WorldWideScience

Sample records for asymmetric dimethylarginine adma

  1. [Asymmetric dimethylarginine (ADMA) in children with diabetes type 1].

    Science.gov (United States)

    Głowińska-Olszewska, Barbara; Luczyński, Włodzimierz; Jabłońska, Jolanta; Otocka, Agnieszka; Florys, Bożena; Bossowski, Artur

    2010-01-01

    Asymmetric dimethylarginine (ADMA), a naturally occurring product of asymmetric methylation of proteins, is an endogenous inhibitor of endothelial nitric oxide synthase. ADMA is now recognized as an independent marker of endothelial dysfunction and atherosclerosis. Data concerning ADMA level in type 1 diabetes (DM1) are controversial. The aim of the study was to evaluate ADMA level in children with DM1, without clinical evidence of vascular complications, with particular attention to additional cardiovascular risk factors (hypertension, obesity, hyperlipidemia). The study group included 72 children with DM1, aged mean 15±3 yrs (8-20 yrs), 33 boys and 39 girls, with diabetes duration time mean 6.6±3.5 yrs (1-14 yrs), HBA1c mean level 8.2±2.3% (5.6-15%). The control group consisted of 41 (19 boys and 22 girls) healthy children, aged mean--14.8±2.6 yrs, from 8 to 18 yrs, gender matched, with no family history of cardiovascular disease. ADMA level was determined in plasma using ELISA kit (DLD Diagnostica, Hamburg, Germany) ADMA level was similar in children with diabetes and in the control group: 0.69±0.33 vs. 0.7±0.27 μmol/L, ns. We did not find differences in ADMA level in diabetic children with the presence of additional diseases being cardiovascular risk factors. In the group of 13 children with hypertension ADMA level was the highest: 0.79±0.25 μmol/L, but the difference was statistically insignificant in comparison to children with diabetes without hypertension and in comparison to healthy controls. Children with DM1, without clinically evident vascular complications, have ADMA levels similar to healthy children. A possible relationship between ADMA and hypertension in these patients requires further investigation.

  2. MCD diet-induced steatohepatitis is associated with alterations in asymmetric dimethylarginine (ADMA) and its transporters.

    Science.gov (United States)

    Di Pasqua, Laura G; Berardo, Clarissa; Rizzo, Vittoria; Richelmi, Plinio; Croce, Anna Cleta; Vairetti, Mariapia; Ferrigno, Andrea

    2016-08-01

    Using an experimental model of NASH induced by a methionine-choline-deficient (MCD) diet, we investigated whether changes occur in serum and tissue levels of asymmetric dimethylarginine (ADMA). Male Wistar rats underwent NASH induced by 8-week feeding with an MCD diet. Serum and hepatic biopsies at 2, 4 and 8 weeks were taken, and serum enzymes, ADMA and nitrate/nitrite (NOx), were evaluated. Hepatic biopsies were used for mRNA and protein expression analysis of dimethylarginine dimethylaminohydrolase-1 (DDAH-1) and protein methyltransferases (PRMT-1), enzymes involved in ADMA metabolism and synthesis, respectively, and ADMA transporters (CAT-1, CAT-2A and CAT-2B). Lipid peroxides (TBARS), glutathione, ATP/ADP and DDAH activity were quantified. An increase in serum AST and ALT was detected in MCD animals. A time-dependent decrease in serum and tissue ADMA and increase in mRNA expression of DDAH-1 and PRMT-1 as well as higher rates of mRNA expression of CAT-1 and lower rates of CAT-2A and CAT-2B were found after 8-week MCD diet. An increase in serum NOx and no changes in protein expression in DDAH-1 and CAT-1 and higher content in CAT-2 and PRMT-1 were found at 8 weeks. Hepatic DDAH activity decreased with a concomitant increase in oxidative stress, as demonstrated by high TBARS levels and low glutathione content. In conclusion, a decrease in serum and tissue ADMA levels in the MCD rats was found associated with a reduction in DDAH activity due to the marked oxidative stress observed. Changes in ADMA levels and its transporters are innovative factors in the onset and progression of hepatic alterations correlated with MCD diet-induced NASH.

  3. Association between vitamin D status and asymmetric dimethylarginine (ADMA) concentration in the Korean elderly population.

