 6 weeks of Normal control group, the LVMI, cardiac hypertrophy condition, CaMKII and CT-1 were increased in 4 and 6 weeks of Hypoxia group, all P Conclusion: The Chronic intermittent hypoxia could induce myocardial hypertrophy via endocannabinoid system disorders, such pathological processing could be reduced by rimonabant intervention.%目的:探讨内源性大麻素系统在慢性间歇低氧大鼠心肌肥厚中作用及使用内源性大麻素受体拮抗剂利莫那班后对其的影响。  方法:48只雄性Wistar大鼠,根据实验设计在实验4、6周时随机分组,即正常对照4周组、6周组,低氧4周组、6周组,低氧+利莫那班即拮抗低氧4周组、6周组,共6组,随机取8只大鼠,处死后测左心室质量指数(LVMI),光学显微镜下观察心肌细胞形态变化,免疫组化测钙/钙调素依赖性蛋白激酶II(CaMKII)、心肌营养素-1(CT-1)表达。  结果:低氧4周组、6周组分别与正常对照4周组、6周组相比,LVMI、光镜下心肌细胞肥厚及免疫组化下CaMKII、CT-1均明显升高,组间比较差异均有统计学意义(P  结论:慢性间歇

  18. 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...

  19. 褪黑素对慢性间歇性缺氧性心肌cTnT及Ca2+-ATPase的影响%Effect of melatonin on the cTnT and Ca2+- AT Pase of chronic intermittent hypoxia cardiac muscular tissues

    Institute of Scientific and Technical Information of China (English)

    董译元; 凌月福; 张耀庭

    2014-01-01

    Objective To investigate whether the melatonin (melatonin,MLT)could protect SD rats’cardiac muscu-lar tissues from chronic intermittent hypoxia damage in the atmospheric pressure.Methods The 24 male,SD rats(5 weeks)were randomly divided into three groups:the Control group,the experimental group A and the experimental group B.The control group rats were fed with normally reared in the air,and the experimental group A and B rats were living in the atmospheric pressure and chronic intermittent hypoxia boxes.The control group rats and the experimental group B rats were fed with normal saline solution (NS ),and the experimental group A rats were fed with melatonin (MLT).After 8 weeks,the cTnT capacity and Ca2+-ATPase activity of each rat were detected,and the right ventri-cles were taken for pathological section.Results ①Comparison of the experimental group B and the experimental group A:The cTnT capacity of the experimental group B was increased (P0.05).There was a small amount of bleeding between myocardial.③Comparison of the experimental group B and the control group:The cTnT capacity of the experimental group B was increased (P<0.05),and the Ca2+-ATPase activity of the experimental group B was decreased (P<0.05).Individual myocardial cell nuclei disappeared.Myocardial cells were hypertrophy,and there was a large amount of bleeding in myocardial.Conclusion MLT can protect rats’cardiac muscular tissue from injury of chronic intermittent hypoxia.%目的:探讨褪黑素(MLT)对常压下慢性间歇性缺氧SD大鼠心肌的保护作用。方法将24只雄性SD大鼠(5周龄)随机分成3组:对照组、实验A组、实验B组。对照组在空气中正常饲养,实验A组和实验B组在常压慢性间歇性低氧箱内,对照组和实验B组灌服生理盐水,实验A组灌服褪黑素。8周后用光电比色法测定血清肌钙蛋白T(cTnT)的浓度和心肌钙离子ATP酶(Ca2+-ATPase)的活性,取大鼠右心室做病理切片

  20. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

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

    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...... 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...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  1. Sky dancer: an intermittent system

    Science.gov (United States)

    Cros, Anne; Rodríguez Romero, Jesse Alexander; Damián Díaz Andrade, Oscar

    2009-11-01

    Sky dancers attract people sight to make advertising. What is the origin of those large vertical tubes fluctuations above an air blower? This study complements the previous one [1] about the system analysis from a dynamical system point of view. As a difference from the ``garden hose-instability'' [2], the tube shape has got ``break points''. Those ``break points'' separate the air-filled bottom tube portion from its deflated top portion. We record the tube dynamics with a high-speed videocamera simultaneously that we measure the pressure at the air blower exit. The intermittent pressure evolution displays picks when the tube fluctuates. We compare those overpressure values with the ones that appears in a rigid tube whose exit is partially obstructed. [1] F. Castillo Flores & A. Cros ``Transition to chaos of a vertical collapsible tube conveying air flow'' J. Phys.: Conf. Ser. 166, 012017 (2009). [2] A. S. Greenwald & J. Dungundji ``Static and dynamic instabilities of a propellant line'' MIT Aeroelastic and Structures Research Lab, AFOSR Sci. Report: AFOSR 67-1395 (1967).

  2. 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...

  3. 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.

  4. NF-κB,IL-6 and PGE2 expression in periodontal tissue of rats with periodontitis under chronic intermittent hypoxia%间歇性低氧对牙周炎大鼠牙周组织中 NF-κB、IL-6及 PGE2含量的影响

    Institute of Scientific and Technical Information of China (English)

    王月昊; 王小琴; 苗伟; 柴晶; 程宇钊; 马小雯

    2016-01-01

    Objective:To examine the effects of chronic intermittent hypoxia(CIH)on the NF-κB,IL-6 and PGE2 level in rats with periodontitis.Methods:32 male SD rats(6 weeks old)were randomly divided into 4 groups(n =8),group A(normoxic control),B (normoxic periodontitis),C(CIH)and D(periodontitis +CIH).Periodontitis model was established in the upper second molars by liga-tion technique and high-glucose diet in the rats of group B and D.The rats in the group C and D were subjected to CIH in a cycle of al-ternative nitrogen and oxygen in a closed chamber.The chamber was filled with nadir and zenith ambient oxygen every 1 20 seconds per cycle for 8 hours per day.The rats were sacrificed and the gingival tissues were examined for the detection of IL-6 and PGE2 expression by ELISA,and NF-κB expression by immunohistochemistry.Results:Histology revealed apical migration of junctional epithetlium and crestal alveolar bone resorption in group B and D,and in the above phenomena of group D was the severest.The content of NF-κB,IL-6 and PGE2 in group B,C,D was higher than that in group A(P <0.05),and in group D was the highest(P <0.05).Conclusion:Chro-nic intermittent hypoxia can aggravate the inflammation of periodontitis.%目的:建立慢性间歇性低氧(CIH)及牙周炎大鼠模型,研究 NF-κB、IL-6及 PGE2水平的变化。方法:将32只普通级6周龄雄性 SD 大鼠随机分为4组(n =8):A:常氧空白组、B:常氧牙周炎组、C:CIH 组、D:CIH 合并牙周炎组。B、D 组大鼠上颌第二磨牙进行结扎处理,辅以高糖饮食;A、C 组正常饮食。C、D 组置于低氧舱8 h/d。8周后处死,HE 染色,免疫组化检测牙周组织 NF-κB 含量,ELISA 检测牙龈组织 IL-6、PGE2。结果:HE 染色:8周后 B 组、D 组牙周炎症表现明显。免疫组化:B、C、D 组 NF-κB 表达均高于 A 组(P <0.05);ELISA 检测:B、C、D 组 IL-6、PGE2含量高于 A 组(P <0.05),且 D 组 IL-6

  5. Intermittent preventive treatment of malaria in pregnancy

    DEFF Research Database (Denmark)

    Mbonye, A.K.; Bygbjerg, Ib Christian; Magnussen, Pascal

    2008-01-01

    OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non-randomized comm......OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non...

  6. 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.

  7. Beneficial effects of intermittent suction and pressure treatment in intermittent claudication

    DEFF Research Database (Denmark)

    Mehlsen, J; Himmelstrup, H; Himmelstrup, Bodil;

    1993-01-01

    The present study reports on the effects of a physical treatment modality in patients with intermittent claudication. During this treatment a major part of the skin surface is subjected to intermittent suction and pressure. In a previous, preliminary study the authors found a beneficial effect of...

  8. Intermittent ephemeral river-breaching

    Science.gov (United States)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  9. Intermittent changing axis deviation with intermittent left anterior hemiblock during atrial flutter with subclinical hyperthyroidism.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo

    2009-06-26

    Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes but it is usually associated with a higher heart rate and a higher risk of supraventricular arrhythmias including atrial fibrillation and atrial flutter. Intermittent changing axis deviation during atrial fibrillation has also rarely been reported. We present a case of intermittent changing axis deviation with intermittent left anterior hemiblock in a 59-year-old Italian man with atrial flutter and subclinical hyperthyroidism. To our knowledge, this is the first report of intermittent changing axis deviation with intermittent left anterior hemiblock in a patient with atrial flutter.

  10. 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...

  11. 参芪花粉片对高原慢性间歇性缺氧暴露期间脱习服的疗效观察%Curative effect observation of Shenqipollen tablet on deacclimatization during exposure period of the chronic intermittent hypoxia in high altitude regions

    Institute of Scientific and Technical Information of China (English)

    娄晓敏; 张雪峰; 周其全; 王胜玉

    2013-01-01

    OBJECTIVE To investigate the intervention effects of Shenqi pollen tablets on deacclimatization during exposure period of chronic plateau intermittent hypoxic hypoxia. METHODS Selected 380 young healthy workers from the plains and low lying areas into the work area altitude 4 300m, with weekly indoor at an altitude of 4 300m for 5 working days, then returned to the elevation of 2 800m fixed base rest mode, continuously observed the intervention effect of Shenqi pollen tablets on symptom occurrence rate of plateau deacclimatization during rest period exposure period of 3 years in the highlands at an altitude of 2 800m. RESULTS The total detectable rate of altitude deacclimatization was 82.37% (313/380); the top 10 symptoms and the order were: lethargy (66.31%) , fatigue (42.37%) , dizziness (35.78%) , insomnia (30.79%) , decreased appetite (29.73%), upset (29.21%), general malaise (28.95%), depression (27.89%), palpitation (27.10%), and chest tightness (24.47%). The crowd in need of treatment with altitude deacclimatization were detected in the total de-acclimation of those 34.18% (107/313). The intervention effect of Shenqi pollen tablets made the symptoms completely disappear in 92.52% (99/ 107) after medication of 15 days, recurrence rate (cured) was 78.79% (78/99) in who without continue medication in half of one year, even?there were some symptoms and self-medication to ease (CR) 21.21% (21/99) , free remission or partial remission, but often needed medication (inactive) had 7.48% (8/107). There were no adverse drug reactions during observation period. CONCLUSION The high altitude deacclimatization during exposure period of chronic plateau intermittent hypoxic hypoxia has a higher prevalence. Shenqi pollen tablets have better short-term effect and long-term prevention, and is an effective disease prevention and treatment.%目的 探讨参芪花粉片对高原慢性间歇性缺氧暴露期间脱习服的干预效果.方法 选择由平原

  12. Endoscopic excision of a prolapsing malignant polyp which caused intermittent gastric outlet obstruction

    Institute of Scientific and Technical Information of China (English)

    Huqh J Freeman

    2005-01-01

    A 69-year-old male with chronic lymphocytic leukemia presented with iron deficiency anemia and post-prandial abdominal fullness. Endoscopy showed a large polyp on a stalk, protruding through the pylorus into the duodenum causing intermittent gastric outlet obstruction. While prolapsing gastric antral polyps are usually benign and hyperplastic, inflammatory or regenerative in type, excisional snare polypectomy here led to complete resolution of his symptoms, but showed a malignant polyp.

  13. Chronic penile strangulation

    Directory of Open Access Journals (Sweden)

    Lopes Roberto I

    2003-01-01

    Full Text Available Chronic penile strangulation is exceedingly rare with only 5 cases previously reported. We report an additional case of progressive penile lymphedema due to chronic intermittent strangulation caused by a rubber band applied to the penile base for 6 years. A 49-year-old man presented incapacity to exteriorize the glans penis. For erotic purposes, he had been using a rubber-enlarging band placed in the penile base for 6 years. With chronic use, he noticed that his penis swelled. Physical examination revealed lymphedema of the penis, phimosis and a stricture in the penile base. The patient was submitted to circumcision and the lymphedema remained stable 10 months postoperatively. Chronic penile incarceration usually causes penile lymphedema and urinary disturbance. Treatment consists of removal of foreign devices and surgical treatment of lymphedema.

  14. Intermittency in Switching Power Converters: Theoretical Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-fei; CHEN Jun-ning; TSE Chi K.; QIU Shui-sheng; KE Dao-ming; SHI Long-xing; SUN Wei-feng

    2006-01-01

    In view of reasonable explanation of intermittent subharmonics and chaos that can be gained from coupling filter between circuits,this paper discusses a method that maps time bifurcation with parameter bifurcation.Based on this mapping method,the general analysis method of characteristic multiplier,which is originally aimed at parameter bifurcation,can be used for the study of intermittency,i.e.,time bifurcation.In this paper,all researches coming from characteristic multipliers,parameter-bifurcation diagrams,and the largest Lyapunov exponent indicate the same results as those produced by simulation and experiment.Thus,it is proved theoretically that the intermittency in switching power converter can be explained in terms of coupling of spurious interference.

  15. Intermittent rainfall in dynamic multimedia fate modeling.

    Science.gov (United States)

    Hertwich, E G

    2001-03-01

    It has been shown that steady-state multimedia models (level III fugacity models) lead to a substantial underestimate of air concentrations for chemicals with a low Henry's law constant (H multimedia models are used to estimate the spatial range or inhalation exposure. A dynamic model of pollutant fate is developed for conditions of intermittent rainfall to calculate the time profile of pollutant concentrations in different environmental compartments. The model utilizes a new, mathematically efficient approach to dynamic multimedia fate modeling that is based on the convolution of solutions to the initial conditions problem. For the first time, this approach is applied to intermittent conditions. The investigation indicates that the time-averaged pollutant concentrations under intermittent rainfall can be approximated by the appropriately weighted average of steady-state concentrations under conditions with and without rainfall.

  16. The Yo-Yo intermittent recovery test

    DEFF Research Database (Denmark)

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

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2...... (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...

  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. 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.

  19. Synchronization of Intermittently Coupled Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    2013-01-01

    Full Text Available This paper investigates the synchronization phenomenon of an intermittently coupled dynamical network in which the coupling among nodes can occur only at discrete instants and the coupling configuration of the network is time varying. A model of intermittently coupled dynamical network consisting of identical nodes is introduced. Based on the stability theory for impulsive differential equations, some synchronization criteria for intermittently coupled dynamical networks are derived. The network synchronizability is shown to be related to the second largest and the smallest eigenvalues of the coupling matrix, the coupling strength, and the impulsive intervals. Using the chaotic Chua system and Lorenz system as nodes of a dynamical network for simulation, respectively, the theoretical results are verified and illustrated.

  20. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...... 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....

  1. [Chronic inflammatory bowel diseases in cats].

    Science.gov (United States)

    Ghermai, A K

    1989-01-01

    The aetiology of chronic idiopathic intestinal inflammation is unknown. It is characterized by a diffuse infiltration with inflammatory cells into the intestinal mucosa and sometimes submucosa. Cats with chronic intermittent vomiting and diarrhoea, later on accompanied by anorexia and weight loss, are presented. Definitive diagnosis can be obtained by intestinal biopsy only. An immune pathogenesis is suspected, which is supported by the fact, that chronic inflammatory bowel disease responds to steroid therapy.

  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. 慢性间歇低氧对高脂喂养大鼠心肌天冬氨酸特异性半胱氨酸蛋白酶-3和髓过氧化物酶活性的影响%Effect of chronic intermittent hypoxia on the activities of apoptosis regulating factor cysteine-containing aspartate-specific protease-3 and oxidative stress marker myeloperoxidase in cardiomyocyte in rats fed a high-fat diet

    Institute of Scientific and Technical Information of China (English)

    王卉; 田建立; 张蕴; 王林

    2014-01-01

    Objective To investigate the effect of chronic intermittent hypoxia (CIH) on myocardial tissue pathology,oxidative stress and apoptosis in rat fed a high-fat diet,and to explore the possible mechanism of CIH induced cardiomyocyte injury.Methods A total of 24 male Wistar rats were randomly divided into 3 groups (n=8 each).The control group was fed common rat forage,the high-fat group was fed high-fat forage,and the high-fat plus intermittent hypoxia group was fed high-fat forage combined with a 7h/d intermittent hypoxia treatment.The changes of myocardial tissue pathology and ultrastructure of cardiomyocyte,and the activities of apoptosis regulating factor cysteine-containing aspartate-specific proteases-3 (caspase-3) and oxidative stress marker myeloperoxidase (MPO) were observed in the 3 groups after 4 weeks of treatment.Results There were significant differences in the activities of caspase-3 and MPO among the three group (F=89.94,71.24,both P=0.001).The activities of caspase-3 and MPO were lower in the control group than in the high-fat group and in high fat plus intermittent hypoxia group [(0.21±0.06) vs.(0.80±0.11),(1.15±0.21),(3.20±0.58) vs.(10.87±1.96),(13.17±2.22),P<0.01].The activities of caspase-3 and MPO were higher in the high-fat plus intermittent hypoxia group than in the high fat group[(1.15±0.21) vs.(0.80±0.11),(13.17±2.22) vs.(10.87±1.96),P<0.01].No abnormal findings in the structure of cardiomyocyte were observed in the control group,while multiple pathologic damages in cardiomyocyte were detected in the high-fat group,and more obvious injuries in the high-fat plus intermittent hypoxia group.Conclusions The pathologic damages to cardiomyocyte are more serious in high fat and intermittent hypoxia group than in the high-fat group.Apoptosis induced by oxidative stress may play an important role in the pathogenesis of these injuries.%目的 通过观察慢性间歇低氧对高脂喂养大鼠心肌细胞组织病理学、氧化应激

  4. Pharm GKB: Porphyria, Acute Intermittent [PharmGKB

    Lifescience Database Archive (English)

    Full Text Available Overview Alternate Names: PharmGKB Accession Id: PA166048717 External Vocabularies NDFRT: Porphyria, Acute... Intermittent (N0000003536) Common Searches Search Medline Plus Search CTD Pharm GKB: Porphyria, Acute Intermittent ...

  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. 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

  7. Intermittent resistive faults in digital cmos circuits

    NARCIS (Netherlands)

    Kerkhoff, Hans G.; Ebrahimi, H.

    2015-01-01

    A major threat in extremely dependable high-end process node integrated systems in e.g. Avionics are no failures found (NFF). One category of NFFs is the intermittent resistive fault, often originating from bad (e.g. Via or TSV-based) interconnections. This paper will show the impact of these faults

  8. Intermittent Swimming with a Flexible Propulsor

    Science.gov (United States)

    Akoz, Emre; Zeyghami, Samane; Moored, Keith

    2016-11-01

    Some animals propel themselves by using an intermittent swimming gait known as a burst-and-glide or a burst-and-coast motion. These swimmers tend to have a more pronounced pitching of their caudal fins than heaving leading to low non-dimensional heave-to-pitch ratios. Recent work has shown that when this ratio is sufficiently low the efficiency of an intermittently heaving/pitching airfoil can be significantly improved over a continuously oscillating airfoil. However, fish that swim with an intermittent gait, such as cod and saithe, do not have rigid fins, but instead have highly flexible fins. To examine the performance and flow structures of an intermittent swimmer with a flexible propulsor, a fast boundary element method solver strongly coupled with a torsional-spring structural model was developed. A self-propelled virtual body combined with a flexible-hinged pitching airfoil is used to model a free-swimming animal and its flexible caudal fin. The duty cycle of the active to the coasting phase of motion, the torsional spring flexibility and the forcing frequency are all varied. The cost-of-transport and the swimming speed are measured and connected to the observed wake patterns. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI Grant Number N00014-14-1-0533.

  9. Management of patients with intermittent claudication

    NARCIS (Netherlands)

    S. Spronk (Sandra)

    2008-01-01

    textabstractIntermittent claudication is the first and mildest manifestation of peripheral arterial disease, caused by the atherosclerotic process of progressive narrowing of one or more of the arteries of the peripheral circulation.1 If the arterial system fails, it results in a progressive oxygen

  10. 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

  11. 40 CFR 51.119 - Intermittent control systems.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in... of any constant pollution control system which was in use before December 31, 1970, or the...

  12. An update of clinical management of acute intermittent porphyria

    Directory of Open Access Journals (Sweden)

    Pischik E

    2015-09-01

    mutation-positive family members. C, management of patients with recurrent attacks: 1 evaluation of the lifestyle, 2 evaluation of hormonal therapy in women, 3 prophylactic heme therapy, and 4 liver transplantation in patients with severe recurrent attacks. D, follow-up of the AIP patients for long-term complications: chronic hypertension, chronic kidney insufficiency, chronic pain syndrome, and hepatocellular carcinoma. Keywords: porphyria, acute intermittent porphyria, neuropathy, treatment, heme

  13. Chronic pancreatitis

    Science.gov (United States)

    Chronic pancreatitis - chronic; Pancreatitis - chronic - discharge; Pancreatic insufficiency - chronic; Acute pancreatitis - chronic ... alcohol abuse over many years. Repeated episodes of acute ... chronic pancreatitis. Genetics may be a factor in some cases. ...

  14. 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.

  15. Towards an intermittency-friendly energy system

    DEFF Research Database (Denmark)

    Blarke, Morten

    2012-01-01

    Distributed cogeneration has played a key role in the implementation of sustainable energy policies for three decades. However, increasing penetration levels of intermittent renewables is challenging that position. The paradigmatic case of West Denmark indicates that distributed operators...... 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....... However, well-designed heat pump concepts are more cost-effective than electric boilers, and in future markets where the gas/electricity price ratio is likely to increase, compression heat pumps in combination with intermediate thermal storages represent a superior potential for combining an intermittency...

  16. 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.

  17. A simple model for turbulence intermittencies

    CERN Document Server

    Rimbert, Nicolas

    2009-01-01

    Whether turbulence intermittencies shall be described by a log-Poisson, a log-stable pdf or other distributions is still debated nowadays. In this paper, a bridge between polymer physics, self-avoiding walk and random vortex stretching is established which may help in getting a new insight on this topics. Actually a very simple relationship between stability index of the stable law and the well known Flory exponent stemming from polymer physics is established. Moreover the scaling of turbulence intermittencies with Reynolds number is also obtained and the overall picture is very close to Tennekes' simple model for the fine scale structure of turbulence [Phys. Fluids, 11, 3 (1968)] : vortex tubes of Kolmogorov length width are bend by bigger vortices of Taylor length scale. This thus results in both a simple and sound model with no fitting parameter needed.

  18. 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.

  19. Treatment of febrile seizures with intermittent clobazam

    OpenAIRE

    1997-01-01

    Fifty children, 24 female and 26 male, with ages varying from 6 to 72 months (mean=23.7 m.) that experienced at least one febrile seizure (FS) entered a prospective study of intermittent therapy with clobazam. Cases with severe neurological abnormalities, progressive neurological disease, afebrile seizures, symptomatic seizures of other nature, or seizures during a central nervous system infection were excluded. Seizures were of the simple type in 25 patients, complex in 20 and unclassified i...

  20. Bladder calculi complicating intermittent clean catheterization.

    Science.gov (United States)

    Amendola, M A; Sonda, L P; Diokno, A C; Vidyasagar, M

    1983-10-01

    Eight male patients on clean intermittent catheterization programs for neurogenic bladder dysfunction developed vesical calculi around pubic hairs inadvertently introduced into the bladder, acting as a nidus for incrustation. In three patients, the radiographic appearance of serpentine calcifications in the pelvis was highly consistent with calcareous deposits on strands of hair. Familiarity with this radiologic appearance should suggest the diagnosis in the appropriate clinical setting and help avoid misinterpretation of these calcifications, atypical of usual bladder stones.

  1. 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.

  2. Intermittent radio galaxies and source statistics

    CERN Document Server

    Reynolds, C S

    1997-01-01

    We suggest that extragalactic radio sources are intermittent on timescales of 10^4-10^5 yr. Using a simple spherical model of a cocoon/shock system, it is found that inactive sources fade rapidly in radio luminosity but the shock in the ambient medium continues to expand supersonically, thereby keeping the whole source structure intact during the inactive phases. The fading of inactive sources, and the effect of the intermittency on the expansion velocity, can readily explain the observed over-abundance of small radio sources. In particular, the plateau in the observed distribution of sizes found by O'Dea & Baum (1997) can be interpreted as being due to intermittency. The model predicts that very young sources will be particularly radio luminous, once the effects of absorption have been accounted for. Furthermore, it predicts the existence of a significant number of faint `coasting' sources. These might be detectable in deep, low-frequency radio maps, or via the X-ray and optical emission line properties ...