    Science.gov (United States)

    Choi, Hye Rin; Lee, Seung Won; Yeom, Hyungseon; Jeon, Da-Hye; Kim, Hyeon Chang; Youm, Yoosik

    2017-08-01

    Vitamin D deficiency has been reported to be associated with the risk of cardiovascular disease. We investigated the relationship between vitamin D status and asymmetric dimethylarginine (ADMA) concentration, a marker of endothelial dysfunction, in the Korean elderly population. A cross-sectional study was conducted on 269 men and 382 women (mean age, 71.6 years) enrolled in the Korean Social Life, Health, and Aging Project (KSHAP), a population-based longitudinal study of health determinants in elderly Koreans. We stratified patients by vitamin D status into three groups according to serum 25-hydroxyvitamin D [25(OH)D] level: sufficient (≥30ng/mL, n=25), insufficient (10-D status and ADMA concentration was analyzed by multiple linear regression models. The mean ADMA concentration was significantly higher in the insufficient 25(OH)D group (0.665μmol/L, p=0.001) and the deficient 25(OH)D group (0.734μmol/L, pD group (0.589μmol/L). Even after adjusting for sex, age, body mass index, blood pressure, diabetes mellitus, total and HDL cholesterol, estimated glomerular filtration rate (eGFR), smoking status, and drinking status, ADMA concentrations were higher in the insufficient group (β=0.0742μmol/L, p=0.001) and the deficient group (β=0.1417μmol/L, pD deficiency was associated with higher ADMA levels in both women (pD deficiency was associated with higher ADMA levels in women (pD level may be associated with endothelial dysfunction in elderly Korean people. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Effect of Lowering Asymmetric Dimethylarginine (ADMA on Vascular Pathology in Atherosclerotic ApoE-Deficient Mice with Reduced Renal Mass

    Directory of Open Access Journals (Sweden)

    Johannes Jacobi

    2014-03-01

    Full Text Available The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS inhibitor asymmetric dimethylarginine (ADMA and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1, on atherosclerosis in subtotally nephrectomized (SNX ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n = 39 and C57Bl/6J wild-type littermates (WT, n = 27 with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction ApoE-competent DDAH1 transgenic and wild-type littermates (n = 11 served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD in this mouse model.

  5. Inverse correlation between maternal plasma asymmetric dimethylarginine (ADMA) and birthweight percentile in women with impaired placental perfusion: circulating ADMA as an NO-independent indicator of fetal growth restriction?

    Science.gov (United States)

    Tsikas, Dimitrios; Bollenbach, Alexander; Savvidou, Makrina D

    2018-02-01

    L-Arginine (Arg) is the enzymatic precursor of nitric oxide (NO) which has multiple biological functions. Asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are endogenous inhibitors of NO. We hypothesized that the ADMA and SDMA have additional biological functions in pregnancy, beyond NO synthesis, and may play a role in the regulation of birthweight (BW). To investigate this issue, we measured the plasma concentration of ADMA, SDMA, Arg and the NO metabolites nitrite and nitrate, at 23-25 weeks of gestation in women with normal placental function (Group 1) and in women with impaired placental perfusion; 19 of these women had normal outcome (Group 2), 14 had a fetus that was growth restricted (Group 3), and 10 women eventually developed preeclampsia (Group 4). BW percentile was found to inversely correlate with maternal plasma ADMA concentration in Group 3 (r = - 0.872, P restriction in women with impaired placental perfusion independent of NO.

  6. Elevated Levels of Asymmetric Dimethylarginine (ADMA in the Pericardial Fluid of Cardiac Patients Correlate with Cardiac Hypertrophy.

    Directory of Open Access Journals (Sweden)