  3. Eeffects of Coptis Chinensis on vasoconstrictive activity of isolated thoracic aorta of normoxic and chronic intermittent hypobaric hypoxic rats%黄连对正常氧和慢性间歇性低压低氧大鼠离体胸主动脉收缩活动的影响

    Institute of Scientific and Technical Information of China (English)

    张鹏; 宋士军; 刘威兰; 李连连; 赵卫丽; 张翼

    2011-01-01

    Objective: To observe the effects of Coptis Chinensis on vasoconstrictive activity of isolated thoracic aorta rings of normoxic and chronic intermittent hypobaric hypoxic(CIHH) rats, and to investigate the underlying mechanisms. Methods: Young male Sprague-Dawley rats were randomly divided into normoxic group and QHH group: the former were not given any special treatment; the latter were exposed to hypoxia in a hypobaric chamber simulating 5000 m altitude (PB = 404 mmHg, PO2= 84 mmHg, 11.1% O2), 6 hours daily for 28 days. The isolated thoracic aorta rings of rats were prepared and perfused in thermostat, and the effects of Coptis on vasoconstrictive activity of aorta rings were recorded, the mechanisms were investigated simultaneouly. Results: Coptis Chinensis significantly decreased NE and KCl-induced vaso-constriction of normoxic and QHH rats' isolated aortic rings, but the inhibitive effects had no obvious discrepancy between the two groups. The contractive amplitude had no marked change after the removal of endothelium. When calculated by Logit Loglinear analysis, IC50 of NE and KCl-induced contractive amplitude in normoxic group were respectively 2.99 g/L and 6.14 g/L, while they were 3.45 g/L and 5.81 g/L in CIHH group. The inhibitive effect of Coptis on vasoconstrictive activity of both groups could be partly decreased by Glibenclamide and nitro-L-arginine methyl ester; Indomethacin suppressed the effect on normoxic group as well. Also Coptis significantly inhibited NE-induced both intra-cellular and extracellular calciumion-depended vasoconstriction. Conclusion: Coptis Chinensis obviously relaxes isolated thoracic aorta rings of normoxic and CIHH rats, but the effects are endothelium-independent and have no marked discrepancy between the two groups. The mechanisms of the effects may be related to the opening of ATP-sensitive K+ channel, raise of nitric oxide concentration in both groups, and the increasing of PGI2 in normoxic group. Besides, Coptis may

  4. 室旁核中血管紧张素Ⅱ通过活性氧介导慢性间歇性低氧大鼠的升压作用%Angiotensin Ⅱ inparaventricular nucleus contributes to hypertension in chronic intermittent hypoxia rats by reactive oxygen species

    Institute of Scientific and Technical Information of China (English)

    唐志强; 范一菲; 汪金丽; 程文慧; 沈兵; 钟明奎

    2016-01-01

    目的:研究室旁核( PVN)中血管紧张素Ⅱ( Ang Ⅱ)-活性氧(ROS)通路在慢性间歇性低氧(CIH)大鼠的升压作用。方法将雄性SD大鼠随机分为对照组和慢性间歇性低氧组(CIH 组)(8 h/d,连续15 d)。用立体定位仪进行PVN核团定位微量注射,采用颈动脉插管法在体测量大鼠平均动脉压(MAP),ELISA 法测量 PVN 中 Ang Ⅱ、ROS 含量, Western blot 法测定 PVN 中血管紧张素Ⅱ1型受体(AT1R)的蛋白表达,应用试剂盒(羟胺法)测定PVN中的总超氧化物歧化酶(T-SOD)活力。结果与对照组比较,CIH组大鼠PVN中ROS(P<0.05)和Ang Ⅱ含量显著升高(P<0.01),AT1R的表达显著增加(P<0.05),而T-SOD活力则明显下降( P <0.01)。双侧 PVN 内微量注射 Ang Ⅱ(0.3 nmol)可升高两组大鼠的MAP,而CIH大鼠MAP升高更显著(P<0.01);超氧阴离子清除剂Tempol可降低两组大鼠的MAP,而CIH大鼠MAP降低更显著(P<0.01);Tempol预处理可抑制Ang Ⅱ对两组大鼠的升压作用,且在CIH组中抑制作用更加明显( P<0.01)。结论室旁核中ROS介导了Ang Ⅱ在CIH大鼠中的升压作用。%Objective To investigate the effect of Ang II-ROS signal pathway in the hypothalamic paraventricular nucleus ( PVN) on chronic intermittent hypoxia( CIH) induced-hypertension in rats. Methods Male SD rats were randomly divided into control and CIH groups. The control rats were exposed to continuous normoxia, while the CIH rats were submitted to CIH (8 h per day for 15 days) . Rats were fixed on the stereotaxic instrument to conduct microinjection in the PVN according to Paxinos and Watson rat atlas. Mean arterial pressure ( MAP) was recorded in vivo on a PowerLab data acquisition system. We used ELISA kit to measure the content of AngⅡ, ROS, total-superoxide dismutase (T-SOD) and Western blot to measure AngⅡtype 1 receptor (AT1R) protein expression in PVN. Results The contents of PVN ROS(P<0. 05)and AngⅡ(P<0. 01) were significantly higher than

  5. Analysis of liver stiffness measurement in chronic hepatitis B patients with persistently normal ALT and persistently or intermittently elevated ALT%ALT持续正常及持续或间断升高的慢性乙型肝炎患者肝脏硬度值分析

    Institute of Scientific and Technical Information of China (English)

    钟曼华; 梁携儿; 陈永鹏; 杨淑玲; 彭劼; 谭文娟; 于文轩; 孙剑

    2014-01-01

    目的:目前ALT持续正常(PNALT)以及持续或间断升高(PIEALT)的慢性乙型肝炎(CHB)患者肝脏硬度值(LSM)的数据十分有限。本研究对该组患者LSM范围及其影响因素进行了探讨,以供临床应用参考。方法将在2012年9月-2013年3月于本院就诊的208例初治CHB患者纳入研究,均接受瞬时弹性扫描仪(FS)检查。PNALT组:在最近1 a随访至少3次,每次间隔2个月以上,ALT水平均正常,入组时ALT正常;PIEALT组进一步分为ALT轻度升高(过去1 a随访中ALT水平至少有1次升高但<2×ULN)以及ALT明显升高(过去1 a随访中ALT水平至少有1次升高>2×ULN),入组时ALT<2×ULN。根据现有的研究结果,当ALT<2×ULN时,用于诊断以及排除进展性肝纤维化的标准分别为LSM≥10.6 kPa和LSM<7.4 kPa。计量资料分析采用t检验、方差分析和秩和检验,计数资料采用χ2检验,相关因素采用双变量相关分析及Logistic回归分析。结果受试人群平均LSM为(6.2±2.9) kPa。在PNALT患者中,LSM≥7.4 kPa占14.3%(18/126),LSM≥10.6 kPa占2.4%(3/126)。在总体PIEALT患者中,这个比例分别是35.4%(29/82)以及13.4%(11/82)。多元回归分析中,ALT>1×ULN(OR=2.63,P=0.037)、男性(OR=5.29,P=0.012)是LSM≥7.4 kPa的独立影响因素;HBV DNA定量>5 log10拷贝/ml是LSM≥10.6 kPa唯一的独立影响因素(OR=13.84,P=0.046)。结论在PIEALT和PNALT的CHB患者中,分别有35%及14%的患者不能排除进展性肝纤维化的可能;大约13%的PIEALT患者根据LSM结果可判断为进展性肝纤维化。对于ALT>1×ULN、HBV DNA拷贝数的对数值大于5的男性CHB患者,建议对其进行密切随访。%Objective Data on liver stiffness measurement (LSM)in chronic hepatitis B (CHB)patients with persistently normal alanine amin-otransferase (ALT

  6. Steroids for Chronic Inflammatory Demyelinating Polyneuropathy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-03-01

    Full Text Available The efficacy and safety of high-dose, intermittent IV methylprednisolone (IVMP as initial and long-term maintenance therapy for chronic inflammatory demyelinating polyneuropathy (CIDP were analyzed by a retrospective review of outcome data derived from patients’ medical records between 1992 and 2003 at Washington University School of Medicine, St Louis, MO.

  7. 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.

  8. 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.

  9. Clinical investigation of surgery for intermittent exotropia

    Institute of Scientific and Technical Information of China (English)

    Chong-qing YANG; Ye SHEN; Yang-shun GU; Wei HAN

    2008-01-01

    Objective: To investigate the time and postoperative binocular vision of strabismus surgery for children with intermittent exotropia (X (T)). Methods: A retrospective investigation was conducted in 80 child patients with intermittent exotropia. Pre- and postoperative angles of deviation fixating at near (33cm) and distant targets (6m) were measured with the prolonged alternate cover testing. The binocular function was assessed with synoptophore. Twenty-one patients took the postoperative synoptophore exercise. Results: (1) A week after surgery, 96.2% of the 80 patients had binocular normotopia, while a year after surgery, 91.3% of the 80 patients had binocular normotopia; (2) Preoperatively, 58 patients had near stereoacuity, while postoperatively, 72 patients achieved near stereoacuity (P<0.05); (3) Preoperatively, 64 patients had Grade I for the synoptophore evaluation and postoperatively, 76 patients achieved Grade I. Meanwhile, 55 patients had Grade Ⅱpreoperatively and 72 achieved Grade Ⅱ postoperatively. For Grade Ⅲ, there were 49 patients preoperatively and 64 patients postoperatively (P<0.05); (4) Patients of 5~8 years old had a significantly better recovery rate of binocular vision than those of 9~18 years old (P<0.05); (5)Patients taking postoperative synoptophore exercise had a better binocular vision than those taking no exercise (P<0.05). Conclusions: (1) Strabismus surgery can help to preserve or restore the binocular vision for intermittent exotropia; (2) Receiving the surgery at young ages may develop better postoperative binocular vision; (3) The postoperative synoptophore exercise can help to restore the binocular vision.

  10. Hovering and intermittent flight in birds

    Energy Technology Data Exchange (ETDEWEB)

    Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

    2010-12-15

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

  11. Acute intermittent porphyria in the puerperium

    Directory of Open Access Journals (Sweden)

    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.

  12. Intermittent Microwave Drying of Wheat (Triticum aestivum L.) Seeds

    OpenAIRE

    Yan Li; Tao Zhang; Chenglai Wu; Chunqing Zhang

    2014-01-01

    The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP) and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s) without significantly decreasing the germination rate was...

  13. Long term and transitional intermittent smokers: a longitudinal study.

    OpenAIRE

    Lindström, Martin; Isacsson, Sven-Olof

    2002-01-01

    Objective: To investigate differences in snuff consumption, sociodemographic and psychosocial characteristics between baseline intermittent smokers that had become daily smokers, stopped smoking or remained intermittent smokers at the one year follow up. Design/setting/participants/measurements: A population of 12 507 individuals interviewed at baseline in 1992-94 and at a one year follow up, aged 45-69 years, was investigated in a longitudinal study. The three groups of baseline intermittent...

  14. Intermittent fasting: a "new" historical strategy for controlling seizures?

    Science.gov (United States)

    Hartman, Adam L; Rubenstein, James E; Kossoff, Eric H

    2013-05-01

    In antiquity, fasting was a treatment for epilepsy and a rationale for the ketogenic diet (KD). Preclinical data indicate the KD and intermittent fasting do not share identical anticonvulsant mechanisms. We implemented an intermittent fasting regimen in six children with an incomplete response to a KD. Three patients adhered to the combined intermittent fasting/KD regimen for 2 months and four had transient improvement in seizure control, albeit with some hunger-related adverse reactions.

  15. Physiological responses of three species of unionid mussels to intermittent exposure to elevated carbon dioxide

    Science.gov (United States)

    Hannan, Kelly D.; Jeffrey, Jennifer D.; Hasler, Caleb T.; Suski, Cory D.

    2016-01-01

    Freshwater systems are at risk owing to increasing carbon dioxide (CO2) levels, and one of the possible reasons for these elevations is the deployment of non-physical fish barriers to prevent invasive fish movements. Carbon dioxide barriers have the potential to create short, chronic and intermittent exposures of CO2 for surrounding freshwater biota. Although intermittent exposures to a stressor may be more ecologically relevant, the majority of laboratory tests use chronic or short-term time periods to determine how organisms will respond to an environmental stressor. Measurements of the physiological responses of three species of unionid mussel, giant floaters (Pyganodon grandis), threeridge (Amblema plicata) and plain pocketbook (Lampsilis cardium), exposed to control pCO2 (~1000 µatm) or intermittent conditions of pCO2 (ranging from ~1000 to ~55 000 µatm) 12 times per day over a 28 day period were gathered. There was no indication of recovery in the physiological responses of mussels between applications of CO2, suggesting that the recovery time between CO2 pulses (1.5 h) was not sufficient for recovery from the CO2 exposure period (0.5 h). Observations of acid–base and stress responses were consistent with what has been observed in chronic studies of freshwater mussels exposed to elevated pCO2 (i.e. elevations in HCO3 −, Ca2+, Na+ and glucose, and decreases in Mg2+ and Cl−). However, species differences were observed across almost all variables measured, which emphasizes the need for multispecies studies. PMID:28066552

  16. [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.

  17. Intermittent Atrioventricular Block following Fingolimod Initiation

    Directory of Open Access Journals (Sweden)

    E. Gialafos

    2014-01-01

    Full Text Available A 47-year-old female patient with multiple sclerosis (MS developed symptomatic intermittent 2nd degree atrioventricular block (AVB of five-hour duration, five hours after the first two doses of fingolimod, that resolved completely. Frequency domain analysis of heart rate variability (HRV revealed increased parasympathetic activity and decreased sympathetic tone, while modified Ewing tests were suggestive of impaired cardiac sympathetic function. We hypothesize that expression of this particular arrhythmia might be related to autonomic nervous system (ANS dysfunction due to demyelinating lesions in the upper thoracic spinal cord, possibly augmented by the parasympathetic effect of the drug.

  18. 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.

  19. Chronic Pseudomonas aeruginosa infection definition: EuroCareCF Working Group report

    DEFF Research Database (Denmark)

    Pressler, T; Bohmova, C; Conway, S;

    2011-01-01

    Chronic pulmonary infection with P. aeruginosa develops in most patients with cystic fibrosis (CF); by adulthood 80% of patients are infected and chronic P. aeruginosa infection is the primary cause of increased morbidity and mortality in CF. Chronic infection is preceded by an intermittent stage...

  20. 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.

  1. Diagnosing Intermittent and Persistent Faults using Static Bayesian Networks

    Science.gov (United States)

    Megshoel, Ole Jakob

    2010-01-01

    Both intermittent and persistent faults may occur in a wide range of systems. We present in this paper the introduction of intermittent fault handling techniques into ProDiagnose, an algorithm that previously only handled persistent faults. We discuss novel algorithmic techniques as well as how our static Bayesian networks help diagnose, in an integrated manner, a range of intermittent and persistent faults. Through experiments with data from the ADAPT electrical power system test bed, generated as part of the Second International Diagnostic Competition (DXC-10), we show that this novel variant of ProDiagnose diagnoses intermittent faults accurately and quickly, while maintaining strong performance on persistent faults.

  2. 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.

  3. Influencia del trabajo aeróbico programado en el desarrollo de la gestación : Parámetros materno-fetales

    OpenAIRE

    Barakat Carballo, Ruben

    2011-01-01

    A través de la historia, las recomendaciones acerca del ejercicio durante la gestación han estado basadas más en razones sociales y culturales que en evidencias puramente científicas. Tradicionalmente, los consejos médicos alentaban a la moderación, aunque el concepto de "moderado" era algo conservador. No obstante, esta opinión no se dirigía en la misma dirección del creciente número de mujeres incluidas en programas de actividades físicas recreacionales y deportes. Actualmente, con el ejerc...

  4. Resultados materno-fetales de la gestación tras cirugía bariátrica Maternal and fetal outcomes in pregnancy following bariatric surgery

    Directory of Open Access Journals (Sweden)

    I. González Navarro

    2011-04-01

    Full Text Available Introducción: La obesidad es la enfermedad metabòlica más frecuente en el mundo y conlleva múltiples co-morbilidades, siendo la cirugía bariátrica (CB una opción terapéutica cuando fallan las medidas clásicas. La mitad de los pacientes intervenidos son mujeres en edad fértil y está demostrado que la obesidad se asocia a peores resultados obstétricos y fetales. Dado que el estado nutricional se ve afectado por la CB y es un factor esencial para el adecuado desarrollo del embarazo, el objetivo de nuestro trabajo es valorar los efectos de la CB sobre la gestación en mujeres obesas intervenidas. Material y métodos: Seguimiento de 10 mujeres y 15 gestaciones tras CB durante el periodo 2003-2009. Se realizaron visitas trimestrales en consultas de Nutrición y Obstetricia, con evaluación clínica y de laboratorio en cada una. Resultados: Se evidenció deficiencia de hierro en el 80% de las gestaciones, de vitamina D en el 46,7%, de vitamina A en el 20%, de vitamina E en el 13,3% y de vitamina B12 en el 26,7%. No hubo complicaciones durante la gestación salvo un caso de hiperemesis gravidica. Hubo 9 partos de recién nacidos vivos sin malformaciones de los cuales 3 fueron recién nacidos pequeños para la edad gestacional (RNPEG y uno presentó neumonía por aspiración de meconio. Hubo 3 abortos y un parto prematuro con feto muerto. Conclusiones: En nuestro grupo de estudio hubo menos complicaciones durante la gestación comparado con lo descrito en obesas no operadas y similares a la población general.Background: Obesity is the most frecuent metabolic disease in the World, and is associated with several comorbidities. Bariatric procedures arise as a promising treatment when classical approach is ineffective. Half of the operated patients are reproductive-aged women and there is evidence that obesity is related to worse maternal and fetal outcomes. Because nutritional status is affected by bariatric surgery and is a vital component during pregnancy, the aim of our study is to asses the impact of bariatric surgery on pregnancy in these pacients. Material and methods: We studied 10 women and 15 pregnancies following bariatric surgery between 2003 and 2009. The visits took place every three months by an obstetrician and an endocrinologist with experience in nutrition, recording clinical features and lab work. Results: We found iron deficiency in 80% of the pregnancies, vitamin D in 46,7%, vitamin A in 20%, vitamin E in 13,3% and vitamin B12 in 26,7%. There were no complications during pregnancy, except one case of gravidic hiperemesis. There were nine deliveries without malformations, three of them were small for gestational age newborns and one suffered aspiration pneumonia. There were three stillbirths and one preterm delivery with fetal death. Conclusions: our results show fewer complications during pregnancy in these women than obese women and similar to general population.

  5. Resultados materno-fetales de la gestación tras cirugía bariátrica Maternal and fetal outcomes in pregnancy following bariatric surgery

    OpenAIRE

    I. González Navarro; Pereira Cunill, J. L.; P. Serrano Aguayo; S. Morales Conde; J. M. Martos Martínez; P. P. García Luna

    2011-01-01

    Introducción: La obesidad es la enfermedad metabòlica más frecuente en el mundo y conlleva múltiples co-morbilidades, siendo la cirugía bariátrica (CB) una opción terapéutica cuando fallan las medidas clásicas. La mitad de los pacientes intervenidos son mujeres en edad fértil y está demostrado que la obesidad se asocia a peores resultados obstétricos y fetales. Dado que el estado nutricional se ve afectado por la CB y es un factor esencial para el adecuado desarrollo del embarazo, el objetivo...

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Amelioration of capillary regression and atrophy of the soleus muscle in hindlimb-unloaded rats by astaxanthin supplementation and intermittent loading.

    Science.gov (United States)

    Kanazashi, Miho; Tanaka, Masayuki; Murakami, Shinichiro; Kondo, Hiroyo; Nagatomo, Fumiko; Ishihara, Akihiko; Roy, Roland R; Fujino, Hidemi

    2014-08-01

    A chronic decrease in neuromuscular activity (activation and/or loading) results in muscle atrophy and capillary regression that are due, in part, to the overproduction of reactive oxygen species. We have reported that antioxidant treatment with astaxanthin attenuates the overexpression of reactive oxygen species in atrophied muscles that, in turn, ameliorates capillary regression in hindlimb-unloaded rats. Astaxanthin supplementation, however, had little effect on muscle mass and fibre cross-sectional area. In contrast, intermittent loading of the hindlimbs of hindlimb-unloaded rats ameliorates muscle atrophy. Therefore, we hypothesized that the combination of astaxanthin supplementation and intermittent loading would attenuate both muscle atrophy and capillary regression during hindlimb unloading. As expected, 2 weeks of hindlimb unloading resulted in atrophy, a decrease in capillary volume and a shift towards smaller-diameter capillaries in the soleus muscle. Intermittent loading alone (1 h of cage ambulation per day) attenuated atrophy of the soleus, while astaxanthin treatment alone maintained the capillary network to near control levels. The combination of intermittent loading and astaxanthin treatment, however, ameliorated atrophy of the soleus and maintained the capillary volume and luminal diameters and the superoxide dismutase-1 protein levels near control values. These results indicate that intermittent loading combined with astaxanthin supplementation could be an effective therapy for both the muscle atrophy and the capillary regression associated with a chronic decrease in neuromuscular activity.

  11. 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)...

  12. 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…

  13. Environmental heat stress, hyperammonemia and nucleotide metabolism during intermittent exercise

    DEFF Research Database (Denmark)

    Mohr, Magni; Rasmussen, Peter; Drust, Barry

    2006-01-01

    Abstract  This study investigated the influence of environmental heat stress on ammonia (NH3) accumulation in relation to nucleotide metabolism and fatigue during intermittent exercise. Eight males performed 40 min of intermittent exercise (15 s at 306±22 W alternating with 15 s of unloaded cycli...

  14. On dual descriptions of intermittency in a jet

    CERN Document Server

    Peschanski, R

    1996-01-01

    Models of intermittent behaviour are usually formulated using a set of multiplicative random weights on a Cayley tree. However, intermittency in particle multiproduction from QCD jets is related to fragmentation of an additive quantum number, e.g. energy-momentum. We exhibit the non-trivial stochastic mapping between these {\\it additive} and {\\it multiplicative} cascading processes.

  15. 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…

  16. Intermittent Behavior and Synchronization of Two Coupled Noisy Driven Oscillators

    Directory of Open Access Journals (Sweden)

    Ângela Maria dos Santos

    2009-01-01

    Full Text Available The coupled system of two forced Liénard-type oscillators has applications in diode-based electric circuits and phenomenological models for the heartbeat. These systems typically exhibit intermittent transitions between laminar and chaotic states; what affects their performance and, since noise is always present in such systems, dynamical models should include these effects. Accordingly, we investigated numerically the effect of noise in two intermittent phenomena: the intermittent transition to synchronized behavior for identical and unidirectionally coupled oscillators, and the intermittent transition to chaos near a periodic window of bidirectionally coupled oscillators. We found that the transition from a nonsynchronized to a synchronized state exhibits a power-law scaling with exponent 3/2 characterizing on-off intermittency. The inclusion of noise adds an exponential tail to this scaling.

  17. 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...

  18. Population dynamics in an intermittent refuge

    Science.gov (United States)

    Colombo, E. H.; Anteneodo, C.

    2016-10-01

    Population dynamics is constrained by the environment, which needs to obey certain conditions to support population growth. We consider a standard model for the evolution of a single species population density, which includes reproduction, competition for resources, and spatial spreading, while subject to an external harmful effect. The habitat is spatially heterogeneous, there existing a refuge where the population can be protected. Temporal variability is introduced by the intermittent character of the refuge. This scenario can apply to a wide range of situations, from a laboratory setting where bacteria can be protected by a blinking mask from ultraviolet radiation, to large-scale ecosystems, like a marine reserve where there can be seasonal fishing prohibitions. Using analytical and numerical tools, we investigate the asymptotic behavior of the total population as a function of the size and characteristic time scales of the refuge. We obtain expressions for the minimal size required for population survival, in the slow and fast time scale limits.

  19. Scale Dependence of Spatiotemporal Intermittence of Rain

    Science.gov (United States)

    Kundu, Prasun K.; Siddani, Ravi K.

    2011-01-01

    It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

  20. Turbulent flows and intermittency in laboratory experiments

    Science.gov (United States)

    Anselmet, F.; Antonia, R. A.; Danaila, L.

    2001-10-01

    In turbulent flows, the transfer of energy from large to small scales is strongly intermittent, in contradiction with Kolmogorov's (Dokl. Akad. Nauk. SSSR 30 (1941) 299; hereafter K41) assumptions. The statistical properties associated with these energy transfer fluctuations at a given scale r have been widely studied theoretically, experimentally and numerically over the last 30 years or so. Such fluctuations are also encountered in various Planetary and Space Science domains. The present paper presents a review of laboratory experiments which clearly display the fractal nature of the (spatial or temporal) energy distribution at scale r, the departures from the K41 predictions being generally quantified through high-order moments of velocity increments.

  1. 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.

  2. [Intermittent compression of the subclavian vein].

    Science.gov (United States)

    Maraval, M

    1980-01-01

    The pathology of the cervico-thoracic channel is now well understood. Intermittent venous compression in the costo-clavicular space by the subclavian muscle can lead to acute occlusion of the venous trunk. It is important to make an early diagnosis of such compression before the stage of occlusive phlebitis. Clinical examination and dynamic phlebography allow the diagnosis to be made. Resection of the first rib is the ideal treatment. The mode of approach to the first rib is debatable since it seems that when venous symptomatology is dominant, the axillary method of Roos is not the best approach. A combined sub- and supra-clavicular approach permits a wide decompression of the vein and a more complete excision of the rib.

  3. Treatment of febrile seizures with intermittent clobazam.

    Science.gov (United States)

    Manreza, M L; Gherpelli, J L; Machado-Haertel, L R; Pedreira, C C; Heise, C O; Diament, A

    1997-12-01

    Fifty children, 24 female and 26 male, with ages varying from 6 to 72 months (mean = 23.7 m.) that experienced at least one febrile seizure (FS) entered a prospective study of intermittent therapy with clobazam. Cases with severe neurological abnormalities, progressive neurological disease, afebrile seizures, symptomatic seizures of other nature, or seizures during a central nervous system infection were excluded. Seizures were of the simple type in 25 patients, complex in 20 and unclassified in 5. The mean follow-up period was 7.9 months (range = 1 to 23 m.), and the age at the first seizure varied from 5 to 42 months (mean = 16.8 m.). Clobazam was administered orally during the febrile episode according to the child's weight: up to 5 kg, 5 mg/day; from 5 to 10 kg, 10 mg/day; from 11 to 15 kg, 15 mg/day, and over 15 kg, 20 mg/day. There were 219 febrile episodes, with temperature above 37.8 degrees C, in 40 children during the study period. Twelve children never received clobazam and 28 received the drug at least once. Drug efficacy was measured by comparing FS recurrence in the febrile episodes that were treated with clobazam with those in which only antipyretic measures were taken. Ten children (20%) experienced a FS during the study period. Of the 171 febrile episodes treated with clobazam there were only 3 recurrences (1.7%), while of the 48 episodes treated only with antipyretic measures there were 11 recurrences (22.9%), a difference highly significant (p diazepam in the intermittent treatment of FS recurrence.

  4. The Role of Acute Intermittent Hypoxia in Neutrophil-Generated Superoxide, Sympathovagal Balance, and Vascular Function in Healthy Subjects

    Science.gov (United States)

    Almeida, Germana P. L.; Trombetta, Ivani C.; Cepeda, Felipe X.; Hatanaka, Elaine; Curi, Rui; Mostarda, Cristiano; Irigoyen, Maria C.; Barreto-Filho, José A. S.; Krieger, Eduardo M.; Consolim-Colombo, Fernanda M.

    2017-01-01

    Introduction: Recurrent hypoxia (HPX), a hallmark of the obstructive sleep apnea (OSA), impairs autonomic balance, and increases arterial blood pressure (BP). Oxidative stress is one of the mechanisms involved in these alterations. The cumulative effect of acute intermittent HPX and the chronicity may determine whether the response crosses the threshold from having protective value to pathology. However, the impact of acute intermittent HPX–reoxygenation on markers of oxidative stress in healthy individuals remains to be fully understood. Objective: To analyze the effects of the acute intermittent HPX on the generation of neutrophil-derived superoxide, sympathovagal balance, and vascular function in healthy subjects. Methods: We applied six cycles of intermittent HPX (10% O2 and 90% N2) for 5 min followed by 2 min of room-air in 15 healthy volunteers (34 ± 2 years; 22.3 ± 0.46 kg/m2), without OSA (polysomnography), during wakefulness. During the experimental protocol, we recorded O2 saturation, end-tidal CO2, heart rate (HR), systolic, and diastolic BP, cardiac output (CO) and peripheral resistance (PR). Cardiac sympathovagal balance was determined by HR variability analysis (low frequency and high frequency bands, LF/HF). Superoxide generation in polymorphonuclear neutrophil cells were established using relative luminescence units (PMNs RLU) at baseline (pre-HPX) and immediately after hypoxia induction (post-HPX6). Results: The studied subjects had normal levels of BP, plasma glucose, lipid profile, and inflammatory marker (C-reactive protein). Acute intermittent HPX increased HR, systolic BP, CO, and decreased PR. Additionally, acute intermittent HPX increased PMNs RLU, measured post-HPX6 (470 ± 50 vs. 741 ± 135, P < 0.05). We found a similar increase in LF/HF post-HPX6 (0.91 ± 0.11 vs. 2.85 ± 0.40, P < 0.05). PR was diminished from pre-HPX to post-HPX6 (1.0 ± 0.03 vs. 0.85 ± 0.06, P < 0.05). Further analysis showed significant association between O2

  5. Intermittent hypoxia exacerbates metabolic effects of diet-induced obesity.

    Science.gov (United States)

    Drager, Luciano F; Li, Jianguo; Reinke, Christian; Bevans-Fonti, Shannon; Jun, Jonathan C; Polotsky, Vsevolod Y

    2011-11-01

    Obesity causes insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD), but the relative contribution of sleep apnea is debatable. The main aim of this study is to evaluate the effects of chronic intermittent hypoxia (CIH), a hallmark of sleep apnea, on IR and NAFLD in lean mice and mice with diet-induced obesity (DIO). Mice (C57BL/6J), 6-8 weeks of age were fed a high fat (n = 18) or regular (n = 16) diet for 12 weeks and then exposed to CIH or control conditions (room air) for 4 weeks. At the end of the exposure, fasting (5 h) blood glucose, insulin, homeostasis model assessment (HOMA) index, liver enzymes, and intraperitoneal glucose tolerance test (1 g/kg) were measured. In DIO mice, body weight remained stable during CIH and did not differ from control conditions. Lean mice under CIH were significantly lighter than control mice by day 28 (P = 0.002). Compared to lean mice, DIO mice had higher fasting levels of blood glucose, plasma insulin, the HOMA index, and had glucose intolerance and hepatic steatosis at baseline. In lean mice, CIH slightly increased HOMA index (from 1.79 ± 0.13 in control to 2.41 ± 0.26 in CIH; P = 0.05), whereas glucose tolerance was not affected. In contrast, in DIO mice, CIH doubled HOMA index (from 10.1 ± 2.1 in control to 22.5 ± 3.6 in CIH; P < 0.01), and induced severe glucose intolerance. In DIO mice, CIH induced NAFLD, inflammation, and oxidative stress, which was not observed in lean mice. In conclusion, CIH exacerbates IR and induces steatohepatitis in DIO mice, suggesting that CIH may account for metabolic dysfunction in obesity.

  6. 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.)

  7. 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...... myocardial topical negative pressure of -50 mmHg....

  8. Adaptations with intermittent exercise training in post- and premenopausal women

    DEFF Research Database (Denmark)

    Seidelin, Kåre; Nyberg, Michael Permin; Piil, Peter Bergmann

    2017-01-01

    INTRODUCTION: The purposes of the present study was to examine the effect of intermittent exercise training on musculoskeletal and metabolic health in postmenopausal (PM) and premenopausal (PRM) women and, furthermore, to evaluate whether the adaptations can be maintained with a reduced training......: Twelve weeks of intermittent exercise training increased BMD, intermittent exercise capacity, and V˙O2max in PM and PRM, with PM also having positive changes in body composition. Additional 40 wk of training with a reduced frequency was sufficient to preserve these physiological adaptations and also...

  9. 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 training. The 5-wk sprint training induced a significantly higher (P ...-977) arbitrary units Ca(2+). g protein(-1). min(-1) (after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% (P

  10. Characterizing and Comparing Young Adult Intermittent and Daily Smokers

    OpenAIRE

    Lenk, Kathleen M.; Chen, Vincent; Bernat, Debra H.; Forster, Jean L.; Rode, Peter A.

    2009-01-01

    To examine young adult smoking patterns, we interviewed 732 smokers (from five U.S. upper Midwestern states) via telephone in 2006. We first defined two groups of intermittent smokers—low (smoked 1–14 days in past 30) and high (smoked 15–29 days in past 30), and then analyzed differences between these two groups and daily smokers. Low intermittent smokers were much less likely than high intermittent smokers to consider themselves smokers, feel addicted, or smoke with friends. Daily smokers we...

  11. 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

  12. 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.

  13. 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.

  14. Intermittent everolimus administration for malignant insulinoma

    Science.gov (United States)

    Brizzi, Maria Pia; Tampellini, Marco; Scagliotti, Giorgio Vittorio; Priola, Adriano; Terzolo, Massimo; Pia, Anna; Berruti, Alfredo

    2014-01-01

    Summary Insulinoma is a rare form of insulin-secreting pancreatic islet cell neuroendocrine (NE) tumor. The medical treatment of the malignant NE disease of the pancreas deeply changed in the last years, thanks to the introduction of new target molecules, as everolimus. Even if the exact mechanism is not actually known, one of the side effects of everolimus, hyperglycemia, has been demonstrated to be useful to contrast the typical hypoglycemia of the insulinoma. We report the case of a patient with a metastatic malignant insulinoma treated with intermittent everolimus, obtaining an important improvement in the quality of life; this suggests the necessity of preclinical studies to analyze the cellular pathways involved in insulin-independent gluconeogenesis. Learning points Effect of somatostatin analogs is long-lasting in the control of functioning NE tumors.Persistent everolimus control of hypoglycemia despite serum insulin levels and disease progression.Open issue: are disease progression and the increase in serum markers the only valid criteria to reject a treatment? PMID:25298880

  15. 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.

  16. 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.

  17. Multifractality and intermittency in the solar wind

    Directory of Open Access Journals (Sweden)

    W. M. Macek

    2007-11-01

    Full Text Available Within the complex dynamics of the solar wind's fluctuating plasma parameters, there is a detectable, hidden order described by a chaotic strange attractor which has a multifractal structure. The multifractal spectrum has been investigated using Voyager (magnetic field data in the outer heliosphere and using Helios (plasma data in the inner heliosphere. We have also analyzed the spectrum for the solar wind attractor. The spectrum is found to be consistent with that for the multifractal measure of the self-similar one-scale weighted Cantor set with two parameters describing uniform compression and natural invariant probability measure of the attractor of the system. In order to further quantify the multifractality, we also consider a generalized weighted Cantor set with two different scales describing nonuniform compression. We investigate the resulting multifractal spectrum depending on two scaling parameters and one probability measure parameter, especially for asymmetric scaling. We hope that this generalized model will also be a useful tool for analysis of intermittent turbulence in space plasmas.

  18. Contraction stress test by intermittent nipple stimulation.

    Science.gov (United States)

    Huddleston, J F; Sutliff, G; Robinson, D

    1984-05-01

    Although the nonstress test has generally supplanted the contraction stress test as the primary test for assessment of fetal well-being, the contraction stress test continues to be useful. Objectionable factors of the contraction stress test have included the time required to complete the test and the frequent necessity for intravenous oxytocin. The authors developed a contraction stress test protocol using contractions produced by intermittent nipple stimulation and used the method for 345 tests on 193 high-risk pregnancies during a 15-month period. The women were instructed to stimulate one breast, through their clothes, for two minutes and then to rest for five minutes. This cycle was repeated as necessary, but was interrupted whenever contractions began. Using this protocol, the authors were successful in achieving an adequate contraction frequency with every attempt, and hyperstimulation was not more frequent than previously reported with the standard contraction stress test. The average time requirement was 45 minutes. No unexplained stillbirths occurred after a negative test.

  19. 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 that...

  20. Revealing Intermittency in Nuclear Multifragmentation with 4$\\PI$ Detectors

    CERN Document Server

    Baldo, Marcello; Rapisarda, A

    1993-01-01

    The distortion on the intermittency signal, due to detection efficiency and to the presence of pre--equilibrium emitted particles, is studied in a schematic model of nuclear multi- fragmentation. The source of the intermittency signal is modeled with a percolating system. The efficiency is schematized by a simple function of the fragment size, and the presence of pre--equilibrium particles is simulated by an additional non--critical fragment source. No selection on the events is considered, and therefore all events are used to calculate the moments. It is found that, despite the absence of event selection, the intermittency signal is quite resistant to the distortion due to the apparatus efficiency, while the inclusion of pre--equilibrium particles in the moment calculation can substantially reduce the strength of the signal. Pre--equilibrium particles should be therefore carefully separated from the rest of the detected fragments, before the intermittency analysis on experimental charge or mass distributions...

  1. Characterizing and comparing young adult intermittent and daily smokers.

    Science.gov (United States)

    Lenk, Kathleen M; Chen, Vincent; Bernat, Debra H; Forster, Jean L; Rode, Peter A

    2009-01-01

    We interviewed 732 smokers (from five US upper Midwestern states) via telephone in 2006 to examine young adult smoking patterns. We first defined two groups of intermittent smokers-low (who smoked for 1-14 days in the past 30 days) and high (who smoked for 15-29 days in the past 30 days), and then analyzed differences between these two groups and daily smokers. Low intermittent smokers were much less likely to consider themselves smokers, feel addicted, or smoke with friends than high intermittent smokers. Daily smokers were more likely to feel addicted and have trouble quitting smoking than high intermittent smokers. Implications, limitations, and ideas for future studies will be discussed.

  2. 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.

  3. 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.

  4. 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).

  5. Intermittency and solitons in the driven dissipative nonlinear Schroedinger equation

    Science.gov (United States)

    Moon, H. T.; Goldman, M. V.

    1984-01-01

    The cubic nonlinear Schroedinger equation, in the presence of driving and Landau damping, is studied numerically. As the pump intensity is increased, the system exhibits a transition from intermittency to a two-torus to chaos. The laminar phase of the intermittency is also a two-torus motion which corresponds in physical space to two identical solitons of amplitude determined by a power-balance equation.

  6. Decarbonizing electricity generation with intermittent sources of energy

    OpenAIRE

    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 ...

  7. MUSCLE FIBER SPECIFIC ANTIOXIDATIVE SYSTEM ADAPTATION TO SWIM TRAINING IN RATS: INFLUENCE OF INTERMITTENT HYPOXIA

    Directory of Open Access Journals (Sweden)

    Olga Gonchar

    2005-06-01

    Full Text Available The aim of the present study was to examine the influence of intermittent hypoxia at rest and in combination with long-term high-intensity swimming exercise on lipid peroxidation and antioxidant defense system adaptation in skeletal muscles differing in fiber type composition. High-intensity chronic exercise was performed as swimming training with load that corresponded to ~ 75 % VO2max (30 min·day-1, 5 days·wk-1, for 4 wk. Intermittent hypoxic training (IHT consisted of repeated episodes of hypoxia (12%O2, 15 min, interrupted by equal periods of recovery (5 sessions/day, for 2 wk. Sessions of IHT were used during the first two weeks and during the last two weeks of chronic exercise. Oxidative (red gastrocnemius and soleus, mix and glycolytic (white gastrocnemius muscles were sampled. Our results indicated that high-intensity swim training in combination with sessions of IHT induced more profound antioxidative adaptations in skeletal muscles than the exercise training only. This adaptation has muscle fiber type specificity and is reflected in significantly elevated superoxide dismutase and catalase activities in highly oxidative muscle only. Training adaptation of GSH system (reduced glutathione content, activities of glutathione reductase, glutathione peroxidase, NADPH-supplying enzyme glucose-6-phosphate dehydrogenase occurred both in slow- and fast-twitch muscles. However, this process was more effective in oxidative muscles. IHT attenuated the increase in TBARS content induced by high-intensity swimming training. The test on exercise tolerance demonstrated a significant elevation of the swimming time to exhaustion after IHT at rest and after IHT in conjunction with high-intensity exercise in comparison with untrained and chronically exercised rats. These results confirmed that sessions of IHT might improve exercise tolerance and increase maximal work capacity

  8. Quality of life improvement in treatment of psoriasis with intermittent short course cyclosporin (Neoral).

    Science.gov (United States)

    Salek, M S; Finlay, A Y; Lewis, J J C; Sumner, M I

    2004-02-01

    Due to concern over long term safety of continuous treatment with cyclosporin, the aim of this 1-year study was to assess the effect of intermittent therapy with cyclosporin (Neoral) on the quality of life of patients suffering from chronic plaque psoriasis. A total of 41 patients with chronic plaque psoriasis (26 male, mean age: 36 years, range: 18-61; duration of psoriasis 17 years, range: 2-31) entered a 9-centre open study in which cyclosporin was taken as an initial dose of 5 mg/kg/daily for a maximum of 12 weeks for up to three cycles. Each patient completed a psoriasis specific QOL measure (Psoriasis Disability Index, PDI) at the beginning and end of each treatment cycle and at the end of study. Clinical parameters including Psoriasis Area and Severity Index (PASI) were measured. The PDI scores showed a significant improvement (p < 0.01) between the beginning and end of all three treatment cycles. The various clinical assessments for each treatment period also showed significant improvement (p < 0.001) for all three cycles. When comparing the last follow-up value to baseline there was a clear indication of relapse, but these scores were still significantly better than at baseline (p < 0.01). Notably, the mean PASI score improved by more than 50% (p < 0.001) between first baseline and end of the study. These findings indicate that a short course of intermittent therapy with cyclosporin in microemulsion formulation, used at starting doses of 5 mg/kg/day, improves QOL of patients with chronic plaque psoriasis. Once again, the applicability and validity of the PDI as a useful QOL tool has been demonstrated.

  9. Suppression of methanogenesis in hydrogen fermentation by intermittent feeding.

    Science.gov (United States)

    Yun, Jeonghee; Kim, Tae Gwan; Cho, Kyung-Suk

    2015-01-01

    This study investigated whether intermittent feeding by using a concentrated carbon source is an appropriate method for selective enrichment of hydrogenesis by means of methanogen suppression. In a conventional reactor fed continuously for 10 d, methanogens increased from 2.8 × 10(7) to 1.1 × 10(9) gene copy number (GCN)/mg-cell dry weight, and methane concentration in the resulting biogas was 5.8%. However, when a carbon source was intermittently supplied for 10 d to the reactor, the number of methanogens was reduced 98.9% from 2.77 × 10(7) to 1.2 × 10(3) GCN/mg-cell dry weight, and methane was not detected during this period of intermittent feeding. Intermittent feeding shifted the dominants in the reactor from Clostridiaceae (70.5%) and Lactobacillaceae (11.0%) to Acetobacteraceae (62.0%) and Clostridiaceae (38.0%). In the reactor operated in continuous feeding mode after intermittent feeding, methane concentration was below 0.3% and the portion of methanogens in the bacterial community was maintained below 0.2%. These results suggest that the intermittent feeding of a carbon source during hydrogen production processes is a suitable method to suppress the activity of methanogens.

  10. The 30-15 intermittent fitness test: accuracy for individualizing interval training of young intermittent sport players.

    Science.gov (United States)

    Buchheit, Martin

    2008-03-01

    The objective of this study was to gather evidence supporting the accuracy of the 30-15 Intermittent Fitness Test (30-15IFT) for individualizing interval training of young intermittent sport players. In 59 young intermittent sport players (age, 16.2 +/- 2.3 years), we observed the relationships between the maximal running speed (MRS) reached at the end of the 30-15IFT (MRS30-15IFT) and physiological variables elicited by shuttle intermittent runs, including maximal oxygen uptake, explosive power of lower limbs, and the ability to repeat intense exercise bouts through cardiorespiratory recovery kinetics during exercise. To observe the capacity of the 30-15IFT to prescribe suitable running intensities for interval training sessions, we compared heart rates (HRs) reached during 3 series of intermittent runs, where distances were set according to the MRS30-15IFT and to MRS reached with 2 popular continuous field tests: the University of Montreal track test and the 20-m shuttle run test. The results show that the MRS30-15IFT is significantly correlated with all physiological variables elicited by shuttle intermittent runs (P intermittent runs, HR recorded during the runs based on MRS30-15IFT presented significantly less interindividual variation than when the continuously determined MRS were used as reference speeds. In conclusion, we can say that the 30-15IFT leads to an MRS that simultaneously takes into account various physiological qualities elicited when performing shuttle intermittent runs. For scheduling interval training sessions, the MRS30-15IFT appears to be an accurate reference speed for getting players with different physiological profiles to a similar level of cardiorespiratory demand and thus for standardizing training content.

  11. 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

  12. 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

  13. 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.

  14. PATTERN OF CHOLINESTERASE INHIBITION IN ADULT, MALE RATS CHRONICALLY EXPOSED TO DIETARY CHLORPYRIFOS.

    Science.gov (United States)

    Very little is known about the effects of chronic exposure to relatively low levels of anticholinesterase insecticides or how the effects of chronic exposure compare to higher, intermittent exposure of the same compound for the same duration. To that end, we exposed adult male ra...

  15. Chronic myelogenous leukemia (CML)

    Science.gov (United States)

    CML; Chronic myeloid leukemia; Chronic granulocytic leukemia; Leukemia - chronic granulocytic ... Chronic myelogenous leukemia is grouped into phases: Chronic Accelerated Blast crisis The chronic phase can last for ...

  16. Valvoplastia aórtica por cateter-balão em emergência materno-fetal na adolescência Valvuloplastia aórtica por catéter con balón en emergencia materno-fetal en la adolescencia Aortic valvuloplasty with balloon catheter in maternal-fetal emergency in adolescence

    Directory of Open Access Journals (Sweden)

    Walkiria Samuel Avila

    2009-12-01

    Full Text Available O aumento do débito cardíaco durante a gravidez é causa de insuficiência cardíaca em portadoras de estenose valvar aórtica grave. A valvoplastia aórtica percutânea tem sido associada a graves complicações e reestenose valvar em curto prazo. O presente caso mostrou que a valvoplastia aórtica percutânea permitiu o alcance do parto com sobrevida da mãe e do feto, e que a interrupção do tratamento no pós-parto resultou em morte materna no puerpério tardio.El aumento del gasto cardiaco durante el embarazo es la causa de insuficiencia cardiaca en portadoras de estenosis valvular aórtica severa. Se viene asociando la valvuloplastia aórtica percutánea a severas complicaciones y reestenosis valvular en corto plazo. El presente caso reveló que la valvuloplastia aórtica percutánea permitió el alcance del parto con sobrevida de la madre y del feto, y que la interrupción del tratamiento en el postparto resultó en muerte materna en el puerperio tardío.The increase of cardiac output during pregnancy is the cause of heart failure in women with severe aortic valvular stenosis. Percutaneous aortic valvuloplasty has been associated with severe complications and short-term valvar restenosis. This case showed that percutaneous aortic valvuloplasty allowed both mother and fetus to survive after childbirth, and that postpartum treatment interruption resulted in maternal death in late postpartum care.

  17. Supporting the Learning of Children with Chronic Illness

    Science.gov (United States)

    A'Bear, David

    2014-01-01

    This qualitative study explores the challenges that chronically ill students face in their learning as a result of prolonged and intermittent absences from school. It shows how the use of iPod technology as a communicative link minimized the impact of absences and allowed the student to experience true inclusion in their classroom, enabling the…

  18. Intermittent Turbulence in the Very Stable Ekman Layer

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, James C [Univ. of Washington, Seattle, WA (United States)

    2001-01-01

    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).

  19. 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.

  20. 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.

  1. 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.

  2. Continuous versus intermittent administration of piperacillin-tazobactam in intensive care unit patients with ventilator-associated pneumonia

    Directory of Open Access Journals (Sweden)

    Fanak Fahimi

    2012-01-01

    Full Text Available Background and Aims: Ventilator-associated pneumonia (VAP is one of the most common Intensive Care Unit (ICU-acquired infection. The aim of this study was to compare the clinical outcome of continuous and intermittent administration of piperacillin-tazobactam by serial measurements of the Clinical Pulmonary Infection Score (CPIS. Subjects and Methods: Groups were designed as parallel and the study was designed as quasi-experimental and conducted at a semi-closed ICU between September 2008 and May 2010. Patients received 3.375 g (piperacillin 3 g/tazobactam 0.375 g either through intermittent infusion every 6 h for 30 min [Intermittent Infusion (II group; n = 30] or through continuous infusion every 8 h for 4 h [Continuous Infusion (CI group; n = 31]. CPIS was used to assess the clinical diagnosis and outcome of VAP patients. Results: Sex, age, Acute Physiology and Chronic Health Evaluation II II score on ICU admission, diagnosis and underlying disease of VAP patients were not significantly different in the CI (n = 31 and II (n = 30 groups. Duration of mechanical ventilation, length of stay, total number of antibiotics used per patient and duration of piperacillin/tazobactam treatment were similar in both groups. Mortality rates of VAP patients were similar between both groups during hospitalization. Conclusion: There was no significant difference in clinical outcomes of patients receiving piperacillin-tazobactam via CI or II when measured by serial CPIS score.

  3. Intermittent Microwave Drying of Wheat (Triticum aestivum L. Seeds

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-02-01

    Full Text Available The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s without significantly decreasing the germination rate was obtained at initial moisture content≤ 20.3% along with 20% MOTP. While, if initial moisture content of seeds was ≤ 16.7%, the seeds can be dried more rapidly using MOTP 30% without affecting germination capacity. The results obtained from this study would provide technical basis to select optimal wheat seed processing and design seed drying equipments.

  4. 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...

  5. 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.

  6. Intermittency in Hall-magnetohydrodynamics with a strong guide field

    CERN Document Server

    Imazio, P Rodriguez; Dmitruk, P; Mininni, P D

    2013-01-01

    We present a detailed study of intermittency in the velocity and magnetic field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an external guide field. To solve the equations numerically, a reduced model valid when a strong guide field is present is used. Different values for the ion skin depth are considered in the simulations. The resulting data is analyzed computing field increments in several directions perpendicular to the guide field, and building structure functions and probability density functions. In the magnetohydrodynamic limit we recover the usual results with the magnetic field being more intermittent than the velocity field. In the presence of the Hall effect, field fluctuations at scales smaller than the ion skin depth show a substantial decrease in the level of intermittency, with close to monofractal scaling.

  7. Intermittency of riometer auroral absorption observed at South Pole

    Science.gov (United States)

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

    2005-12-01

    Auroral radio-wave absorption values measured at South Pole for 3 years using a riometer are analyzed in order to test whether they show evidence of intermittency. The properties of the parameters of the probability density functions determined for several magnetic local time sectors are found to be significantly different. The probability density functions for the pre-midnight sector show the typical shape associated to intermittency. No results are given for the afternoon sector because few auroral absorption events meet the selection criteria to give statistically significant results. It is suggested that if the precipitating particle population responsible for the riometer auroral absorption shared the intermittency features of the absorption then the present results would allow the study of the properties of the induction component of magnetospheric turbulence.

  8. 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.

  9. MEASURING INTERMITTENCY PARAMETERS OF ENERGY CASCADE IN TURBULENCE

    Institute of Scientific and Technical Information of China (English)

    佘振苏; 刘立

    2003-01-01

    Method of measuring physical parameters characterizing intermittency effects of energy cascade in turbulence is presented in the framework of the Hierarchical Structure model. The method of β-test and γ-test enables to verify the existence of hierarchical symmetry and to derive the degree of singularity for the most intermittent structures. The method is applied to analyze data for a high Reynolds number, low-temperature helium turbulent flow. Evidence for universal hierarchical symmetry constant β is reported. Effects of finite statistical sample size are discussed in detail.

  10. 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...

  11. Additional parameter in evaluating the performance of intermittent solar refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    El-Shaarawi, M.A.I.; Ramadan, R.A.

    1988-01-01

    The parameters which have been considered by previous investigators in evaluating the performance of intermittent solar refrigerators are: the maximum attainable generator temperature, the condensing temperature and the initial solution conditions. The present investigation shows that an additional parameter, viz. the temperature of the condensate at the beginning of the absorption process, should be taken into consideration. Results of a thermodynamic analysis for the theoretical constant-temperature-absorption refrigeration cycle reveal that this parameter has considerable influence on the performance of intermittent solar refrigerators utilizing an ammonia-water solution as the working fluid.

  12. 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.

  13. Intermittent screening and treatment versus intermittent preventive treatment of malaria in pregnancy: provider knowledge and acceptability.