    Zoltan Nemeth

    Full Text Available Pericardial fluid (PF contains several biologically active substances, which may provide information regarding the cardiac conditions. Nitric oxide (NO has been implicated in cardiac remodeling. We hypothesized that L-arginine (L-Arg precursor of NO-synthase (NOS and asymmetric dimethylarginine (ADMA, an inhibitor of NOS, are present in PF of cardiac patients and their altered levels may contribute to altered cardiac morphology.L-Arg and ADMA concentrations in plasma and PF, and echocardiographic parameters of patients undergoing coronary artery bypass graft (CABG, n = 28 or valve replacement (VR, n = 25 were determined.We have found LV hypertrophy in 35.7% of CABG, and 80% of VR patients. In all groups, plasma and PF L-Arg levels were higher than that of ADMA. Plasma L-Arg level was higher in CABG than VR (75.7 ± 4.6 μmol/L vs. 58.1 ± 4.9 μmol/L, p = 0.011, whereas PF ADMA level was higher in VR than CABG (0.9 ± 0.0 μmol/L vs. 0.7 ± 0.0 μmol/L, p = 0.009. L-Arg/ADMA ratio was lower in the VR than CABG (VRplasma: 76.1 ± 6.6 vs. CABGplasma: 125.4 ± 10.7, p = 0.004; VRPF: 81.7 ± 4.8 vs. CABGPF: 110.4 ± 7.2, p = 0.009. There was a positive correlation between plasma L-Arg and ADMA in CABG (r = 0.539, p = 0.015; and plasma and PF L-Arg in CABG (r = 0.357, p = 0.031; and plasma and PF ADMA in VR (r = 0.529, p = 0.003; and PF L-Arg and ADMA in both CABG and VR (CABG: r = 0.468, p = 0.006; VR: r = 0.371, p = 0.034. The following echocardiographic parameters were higher in VR compared to CABG: interventricular septum (14.7 ± 0.5 mm vs. 11.9 ± 0.4 mm, p = 0.000; posterior wall thickness (12.6 ± 0.3 mm vs. 11.5 ± 0.2 mm, p = 0.000; left ventricular (LV mass (318.6 ± 23.5 g vs. 234.6 ± 12.3 g, p = 0.007; right ventricular (RV (33.9 ± 0.9 cm2 vs. 29.7 ± 0.7 cm2, p = 0.004; right atrial (18.6 ± 1.0 cm2 vs. 15.4 ± 0.6 cm2, p = 0.020; left atrial (19.8 ± 1.0 cm2 vs. 16.9 ± 0.6 cm2, p = 0.033 areas. There was a positive correlation

  7. Plasma concentration of asymmetric dimethylarginine (ADMA) predicts cardiovascular morbidity and mortality in type 1 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Lajer, Maria Stenkil; Tarnow, Lise; Jorsal, Anders

    2008-01-01

    OBJECTIVE: To investigate whether circulating asymmetric dimethylarginine (ADMA) levels are predictive of cardiovascular events, decline in glomerular filtration rate (GFR), end-stage renal disease (ESRD), and all-cause mortality in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: We...... performed a prospective observational follow-up study including 397 type 1 diabetic patients with overt diabetic nephropathy (243 men aged 42.1 +/- 10.5 years, GFR 76 +/- 34 ml/min per 1.73 m(2)) and a control group of 175 patients with longstanding type 1 diabetes and persistent normoalbuminuria (104 men...... aged 42.7 +/- 9.7 years, duration of diabetes 27.7 +/- 8.3 years). Patients were followed for a median 11.3 years (range 0.0-12.9) with yearly measurements of GFR ((51)Cr-EDTA plasma clearance) in patients with diabetic nephropathy. Endpoints were fatal and nonfatal cardiovascular disease (CVD...

  8. Asymmetric Dimethylarginine (ADMA Levels Are Lower in Hemodialysis Patients Treated With Paricalcitol

    Directory of Open Access Journals (Sweden)

    Elena Oliva-Damaso

    2017-03-01

    Discussion: Hemodialysis patients treated with paricalcitol presented significantly decreased ADMA levels compared with those who did not receive this treatment. Possible beneficial effects in terms of cardiovascular morbidity and mortality by paricalcitol and its association with ADMA and nitric oxide synthesis are unknown. Studies to confirm this effect and determine the underlying pathophysiological mechanism are necessary.

  9. The usefulness of plasma asymmetric dimethylarginine (ADMA) levels and tissue doppler echocardiography for heart function in term infants born to mothers with gestational diabetes mellitus.

    Science.gov (United States)

    Arslan, Derya; Oran, Bulent; Vatansev, Husamettin; Cimen, Derya; Guvenc, Osman

    2013-11-01

    The aim of this study was to examine whether asymmetric dimethylarginine (ADMA) concentrations are associated with ventricular function in the infants of mothers with gestational diabetes. Twenty-five term newborns of mothers with gestational diabetes and term newborns as the control group (n = 25) with normal general health status were evaluated at two time points, on the 3rd postnatal day, at the 3th months. Echocardiographic evaluations of all participants were performed and ADMA level was measured. In the first analysis, 10 patients (40%) had a septal thickness of 6 mm or more, indicating septal hypertrophy. In the first and second analysis, interventricular septum end-diastolic thickness (IVSTd) and the left ventricular posterior wall end-diastolic thickness (LVPWTd) in the patient group were higher than the control group. ADMA level measurement was not significantly different between the groups the first and second analysis. There was no difference in ADMA levels of the group with septal thickness ≥6 mm and the group with Gestational diabetes mellitus (GDM), and the increase was independent of glycemic control. Diastolic newborn cardiac function was impaired in GDM, and this effect was independent of septal thickness. We found no association between ADMA levels and cardiac systolic, diastolic functions or septum thickness in the GDM newborn.