    Directory of Open Access Journals (Sweden)

    Lucy Smith Paintain

    Full Text Available Malaria in pregnancy (MiP is associated with increased risks of maternal and foetal complications. The WHO recommends a package of interventions including intermittent preventive treatment (IPT with sulphadoxine-pyrimethamine (SP, insecticide-treated nets and effective case management. However, with increasing SP resistance, the effectiveness of SP-IPT has been questioned. Intermittent screening and treatment (IST has recently been shown in Ghana to be as efficacious as SP-IPT. This study investigates two important requirements for effective delivery of IST and SP-IPT: antenatal care (ANC provider knowledge, and acceptance of the different strategies. Structured interviews with 134 ANC providers at 67 public health facilities in Ashanti Region, Ghana collected information on knowledge of the risks and preventative and curative interventions against MiP. Composite indicators of knowledge of SP-IPT, and case management of MiP were developed. Log binomial regression of predictors of provider knowledge was explored. Qualitative data were collected through in-depth interviews with fourteen ANC providers with some knowledge of IST to gain an indication of the factors influencing acceptance of the IST approach. 88.1% of providers knew all elements of the SP-IPT policy, compared to 20.1% and 41.8% who knew the treatment policy for malaria in the first or second/third trimesters, respectively. Workshop attendance was a univariate predictor of each knowledge indicator. Qualitative findings suggest preference for prevention over cure, and increased workload may be barriers to IST implementation. However, a change in strategy in the face of SP resistance is likely to be supported; health of pregnant women is a strong motivation for ANC provider practice. If IST was to be introduced as part of routine ANC activities, attention would need to be given to improving the knowledge and practices of ANC staff in relation to appropriate treatment of MiP. Health

  14. Chronic cholecystitis

    Science.gov (United States)

    Cholecystitis - chronic ... Most of the time, chronic cholecystitis is caused by repeated attacks of acute (sudden) cholecystitis. Most of these attacks are caused by gallstones in the gallbladder. These ...

  15. Chronic Pain

    Science.gov (United States)

    ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. × ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. ...

  16. Chronic Pain

    Science.gov (United States)

    ... a problem you need to take care of. Chronic pain is different. The pain signals go on ... there is no clear cause. Problems that cause chronic pain include Headache Low back strain Cancer Arthritis ...

  17. 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....

  18. 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.

  19. 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.

  20. Dynamic droop scheme considering effect of intermittent renewable energy source

    DEFF Research Database (Denmark)

    Wang, Yanbo; Chen, Zhe; Deng, Fujin

    2016-01-01

    This paper presents a dynamic droop control scheme for islanded microgrids dominated by intermittent renewable energy sources, which is able to perform desirable power sharing in the presence of renewable energy source fluctuation. First, allowable maximum power points of wind generator and PV ge...

  1. 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.

  2. 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.

  3. Intermittent energy harvesting improves the performance of microbial fuel cells.

    Science.gov (United States)

    Dewan, Alim; Beyenal, Haluk; Lewandowski, Zbigniew

    2009-06-15

    In this study, we compare the efficiencies of harvesting energy from microbial fuel cells (MFC) using two modes of operation: (1) continuous-passing the current through an electrical load-and (2) intermittent-first accumulating the energy in a capacitor and then discharging it through the load. Each of these two modes of operation has advantages and disadvantages: the first mode of operation allows the continuous powering of low-power-consuming devices, and the second mode of operation allows the intermittent powering of high-power-consuming devices. We used a two-compartment MFC: in the anodic compartment, Shewanella oneidensis MR-1 was grown using lactate as an electron donor, whereas in the cathodic compartment we used an electrode made of manganese-based catalyzed carbon bonded to a current-collecting screen made of platinum mesh and oxygen as the electron acceptor. The maximum power generated by harvesting energy intermittently was 152 microW, which is 111% higher than the 72 microW generated by harvesting the energy continuously. We conclude that in the operation of MFCs it is beneficial to harvest the energy intermittently. This not only allows the powering of external devices of high power consumption but also allows generating power with greater energy efficiency than does harvesting the energy continuously.

  4. 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

    . The intermittent behavior shows no threshold value in the applied field, in contrast to conventional flux jumping. The results strongly suggest that the quasi-one-dimensional flux jumps are of a different nature than the thermomagnetic dendritic (branching) avalanches that are commonly found in superconducting...

  5. 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.

  6. Clean intermittent self-catheterisation - principles and practice

    Directory of Open Access Journals (Sweden)

    Arun Narayanaswamy

    2000-01-01

    Full Text Available This review of the literature on the principles and prac-tice of clean intermittent self-catheterisation includes the role of antiseptics/antibiotics, and outcome. It covers ac-ceptance of the technique, urinary tract infection, conti-nence, and preservation of upper urinary tract.

  7. 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…

  8. 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

  9. Chronic prostatitis

    OpenAIRE

    Le, Brian; Schaeffer, Anthony J.

    2011-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome [CP/CPPS]). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  10. Chronic prostatitis

    OpenAIRE

    Erickson, Bradley A.; Schaeffer, Anthony J.; Le, Brian

    2008-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome, CP/CPPS). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  11. 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....

  12. 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

  13. 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.

  14. 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.

  15. Metallothionein as a compensatory component prevents intermittent hypoxia-induced cardiomyopathy in mice

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xia; Zhou, Shanshan [The First Hospital of Jilin University, Changchun, 130021 (China); KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Zheng, Yang, E-mail: zhengyang@jlu.edu.cn [The First Hospital of Jilin University, Changchun, 130021 (China); Tan, Yi [KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Chinese–American Research Institute for Diabetic Complications, Wenzhou Medical College School of Pharmacy, Wenzhou, 325035 (China); Kong, Maiying [Department of Bioinformatics and Biostatistics, School of Public Health and Information Sciences, University of Louisville, Louisville, KY 40202 (United States); Wang, Bo [KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Department of Pathology, Inner Mongolia Forestry General Hospital, Yakeshi, 022150 (China); Feng, Wenke [Department of Medicine, School of Medicine, University of Louisville, Louisville, 40202 (United States); Epstein, Paul N. [KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Cai, Jun, E-mail: j0cai002@louisville.edu [KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Cai, Lu [KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202 (United States); Chinese–American Research Institute for Diabetic Complications, Wenzhou Medical College School of Pharmacy, Wenzhou, 325035 (China); Department of Medicine, School of Medicine, University of Louisville, Louisville, 40202 (United States)

    2014-05-15

    Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (IH) to induce cardiovascular disease, which may be related to oxidative damage. Metallothionein (MT) has been extensively proved to be an endogenous and highly inducible antioxidant protein expressed in the heart. Therefore, we tested the hypotheses that oxidative stress plays a critical role in OSA induced cardiac damage and MT protects the heart from OSA-induced cardiomyopathy. To mimic hypoxia/reoxygenation events that occur in adult OSA patients, mice were exposed to IH for 3 days to 8 weeks. The IH paradigm consisted of alternating cycles of 20.9% O{sub 2}/8% O{sub 2} F{sub I}O{sub 2} (30 episodes per hour) with 20 s at the nadir F{sub I}O{sub 2} for 12 h a day during daylight. IH significantly increased the ratio of heart weight to tibia length at 4 weeks with a decrease in cardiac function from 4 to 8 weeks. Cardiac oxidative damage and fibrosis were observed after 4 and 8 weeks of IH exposures. Endogenous MT expression was up-regulated in response to 3-day IH, but significantly decreased at 4 and 8 weeks of IH. In support of MT as a major compensatory component, mice with cardiac overexpression of MT gene and mice with global MT gene deletion were completely resistant, and highly sensitive, respectively, to chronic IH induced cardiac effects. These findings suggest that chronic IH induces cardiomyopathy characterized by oxidative stress-mediated cardiac damage and the antioxidant MT protects the heart from such pathological and functional changes. - Highlights: • The effect of intermittent hypoxia (IH) on cardiac metallothionein (MT) • Cardiac MT expression was up-regulated in response to 3-day IH. • Exposure to 4- or 8-week IH downregulated cardiac MT expression. • Overexpression of cardiac MT protects from IH-induced cardiac damage. • Global deletion of MT gene made the heart more sensitive to IH damage.

  16. Xanthine oxidase mediates hypoxia-inducible factor-2α degradation by intermittent hypoxia.

    Directory of Open Access Journals (Sweden)

    Jayasri Nanduri

    Full Text Available Sleep-disordered breathing with recurrent apnea produces chronic intermittent hypoxia (IH. We previously reported that IH leads to down-regulation of HIF-2α protein via a calpain-dependent signaling pathway resulting in oxidative stress. In the present study, we delineated the signaling pathways associated with calpain-dependent HIF-2α degradation in cell cultures and rats subjected to chronic IH. Reactive oxygen species (ROS scavengers prevented HIF-2α degradation by IH and ROS mimetic decreased HIF-2α protein levels in rat pheochromocytoma PC12 cell cultures, suggesting that ROS mediate IH-induced HIF-2α degradation. IH activated xanthine oxidase (XO by increased proteolytic conversion of xanthine dehydrogenase to XO. ROS generated by XO activated calpains, which contributed to HIF-2α degradation by IH. Calpain-induced HIF-2α degradation involves C-terminus but not the N-terminus of the HIF-2α protein. Pharmacological blockade as well as genetic knock down of XO prevented IH induced calpain activation and HIF-2α degradation in PC12 cells. Systemic administration of allopurinol to rats prevented IH-induced hypertension, oxidative stress and XO activation in adrenal medulla. These results demonstrate that ROS generated by XO activation mediates IH-induced HIF-2α degradation via activation of calpains.

  17. 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.

  18. Superficial Burn Wound Healing with Intermittent Negative Pressure Wound Therapy Under Limited Access and Conventional Dressings

    Science.gov (United States)

    Honnegowda, Thittamaranahalli Muguregowda; Padmanabha Udupa, Echalasara Govindarama; Rao, Pragna; Kumar, Pramod; Singh, Rekha

    2016-01-01

    BACKGROUND Thermal injury is associated with several biochemical and histopathological alteration in tissue. Analysis of these objective parameters in research and clinical field are common to determine healing rate of burn wound. Negative pressure wound therapy has been achieved wide success in treating chronic wounds. This study determines superficial burn wound healing with intermittent negative pressure wound therapy under limited access and conventional dressings METHODS A total 50 patients were randomised into two equal groups: limited access and conventional dressing groups. Selective biochemical parameters such as hydroxyproline, hexosamine, total protein, and antioxidants, malondialdhyde (MDA), wound surface pH, matrix metalloproteinase-2 (MMP-2), and nitric oxide (NO) were measured in the granulation tissue. Histopathologically, necrotic tissue, amount of inflammatory infiltrate, angiogenesis and extracellular matrix deposition (ECM) were studied to determine wound healing under intermittent negative pressure. RESULTS Patients treated with limited access have shown significant increase in the mean hydroxyproline, hexosamine, total protein, reduced glutathione (GSH), glutathione peroxidase (GPx), and decrease in MDA, MMP-2, wound surface pH, and NO. Histopathologic study showed that there was a significant difference after 10 days of treatment between limited access vs conventional dressing group, Median (Q1, Q3)=3 (2, 4.25) vs 2 (1.75, 4). CONCLUSION Limited access was shown to exert its beneficial effects on wound healing by increasing ground substance, antioxidants and reducing MMP-2 activity, MDA, NO and providing optimal pH, decreasing necrotic tissue, amount of inflammatory infiltrate, increasing ECM deposition and angiogenesis. PMID:27853690

  19. 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...

  20. 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.

  1. Positive effects of intermittent fasting in ischemic stroke.

    Science.gov (United States)

    Fann, David Yang-Wei; Ng, Gavin Yong Quan; Poh, Luting; Arumugam, Thiruma V

    2017-03-01

    Intermittent fasting (IF) is a dietary protocol where energy restriction is induced by alternate periods of ad libitum feeding and fasting. Prophylactic intermittent fasting has been shown to extend lifespan and attenuate the progress and severity of age-related diseases such as cardiovascular (e.g. stroke and myocardial infarction), neurodegenerative (e.g. Alzheimer's disease and Parkinson's disease) and cancerous diseases in animal models. Stroke is the second leading cause of death, and lifestyle risk factors such as obesity and physical inactivity have been associated with elevated risks of stroke in humans. Recent studies have shown that prophylactic IF may mitigate tissue damage and neurological deficit following ischemic stroke by a mechanism(s) involving suppression of excitotoxicity, oxidative stress, inflammation and cell death pathways in animal stroke models. This review summarizes data supporting the potential hormesis mechanisms of prophylactic IF in animal models, and with a focus on findings from animal studies of prophylactic IF in stroke in our laboratory.

  2. Intermittent Bellerophon state in frequency-weighted Kuramoto model

    Science.gov (United States)

    Zhou, Wenchang; Zou, Yong; Zhou, Jie; Liu, Zonghua; Guan, Shuguang

    2016-12-01

    Recently, the Bellerophon state, which is a quantized, time dependent, clustering state, was revealed in globally coupled oscillators [Bi et al., Phys. Rev. Lett. 117, 204101 (2016)]. The most important characteristic is that in such a state, the oscillators split into multiple clusters. Within each cluster, the instantaneous frequencies of the oscillators are not the same, but their average frequencies lock to a constant. In this work, we further characterize an intermittent Bellerophon state in the frequency-weighted Kuramoto model with a biased Lorentzian frequency distribution. It is shown that the evolution of oscillators exhibits periodical intermittency, following a synchronous pattern of bursting in a short period and resting in a long period. This result suggests that the Bellerophon state might be generic in Kuramoto-like models regardless of different arrangements of natural frequencies.

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

    DEFF Research Database (Denmark)

    Ingebrigtsen, Jørgen

    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...... with other field tests the Yo-Yo IR2 has become an important tool for monitoring the physical fitness of football players. However, the burden of testing, for players (physically and mentally) and the coaching staff (time consuming), is large and there is a probability that the tests may contain overlapping...... on the Yo-Yo IR2 test and other field- and laboratory tests of intermittent interval training performed as anaerobic speed-endurance production training is very limited for football players. Hence, this latter question is examined in Study IV.In Study I we find no differences in anthropometric...

  4. 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.

  5. Intermittent contact mode piezoresponse force microscopy in a liquid environment

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Brian J [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Jesse, Stephen; Kalinin, Sergei V [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Habelitz, Stefan [Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA 94143 (United States); Proksch, Roger [Asylum Research, Santa Barbara, CA 93117 (United States)], E-mail: brian.rodriguez@ucd.ie, E-mail: sergei2@ornl.gov

    2009-05-13

    Probing electromechanical coupling in biological systems and electroactive molecules requires high resolution functional imaging. Here, we investigate the feasibility of intermittent contact mode piezoresponse force microscopy based on simultaneous mechanical and electrical probe modulation. It is shown that imaging at frequencies corresponding to the first contact resonance in liquid allows contrast consistent with the electromechanical signal to be obtained for model ferroelectric systems and piezoelectric tooth dentin.

  6. Intermittent contact mode piezoresponse force microscopy in a liquid environment

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Brian [University College, Dublin; Jesse, Stephen [ORNL; Habelitz, S. [University of California, San Francisco; Proksch, Roger [Asylum Research, Santa Barbara, CA; Kalinin, Sergei V [ORNL

    2009-01-01

    Probing electromechanical coupling in biological systems and electroactive molecules requires high resolution functional imaging. Here, we investigate the feasibility of intermittent contact mode piezoresponse force microscopy based on simultaneous mechanical and electrical probe modulation. It is shown that imaging at frequencies corresponding to the first contact resonance in liquid allows contrast consistent with the electromechanical signal to be obtained for model ferroelectric systems and piezoelectric tooth dentin

  7. 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.

  8. Factors Influencing the Surgical Success in Patients with Intermittent Exotropia

    Directory of Open Access Journals (Sweden)

    Uğur Acar

    2013-04-01

    Full Text Available Pur po se: To determine the factors that influence surgical success in patients with intermittent exotropia. Ma te ri al and Met hod: We retrospectively evaluated the records of patients with intermittent exotropia who were diagnosed, operated, and followed up. Successful outcome was defined as alignment ≤10 prism diopters (PD esophoria or exophoria at the last follow-up visit. The clinical findings, exodeviation types, surgical ages, operation types, preoperative and postoperative deviation amounts, presence of anisometropia and amblyopia, presence of A- or V-pattern, and presence of binocular vision and stereoacuity of patients were evaluated. We investigated the independent variables that affected the surgical success in intermittent exotropia patients. Re sults: Among the 379 patients included in the study, 266 (70.18% underwent surgery, and the success rate was 68.05% (181 patients. In this successful surgery group, mean deviation was 25.82±11.27 PD at near and 30.80±10.59 PD at distance versus 30.93±12.47 PD and 34.92±11.02 PD, respectively, in the unsuccessful surgery group. There was a statistically significant difference between the two groups. Preoperative factors, such as presence of binocular vision preoperatively, and postoperative factors, such as followup period and the patients' deviation amount in the 1st week and 6th month, were found to affect the surgical outcome. Dis cus si on: The success rate of surgical treatment of intermittent exotropia increases in the patients with presence of fusion and low preoperative deviation amounts. Also, in the early postoperative period, orthophoric or ≤10 PD esophoric patients have a higher final surgical success rate. (Turk J Ophthalmol 2013; 43: 107-12

  9. 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.

  10. [Unstable angina pectoris in intermittent left bundle branch block].

    Science.gov (United States)

    Albert, S; Flury, G

    1997-11-19

    We present a case report of a 57 year old woman with recurrent chest pain, initially exclusively at exercise and later also at rest. This led to an emergency hospitalization for suspected myocardial infarction. As there were no enzymatic and electrocardiographic signs of acute infarction she was treated, as unstable angina pectoris. Coronary angiography revealed but a modest coronary atheromatosis without significant coronary stenosis. Therefore her symptoms were interpreted as primary manifestation of an intermittant Left Bundle Branch Block (LBBB) with changing heart-rate dependency. A majority of patients with LBBB and chest pain have a relevant Coronary Artery Disease (CAD). There is a small number of reports in literature about patients with intermittant LBBB without significant CAD but with both typical (exercise-induced) and atypical (at rest) chest pain. Special features of our case are presentation of LBBB as unstable angina, documentation of an intermittant LBBB with changing heart-rate dependency and heart-rate-dependent supranormal conduction in the left bundle branch. We review some important aspects of LBBB with regard to this case.

  11. New advances on chaotic intermittency and its applications

    CERN Document Server

    Elaskar, Sergio

    2017-01-01

    One of the most important routes to chaos is the chaotic intermittency. However, there are many cases that do not agree with the classical theoretical predictions. In this book, an extended theory for intermittency in one-dimensional maps is presented. A new general methodology to evaluate the reinjection probability density function (RPD) is developed in Chapters 5 to 8. The key of this formulation is the introduction of a new function, called M(x), which is used to calculate the RPD function. The function M(x) depends on two integrals. This characteristic reduces the influence on the statistical fluctuations in the data series. Also, the function M(x) is easy to evaluate from the data series, even for a small number of numerical or experimental data. As a result, a more general form for the RPD is found; where the classical theory based on uniform reinjection is recovered as a particular case. The characteristic exponent traditionally used to characterize the intermittency type, is now a function depending ...

  12. 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.

  13. 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].

  14. The influence of respiratory muscle training upon intermittent exercise performance.

    Science.gov (United States)

    Nicks, C R; Morgan, D W; Fuller, D K; Caputo, J L

    2009-01-01

    The purpose of this study was to determine the effect of respiratory muscle training (RMT) on intermittent exercise performance, respiratory muscle strength (PI (max)), respiratory muscle fatigue (RMF), and dyspnea in soccer athletes. Collegiate soccer athletes (20 male, 7 female) were randomly divided into either a RMT or control condition during off-season conditioning. The RMT group performed a 30RM protocol (10 times weekly) for 5 weeks using a commercially-available training device, while the controls received no RMT. Performance was evaluated utilizing Level 1 of the Yo-Yo Intermittent Recovery Test (IRT) and dyspnea was assessed during and immediately following the IRT. RMF was quantified within 2 minutes (RMF2) and 10 minutes (RMF10) after completing the IRT. Following training, the RMT group significantly increased IRT performance by 216.6 +/- 231.0 meters (p = .008) while the 49.2 +/- 75.1 meter increase observed in the controls was not significant. PI (max) in the RMT group increased from 138.1 +/- 19.6 to 165.3 +/- 23.5 cmH (2)O (p RMT did not significantly affect RMF or dyspnea. In conclusion, RMT improved intermittent exercise performance in these soccer athletes. The mechanisms by which RMT improves performance warrant further study.

  15. Prevention of Stress Related Mucosal Disease with Intermittent

    Directory of Open Access Journals (Sweden)

    Farshid Rahimi-Bashar

    2015-10-01

    Full Text Available Background: This study aimed to compare intermittent intravenous (IV pantoprazole and ranitidine for control of gastric acid secretion and the possible prevention of Upper Gastrointestinal Bleeding (UGIB in critical care patients.Methods: This was a randomized, double blind clinical trial study of IV pantoprazole (40 mg every12 hour or intermittent IV ranitidine (50 mg bolus every 8 hour in patients at risk for UGIB. The primary endpoint was gastric pH. UGIB was measured as secondary endpoint.Results: ninety two Critical care patients were enrolled. Gastric pH was well controlled by two study drugs. Gastric pH increased in pantoprazole group than in the ranitidine group (4.40±0.39 versus 3.32±0.28; P=0.000. Upper GI bleeding was higher in ranitidine group than pantoprazole group (4/46 versus 2/46; P=0.404.Conclusion: This  study  indicates  that  intermittent  IV pantoprazole  compared  with  bolus  IV ranitidine, more effectively controls gastric pH and may prevent UGIB in high risk critical care patients without the development of tolerance.

  16. Neuromuscular Fatigue after Submaximal Intermittent Contractions in Motorcycle Riders.

    Science.gov (United States)

    Torrado, P; Cabib, C; Morales, M; Valls-Sole, J; Marina, M

    2015-11-01

    Highly repetitive submaximal intermittent contractions of the forearm muscles during periods of 30-50 min partially explain why motorcycle races are so demanding for the neuromuscular system. This study investigated the contribution of central and peripheral mechanisms of fatigue on the exerted and contralateral extensor digitorum communis following an intermittent fatigue protocol (IFP) designed for motorcycle riders. 12 riders performed an IFP, which simulates the braking and throttle handle gesture. We examined the time course of recovery of maximal voluntary contraction (MVC), M-wave, motor evoked potential (MEP) to transcranial magnetic stimuli in relaxed and facilitated condition, and the cortical silent period (CSP) at time windows of 1, 3, 5, 10 and 20 min after the IFP. Whereas MVC, M-wave and MEP decreased, CSP lengthened significantly in the fatigued limb after completion of the IFP. Nevertheless, no differences were observed in the contralateral limb. All neurophysiological parameters reverted to baseline values in less than 20 min, while MVC remained lower in the exercised limb. No cross-over effects were observed in the contralateral non-exercised limb. Our results suggest that local factors are those mainly responsible for the incomplete MVC recovery after an intermittent muscle contraction protocol.

  17. Intermittent outgassing through a non-Newtonian fluid.

    Science.gov (United States)

    Divoux, Thibaut; Bertin, Eric; Vidal, Valérie; Géminard, Jean-Christophe

    2009-05-01

    We report an experimental study of the intermittent dynamics of a gas flowing through a column of a non-Newtonian fluid. In a given range of the imposed constant flow rate, the system spontaneously alternates between two regimes: bubbles emitted at the bottom either rise independently one from the other or merge to create a winding flue which then connects the bottom air entrance to the free surface. The observations are reminiscent of the spontaneous changes in the degassing regime observed on volcanoes and suggest that, in the nature, such a phenomenon is likely to be governed by the non-Newtonian properties of the magma. We focus on the statistical distribution of the lifespans of the bubbling and flue regimes in the intermittent steady state. The bubbling regime exhibits a characteristic time whereas, interestingly, the flue lifespan displays a decaying power-law distribution. The associated exponent, which is significantly smaller than the value 1.5 often reported experimentally and predicted in some standard intermittency scenarios, depends on the fluid properties and can be interpreted as the ratio of two characteristic times of the system.

  18. Acute intermittent porphyria and pregnancy: an obstetric challenge

    Directory of Open Access Journals (Sweden)

    Pragati Meena

    2016-02-01

    Full Text Available Acute intermittent porphyria is a rare autosomal dominant disease caused by a mutation in the gene coding for the porphobillinogen deaminase enzymes in heam biosynthesis. The disease manifests as acute attacks of neuropsychiatric dysfunction and neurovisceral manifestations presenting as acute abdomen. In pregnancy, 54% patient has exacerbation of attacks in the form of seizures and acute abdomen occurs due to hormonal changes. Prevalence of acute intermittent porphyria is 1-2/200000 in general. Here we report a case of 36 year old women, G4P1L2A2 presenting at 10+4 weeks of gestation requesting pregnancy termination. Patient was diagnosed as case of acute intermittent porphyria with porphyic polyneuropathy 6 months back. At that time her main symptoms were acute pain abdomen with numbness and weakness in all four limbs. Her urinary porphobillinogen and 5 ALA raised. Her CECT of brain and nerve conduction studies were normal. Since then she is on Tablet Gabapentin 300 mg H.S. She underwent successful pregnancy termination by suction and evacuation under spinal anesthesia and she refused for copper-T insertion. Only safe drugs were used for procedure and she was discharged with advice of barrier contraception. [Int J Reprod Contracept Obstet Gynecol 2016; 5(2.000: 542-544

  19. 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.

  20. Cost effectiveness of intermittent screening followed by treatment versus intermittent preventive treatment during pregnancy in West Africa

    DEFF Research Database (Denmark)

    Fernandes, Silke; Sicuri, Elisa; Halimatou, Diawara

    2016-01-01

    -to-pay threshold used.  Conclusions: At SP efficacy levels currently observed in the trial settings it would not be cost-effective to switch from IPTp-SP to ISTp-AL, mainly due to the substantially higher costs of ISTp-AL and limited difference in outcomes. The modelling results indicate thresholds below which IPT......Background: Emergence of high-grade sulfadoxine-pyrimethamine (SP) resistance in parts of Africa has led to growing concerns about the efficacy of intermittent preventive treatment of malaria during pregnancy (IPTp) with SP. The incremental cost-effectiveness of intermittent screening and treatment...... (ISTp) with artemether-lumefantrine (AL) as an alternative strategy to IPTp-SP was estimated followed by a simulation of the effects on cost-effectiveness of decreasing efficacy of IPTp-SP due to SP resistance. The analysis was based on results from a multi-centre, non-inferiority trial conducted...

  1. [Chronicity, chronicization, systematization of delusions].

    Science.gov (United States)

    Trapet, P; Fernandez, C; Galtier, M C; Gisselmann, A

    1984-05-01

    Chronicity in psychopathology is indicative of a term, a decay. Chronicization only leads the way to this term. Here, chronicization is taken literally as an inscription in the time course of delusions. The mechanism of systematization seems to be a central mark in the approach to chronic delusions. It is not an alienation or an irreversible closing but an attempted accommodation with reality in the life of psychotic subjects, irrespective of the delusional structure. The role of therapy and drug treatment as a follow-up may in that case assume another meaning.

  2. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Froeling, Fieke EM

    2008-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas owing to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects 3–9 people in 100,000; 70% of cases are alcohol-induced.

  3. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Kadaba, Raghu

    2011-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas due to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects between 3 and 9 people in 100,000; 70% of cases are alcohol-induced.

  4. 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

  5. Thioredoxin and impaired spatial learning and memory in the rats exposed to intermittent hypoxia

    Institute of Scientific and Technical Information of China (English)

    YANG Xiu-hong; LIU Hui-guo; LIU Xue; CHEN Jun-nan

    2012-01-01

    Background Obstructive sleep apnea (OSA) can cause cognitive dysfunction and may be a reversible cause of cognitive loss in patients with Alzheimer's disease (AD).Chronic exposure to intermittent hypoxia (IH),such as encountered in OSA,is marked by neurodegenerative changes in rat brain.We investigated the change of thioredoxin (Trx),spatial learning and memory in rats exposed to chronic intermittent hypoxia (CIH).Methods Forty healthy male Sprague-Dawley (SD) rats were randomly divided into four groups of ten each:a CIH+normal saline (CIH+NS group),a N-acetylcystein-treated CIH (CIH+NAC) group,a sham CIH group (sham CIH+NS),and a sham NAC-treated sham CIH (CIH+NAC) group.Spatial learning and memory in each group was assessed with the Morris water maze.Real-time PCR and Western blotting were used to examine mRNA and protein expression of Trx in the hippocampus tissue.The terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) method was used to detect the apoptotic cells of the hippocampus CA1 region.Results ClH-rats showed impaired spatial learning and memory in the Morris water maze,including longer mean latencies for the target platform,reduced numbers of passes over the previous target platform and a smaller percentage of time spent in the target quadrant.Trx mRNA and protein levels were significantly decreased in the CIH-hippocampus,meanwhile,an elevated apoptotic index revealed apoptosis of hippocampal neurons of rats exposed to CIH.The rats,which acted better in the Morris water maze,showed higher levels of the Trx mRNA and protein in the hippocampus;apoptotic index of the neurons in the hippocampus of each group was negatively correlated with the Trx mRNA and protein levels.Conclusion The Trx deficit likely plays an important role in the impaired spatial learning and memory in the rats exposed to CIH and may work through the apoptosis of neurons in the hippocampus.

  6. The Yo-Yo intermittent recovery test : a useful tool for evaluation of physical performance in intermittent sports.

    Science.gov (United States)

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

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2 (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 of an individual's capacity to perform repeated intense exercise and to examine changes in performance.

  7. The impact of intermittent umbilical cord occlusions on the inflammatory response in pre-term fetal sheep.

    Directory of Open Access Journals (Sweden)

    Andrew P Prout

    Full Text Available Fetal hypoxic episodes may occur antepartum with the potential to induce systemic and cerebral inflammatory responses thereby contributing to brain injury. We hypothesized that intermittent umbilical cord occlusions (UCOs of sufficient severity but without cumulative acidosis will lead to a fetal inflammatory response. Thirty-one chronically instrumented fetal sheep at ∼0.85 of gestation underwent four consecutive days of hourly UCOs from one to three minutes duration for six hours each day. Maternal and fetal blood samples were taken for blood gases/pH and plasma interleukin (IL-1β and IL-6 levels. Animals were euthanized at the end of experimental study with brain tissue processed for subsequent counting of microglia and mast cells. Intermittent UCOs resulted in transitory fetal hypoxemia with associated acidemia which progressively worsened the longer umbilical blood flow was occluded, but with no cumulative blood gas or pH changes over the four days of study. Fetal arterial IL-1β and IL-6 values showed no significant change regardless of the severity of the UCOs, nor was there any evident impact on the microglia and mast cell counts for any of the brain regions studied. Accordingly, intermittent UCOs of up to three minutes duration with severe, but limited fetal hypoxemia and no cumulative acidemia, do not result in either a systemic or brain inflammatory response in the pre-term ovine fetus. However, fetal IL-1B and IL-6 values were found to be well correlated with corresponding maternal values supporting the placenta as a primary source for these cytokines with related secretion into both circulations. Female fetuses were also found to have higher IL-1β levels than males, indicating that gender may impact on the fetal inflammatory response to various stimuli.

  8. Two-year home-based nocturnal noninvasive ventilation added to rehabilitation in chronic obstructive pulmonary disease patients : A randomized controlled trial

    NARCIS (Netherlands)

    Duiverman, Marieke L.; Wempe, Johan B.; Bladder, Gerrie; Vonk, Judith M.; Zijlstra, Jan G.; Kerstjens, Huib A. M.; Wijkstra, Peter J.

    2011-01-01

    Background: The use of noninvasive intermittent positive pressure ventilation (NIPPV) in chronic obstructive pulmonary disease (COPD) patients with chronic hypercapnic respiratory failure remains controversial as long-term data are almost lacking. The aim was to compare the outcome of 2-year home-ba

  9. Chronic alcohol alters rewarded behaviors and striatal plasticity

    OpenAIRE

    DePoy, Lauren; Daut, Rachel; Wright, Tara; Camp, Marguerite; Crowley, Nicole; Noronha, Bianca; Lovinger, David; Holmes, Andrew

    2014-01-01

    Chronic intermittent ethanol (CIE) alters neural functions and behaviors mediated by the dorsolateral striatum (DLS) and prefrontal cortex. Here, we examined the effects of prolonged (16-bout) CIE on DLS plasticity and DLS-mediated behaviors. Ex vivo electrophysiological recordings revealed loss in efficacy of DLS synaptically induced activation and absent long-term depression after CIE. CIE increased two-bottle choice drinking and impaired Pavlovian-to-instrumental transfer but not discrimin...

  10. Hepatobiliary scintigraphy in chronic intrahepatic cholestasis. Diagnosis of primary sclerosing cholangitis

    Energy Technology Data Exchange (ETDEWEB)

    Aburano, Tamio; Takayama, Teruhiko; Shuke, Noriyuki

    1987-05-01

    Primary sclerosing cholangitis (PSC) is a rare disease of unknown origin, leading to chronic intermittent cholestasis. Due to its low incidence, insidious clinical onset and varied clinical picture, the diagnosis is often delayed by years. PSC is sometimes diagnosed falsely as another disease of chronic intermittent cholestasis, primary biliary cirrhosis (PBC). In the present study, the hepatobiliary imaging with Tc-99m diethyl IDA was done in a total of 14 patients with chronic intermittent cholestasis including 3 patients with PSC and 11 patients with PBC, in order to decide its clinical usefulness as a noninvasive method for the differentiation between PSC and PBC. All three patients with PSC showed a typical pattern of radionuclide stasis within the area of intrahepatic and/or extrahepatic ductal system, representing the stenosis on endoscopic retrograde cholangiogram. On the other hand, none of 11 patients with PBC showed any radionuclide stasis within the area of intrahepatic and/or extrahepatic ductal system. This result suggests that the radionuclide hepatobiliary imaging may be a noninvasive method for investigating patients with chronic intermittent cholestasis, leading to earlier differentiation between PSC and PBC.

  11. 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.

  12. Clean intermittent self-catheterization in neuro-urology.

    Science.gov (United States)

    Di Benedetto, P

    2011-12-01

    Neurogenic lower urinary tract dysfunction (NLUTD) is commonly encountered in rehabilitation settings, and is caused by a variety of pathologies. The management of spinal cord injury (SCI) has been the model of reference for the management of other pathologies with NLUTD. The introduction of intermittent catheterization (IC) led to decline in renal related mortality in SCI patients and allowed an improvement of quality of life (QoL) in all neurogenic patients with NLUTD. IC could be sterile, aseptic or clean. Sterile intermittent catheterization (SIC) is the preferred method of bladder drainage in emergency medicine units and during spinal shock in SCI patients, but it is costly and time-consuming. Catheterizations performed in institutions, such as rehabilitation hospitals and nursing homes, are done aseptically. Clean intermittent catheterization (CIC), i.e. self-catheterization (CISC) or third party catheterization, represents the "gold standard" method for bladder emptying in all neuropathic patients with NLUTD: the technique is safe and effective and results in improved kidney and upper urinary tract status, lessening of vesico-ureteral reflux and amelioration of urinary continence. CISC is mandatory in patients with NLUTD secondary to detrusor areflexia/hypocontractility and in patients suffering from neurogenic detrusor overactivity with detrusor external sphincter dyssynergia and high post void residual of urine, often in combination with antimuscarinics/bladder relaxants. The review summarizes the most important aspects of IC and CISC. Attention was focused on the history of urethral catheterization, aims, materials, advantages, indications, and present-day techniques of CISC, emphasizing the importance of teaching in order to perform correctly the catheterization technique.

  13. Intermittent Hypoxia Impairs Endothelial Function in Early Preatherosclerosis.

    Science.gov (United States)

    Tuleta, I; França, C N; Wenzel, D; Fleischmann, B; Nickenig, G; Werner, N; Skowasch, D

    2015-01-01

    Intermittent hypoxia seems to be a major pathomechanism of obstructive sleep apnea-associated progression of atherosclerosis. The goal of the present study was to assess the influence of hypoxia on endothelial function depending on the initial stage of vasculopathy. We used 16 ApoE-/- mice were exposed to a 6-week-intermittent hypoxia either immediately (early preatherosclerosis) or after 5 weeks of high-cholesterol diet (advanced preatherosclerosis). Another 16 ApoE-/- mice under normoxia served as corresponding controls. Endothelial function was measured by an organ bath technique. Blood plasma CD31+/annexin V+ endothelial microparticles as well as sca1/flk1+ endothelial progenitor cells in blood and bone marrow were analyzed by flow cytometry. The findings were that intermittent hypoxia impaired endothelial function (56.6±6.2% of maximal phenylephrine-induced vasoconstriction vs. 35.2±4.1% in control) and integrity (increased percentage of endothelial microparticles: 0.28±0.05% vs. 0.15±0.02% in control) in early preatherosclerosis. Peripheral repair capacity expressed as the number of endothelial progenitor cells in blood was attenuated under hypoxia (2.0±0.5% vs. 5.3±1.9% in control), despite the elevated number of these cells in the bone marrow (2.0±0.4% vs. 1.1±0.2% in control). In contrast, endothelial function, as well as microparticle and endothelial progenitor cell levels were similar under hypoxia vs. control in advanced preatherosclerosis. We conclude that hypoxia aggravates endothelial dysfunction and destruction in early preatherosclerosis.

  14. Chronic non-specific low back pain; has cognitive behavioural therapy effect and

    OpenAIRE

    Hjermann, Mette Kristine

    2005-01-01

    Low back pain (LBP) presents a major public health problem. Half of the population will report acute LBP during the last year; approximately 80-90% is non-specific. Many will develop chronic / intermittent LBP and a part of these patients will become unable to maintain daily function and working life. Although non-specific chronic LBP is common, there is little knowledge of its cause and right treatment. In this paper the cognitive chronification process is seen together with newer neurobiolo...

  15. Studying the intermittent stable theorem and the synchronization of a delayed fractional nonlinear system

    Institute of Scientific and Technical Information of China (English)

    Hu Jian-Bing; Zhao Ling-Dong; Xie Zheng-Guang

    2013-01-01

    In this paper,an intermittent synchronizing delayed fractional nonlinear system is studied.We propose a novel intermittent stable theorem for the delayed fractional system and derive a new synchronization criterion for delayed fractional systems by means of fractional stable theorem and the differential inequality method.Intermittent synchronizing fractional delayed Newton-Leipnik system is taken as an illustrative example and numerical simulation of this example is presented to show the feasibility and effectiveness of the proposed theorem.

  16. Intermittent fasting: A “new” historical strategy for controlling seizures?

    OpenAIRE

    Hartman, Adam L.; Rubenstein, James E.; Kossoff, Eric H.

    2012-01-01

    In antiquity, fasting was a treatment for epilepsy and a rationale for the ketogenic diet (KD). Preclinical data indicate the KD and intermittent fasting do not share identical anticonvulsant mechanisms. We implemented an intermittent fasting regimen in six children with an incomplete response to a KD. Three patients adhered to the combined intermittent fasting/KD regimen for 2 months and four had transient improvement in seizure control, albeit with some hunger-related adverse reactions.

  17. 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.

  18. 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.

  19. 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.

  20. 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

    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......, propagating radially far into the scrape-off layer in the form of field-aligned filaments, or blobs. This results in positively skewed and flattened single-point probability distribution functions of particle density and temperature, reflecting the frequent appearance of large fluctuations. The conditional...

  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. Oxidation processes and clogging in intermittent unsaturated infiltration.

    Science.gov (United States)

    Bancolé, A; Brissaud, F; Gnagne, T

    2003-01-01

    Intermittent infiltration of wastewater through a non saturated sand bed is an extensive treatment process aimed at eliminating organic pollution, oxidizing ammonia and removing pathogens. A 1D numerical model, IPOX, has been worked out to simulate the transfer and oxidation of dissolved organic matter and nitrogen in unsaturated sand beds. IPOX was calibrated after real scale tests performed in Spain and Burkina Faso. Simulations allowed us to point out the influence of (i) kinetics on oxidation performances and (ii) biomass development on the process sustainability. These results brought a new light on the sizing and operation of infiltration percolation and soil aquifer treatment (SAT) plants.

  3. The intermittency of plasticity in an Al3%Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Bougherira, Y; Entemeyer, D; Fressengeas, C; Lebyodkin, M A [Laboratoire de Physique et Mecanique des Materiaux, Universite Paul Verlaine-Metz, CNRS, Ile du Saulcy, 57045 Metz (France); Kobelev, N P; Lebedkina, T A, E-mail: Youcef.bougherira@univ-metz.f [Institute of Solid State Physics, Russian Ac. Sci., 142432 Chernogolovka (Russian Federation)

    2010-07-01

    Statistics of acoustic emission accompanying plastic deformation and of stress serrations caused by the Portevin-Le Chatelier effect are studied during tension of an Al3%Mg alloy at room temperature. Power-law distributions of acoustic emission reflecting self-organization of dislocations and intermittency of plastic flow are found, irrespective of the strain rate, both before and after the critical strain for the onset of the serrated flow. In contrast, several regimes including both power-law and peaked distributions are observed at the macroscopic scale of stress serrations, depending on the applied strain rate.

  4. Synchronization of Spatiotemporal Chaos The regime of coupled Spatiotemporal Intermittency

    CERN Document Server

    Amengual, A; Montagne, R; Miguel, M S

    1996-01-01

    Synchronization of spatiotemporally chaotic extended systems is considered in the context of coupled one-dimensional Complex Ginzburg-Landau equations (CGLE). A regime of coupled spatiotemporal intermittency (STI) is identified and described in terms of the space-time synchronized chaotic motion of localized structures. A quantitative measure of synchronization as a function of coupling parameter is given through distribution functions and information measures. The coupled STI regime is shown to dissapear into regular dynamics for situations of strong coupling, hence a description in terms of a single CGLE is not appropiate.

  5. 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...

  6. Periodic versus Intermittent Adaptive Cycles in Quasispecies Coevolution

    Science.gov (United States)

    Seeholzer, Alexander; Frey, Erwin; Obermayer, Benedikt

    2014-09-01

    We study an abstract model for the coevolution between mutating viruses and the adaptive immune system. In sequence space, these two populations are localized around transiently dominant strains. Delocalization or error thresholds exhibit a novel interdependence because immune response is conditional on the viral attack. An evolutionary chase is induced by stochastic fluctuations and can occur via periodic or intermittent cycles. Using simulations and stochastic analysis, we show how the transition between these two dynamic regimes depends on mutation rate, immune response, and population size.

  7. Soft Physics and Intermittency Open Question(s) in Krakow

    CERN Document Server

    Peschanski, R

    1993-01-01

    This contribution contains a summary of the Krakow meeting on Soft Physics and Fluctuations. It emphasizes both the experimental and the theoretical investigations on correlations/fluctuations and intermittency in multi-particle processes and discusses of the present status of this concept. A clarification of the main open questions in this field of research is now within reach, thanks to the studies presented at the meeting. Summary Talk of the Krakow Workshop on Multiparticle Physics, May, 4-7, 1993. E-mail contact: pesch@amoco.saclay.cea.fr

  8. 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.

  9. 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...

  10. Ear infection - chronic

    Science.gov (United States)

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... up. When this happens, infection can occur. A chronic ear infection develops when fluid or an infection ...

  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. Use of home automated intermittent peritoneal dialysis in the treatment of end stage renal failure.

    Science.gov (United States)

    Li, P K; Wang, A Y; Leung, C B; Lui, S F; Lai, K N

    1994-01-01

    We report our retrospective analysis of 16 uraemic patients who were treated with home automated intermittent peritoneal dialysis (IPD) from 1988 to 1993. Six patients were diabetic. The mean age was 58.5 years. The reasons for home automated IPD were: old age, poor eyesight, low intelligence or poor dexterity, family or patient request and old stroke. It took an average of 8.8 sessions to train the helper. The mean frequency of the home IPD was once every 5.8 days with a mean volume of 48 litres of dialysate used during each dialysis. There were 3 peritonitis episodes making the peritonitis rate once every 93 patient months. Four patients were still on home IPD and two were transplanted. Ten patients died of stroke, myocardial infarction, tuberculosis, chronic obstructive lung disease or suicide. A low plasma albumin is the only significant parameter in the early mortality group. Such high mortality can be accounted for by the fact that patients were older and forty per cent were diabetic. We conclude that home automated IPD can be an alternative for some patients in whom other modes of dialysis are difficult.

  13. Effect of intermittent umbilical cord occlusion on fetal respiratory activity and brain adenosine in late-gestation sheep.

    Science.gov (United States)

    Watson, Carole S; Schaefer, Rachel; White, Susan E; Homan, Jacobus H; Fraher, Laurence; Harding, Richard; Bocking, Alan D

    2002-01-01

    It was hypothesized that intermittent umbilical cord occlusion (UCO) would inhibit ovine fetal breathing movements (FBM) in association with increased cerebral adenosine levels. To test this hypothesis, on two successive days during late gestation (133-134 days; term = 146 days), microdialysis samples were collected from the brains of 10 chronically instrumented fetal sheep during 2-h periods of complete UCO induced every 30 min (Day 1: 2-min UCOs; Day 2: 4-min UCOs). Control fetuses (n = 10) underwent no UCO. Tracheal pressure was measured throughout. This regimen resulted in a decrease in fetal arterial PO2 (PaO2) during each UCO to 7.3 +/- 0.8 mmHg (Pfluid (ECF) adenosine during UCO increased by 219 +/- 215% (Pmechanisms.

  14. Exercise-based interventions and health-related quality of life in intermittent claudication: a 20-year (1989-2008) review.

    Science.gov (United States)

    Guidon, Marie; McGee, Hannah

    2010-04-01

    Peripheral arterial disease (PAD) is a chronic, progressive disease with significant cardiovascular risk. Symptoms include pain in leg muscles on walking, relieved by rest (intermittent claudication). Treatment aims to maintain or improve quality of life (QoL) by minimising ischaemic symptoms and preventing progression to vascular occlusion. Management strategies include exercise-based interventions. Research from 1989 to 2008 was systematically reviewed to identify the QoL impact of exercise-based interventions in patients with intermittent claudication. Twenty-three studies were identified. Five were randomized controlled trials. Studies were summarized in terms of exercise interventions, QoL measures used and QoL findings. The majority used a generic QoL instrument; most commonly the Short Form Health Survey (SF-36). Eleven studies reported beneficial effects on the SF-36 Physical Functioning scale. Some also reported positive effects on the scales of Bodily Pain, Role-Physical, Vitality, General Health and the Physical Component Score. In seven studies, a disease-specific measure was used. In six of these, both generic and disease-specific questionnaires were used. Disease-specific measures demonstrated greater improvements across a range of QoL domains. Greater use of disease-specific measures and an extended follow-up period may enable a more definitive picture to emerge regarding effects of exercise on QoL in intermittent claudication.

  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. 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.

  17. 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.

  18. Intermittent bursts induced by double tearing mode reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Lai; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    Reversed magnetic shear (RMS) configuration is assumed to be the steady-state operation scenario for the future advanced tokamaks like International Thermonuclear Experimental Reactor. In this work, we numerically discover a phenomenon of violent intermittent bursts induced by self-organized double tearing mode (DTM) reconnection in the RMS configuration during the very long evolution, which may continuously lead to annular sawtooth crashes and thus badly impact the desired steady-state operation of the future advanced RMS tokamaks. The key process of the intermittent bursts in the off-axis region is similar to that of the typical sawtooth relaxation oscillation in the positive magnetic shear configuration. It is interestingly found that in the decay phase of the DTM reconnection, the zonal field significantly counteracts equilibrium field to make the magnetic shear between the two rational surfaces so weak that the residual self-generated vortices of the previous DTM burst are able to trigger a reverse DTM reconnection by curling the field lines.

  19. 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.

  20. Intermittent filtration of bacteria and colloids in porous media

    Science.gov (United States)

    Auset, Maria; Keller, Arturo A.; Brissaud, François; Lazarova, Valentina

    2005-09-01

    Intermittent filtration through porous media used for water and wastewater treatment can achieve high pathogen and colloid removal efficiencies. To predict the removal of bacteria, the effects of cyclic infiltration and draining events (transient unsaturated flow) were investigated. Using physical micromodels, we visualized the intermittent transport of bacteria and other colloids in unsaturated porous media. Column experiments provided quantitative measurements of the phenomena observed at the pore scale. Tagged Escherichia coli and a conservative tracer (NaI) were introduced in an initial pulse into a 1.5 m sand column. Subsequent hydraulic flushes without tagged bacteria or tracer were repeated every 4 hours for the next 4 days, during which outflow concentrations were monitored. Breakthrough behavior between colloids and dissolved tracer differed significantly, reflecting the differences in transport processes. Advancement of the wetting front remobilized bacteria which were held in thin water films, attached to the air-water interface (AWI), or entrapped in stagnant pore water between gas bubbles. In contrast, the tracer was only remobilized by diffusion from immobile to mobile water. Remobilization led to successive concentration peaks of bacteria and tracer in the effluent but with significant temporal differences. Observations at the pore-scale indicated that the colloids were essentially irreversibly attached to the solid-water interface, which explained to some extent the high removal efficiency of microbes in the porous media. Straining, cluster filtration, cell lysis, protozoa grazing, and bacteriophage parasitism could also contribute to the removal efficiency of bacteria.

  1. Tracking Intermittently Speaking Multiple Speakers Using a Particle Filter

    Directory of Open Access Journals (Sweden)

    Angela Quinlan

    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.

  2. Intermittency measurement in two-dimensional bacterial turbulence

    Science.gov (United States)

    Qiu, Xiang; Ding, Long; Huang, Yongxiang; Chen, Ming; Lu, Zhiming; Liu, Yulu; Zhou, Quan

    2016-06-01

    In this paper, an experimental velocity database of a bacterial collective motion, e.g., Bacillus subtilis, in turbulent phase with volume filling fraction 84 % provided by Professor Goldstein at Cambridge University (UK), was analyzed to emphasize the scaling behavior of this active turbulence system. This was accomplished by performing a Hilbert-based methodology analysis to retrieve the scaling property without the β -limitation. A dual-power-law behavior separated by the viscosity scale ℓν was observed for the q th -order Hilbert moment Lq(k ) . This dual-power-law belongs to an inverse-cascade since the scaling range is above the injection scale R , e.g., the bacterial body length. The measured scaling exponents ζ (q ) of both the small-scale (k >kν ) and large-scale (k intermittency parameters are μS=0.26 and μL=0.17 , respectively, for the small- and large-scale motions. It implies that the former cascade is more intermittent than the latter one, which is also confirmed by the corresponding singularity spectrum f (α ) versus α . Comparison with the conventional two-dimensional Ekman-Navier-Stokes equation, a continuum model indicates that the origin of the multifractality could be a result of some additional nonlinear interaction terms, which deservers a more careful investigation.

  3. 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...

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

    Science.gov (United States)

    Lind, Pedro G.; Wächter, Matthias; Peinke, Joachim

    2014-06-01

    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 important issue in off-shore wind farms.

  5. 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...

  6. 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.