  10. Asymmetric dimethylarginine (ADMA) elevation and arginase up-regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans.

    Science.gov (United States)

    El Assar, Mariam; Angulo, Javier; Santos-Ruiz, Marta; Ruiz de Adana, Juan Carlos; Pindado, María Luz; Sánchez-Ferrer, Alberto; Hernández, Alberto; Rodríguez-Mañas, Leocadio

    2016-06-01

    The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity. Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)-mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway. In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of endothelium-dependent vasodilatation in human morbid obesity and in a non-obese rat model of IR. We show that both increased ADMA and up-regulated arginase are determinant factors in the alteration of the l-arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l-arginine significantly alleviate endothelial dysfunction. These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention. Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO-mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of l-arginine/NO-mediated vasodilatation in human morbid obesity and in a non-obese rat model of IR. Bradykinin-induced vasodilatation was evaluated in microarteries derived from insulin-resistant morbidly obese (IR-MO) and non-insulin-resistant MO (NIR-MO) subjects. Defective endothelial vasodilatation in IR-MO was improved by l-arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR-MO. Serum ADMA positively correlated with IR score and negatively with pD2 for bradykinin. Gene

  11. Asymmetric dimethylarginine (ADMA) elevation and arginase up‐regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans

    Science.gov (United States)

    El Assar, Mariam; Angulo, Javier; Santos‐Ruiz, Marta; Ruiz de Adana, Juan Carlos; Pindado, María Luz; Sánchez‐Ferrer, Alberto; Hernández, Alberto

    2016-01-01

    Key points The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity.Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)‐mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway.In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR‐induced impairment of endothelium‐dependent vasodilatation in human morbid obesity and in a non‐obese rat model of IR.We show that both increased ADMA and up‐regulated arginase are determinant factors in the alteration of the l‐arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l‐arginine significantly alleviate endothelial dysfunction.These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention. Abstract Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO‐mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR‐induced impairment of l‐arginine/NO‐mediated vasodilatation in human morbid obesity and in a non‐obese rat model of IR. Bradykinin‐induced vasodilatation was evaluated in microarteries derived from insulin‐resistant morbidly obese (IR‐MO) and non‐insulin‐resistant MO (NIR‐MO) subjects. Defective endothelial vasodilatation in IR‐MO was improved by l‐arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR‐MO. Serum ADMA positively correlated with

  12. Toxic Dimethylarginines: Asymmetric  Dimethylarginine (ADMA and Symmetric  Dimethylarginine (SDMA

    Directory of Open Access Journals (Sweden)

    You‐Lin Tain

    2017-03-01

    Full Text Available Asymmetric and symmetric dimethylarginine (ADMA and SDMA, respectively are toxic, non‐proteinogenic amino acids formed by post‐translational modification and are uremic toxins that inhibit nitric oxide (NO production and play multifunctional roles in many human diseases. Both ADMA and SDMA have emerged as strong predictors of cardiovascular events and death in a range of illnesses. Major progress has been made in research on ADMA‐lowering therapies in animal studies; however, further studies are required to fill the translational gap between animal models and clinical trials in order to treat human diseases related to elevated ADMA/SDMA levels. Here, we review the reported impacts of ADMA and SDMA on human health and disease, focusing on the synthesis and metabolism of ADMA and SDMA; the pathophysiological roles of these dimethylarginines; clinical conditions and animal models associated with elevated ADMA and SDMA levels; and potential therapies against ADMA and SDMA. There is currently no specific pharmacological therapy for lowering the levels and counteracting the deleterious effects of ADMA and SDMA. A better understanding of the mechanisms underlying the impact of ADMA and SDMA on a wide range of human diseases is essential to the development of specific therapies against diseases related to ADMA and SDMA.

  13. Influence on serum asymmetric dimethylarginine (ADMA) concentrations of human paraoxonase 1 polymorphism (Q192R) and exposure to polycyclic aromatic hydrocarbons (PAHs) in Mexican women, a gene-environment interaction.