  7. Removal of Pharmaceuticals from Wastewater by Intermittent Electrocoagulation

    Directory of Open Access Journals (Sweden)

    Benny Marie B. Ensano

    2017-01-01

    Full Text Available The continuous release of emerging contaminants (ECs in the aquatic environment, as a result of the inadequate removal by conventional treatment methods, has prompted research to explore viable solutions to this rising global problem. One promising alternative is the use of electrochemical processes since they represent a simple and highly efficient technology with less footprint. In this paper, the feasibility of treating ECs (i.e., pharmaceuticals using an intermittent electrocoagulation process, a known electrochemical technology, has been investigated. Diclofenac (DCF, carbamazepine (CBZ and amoxicillin (AMX were chosen as being representative of highly consumed drugs that are frequently detected in our water resources and were added in synthetic municipal wastewater. The removal efficiencies of both individual and combined pharmaceuticals were determined under different experimental conditions: hydraulic retention time (HRT (6, 19 and 38 h, initial concentration (0.01, 4 and 10 mg/L and intermittent application (5 min ON/20 min OFF of current density (0.5, 1.15 and 1.8 mA/cm2. Results have shown that these parameters have significant effects on pharmaceutical degradation. Maximum removals (DCF = 90%, CBZ = 70% and AMX = 77% were obtained at a current density of 0.5 mA/cm2, an initial concentration of 10 mg/L and HRT of 38 h.

  8. Intermittent flow regimes near the convection threshold in ferromagnetic nanofluids.

    Science.gov (United States)

    Krauzina, Marina T; Bozhko, Alexandra A; Putin, Gennady F; Suslov, Sergey A

    2015-01-01

    The onset and decay of convection in a spherical cavity filled with ferromagnetic nanofluid and heated from below are investigated experimentally. It is found that, unlike in a single-component Newtonian fluid where stationary convection sets in as a result of supercritical bifurcation and where convection intensity increases continuously with the degree of supercriticality, convection in a multicomponent ferromagnetic nanofluid starts abruptly and has an oscillatory nature. The hysteresis is observed in the transition between conduction and convection states. In moderately supercritical regimes, the arising fluid motion observed at a fixed temperature difference intermittently transitions from quasiharmonic to essentially irregular oscillations that are followed by periods of a quasistationary convection. The observed oscillations are shown to result from the precession of the axis of a convection vortex in the equatorial plane. When the vertical temperature difference exceeds the convection onset value by a factor of 2.5, the initially oscillatory convection settles to a steady-state regime with no intermittent behavior detected afterward. The performed wavelet and Fourier analyses of thermocouple readings indicate the presence of various oscillatory modes with characteristic periods ranging from one hour to several days.

  9. 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.

  10. Low Dose Intermittent Isotretinoin Therapy in Moderate Acne Vulgaris

    Directory of Open Access Journals (Sweden)

    Belçın İzol

    2012-03-01

    Full Text Available 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, acne grading based on global acne scoring system, side effects and pretreatment and posttreatment Dermatology Life Quality Index scores. Hemogram, liver function tests, lipid profiles at baseline and monthly follow-ups were noted. Results: Global acne scoring of complete response rate in 94.3% of 35 patients was achieved after one year of therapy. The partial response rate was 5.7%. The earliest clinical response was observed after four weeks. The Dermatology Life Quality Index was 7.8 at baseline and 1.8 at the end of the treatment. Cheilitis was the only side effect observed. We observed mild degree relapses in 5 cases in the evaluation 17 months after the end of the treatment.Conclusion: Our results show that low dose intermittent isotretinoin therapy is an effective and tolerable treatment in moderate acne.

  11. [Chronic hepatitis].

    Science.gov (United States)

    Figueroa Barrios, R

    1995-01-01

    Medical literature about chronic hepatitis is reviewed. This unresolving disease caused by viruses, drugs or unknown factors may progress to in cirrhosis and hepatocarcinoma. A classification based on liver biopsy histology into chronic persistent and chronic active types has been largely abandoned and emphasis is placed on recognizing the etiology of the various types. One is associated with continuing hepatitis B virus infection; another is related to chronic hepatitis C virus infection and the third is termed autoinmune, because of the association with positive serum autoantibodies. A fourth type with similar clinical functional and morphologic features is found with some drug reactions. Long term corticoesteroid therapy is usually successful in autoinmune type. Associations between antibodies to liver-kidney microsomes and the hepatitis C virus can cause diagnostic difficulties. Antiviral treatment of chronic hepatitis B and C with interpheron alfa is employed, controlling symptoms and abnormal biochemistry and the progression to cirrhosis and liver cancer in 30 to 40% patients. Alternative therapies or combinations with interpheron are being evaluated waiting for final results.

  12. 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

  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.; 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. 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

  15. Chronic intussusception in children caused by Ascaris lumbricoides.

    Science.gov (United States)

    Nikolić, Harry; Palčevski, Goran; Saina, Giordano; Peršić, Mladen

    2011-05-01

    Chronic intussusception (CI) is defined as an intussusception lasting for 14 days or more. Because the clinical manifestations are non-specific, the diagnosis is usually delayed. Symptoms include intermittent abdominal pain, sometimes an abdominal mass is palpable and there is a marked weight loss. Diagnosis is based on typical features revealed by ultrasound or barium enema and CT investigations. Therapy is surgical with obligatory exclusion of possible underlying lesions. We report a case of a 3.5-year-old girl with chronic intussusception. Laboratory blood findings revealed sideropenic anemia and stools positive for Ascaris lumbricoides. Anti-parasitic therapy with mebendazole was repeatedly administered with early improvements but soon after symptoms relapsed. During surgery an ileocolic chronic intussusception extending to hepatic flexure was found. Postoperative control examinations proved complete healing. We suspected that Ascaris lumbricoides infestation was an etiologic factor for the development of chronic intussusception in the child.

  16. 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),...

  17. Affecting Factors and Outcome on Intermittent Internet Pulling Behavior in Taiwan's Undergraduate Students

    Science.gov (United States)

    Yang, Hui-Jen; Lay, Yun-Long

    2011-01-01

    Nowadays people's lives heavily rely on Internet facilities. Internet users generally have constant Internet connectivity and intermittently click on sites they want to access even amidst studying or working. In this study, we sought to examine the factors affecting intermittent Internet pulling behavior on undergraduate students. Furthermore, the…

  18. 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

  19. Linear response in aging glassy systems, intermittency and the Poisson statistics of record fluctuations

    DEFF Research Database (Denmark)

    Sibani, Paolo

    2007-01-01

    We study the intermittent behavior of the energy decay and the linear magnetic response of a glassy system during isothermal aging after a deep thermal quench, using the Edward-Anderson spin glass model as a paradigmatic example. The large intermittent changes in the two observables occur...

  20. Sound-wave coherence in atmospheric turbulence with intrinsic and global intermittency.

    Science.gov (United States)

    Wilson, D Keith; Ostashev, Vladimir E; Goedecke, George H

    2008-08-01

    The coherence function of sound waves propagating through an intermittently turbulent atmosphere is calculated theoretically. Intermittency mechanisms due to both the turbulent energy cascade (intrinsic intermittency) and spatially uneven production (global intermittency) are modeled using ensembles of quasiwavelets (QWs), which are analogous to turbulent eddies. The intrinsic intermittency is associated with decreasing spatial density (packing fraction) of the QWs with decreasing size. Global intermittency is introduced by allowing the local strength of the turbulence, as manifested by the amplitudes of the QWs, to vary in space according to superimposed Markov processes. The resulting turbulence spectrum is then used to evaluate the coherence function of a plane sound wave undergoing line-of-sight propagation. Predictions are made by a general simulation method and by an analytical derivation valid in the limit of Gaussian fluctuations in signal phase. It is shown that the average coherence function increases as a result of both intrinsic and global intermittency. When global intermittency is very strong, signal phase fluctuations become highly non-Gaussian and the average coherence is dominated by episodes with weak turbulence.

  1. Finite size scaling analysis of intermittency moments in the two dimensional Ising model

    CERN Document Server

    Burda, Z; Peschanski, R; Wosiek, J

    1993-01-01

    Finite size scaling is shown to work very well for the block variables used in intermittency studies on a 2-d Ising lattice. The intermittency exponents so derived exhibit the expected relations to the magnetic critical exponent of the model. Email contact: pesch@amoco.saclay.cea.fr

  2. 77 FR 67743 - Federal Employees Health Benefits Program Coverage for Certain Intermittent Employees

    Science.gov (United States)

    2012-11-14

    ... RIN 3206-AM74 Federal Employees Health Benefits Program Coverage for Certain Intermittent Employees... Personnel Management (OPM) is issuing an interim final rule to amend the Federal Employees Health Benefits Program (FEHBP) regulations to make certain employees who work on intermittent schedules eligible to...

  3. 5 CFR 630.1204 - Intermittent leave or reduced leave schedule.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Intermittent leave or reduced leave schedule. 630.1204 Section 630.1204 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1204 Intermittent leave or reduced leave...

  4. 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...

  5. 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...

  6. Intermittent Hypoxia Elicits Prolonged Restoration of Motor Function in Human SCI

    Science.gov (United States)

    2011-10-01

    performed in rats with/without cervical injuries : 1) shelf controls; 2) sham; 3) daily treadmill training for five days; 4) intermittent hypoxia for...combining our results with parallel behavioral studies. 15. SUBJECT TERMS Spinal Injury , Treatment , Intermittent hypoxia, humans, rats, BDNF 16...the translational partnership award is to assess changes in ventral spinal protein expression in rats with cervical spinal injuries following

  7. 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.

  8. 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.

  9. Intermittent Domestic Water Supply: A Critical Review and Analysis of Causal-Consequential Pathways

    Directory of Open Access Journals (Sweden)

    S. E. Galaitsi

    2016-06-01

    Full Text Available Communities in many parts of the world, especially in developing countries, face obstacles in supplying continuous water to household consumers. Authorities often cite water scarcity as the cause, but we demonstrate that environmental constraints constitute only one aspect of a multi-dimensional problem. By asking what causes intermittent domestic water supply, this literature review (129 articles identifies 47 conditions of intermittent systems and the causal-consequential pathways between them that can reinforce intermittency. These pathways span several disciplines including engineering, government administration and anthropology, and when viewed together they (1 emphasize the human drivers of intermittency; (2 suggest generalized interventions; and (3 reveal a gap in the literature in terms of meaningful categorizations of the reliability of intermittent supplies. Based on the reliability of consumers’ water access, we propose three categories of intermittency—predictable, irregular, and unreliable—to facilitate comparisons between case studies and transfers of solutions.

  10. 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.

  11. 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.

  12. 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.

  13. Intermittency of the turbulent processes in the Earth's magnetosphere detected from the ground-based measurements

    Science.gov (United States)

    Stepanova, Marina; Foppiano, Alberto; Ovalle, Elias; Antonova, Elizavieta; Troshichev, Oleg

    2008-11-01

    Turbulent processes in the Earth's magnetosphere are reflected in the dynamical behavior of the geomagnetic indices and other parameters determined from ground based observations. Intermittent properties of one minute Polar Cap (PC) index and auroral radio wave absorption are studied using 1995-2000 data sets. It was found that the probability distribution functions (PDFs) of both PC-index and absorption fluctuations display a strong non-Gaussian shape. This indicates that they are not characterized by a global time self-similarity but rather exhibit intermittency, as previously reported for solar wind velocity and auroral electrojet index values. In the case of the auroral absorption it was also found that intermittency strongly depends on the magnetic local time, being largest in the nighttime sector. This shows that the acceleration of precipitating particles is intermittent, especially near the substorm eye, where the level of turbulence increases. Application of the Local Intermittency Measure (LIM) technique confirms the aforementioned results to a better precision.

  14. Circuit implementation and multiform intermittency in a hyper-chaotic model extended from the Lorenz system

    Institute of Scientific and Technical Information of China (English)

    Cang Shi-Jian; Chen Zeng-Qiang; Wu Wen-Juan

    2009-01-01

    This paper presents a non-autonomous hyper-chaotic system, which is formed by adding a periodic driving signal to a four-dimensional chaotic model extended from the Lorenz system. The resulting non-autonomous hyper-chaotic system can display any dynamic behaviour among the periodic orbits, intermittency, chaos and hyper-chaos by controlling the frequency of the periodic signal. The phenomenon has been well demonstrated by numerical simulations, bifurcation analysis and electronic circuit realization. Moreover, the system is concrete evidence for the presence of Pomeau-Manneville Type-Ⅰ intermittency and crisis-induced intermittency. The emergence of a different type of intermittency is similarly subjected to the frequency of periodic forcing. By statistical analysis, power scaling laws consisting in different intermittency are obtained for the lifetime in the laminar state between burst states.

  15. Chronic gastritis.

    Science.gov (United States)

    Sipponen, Pentti; Maaroos, Heidi-Ingrid

    2015-06-01

    Prevalence of chronic gastritis has markedly declined in developed populations during the past decades. However, chronic gastritis is still one of the most common serious pandemic infections with such severe killing sequelae as peptic ulcer or gastric cancer. Globally, on average, even more than half of people may have a chronic gastritis at present. Helicobacter pylori infection in childhood is the main cause of chronic gastritis, which microbial origin is the key for the understanding of the bizarre epidemiology and course of the disease. A life-long and aggressive inflammation in gastritis results in destruction (atrophic gastritis) of stomach mucosa with time (years and decades). The progressive worsening of atrophic gastritis results subsequently in dysfunctions of stomach mucosa. Atrophic gastritis will finally end up in a permanently acid-free stomach in the most extreme cases. Severe atrophic gastritis and acid-free stomach are the highest independent risk conditions for gastric cancer known so far. In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.

  16. Chronic Bronchitis

    Science.gov (United States)

    ... breathing. You may also have other tests. Chronic bronchitis is a long-term condition that keeps coming back or never goes away completely. If you smoke, it is important to quit. Treatment can help with your symptoms. It often includes ...

  17. 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. ...

  18. Kinetic Signatures and Intermittent Turbulence in the Solar Wind Plasma

    CERN Document Server

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

    2012-01-01

    A connection between kinetic processes and intermittent turbulence is observed in the solar wind plasma using measurements from the Wind spacecraft at 1 AU. In particular, kinetic effects such as temperature anisotropy and plasma heating are concentrated near coherent structures, such as current sheets, which are non-uniformly distributed in space. Furthermore, these coherent structures are preferentially found in plasma unstable to the mirror and firehose instabilities. The inhomogeneous heating in these regions, which is present in both the magnetic field parallel and perpendicular temperature components, results in protons at least 3--4 times hotter than under typical stable plasma conditions. These results offer a new understanding of kinetic processes in a turbulent regime, where linear Vlasov theory is not sufficient to explain the inhomogeneous plasma dynamics operating near non-Gaussian structures.

  19. 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.

  20. Inhomogeneous kinetic effects related to intermittent magnetic discontinuities.

    Science.gov (United States)

    Greco, A; Valentini, F; Servidio, S; Matthaeus, W H

    2012-12-01

    A connection between kinetic processes and two-dimensional intermittent plasma turbulence is observed using direct numerical simulations of a hybrid Vlasov-Maxwell model, in which the Vlasov equation is solved for protons, while the electrons are described as a massless fluid. During the development of turbulence, the proton distribution functions depart from the typical configuration of local thermodynamic equilibrium, displaying statistically significant non-Maxwellian features. In particular, temperature anisotropy and distortions are concentrated near coherent structures, generated as the result of the turbulent cascade, such as current sheets, which are nonuniformly distributed in space. Here, the partial variance of increments (PVI) method has been employed to identify high magnetic stress regions within a two-dimensional turbulent pattern. A quantitative association between non-Maxwellian features and coherent structures is established.

  1. 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 ...

  2. Modeling integrated water user decisions in intermittent supply systems

    Science.gov (United States)

    Rosenberg, David E.; Tarawneh, Tarek; Abdel-Khaleq, Rania; Lund, Jay R.

    2007-07-01

    We apply systems analysis to estimate household water use in an intermittent supply system considering numerous interdependent water user behaviors. Some 39 household actions include conservation; improving local storage or water quality; and accessing sources having variable costs, availabilities, reliabilities, and qualities. A stochastic optimization program with recourse decisions identifies the infrastructure investments and short-term coping actions a customer can adopt to cost-effectively respond to a probability distribution of piped water availability. Monte Carlo simulations show effects for a population of customers. Model calibration reproduces the distribution of billed residential water use in Amman, Jordan. Parametric analyses suggest economic and demand responses to increased availability and alternative pricing. It also suggests potential market penetration for conservation actions, associated water savings, and subsidies to entice further adoption. We discuss new insights to size, target, and finance conservation.

  3. Intermittent inhaled corticosteroids in infants with episodic wheezing

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Hermansen, Mette Northman; Loland, Lotte;

    2006-01-01

    BACKGROUND: We hypothesized that asthma is preceded by a stage of recurrent episodes of wheezing during the first years of life and that inhaled corticosteroid therapy during symptomatic episodes in this early phase may delay progression to persistent wheezing. METHODS: We assigned one-month-old ......BACKGROUND: We hypothesized that asthma is preceded by a stage of recurrent episodes of wheezing during the first years of life and that inhaled corticosteroid therapy during symptomatic episodes in this early phase may delay progression to persistent wheezing. METHODS: We assigned one...... not affected by treatment. CONCLUSIONS: Intermittent inhaled corticosteroid therapy had no effect on the progression from episodic to persistent wheezing and no short-term benefit during episodes of wheezing in the first three years of life. (ClinicalTrials.gov number, NCT00234390.)....

  4. 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.

  5. Dynamic intermittency in discrete erodible-bed avalanches

    Science.gov (United States)

    Arran, Matthew; Vriend, Nathalie

    2016-11-01

    The coexistence of fluid-like and solid-like behaviour in granular matter allows avalanches of grains to flow on the surface of a static but erodible bed. For sufficiently slow inflow, these avalanches are discrete, with previous experimentalists reporting that avalanche fronts pass a given point quasi-periodically. We report instead observations of dynamic intermittency between two regimes, one in which avalanches occur quasi-periodically and another in which the intervals between them are irregular. Finding the first regime consistent with existing models, we introduce a model for the second regime within the framework of Self-Organised Criticality, and describe the transition between the regimes with reference to the state of the erodible bed.

  6. 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.

  7. 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.

  8. Kinetic signatures and intermittent turbulence in the solar wind plasma.

    Science.gov (United States)

    Osman, K T; Matthaeus, W H; Hnat, B; Chapman, S C

    2012-06-29

    A connection between kinetic processes and intermittent turbulence is observed in the solar wind plasma using measurements from the Wind spacecraft at 1 A.U. In particular, kinetic effects such as temperature anisotropy and plasma heating are concentrated near coherent structures, such as current sheets, which are nonuniformly distributed in space. Furthermore, these coherent structures are preferentially found in plasma unstable to the mirror and firehose instabilities. The inhomogeneous heating in these regions, which is present in both the magnetic field parallel and perpendicular temperature components, results in protons at least 3-4 times hotter than under typical stable plasma conditions. These results offer a new understanding of kinetic processes in a turbulent regime, where linear Vlasov theory is not sufficient to explain the inhomogeneous plasma dynamics operating near non-Gaussian structures.

  9. 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.

  10. 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...

  11. INTERMITTENT INTERFERON-αα USE IN RENAL METASTASES

    Directory of Open Access Journals (Sweden)

    S. L. Gutorov

    2014-08-01

    Full Text Available The immediate and late results of treating patients with renal metastases with a new intermittent interferon-α (IFN-α use regimen are presented.Subjects and methods. The study included 131 patients receiving IFN-α as 3106 IU subcutaneously, days 1—10 at a further 2-week inter- val.Results. Complete and partial effects were achieved in 11 (8.4% and 18 (13.7% patients, respectively; stable disease (≥6 months was observed in 35 (26.7%. The median time to progression was 23.3 months. The sizes and number of lung metastases were found to have a great impact on survival: with metastases sizing ≤2 cm and their number of ≤10, the median overall survival was 29.9 months. These patients are the most promising candidates for the effective first-line IFN-α therapy.

  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. 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.

  14. 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.

  15. Emotional intelligence and impulsive aggression in Intermittent Explosive Disorder.

    Science.gov (United States)

    Coccaro, Emil F; Solis, Oscar; Fanning, Jennifer; Lee, Royce

    2015-02-01

    Emotional intelligence (EI) relates to one's ability to recognize and understand emotional information and then, to use it for planning and self-management. Given evidence of abnormalities of emotional processing in impulsively aggressive individuals, we hypothesized that EI would be reduced in subjects with Intermittent Explosive Disorder (IED: n = 43) compared with healthy (n = 44) and psychiatric (n = 44) controls. The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) was used to assess both Experiential EI and Strategic EI. Strategic, but not Experiential, EI was lower in IED compared with control subjects. These differences were not accounted for demographic characteristics, cognitive intelligence, or the presence of clinical syndromes or personality disorder. In contrast, the relationship between IED and Strategic EI was fully accounted for by a dimension of hostile cognition defined by hostile attribution and hostile automatic thoughts. Interventions targeted at improving Strategic EI and reducing hostile cognition will be key to reducing aggressive behavior in individuals with IED.

  16. Kalman Filtering with Intermittent Observations: Weak Convergence and Moderate Deviations

    CERN Document Server

    Kar, Soummya

    2009-01-01

    The paper considers the problem of Kalman filtering with intermittent observations, where the observation packet arrival process is modeled as a Bernoulli process. We start by extending the results of \\cite{Riccati-weakconv} to show that the sequence of random conditional error covariance matrices converges in distribution to a unique invariant distribution $\\mathbb{\\mu}^{\\bar{\\gamma}}$, as long as the packet arrival probability $\\bar{\\gamma}>0$. We completely characterize the sequence ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ of invariant distributions as $\\bar{\\gamma}\\uparrow 1$, by showing that the sequence ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ satisfies a moderate deviations principle (MDP) with a good rate function $I$, which is explicitly characterized. We then study the sequence of invariant distributions ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ as $\\bar{\\gamma}\\uparrow 1$. We show that, as $\\bar{\\gamma}\\uparrow 1$, ...

  17. Implementing intermittent preventive treatment for malaria in pregnancy

    DEFF Research Database (Denmark)

    Mubyazi, Godfrey Martin; Magnussen, Pascal; Goodman, Catherine;

    2008-01-01

    INTRODUCTION: Implementing Intermittent Preventive Treatment for malaria in Pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) through antenatal care (ANC) clinics is recommended for malaria endemic countries. Vast biomedical literature on malaria prevention focuses more on the epidemiological...... of the recommended interventions. OBJECTIVE: To review literature on policy advances, achievements, constraints and challenges to malaria IPTp implementation, emphasising on its operational feasibility in the context of health-care financing, provision and uptake, resource constraints and psychosocial factors...... and other discriminatory socio-cultural values on pregnancy; target users, perceptions and attitudes towards SP, malaria, and quality of ANC; supply and cost of SP at health facilities; understaffing and demoralised staff; ambiguity and impracticability of user-fee exemption policy guidelines on essential...

  18. Insulin production hampered by intermittent hypoxia via impaired zinc homeostasis.

    Directory of Open Access Journals (Sweden)

    Eung-Kwon Pae

    Full Text Available Without zinc, pancreatic beta cells cannot either assemble insulin molecules or precipitate insulin crystals; thus, a lack of zinc concentration in the beta cells would result in a decreased insulin production. ZIP8 is one of the zinc uptake transporters involved in zinc influx into the cytosol of beta cells. Thus, if ZIP8 is down-regulated, a decreased insulin production would result. We assumed that intermittent hypoxic exposure to the beta cells may result in a decreased production of insulin due to a lack of zinc. To test this hypothesis we harvested pancreatic islets from the rats conditioned under intermittent hypoxia (IH (fluctuating between 20.5% and 10% every 4 min for 1 h and compared the results with those from control animals and islets. We also compared their insulin and glucose homeostasis using glucose tolerance tests (GTT after 3 weeks. GTT results show a significant delay (P<0.05 in recovery of the blood glucose level in IH treated pups. ZIP8 expression in the beta cell membrane was down-regulated. The zinc concentration in the cell as well as insulin production was significantly decreased in the islets harvested from IH animals. However, mRNA for insulin and C-peptide/insulin protein levels in the total cell lysates remained the same as those of controls. When we treated the beta cells using siRNA mediated ZIP8, we observed the commensurate results from the IH-treated islets. We conclude that a transient IH exposure could knockdown ZIP8 transporters at mRNA as well as protein levels in the beta cells, which would decrease the level of blood insulin. However, the transcriptional activity of insulin remains the same. We conclude that the precipitation process of insulin crystal may be disturbed by a lack of zinc in the cytosol that is modulated by mainly ZIP8 after IH exposure.

  19. Hook Phenomenon: Intermittent distal ureteral obstruction following reimplantation

    Directory of Open Access Journals (Sweden)

    M. Mehdizadeh "

    2003-06-01

    Full Text Available Background/Objectives: To evaluate the child with intermittent ureteral obstruction following antireflux surgery and to introduce a new imaging technique for diagnosis of the socalled “hook” phenomenon, the most serious complication of antireflux surgery. Patients and Methods: Twenty-five children with a history of antireflux surgery who were referred for either persistent urinary tract infection (UTI or progressive hydronephrosis were included in the study. All the children with signs and symptoms of voiding dysfunction or persistent reflux were excluded. A new imaging technique was devised to evaluate these patients for the presence of “hook phenomenon”, in which a renal ultrasound was performed both on a full bladder and after voiding. If dilatation of the urinary tract was detected on full bladder, and this dilatation decreased dramatically following micturition, then a catheter was passed into the bladder and was filled with normal saline (based on the estimated bladder capacity in order to avoid over-distension. An intravenous urogram and saline cystogram were performed simultaneously. After 20 minutes, 2 abdominal radiographs were obtained on full and emptied bladder, both. Results: On the intravenous urogram, some children showed typical “J- hook-shaped” ureters. In all the cases marked hydronephrosis was noted, with no contrast material seen entering the bladder on the 20 minute radiogram. Upon evacuation of the bladder, both ureters promptly drained into the bladder and the”J-hooking” of the ureters and hydronephrosis resolved. Conclusion: "J- hook phenomenon” is one of the most common causes of hydronephrosis and hydroureter following ureteral re-implantation is intermittent ureteral obstruction from creation of the new ureteral hiatus at an inappropriate site. This complication is frequently misdiagnosed as irreversible uretero-vesical junction obstruction from ischemia or fibrosis. Once the diagnosis of “J- hook

  20. 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.

  1. Biotrickling filtration of isopropanol under intermittent loading conditions.

    Science.gov (United States)

    San-Valero, Pau; Penya-Roja, Josep M; Sempere, Feliu; Gabaldón, Carmen

    2013-07-01

    This paper investigates the removal of isopropanol by gas-phase biotrickling filtration. Two plastic packing materials, one structured and one random, have been evaluated in terms of oxygen mass transfer and isopropanol removal efficiency. Oxygen mass transfer experiments were performed at gas velocities of 104 and 312 m h⁻¹ and liquid velocities between 3 and 33 m h⁻¹. Both materials showed similar mass transfer coefficients up to liquid velocities of 15 m h⁻¹. At greater liquid velocities, the structured packing exhibited greater oxygen mass transfer coefficients. Biotrickling filtration experiments were carried out at inlet loads (IL) from 20 to 65 g C m⁻³ h⁻¹ and empty bed residence times (EBRT) from 14 to 160 s. To simulate typical industrial emissions, intermittent isopropanol loading (16 h/day, 5 day/week) and intermittent spraying frequency (15 min/1.5 h) were applied. Maximum elimination capacity of 51 g C m⁻³ h⁻¹ has been obtained for the random packing (IL of 65 g C m⁻³ h⁻¹, EBRT of 50 s). The decrease in irrigation frequency to 15 min every 3 h caused a decrease in the outlet emissions from 86 to 59 mg C Nm⁻³ (inlet of 500 mg C Nm⁻³). The expansion of spraying to night and weekend periods promoted the degradation of the isopropanol accumulated in the water tank during the day, reaching effluent concentrations as low as 44 mg C Nm⁻³. After a 7-week starvation period, the performance was recovered in less than 10 days, proving the robustness of the process.

  2. 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.

  3. Response to Switch from Intermittent Therapy to Daily Therapy for Refractory Nodular Bronchiectatic Mycobacterium avium Complex Lung Disease

    OpenAIRE

    Koh, Won-Jung; Jeong, Byeong-Ho; Jeon, Kyeongman; Park, Hye Yun; Kim, Su-Young; Huh, Hee Jae; Ki, Chang-Seok; Lee, Nam Yong; Shin, Sung Jae; Daley, Charles L.

    2015-01-01

    Intermittent three-times-weekly antibiotic therapy is recommended for the initial treatment of patients with noncavitary nodular bronchiectatic Mycobacterium avium complex lung disease. Although some experts recommend switching from intermittent to daily therapy for patients whose sputum has persistent positive cultures after intermittent therapy, the clinical efficacy of these modifications is unknown. Of 20 patients whose sputum had persistent positive cultures after 12 months of intermitte...

  4. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... Information > Children/Pediatric > Chronic Pancreatitis in Children test Chronic Pancreatitis in Children What symptoms would my child ... pancreatitis will develop diabetes in adolescence. Who gets chronic pancreatitis? Those at risk for chronic pancreatitis are ...

  5. Chronic Beryllium Disease

    Science.gov (United States)

    ... Science Education & Training Home Conditions Chronic Beryllium Disease Chronic Beryllium Disease Make an Appointment Find a Doctor ... MD, MSPH, FCCP (February 01, 2016) What is chronic beryllium disease (CBD)? Chronic beryllium disease (CBD) is ...

  6. Chronic motor tic disorder

    Science.gov (United States)

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  7. Chronic Pelvic Pain

    Science.gov (United States)

    ... Education & Events Advocacy For Patients About ACOG Chronic Pelvic Pain Home For Patients Search FAQs Chronic Pelvic Pain ... Pelvic Pain FAQ099, August 2011 PDF Format Chronic Pelvic Pain Gynecologic Problems What is chronic pelvic pain? What ...

  8. Triploidia fetal associada à diminuição da subunidade beta e do estriol não-conjugado no soro materno Fetal triploidy associated with low levels of unconjugated estriol and beta-subunit in maternal serum

    Directory of Open Access Journals (Sweden)

    Eduardo Vieira Neto

    1999-05-01

    Full Text Available Relatamos um caso de triploidia fetal não-molar detectada na 20ª semana gestacional por cordocentese realizada em razão de estudo ultra-sonográfico que revelou retardo do crescimento intra-uterino e grave oligoidrâmnio. Na 19ª semana foram verificados acentuada diminuição da subunidade beta livre da gonadotrofina coriônica humana e do estriol não-conjugado e níveis de alfa-fetoproteína normais, apontando para um risco aumentado de síndrome de Edwards. Houve morte fetal um dia após a cordocentese e a resolução do caso foi por parto vaginal induzido com misoprostol e ocitocina, sob analgesia peridural. Estudo cromossômico das células sangüíneas fetais revelou o cariótipo 69,XXX. O grave retardo do crescimento intra-uterino, a macrocefalia, constatada no estudo anatomopatológico do feto, e os níveis muito baixos de hCG e de estriol não-conjugado sugerem um caso de triploidia por diginia, fertilização de um óvulo diplóide por um espermatozóide haplóide.We report a case of nonmolar fetal triploidy detected by fetal blood sampling at 20 weeks of gestation, performed as an investigation of intrauterine growth retardation and severe oligohydramnios found by ultrasound scan. At 19 weeks of gestation very low levels of maternal free serum beta-subunit of human chorionic gonadotropin and unconjugated estriol, and normal levels of alpha-fetoprotein were found, which were interpreted as a high risk of fetal Edwards syndrome. Fetal death supervened the day after fetal blood sampling, and the pregnancy was terminated by vaginal delivery induced by misoprostol and oxytocin, under epidural anesthesia. Chromosome study of the fetal blood cells showed a 69,XXX karyotype. The severe intrauterine growth retardation and macrocephaly noted on pathological review plus the very low levels of hCG and unconjugated estriol suggest a fetal gynoid triploidy case, caused by the fertilization of a diploid egg by a haploid sperm.

  9. Gestación tras inseminación artificial : factores pronósticos, marcadores de aneuploidías en primer trimestre, morbilidad materno-fetal y resultados perinatales

    OpenAIRE

    Rodríguez Bújez, Ana Belén

    2013-01-01

    El presente trabajo parte de la duda de si realmente son inocuos los tratamientos de inducción de la ovulación seguidos de inseminación artificial (IA) y si podemos considerar estos embarazos iguales en cuanto a su seguimiento y resultados a las gestaciones espontáneas. Todas estas características se encuentran ampliamente descritas en la literatura para los embarazos procedentes de fecundación in vitro, pero muy escasamente para la IA. En nuestro país, al igual que en otros mucho...

  10. La gestación en mujeres obesas mórbidas tras cirugía bariátrica: evolución materno-fetal con distintas técnicas

    OpenAIRE

    González Navarro, Irene

    2016-01-01

    Falta palabras clave Las mujeres obesas constituyen un grupo especial de riesgo por las complicaciones asociadas a la fertilidad y embarazo. La pérdida de peso, a través de modificaciones del estilo de vida, ha demostrado mejorar estos resultados, por lo que sería esperable que ocurriera lo mismo tras la cirugía bariátrica Se calcula que más de la mitad de los pacientes sometidos a estos procedimientos son mujeres en edad fértil. Esta situación ha generado inquietud entre obstet...

  11. Vínculo materno-fetal: implicaciones en el desarrollo psicológico y propuesta de intervención en atención temprana (Maternal-foetal bonding: implications for psychological development and proposal for early intervention

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Roncallo

    2015-09-01

    Full Text Available Health research has identified maternal-foetal bonding as a significant antecedent of post-natal bonding between mother and baby. Maternal-foetal bonding is associated with the emotional and cognitive aspects that allow the foetus to be recreated as another human being. This bond is expressed in health practices aimed at the protection and welfare of the foetus. It has been observed that the psychological state of the mother affects the foetus at the neurobehavioral level and influences the appearance of developmental disorders that also manifest in the post-natal period, thereby significantly affecting the mother-baby relationship. Thus, early intervention practices could be extended to the prenatal period as a prevention strategy to favourably impact the health of the child and mother. To address this issue, we present an interdisciplinary intervention model, which focuses on maternal-foetal bonding as a protective factor for bonding during the postnatal period, and as an enhancer of positive parenting practices that promote healthy psychological development.

  12. Chronic thyroiditis (Hashimoto disease)

    Science.gov (United States)

    Hashimoto thyroiditis; Chronic lymphocytic thyroiditis; Autoimmune thyroiditis; Chronic autoimmune thyroiditis; Lymphadenoid goiter - Hashimoto; Hypothyroidism - Hashimoto; Type 2 polyglandular autoimmune ...

  13. 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.

  14. Bacterial sinusitis can be a focus for initial lung colonisation and chronic lung infection in patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Aanæs, Kasper

    2013-01-01

    A major purpose of treating patients with cystic fibrosis (CF) is to prevent or delay chronic lung infections with CF-pathogenic Gram-negative bacteria. In the intermittent stage, bacteria can usually be eradicated from the lungs with antibiotics, but following eradication, the next lung colonisa...... therapy, e.g. saline and antibiotic irrigations....

  15. OBSERVATION ON THE THERAPEUTIC EFFECT OF ELECTROACUPUNCTURE TREATMENT FOR SIMPLE CHRONIC RHINITIS

    Institute of Scientific and Technical Information of China (English)

    WEN Biling; ZHOU Shuang; YANG Yihong

    2002-01-01

    @@ Simple chronic rhinitis is a reversible chronic inflammatory disorder of nasal mucosa caused by various factors, it is a frequently encountered disorder with clinical manifestations of increased nasal secretion, intermittent alternative nasal obstruction, frequent ( respiratory ) anosmia and rhinophonia while speaking. In severe cases, it may manifest as hypocathexis, hypomnesis, fatigue, headache, head distress, insomnia, etc.that considerably hinder the patient's work or study. In the last 10 years, the authors have chiefly applied electroacupuncture (EA) to treatment of 38 cases of chronic rhinitis and the therapeutic effects are satisfactory. The following is the report of the treatment.

  16. Burden of Placental Malaria among Pregnant Women Who Use or Do Not Use Intermittent Preventive Treatment at Mulago Hospital, Kampala

    Directory of Open Access Journals (Sweden)

    Charles Okot Odongo

    2016-01-01

    Full Text Available Intermittent preventive treatment of malaria in pregnancy with sulphadoxine-pyrimethamine (SP-IPTp is widely used to reduce the incidence of adverse pregnancy outcomes. As a monitor for continued effectiveness of this intervention amidst SP resistance, we aimed to assess malaria burden among pregnant women who use or do not use SP-IPTp. In a descriptive cohort study at Mulago Hospital, Kampala, 87 women who received two supervised doses of SP-IPTp were followed up until delivery. Controls were pregnant women presenting in early labour without history of SP-IPTp. Histopathological investigation for placental malaria (PM was performed using the Bulmer classification criterion. Thirty-eight of the 87 women returned for delivery and 33 placentas were successfully collected and processed along with 33 placentas from SP nonusers. Overall, 12% (4/33 of the users had evidence of PM compared to 48% (16/33 of nonusers. Among nonusers, 17/33, 8/33, 2/33, and 6/33 had no placental infection, active infection, active-chronic infection, and past-chronic infection, respectively. Among users, respective proportions were 29/33, 2/33, 0/33, and 2/33. No difference in birth weights was apparent between the two groups, probably due to a higher proportion of infections occurring later in pregnancy. Histological evidence here suggests that SP continues to offer substantial benefit as IPTp.

  17. Detection of the type of intermittency using characteristic patterns in recurrence plots.

    Science.gov (United States)

    Klimaszewska, Katarzyna; Zebrowski, Jan J

    2009-08-01

    One of the common routes to chaos is intermittency. Identification of the intermittency type is usually made using the properties of the probability distribution of laminar phases and of the average length of the laminar phases. Both have a statistical character and to obtain them a long time series has to be examined. Here, we present a recurrence plot method applicable to the analysis of short time series and through which the type of intermittency may be identified. The three types of intermittency introduced by Pomeau and Manneville and a chaos-chaos intermittency induced by interior crisis were examined. The identification of the type of intermittency is equivalent to the identification of the bifurcation associated with it. Our result seems particularly interesting as our method allows the analysis of short time series. The effect of the measurement noise on the effectiveness of the method is also discussed. An application of the method to the detection of type I intermittency in measured heart rate variability data is discussed.

  18. 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.

  19. 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.

  20. 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.

  1. Reliability and validity of a novel intermittent peak running speed test for Australian football.

    Science.gov (United States)

    Mooney, Mitchell G; Hunter, Jayden R; O'Brien, Brendan J; Berry, Jason T; Young, Warren B

    2011-04-01

    Australian football requires frequent intermittent sprinting close to peak running speed. However, tests assessing the capability to maintain intermittent peak running speed are not reported in scientific literature. Therefore, our objective is to report the reliability and validity of a novel intermittent peak running speed test. The intermittent peak running speed test required footballers to perform 10 repetitions on 25-second intervals. Each repetition required 15-m jogging, 20-m acceleration to peak speed, 10 m to sustain peak speed, 20-m deceleration, and finally a 15-m jog. Intermittent peak running speed was determined by portable global positioning system. To assess reliability, 26 footballers performed the intermittent peak running speed test on 2 occasions 3-5 days apart. Our results revealed that average peak speed had a coefficient of variation of 2.2% and an intraclass correlation of 0.91. To assess construct validity, average peak speed was compared between elite, sub-elite, and regional footballers. The average peak speed of the elite footballers (28.6 ± 1.7 km · h(-1)) was higher than that of the sub-elite (27.4 ± 1.7 km · h(-1)) and regional (27 ± 1.9 km · h(-1)) competitors (p intermittent peak running speed test possesses acceptable reliability and distinguishes between elite and sub-elite footballers.

  2. The immobility produced by intermittent swim stress is not mediated by serotonin.

    Science.gov (United States)

    Christianson, John P; Rabbett, Sarah; Lyckland, Jennifer; Drugan, Robert C

    2008-05-01

    Exposure to uncontrollable stressors such as intermittent swim stress (ISS) produces a behavioral syndrome that resembles behavioral depression including immobility in a Forced Swim Test (FST) and escape learning deficits. The results of previous studies suggest that stress causes a temporary sensitization of the brain serotonin (5-HT) system that is necessary and sufficient for producing behavioral depression. If this hypothesis is true in the ISS paradigm, then enhancing or inhibiting 5-HT transmission during stress should exacerbate or block the development of behavioral depression, respectively. The selective 5-HT uptake inhibitor fluoxetine (FLX) was administered prior to ISS or confinement; 24 h later the FST was used to detect behavioral immobility. ISS, but not FLX, significantly increased immobility in the FST. The purported 5-HT uptake enhancer tianeptine (TPT) was administered in place of FLX. Again ISS increased immobility in the FST, but TPT had no effect. These results suggested that 5-HT is not a critical mediator of ISS induced behavioral depression. However, some authors have raised concern that TPT does not act directly on 5-HT. Therefore, the 5-HT synthesis inhibitor, para-chlorophenylaline (PCPA) was administered to deplete central 5-HT before stress. PCPA did not alter immobility in the FST. Finally, a sub-chronic regimen of FLX given after ISS, but before the FST, was without effect on reversing the ISS-induced immobility. Taken together, these experiments indicate that ISS produces a significant behavioral depression manifested as increased immobility but offer no support of the hypothesis that 5-HT is a critical mediator of these effects.

  3. Adrenergic β2-receptors mediates visceral hypersensitivity induced by heterotypic intermittent stress in rats.

    Directory of Open Access Journals (Sweden)

    Chunhua Zhang

    Full Text Available Chronic visceral pain in patients with irritable bowel syndrome (IBS has been difficult to treat effectively partially because its pathophysiology is not fully understood. Recent studies show that norepinephrine (NE plays an important role in the development of visceral hypersensitivity. In this study, we designed to investigate the role of adrenergic signaling in visceral hypersensitivity induced by heterotypical intermittent stress (HIS. Abdominal withdrawal reflex scores (AWRs used as visceral sensitivity were determined by measuring the visceromoter responses to colorectal distension. Colon-specific dorsal root ganglia neurons (DRGs were labeled by injection of DiI into the colon wall and were acutely dissociated for whole-cell patch-clamp recordings. Blood plasma level of NE was measured using radioimmunoassay kits. The expression of β2-adrenoceptors was measured by western blotting. We showed that HIS-induced visceral hypersensitivity was attenuated by systemic administration of a β-adrenoceptor antagonist propranolol, in a dose-dependent manner, but not by a α-adrenoceptor antagonist phentolamine. Using specific β-adrenoceptor antagonists, HIS-induced visceral hypersensitivity was alleviated by β2 adrenoceptor antagonist but not by β1- or β3-adrenoceptor antagonist. Administration of a selective β2-adrenoceptor antagonist also normalized hyperexcitability of colon-innervating DRG neurons of HIS rats. Furthermore, administration of β-adrenoceptor antagonist suppressed sustained potassium current density (IK without any alteration of fast-inactivating potassium current density (IA. Conversely, administration of NE enhanced the neuronal excitability and produced visceral hypersensitivity in healthy control rats, and blocked by β2-adrenoceptor antagonists. In addition, HIS significantly enhanced the NE concentration in the blood plasma but did not change the expression of β2-adrenoceptor in DRGs and the muscularis externa of the

  4. Effects of the Intermittent Pneumatic Circulator on Blood Pressure during Hemodialysis

    Directory of Open Access Journals (Sweden)

    Miao-Ju Hsu

    2010-11-01

    Full Text Available Hypotension is frequently reported during hemodialysis. This study aimed to examine the effect of the intermittent pneumatic circulator on blood pressure during hemodialysis. Sixteen subjects with chronic hemodialysis were recruited. Each subject randomly received two test conditions on separate days, hemodialysis with and without the circulator. The circulator was applied to the subject on lower extremities during 0.5–1 hr, 1.5–2 hr, 2.5–3 hr, and 3.5–4 hr of hemodialysis. Systolic and diastolic blood pressures (SBP and DBP and heart rate (HR were analyzed at pre-dialysis, 1 hr, 2 hr, and 3 hr of hemodialysis. Stroke volume (SV and cardiac output (CO were evaluated between 2.5 and 3.0 hr of hemodialysis. Blood chemicals (sodium, calcium, potassium, and phosphorous and Kt/V before and after each hemodialysis session were analyzed. The number of episodes of hypotension was also recorded. The circulator intervention significantly improved SBP and DBP across all time points (P = 0.002 for SBP; P = 0.002 for DBP. The frequency of hypotension was significantly decreased (P = 0.028. SV and CO were significantly improved with the circulator intervention (P = 0.017 for SV; P = 0.026 for CO and no statistical significances were found on blood chemicals or Kt/V analyses. The results suggested that the circulator intervention helps stabilize blood pressure and appears to be a practical treatment. Future studies are suggested to develop new circulator innovations with sensor feedback systems to enhance safety and maximize treatment efficiency.

  5. 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.

  6. Combination of intermittent calorie restriction and eicosapentaenoic acid for inhibition of mammary tumors.

    Science.gov (United States)

    Mizuno, Nancy K; Rogozina, Olga P; Seppanen, Christine M; Liao, D Joshua; Cleary, Margot P; Grossmann, Michael E

    2013-06-01

    There are a number of dietary interventions capable of inhibiting mammary tumorigenesis; however, the effectiveness of dietary combinations is largely unexplored. Here, we combined 2 interventions previously shown individually to inhibit mammary tumor development. The first was the use of the omega-3 fatty acid, eicosapentaenoic acid (EPA), and the second was the implementation of calorie restriction. MMTV-Her2/neu mice were used as a model for human breast cancers, which overexpress Her2/neu. Six groups of mice were enrolled. Half were fed a control (Con) diet with 10.1% fat calories from soy oil, whereas the other half consumed a diet with 72% fat calories from EPA. Within each diet, mice were further divided into ad libitum (AL), chronic calorie-restricted (CCR), or intermittent calorie-restricted (ICR) groups. Mammary tumor incidence was lowest in ICR-EPA (15%) and highest in AL-Con mice (87%), whereas AL-EPA, CCR-Con, CCR-EPA, and ICR-Con groups had mammary tumor incidence rates of 63%, 47%, 40%, and 59%, respectively. Survival was effected similarly by the interventions. Consumption of EPA dramatically reduced serum leptin (P < 0.02) and increased serum adiponectin in the AL-EPA mice compared with AL-Con mice (P < 0.001). Both CCR and ICR decreased serum leptin and insulin-like growth factor I (IGF-I) compared with AL mice but not compared with each other. These results illustrate that mammary tumor inhibition is significantly increased when ICR and EPA are combined as compared with either intervention alone. This response may be related to alterations in the balance of serum growth factors and adipokines.

  7. Effect of intermittent feeding, structural components and phytase on performance and behaviour of broiler chickens.

    Science.gov (United States)

    Svihus, B; Lund, V B; Borjgen, B; Bedford, M R; Bakken, M

    2013-01-01

    1. Two experiments were conducted to study the effect of intermittent feeding on performance and the efficacy of an exogenous phytase, and to assess whether intermittent feeding changed the activity pattern of broiler chickens. 2. Broiler chickens were given, either ad libitum or intermittently, a phosphorus deficient pelleted diet containing either coarsely or finely ground oat hulls and either no enzyme or a phytase added from 10 d of age, in a 2 × 2 × 2 factorial arrangement. Ad libitum feeding consisted of continuous access to feed in a room with 18 h of light and 6 h of complete darkness, whereas birds on intermittent feeding had restricted access to feed from 7 d of age, with 4 1-h feeding bouts/d and one 2-h feeding bout/d from d 14. 3. Performance, characteristics of the anterior digestive tract and phosphorus retention were assessed in experiment 1, while in experiment 2, birds were observed during 4-h periods to quantify different behaviours. 4. Intermittent feeding and phytase improved performance, but intermittent feeding did not improve the efficacy of the enzyme added. Ad libitum fed broiler chickens ate and drank on average twice per hour, and spent close to three-quarters of their time resting. Apart from an increased standing and feed searching activity for intermittently fed birds compared to ad libitum fed birds during the last hour before feed was presented, no differences in activity was detected. 5. It was concluded that broiler chickens quickly adapt to intermittent feeding without reduction in final body weight and with improvements in feed efficiency, but without improving the efficacy of dietary phytase. Only small changes occur in the behaviour of intermittently fed birds compared to ad libitum fed birds.

  8. 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.

  9. Distance stereo acuity improvement in intermittent exotropic patients following strabismus surgery.

    Science.gov (United States)

    O'Neal, T D; Rosenbaum, A L; Stathacopoulos, R A

    1995-01-01

    To determine whether distance stereo acuity improved following strabismus surgery in patients with intermittent exotropia, we tested 20 patients (5 to 87 years old) preoperatively and postoperatively using the Mentor BVAT II Video acuity tester (Santa Barbara, Calif) and binocular visual system. Acuity improved in 75% as assessed by contour circles and in 45% as assessed by random dot E tests at distance. Our results suggest that surgical realignment of intermittent exotropia restores distance stereo acuity. We conclude that measuring distance stereo acuity offers valuable information in the evaluation of the intermittent exotropic patient.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Intermittent prophylaxis of recurrent febrile seizures with clobazam versus diazepam.

    Science.gov (United States)

    Sattar, S; Saha, S K; Parveen, F; Banu, L A; Momen, A; Ahmed, A U; Quddush, M R; Karim, M M; Begum, S A; Haque, M A; Hoque, M R

    2014-10-01

    Febrile seizures are the most common type of seizure among children that can be prevented by using prophylactic drugs like Clobazam and Diazepam. The present prospective study was conducted in the Department of Pediatrics, Mymensingh Medical College Hospital and Community Based Medical College Hospital, Bangladesh over a period of 1 year from July 2012 to June 2013 to compare the effectiveness of intermittent Clobazam versus Diazepam therapy in preventing the recurrence of febrile seizures and assessed adverse effects of each drug. A total of 65 patients (32 children administered Clobazam and rest 33 children received Diazepam) of simple and complex febrile seizures aged 6 months to 5 years of both sexes were the study population. Data were collected by interview of the patients, clinical examination and laboratory investigations using the research instrument. Data were analyzed by using Chi-square (χ2) Test, Student's 't' Test and Fisher's Exact Test. For all analytical tests, the level of significance was set at 0.05 and pClobazam and Diazepam groups. Over 31% of patients in Clobazam group who experienced episode of fever within 3 months, 40.6% within 6 months and 9.4% within 9 months compared to 36.4% in Diazepam group within 3 months, 45.5% within 6 months & 12.1% within 9 months after discharge from the hospital. Three (9.4%) patients in Clobazam group and 7(21.3%) in Diazepam group who experienced febrile convulsion during the follow up period. From the data adverse effects within 3 and 6 months experienced by the patient's drowsiness, sedation and ataxia were higher in Diazepam group than those in Clobazam group. However, within 9 months lethargy and irritability were somewhat higher in Clobazam group than those in Diazepam group. The mean duration of hospitalization was significantly higher in Diazepam group compared to Clobazam group (6.0±1.0 vs. 4.6±0.08 days, PDiazepam group had a history of recurrent seizures, whereas 3(9.4%) of 32 children in the

  15. 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

  16. Intermittent vs continuous operation of upflow anaerobic sludge bed reactors for dairy wastewater and related microbial changes.

    Science.gov (United States)

    Nadais, H; Capela, I; Arroja, L

    2006-01-01

    This work compares continuous vs intermittent UASB reactors inoculated with flocculent sludge for the treatment of dairy effluents. The effects of effluent recirculation on the performance of intermittent reactors were assessed as well as the differences in specific methanogenic activity (SMA) with different substrates for the biomass from continuous and intermittent UASB reactors. Compared to the continuous operation the intermittent operation resulted in higher methanization of the removed COD (64-78% and 65-88%, respectively) whilst the effluent recirculation presented beneficial effects when applied during the stabilization period and was clearly detrimental when applied during the feed period of the intermittent operation. The SMA tests showed that the intermittent operation causes a shift in the microbial populations towards a better adaptation for the degradation of complex substrates confirmed by the meaningfull contribution of methane production through a pathway other than acetoclastic methanogenesis observed in the biomass taken from intermittent UASB reactors.

  17. Potential Benefits and Harms of Intermittent Energy Restriction and Intermittent Fasting Amongst Obese, Overweight and Normal Weight Subjects—A Narrative Review of Human and Animal Evidence

    Science.gov (United States)

    Harvie, Michelle; Howell, Anthony

    2017-01-01

    Intermittent energy restriction (IER) has become popular as a means of weight control amongst people who are overweight and obese, and is also undertaken by normal weight people hoping spells of marked energy restriction will optimise their health. This review summarises randomised comparisons of intermittent and isoenergetic continuous energy restriction for weight loss to manage overweight and obesity. It also summarises the potential beneficial or adverse effects of IER on body composition, adipose stores and metabolic effects from human studies, including studies amongst normal weight subjects and relevant animal experimentation. Six small short term (animal models highlight the potential beneficial and adverse effects of intermittent compared to continuous energy restriction on ectopic and visceral fat stores, adipocyte size, insulin resistance, and metabolic flexibility. The longer term benefits or harms of IER amongst people who are overweight or obese, and particularly amongst normal weight subjects, is not known and is a priority for further investigation. PMID:28106818

  18. Top predator absence enhances leaf breakdown in an intermittent stream.

    Science.gov (United States)

    Rodríguez-Lozano, Pablo; Rieradevall, Maria; Prat, Narcís

    2016-12-01

    Current biodiversity loss is characterized by the extinction of top predators, but small-bodied freshwater fish are often overlooked in research and conservation management even when threatened because they usually lack commercial value. Therefore, the ecosystem impacts of their possible loss remain mostly unknown. We assessed whether the presence/absence of an endangered predatory fish (Barbus meridionalis (A. Risso, 1827)) in an intermittent stream affects leaf fungal biomass and leaf quality (i.e. leaf carbon:nitrogen ratio and leaf toughness), macroinvertebrate assemblages colonizing leaf packs, and leaf breakdown rates. We conducted a leaf bag experiment comparing a control reach with a population of B. meridionalis with an adjacent upstream fishless reach. In the fishless reach, leaf fungal biomass and microbially mediated breakdown rate were lower compared to the control reach. This was probably caused by the lack of the bottom-up stimulation through nutrient recycling by fish. Shredders and scrapers were found at higher abundance and biomass in the fishless compared to the control reach, and the whole macroinvertebrate community composition changed with fish absence. Consequently, macroinvertebrate mediated leaf breakdown was faster in the fishless than in the control reach, not only compensating for the lower microbially mediated leaf breakdown in the fishless reach, but accelerating the overall leaf breakdown rate. Our study contributes to understand the potential cascading effects produced by the extirpation of endangered small-bodied fish.

  19. 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.

  20. Smoking patterns and stimulus control in intermittent and daily smokers.

    Directory of Open Access Journals (Sweden)

    Saul Shiffman

    Full Text Available Intermittent smokers (ITS - who smoke less than daily - comprise an increasing proportion of adult smokers. Their smoking patterns challenge theoretical models of smoking motivation, which emphasize regular and frequent smoking to maintain nicotine levels and avoid withdrawal, but yet have gone largely unexamined. We characterized smoking patterns among 212 ITS (smoking 4-27 days per month compared to 194 daily smokers (DS; smoking 5-30 cigarettes daily who monitored situational antecedents of smoking using ecological momentary assessment. Subjects recorded each cigarette on an electronic diary, and situational variables were assessed in a random subset (n=21,539 smoking episodes; parallel assessments were obtained by beeping subjects at random when they were not smoking (n=26,930 non-smoking occasions. Compared to DS, ITS' smoking was more strongly associated with being away from home, being in a bar, drinking alcohol, socializing, being with friends and acquaintances, and when others were smoking. Mood had only modest effects in either group. DS' and ITS' smoking were substantially and equally suppressed by smoking restrictions, although ITS more often cited self-imposed restrictions. ITS' smoking was consistently more associated with environmental cues and contexts, especially those associated with positive or "indulgent" smoking situations. Stimulus control may be an important influence in maintaining smoking and making quitting difficult among ITS.

  1. 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...

  2. Heterogeneous fluorescence intermittency in single layer reduced graphene oxide

    Science.gov (United States)

    Si, Jixin; Volkan-Kacso, Sandor; Eltom, Ahmed; Morozov, Yurii; McDonald, Matthew P.; Ruth, Anthony; Kuno, Masaru; Janko, Boldizsar

    Fluorescence intermittency, or blinking, has been observed in a wide range of systems, including quantum dots, nanorods, and nanowires. Striking similarities have been documented in the optical response of these nanoscale emitters. However, the mechanism behind blinking still remains elusive. For the first time, blinking has been observed in a two-dimensional system in recent experiments on reduced graphene oxide (rGO). Here we reveal the power spectral density (PSD) of the blinking in rGO shares the same 1/f-like behavior of previously known blinking systems; meanwhile, the heterogeneous dynamic evolution and spatial correlation make rGO a unique blinking system. To investigate the origin of blinking, we self-consistently explain the evolution of rGO blinking using the phenomenological multiple recombination center (MRC) model that captures common features of nanoscale blinking. Furthermore, tight binding method and ab-initio method calculations of carbon nanodots are utilized to look for the microscopic structure corresponding to the RCs in the MRC model. M. K. thanks the American Chemical Society Petroleum Research Fund, the Army Research Office (W911NF-12-1-0578) for support. B.J. was supported in part by the U. S. DOE, Office of Science, Office of Basic Energy Sciences, under Contract W-31-109-Eng-38.

  3. 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.

  4. 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.

  5. Intermittent motion in desert locusts: behavioural complexity in simple environments.

    Directory of Open Access Journals (Sweden)

    Sepideh Bazazi

    Full Text Available Animals can exhibit complex movement patterns that may be the result of interactions with their environment or may be directly the mechanism by which their behaviour is governed. In order to understand the drivers of these patterns we examine the movement behaviour of individual desert locusts in a homogenous experimental arena with minimal external cues. Locust motion is intermittent and we reveal that as pauses become longer, the probability that a locust changes direction from its previous direction of travel increases. Long pauses (of greater than 100 s can be considered reorientation bouts, while shorter pauses (of less than 6 s appear to act as periods of resting between displacements. We observe power-law behaviour in the distribution of move and pause lengths of over 1.5 orders of magnitude. While Lévy features do exist, locusts' movement patterns are more fully described by considering moves, pauses and turns in combination. Further analysis reveals that these combinations give rise to two behavioural modes that are organized in time: local search behaviour (long exploratory pauses with short moves and relocation behaviour (long displacement moves with shorter resting pauses. These findings offer a new perspective on how complex animal movement patterns emerge in nature.

  6. Acute intermittent porphyria: psychosis as the only clinical manifestation.

    Science.gov (United States)

    Ellencweig, Natalie; Schoenfeld, Nili; Zemishlany, Zvi

    2006-01-01

    Acute intermittent porphyria (AIP) is the most common of the four forms of neuroporphyria. AIP mimics a variety of disorders and thus poses a diagnostic quagmire. Abdominal pain occurs in 90-95% of the attacks. Some patients develop psychiatric symptoms such as psychosis similar to schizophrenia. The diagnostic difficulty may lead to under-diagnosis of patients who present with strictly psychiatric symptoms. This assumption is supported by a high prevalence of AIP in psychiatric hospitals. Therefore, we encourage a high index of suspicion for AIP in psychiatric patients in order to prevent false psychiatric diagnosis. In addition we discuss psychotropic drugs that may exacerbate acute attacks in undiagnosed patients. We report a case in which the diagnosis of AIP was clouded by the presence of only psychiatric symptoms. The clue for diagnosis was an anamnestic detail of the use of a porphyrogenic drug prior to the admission. The diagnosis of AIP was supported by excess of alpha aminolevulinic acid (ALA) and porphobilinogen (PBG) in urine concomitantly with a decrease in porphobilinogen deaminase (PBGD) activity in erythrocytes. The diagnosis was further strengthened by the fact that the patient's father was identified as an AIP carrier. However, in the absence of typical organic symptoms of porphyria, one cannot definitely rule out the presence of schizophrenia in this patient in addition to AIR

  7. 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.

  8. Coherent structure and Intermittent Turbulence in the Solar Wind Plasma

    Science.gov (United States)

    Sondhiya, Deepak Kumar; Gwal, Ashok Kumar; Kasde, Satish Kumar

    2016-07-01

    We analyze the coherent structures and intermittent turbulence in the solar wind plasma using measurements from the Wind spacecraft. Previously established novel wavelet and higher order statistics are used in this work. We analyze the wavelet power spectrum of various solar wind plasma parameters. We construct a statistical significance level in the wavelet power spectrum to quantify the interference effects arising from filling missing data in the time series, allowing extraction of significant power from the measured data. We analyze each wavelet power spectra for transient coherency, and global periodicities resulting from the superposition of repeating coherent structures. Furthermore, these coherent structures are preferentially found in plasma unstable to the mirror and firehose instabilities. These results offer a new understanding of various processes in a turbulent regime. Finally, we discuss the implications of our results for current theories of solar wind generation and describe future work for determining the relationship between the coherent structures in our ionic composition data and the structure of the coronal magnetic field. Keywords: Wavelet Power Spectrum, Coherent structure and Solar wind plasma

  9. Intermittent explosions of dissipative solitons and noise-induced crisis

    Science.gov (United States)

    Cisternas, Jaime; Descalzi, Orazio

    2013-08-01

    Dissipative solitons show a variety of behaviors not exhibited by their conservative counterparts. For instance, a dissipative soliton can remain localized for a long period of time without major profile changes, then grow and become broader for a short time—explode—and return to the original spatial profile afterward. Here we consider the dynamics of dissipative solitons and the onset of explosions in detail. By using the one-dimensional complex Ginzburg-Landau model and adjusting a single parameter, we show how the appearance of explosions has the general signatures of intermittency: the periods of time between explosions are irregular even in the absence of noise, but their mean value is related to the distance to criticality by a power law. We conjecture that these explosions are a manifestation of attractor-merging crises, as the continuum of localized solitons induced by translation symmetry becomes connected by short-lived trajectories, forming a delocalized attractor. As additive noise is added, the extended system shows the same scaling found by low-dimensional systems exhibiting crises [J. Sommerer, E. Ott, and C. Grebogi, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.43.1754 43, 1754 (1991)], thus supporting the validity of the proposed picture.

  10. 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.

  11. 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.

  12. Data analysis considerations in probing single quantum dot fluorescence intermittency

    Science.gov (United States)

    Krogmeier, Jeffrey R.; Hwang, Jeeseong

    2005-04-01

    The fluorescence intermittency of single, bare, CdSe/ZnS quantum dots was probed using single molecule confocal microscopy and found to demonstrate power law kinetics. Various threshold values and line fitting parameters are employed in the data analysis and their effects on the extracted power law exponents, moff and mon, are presented. The threshold is found to be critical in determining moff while having no significant effect on mon. The mean plus 2σ threshold, calculated from the background noise in the measurement, results in a more negative moff slope in comparison to the mean plus 3σ or mean plus 4σ thresholds. This is likely due to the mean plus 2σ threshold lying within the background noise outliers which mimic short on events. In contrast, the mean plus 4σ threshold is above 99.99% of the background noise while adequately below the fluorescence signal. Additionally, it is found that fitting only the ten most probable data points rather than all the data points in the log-log probability density graphs results in no significant change in moff and mon.

  13. Phase locking of wind turbines leads to intermittent power production

    Science.gov (United States)

    Anvari, M.; Wächter, M.; Peinke, J.

    2016-12-01

    Wind energy, inserted into the power grid by wind turbines, is strongly influenced by the turbulent fluctuations of wind speed in the atmospheric layer. Here we investigate the power production of a wind farm and show that due to the presence of large-scale and long-time correlation in wind velocity, turbines interact with each other. This interaction can result in phase locking in pairs of turbines. We show that there are time intervals during which some pairs of turbines are temporally phase locked. This intermediate phase locking leads to the statistical effect that the short-time fluctuations of the cumulative power output of the wind farm become non-Gaussian, i.e., intermittent power production occurs. Contrary to phase-locked states, there are some time intervals where all turbines are phase unlocking and consequently the probability density function of the temporal increment of cumulative power production of the wind farm has almost Gaussian distribution. The phase-locked states, which can be distinct from phase-unlocked states by their dynamical features, are evaluated by reconstructed stochastic differential equations.

  14. 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.

  15. Slow and Fast Escape for Open Intermittent Maps

    Science.gov (United States)

    Demers, Mark F.; Todd, Mike

    2017-04-01

    If a system mixes too slowly, putting a hole in it can completely destroy the richness of the dynamics. Here we study this instability for a class of intermittent maps with a family of slowly mixing measures. We show that there are three regimes: (1) standard hyperbolic-like behavior where the rate of mixing is faster than the rate of escape through the hole, there is a unique limiting absolutely continuous conditionally invariant measure (accim) and there is a complete thermodynamic description of the dynamics on the survivor set; (2) an intermediate regime, where the rate of mixing and escape through the hole coincide, limiting accims exist, but much of the thermodynamic picture breaks down; (3) a subexponentially mixing regime where the slow mixing means that mass simply accumulates on the parabolic fixed point. We give a complete picture of the transitions and stability properties (in the size of the hole and as we move through the family) in this class of open systems. In particular, we are able to recover a form of stability in the third regime above via the dynamics on the survivor set, even when no limiting accim exists.

  16. Introspection-based periodicity awareness model for intermittently connected mobile networks

    NARCIS (Netherlands)

    Türkes, Okan; Scholten, Hans; Havinga, Paul

    2013-01-01

    Recently, context awareness in Intermittently Connected Mobile Networks (ICMNs) has gained popularity in order to discover social similarities among mobile entities. Nevertheless, most of the contextual methods depend on network knowledge obtained with unrealistic scenarios. Mobile entities should h

  17. Anisotropic Homogeneous Turbulence: Hierarchy and Intermittency of Scaling Exponents in the Anisotropic Sectors

    NARCIS (Netherlands)

    Biferale, Luca; Toschi, Federico

    2001-01-01

    We present the first measurements of anisotropic statistical fluctuations in perfectly homogeneous turbulent flows. We address both problems of intermittency in anisotropic sectors and hierarchical ordering of anisotropies on a direct numerical simulation of a three dimensional random Kolmogorov flo

  18. 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.

  19. 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...

  20. Effects of continuous and intermittent magnetic fields on oxidative parameters in vivo.

    Science.gov (United States)

    Coşkun, Sule; Balabanli, Barbaros; Canseven, Ayşe; Seyhan, Nesrin

    2009-02-01

    Continuous and intermittent 50 Hz, 1.5 mT magnetic field with the exposure period of 4 h/day for 4 days was used to investigate its possible effect on adult guinea pigs. Tissues and plasma specimens were assessed by biochemical parameters. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and myeloperoxidase activity (MPO) were examined in plasma, liver and brain tissues. All parameters were determined by spectrophotometer. While intermittent magnetic field was effective on plasma lipid peroxidation, continuous magnetic field was found to be effective on plasma MPO activity and NO levels. Augmentation of lipid peroxidation was also observed in liver tissue both intermittent and continuous magnetic field exposures. These results indicate that both the intermittent and continuous magnetic field exposures affect various tissues in a distinct manner because of having different tissue antioxidant status and responses.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation

    DEFF Research Database (Denmark)

    Mohr, Magni; Nielsen, Jens Jung; Bangsbo, Jens

    2011-01-01

    The effect of oral caffeine ingestion on intense intermittent exercise performance and muscle interstitial ion concentrations was examined. The study consists of two studies (S1 and S2). In S1 twelve subjects completed the Yo-Yo intermittent recovery level 2 (Yo-Yo IR2) test with prior caffeine (6......(+) with microdialysis. In S1 Yo-Yo IR2 performance was 16% better (P...

  7. Intermittent pneumatic compression for prevention of pulmonary thromboembolism after gynecologic surgery

    OpenAIRE

    Tomita Akiyo; Nomura Hiroyuki; Ezawa Sachiko; Hirao Takeshi; Higashiguchi Atsushi; Kataoka Fumio; Suzuki Nao; Susumu Nobuyuki; Aoki Daisuke

    2005-01-01

    Abstract Background To investigate the incidence of pulmonary embolism and risk factors for this condition after obstetric and gynecologic surgery, as well as the efficacy of intermittent pneumatic compression. Methods A total of 6,218 patients operated at Keio University Hospital excluding obstetric or infertility-related surgery and uterine cervical conization were evaluated retrospectively to determine the preventive effect of intermittent pneumatic compression on postoperative pulmonary e...

  8. 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...

  9. 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.

  10. Modeled intermittency risk for small streams in the Upper Colorado River Basin under climate change

    Science.gov (United States)

    Reynolds, Lindsay V.; Shafroth, Patrick B.; Poff, N. LeRoy

    2015-01-01

    Longer, drier summers projected for arid and semi-arid regions of western North America under climate change are likely to have enormous consequences for water resources and river-dependent ecosystems. Many climate change scenarios for this region involve decreases in mean annual streamflow, late summer precipitation and late-summer streamflow in the coming decades. Intermittent streams are already common in this region, and it is likely that minimum flows will decrease and some perennial streams will shift to intermittent flow under climate-driven changes in timing and magnitude of precipitation and runoff, combined with increases in temperature. To understand current intermittency among streams and analyze the potential for streams to shift from perennial to intermittent under a warmer climate, we analyzed historic flow records from streams in the Upper Colorado River Basin (UCRB). Approximately two-thirds of 115 gaged stream reaches included in our analysis are currently perennial and the rest have some degree of intermittency. Dry years with combinations of high temperatures and low precipitation were associated with more zero-flow days. Mean annual flow was positively related to minimum flows, suggesting that potential future declines in mean annual flows will correspond with declines in minimum flows. The most important landscape variables for predicting low flow metrics were precipitation, percent snow, potential evapotranspiration, soils, and drainage area. Perennial streams in the UCRB that have high minimum-flow variability and low mean flows are likely to be most susceptible to increasing streamflow intermittency in the future.

  11. Comparison of techniques to determine intermittency of riometer auroral absorption at South Pole

    Science.gov (United States)

    Ovalle, E. M.; Stepanova, M.; Foppiano, A. J.

    2008-05-01

    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 nighttime 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, different techniques to determine intermittency of auroral absorption measured by a riometer at South Pole (-90°S) are compared. The techniques are (i) the standard Castings formulation, (ii) the Local Intermittency Measure, (iii) the superstatistic, and (iv) the non-extensive statistics. It is shown that results obtained using the superstatistic and non-extensive statistic techniques confirm previously published results for auroral absorption at South Pole using the Castings and the Local Intermittency Measure techniques. Furthermore, a preliminary comparison between techniques indicates technique differences seem to be more related to the conceptual approach of each one rather than to the numerical results given by them.

  12. White Matter Integrity Reductions in Intermittent Explosive Disorder.

    Science.gov (United States)

    Lee, Royce; Arfanakis, Konstantinos; Evia, Arnold M; Fanning, Jennifer; Keedy, Sarah; Coccaro, Emil F

    2016-10-01

    Intermittent explosive disorder (IED), as described in DSM-5, is the categorical expression of pathological impulsive aggression. Previous work has identified neurobiological correlates of the disorder in patterns of frontal-limbic brain activity and dysregulation of serotonergic neurotransmission. Given the importance of short- and-long range white matter connections of the brain in social and emotional behavior, studies of white matter connectivity in impulsive aggression are warranted. Diffusion tensor imaging (DTI) studies in the related conditions of antisocial and borderline personality disorder have produced preliminary evidence of disturbed white matter connectivity in these disorders, but to date there have been no DTI studies in IED. A total of 132 male and female adults between the ages of 18 and 55 years underwent Turboprop-DTI on a 3-Tesla MRI scanner. Of these, 42 subjects had IED, 40 were normal controls, and 50 were clinical psychiatric controls with psychiatric disorders without IED. All subjects were free of alcohol, psychotropic medications, or drugs of abuse. The diffusion tensor was calculated in each voxel and maps of fractional anisotropy (FA) were generated. Tract-based spatial statistics (TBSS) were used to compare FA along the white matter skeleton among the three subject groups. IED was associated with lower FA in two clusters located in the superior longitudinal fasciculus (SLF) when compared with the psychiatric and healthy controls. Impulsive aggression and borderline personality disorder, but not psychopathy or antisocial personality disorder, was associated with lower FA in the two clusters within the SLF. In conclusion, IED was associated with lower white matter integrity in long-range connections between the frontal and temporoparietal regions.

  13. Surplus from and storage of electricity generated by intermittent sources

    Science.gov (United States)

    Wagner, Friedrich

    2016-12-01

    Data from the German electricity system for the years 2010, 2012, 2013, and 2015 are used and scaled up to a 100% supply by intermittent renewable energy sources (iRES). In the average, 330GW wind and PV power are required to meet this 100% target. A back-up system is necessary with the power of 89% of peak load. Surplus electricity accrues at high power levels. Curtailing surplus power to a large extent is found to be uneconomic. Demand-side management will suffer from the strong day-to-day variation of available surplus energy. A day storage is ineffective because of the day-night correlation of surplus power during winter. A seasonal storage loses its character when transformation losses are considered because it can contribute only after periods with excessive surplus production. The option of an oversized iRES system to feed the storage is also not effective because, in this case, energy can be taken directly from the large iRES supply, making storage superfluous. The capacities to be installed stress the difficulty to base heat supply and mobility also on iRES generated electricity in the future. As the German energy transition replaces one CO2-free electricity supply system by another one, no major reduction in CO2 emission can be expected till 2022, when the last nuclear reactor will be switched off. By 2022, an extremely oversized power supply system has to be created, which can be expected to continue running down spot-market electricity prices. The continuation of the economic response -to replace expensive gas fuel by cheap lignite- causes an overall increase in CO2 emission. The German GHG emission targets for 2020 and beyond are therefore in jeopardy.

  14. Chronic inflammatory demyelinating polyneuropathy

    Science.gov (United States)

    Polyneuropathy - chronic inflammatory; CIDP; Chronic inflammatory polyneuropathy; Guillain-Barré - CIDP ... Health care providers also consider CIDP as the chronic form of Guillain-Barré syndrome. The specific triggers ...

  15. Dealing with chronic cancer

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000933.htm Dealing with chronic cancer To use the sharing features on this ... be controlled for a period of time. Controlling Chronic Cancer When you have a chronic cancer, the ...

  16. The acceptability of intermittent screening and treatment versus intermittent preventive treatment during pregnancy: results from a qualitative study in Northern Ghana

    NARCIS (Netherlands)

    Pell, C.; Meñaca, A.; Chatio, S.; Hodgson, A.; Tagbor, H.; Pool, R.

    2014-01-01

    Background: Affecting mother and child, malaria during pregnancy (MiP) provokes a double morbidity and mortality burden. Within a package of interventions to prevent MiP in endemic areas, the WHO currently recommends intermittent preventive treatment (IPTp). Concerns about anti-malarial resistance h

  17. X-ray changes of children with chronic renal insufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Ponhold, W.; Balzar, E. (Vienna Univ. (Austria). Kinderklinik)

    1983-01-01

    The typical changes of renal osteopathy are shown in the X-rays of 7 children with end-stage renal disease treated with chronic intermittent hemodialysis. The exact evaluation of the granular structural changes of the cranium, the evidence of osteomalacia because of the hazy appearance of the vertebrae and the broadening of the sacroilical joints depend highly on subjective judgement and the technical X-ray procedures used. Unmistakable radiological diagnoses can be made when a broadening of the metalphyseal zones, epiphysioloysis as well as characteristic changes in the finder phalanges (acroosteolyses, spiculae, tunnelation) are present.

  18. Hepatitis B e Antigen-Negative Chronic Hepatitis B

    OpenAIRE

    2006-01-01

    IntroductionHepatitis B virus (HBV) infection is a global health problem. Current estimates are that 2 billion people have been infected worldwide, of these, 360 million suffer from chronic HBV infection resulting in over 520 000 deaths from acute hepatitis B and 470 000 from cirrhosis or liver cancer(1). The prevalence of hepatitis B carriers varies in different parts of the world, ranging from less than 1% to 15%. In the Middle East, the endemicity is intermittent, with a carrier rate of 2%...

  19. Chronic mucus hypersecretion

    DEFF Research Database (Denmark)

    Harmsen, L; Thomsen, S F; Sylvan Ingebrigtsen, Truls;

    2010-01-01

    Chronic mucus hypersecretion (CMH) is a common condition in patients with chronic respiratory diseases. Little is known about the incidence, prevalence and determinants of CMH in younger individuals....

  20. Spirochetes in the spleen of a patient with chronic Lyme disease.

    Science.gov (United States)

    Cimmino, M A; Azzolini, A; Tobia, F; Pesce, C M

    1989-01-01

    A 54-year-old man had intermittent evening fever, arthralgia, transient erythematous macular eruption on the skin, and splenomegaly of two year's duration. Immunofluorescence tests for Borrelia burgdorferi serum antibodies had positive results, but G-penicillin treatment was ineffective. Splenectomy with lymph node biopsy was performed to rule out lymphoproliferative disorders. Borrelia-like spirochetes were identified histologically in the spleen; this finding was consistent with persistence of B. burgdorferi organisms in inner organs in chronic Lyme disease.