    Science.gov (United States)

    Ochoa-Martínez, Ángeles C; Ruíz-Vera, Tania; Almendarez-Reyna, Claudia I; Orta-García, Sandra T; Pérez-Maldonado, Iván N

    2017-11-01

    It has been demonstrated that Cardiovascular Diseases (CVD) are a consequence of the combination of genetic and environmental factors and/or the interaction between them. Therefore, the aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbon (PAHs) exposure and PON1 Q192R polymorphism (genetic susceptibility) on serum asymmetric dimethylarginine (ADMA) levels in Mexican women (n = 206). Urinary 1-hydroxypyrene concentrations (1-OHP; exposure biomarker for PAHs) were quantified using a high-performance liquid chromatography technique, PON1 Q192R polymorphism was genotyped using TaqMan probes and serum ADMA concentrations were evaluated using a commercially available ELISA kit. Urinary 1-OHP levels detected in this study ranged from 0.07 to 9.37 μmol/mol of creatinine (0.13-18.0 μg/g of creatinine). Regarding allele frequency (PON1 Q192R polymorphism), the 192Q-allele frequency was 0.43 and for the 192R-allele it was 0.57. In relation to serum ADMA levels, the levels ranged from 0.06 to 1.46 μmol/L. Moreover, multiple linear regression analysis was performed and associations between urinary 1-OHP levels (β = 0.05, p = 0.002), PON1 Q192R polymorphism (β = 0.04, p = 0.003) and serum ADMA concentrations were found. Besides, an interaction (gene-environment interaction) of both independent variables (1-OHP and PON1 polymorphism) on serum ADMA levels was found (β = 0.04, p = 0.02) in the constructed multiple linear model. Therefore, according to the significance of this research, it is necessary to execute health programs to reduce cardiovascular risk in the assessed population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Diabetic Retinopathy Is Associated With Elevated Serum Asymmetric and Symmetric Dimethylarginines

    OpenAIRE

    Abhary, Sotoodeh; Kasmeridis, Nicholas; Burdon, Kathryn P.; Kuot, Abraham; Whiting, Malcolm J.; Yew, Wai Ping; Petrovsky, Nikolai; Craig, Jamie E.

    2009-01-01

    OBJECTIVE Asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and l-arginine directly influence nitric oxide production. Our objective was to test whether serum ADMA, SDMA, or l-arginine levels correlate with diabetic retinopathy subtype or severity. RESEARCH DESIGN AND METHODS A total of 162 subjects with type 1 diabetes and 343 with type 2 diabetes, of whom 329 subjects had no diabetic retinopathy, 27 had nonproliferative diabetic retinopathy (NPDR), 101 had proliferative...

  15. Comparison of Three Sample Preparation Procedures for the Quantification of L-Arginine, Asymmetric Dimethylarginine, and Symmetric Dimethylarginine in Human Plasma Using HPLC-FLD

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie Voigt; Lykkesfeldt, Jens

    2018-01-01

    Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were co...... sample preparation of human plasma samples before HPLC-FLD in providing important information regarding elevated ADMA concentrations.......Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were...... compared regarding the quantification of L-arginine and ADMA in human plasma: (A) protein precipitation (PP) based on aqueous trichloroacetic acid (TCA), (B) PP using a mixture of ammonia and acetonitrile, and (C) solid-phase extraction (SPE). The samples were analysed by using high-performance liquid...

  16. Paraoxonase lactonase activity (PON-HTLase), asymmetric dimethylarginine (ADMA) and platelet activating factor-acetylhydrolase (PAF-AH) activity in non-obese women with PCOS.

    Science.gov (United States)

    Bayrak, Tulin; Dursun, Polat; Bayrak, Ahmet; Gültekin, Murat; Kolusarı, Ali; Cakır, Erdinç; Ozyurt, Merve; Zeyneloğlu, Hulusi B

    2012-11-01

    Paraoxonase1 (PON1), exhibits both esterase activity (PON1-AREase) and homocysteine thiolactonase activity (PON1-HTLase) which respectively prevent LDL oxidation and detoxify homocysteine thiolactone (HTL). Platelet-activating factor-acetylhydrolase (PAF-AH) is an antioxidant enzyme preventing LDL oxidation by hydrolysis of oxidized phospholipids. Both of these enzymes exhibit a proatherogenic role. ADMA is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction. The aim was to compare non-obese PCOS patients with a BMI matched control group using the following characteristics: serum PON1-HTLase, ADMA, PAF-AH, and lipid and hormonal parameters. 77 women with PCOS and 25 healthy subject were recruited for this study, The controls were non-obese BMI and age matched with the patients. There were no significant differences with respect to age, BMI, FSH, free testosterone, DHEA, androstenadion, total cholesterol, triglycerides, HDL, LDL, VLDL, fasting glucose/insulin ratio and HOMA-IR among the groups (p > 0.05). However, total testosterone and fasting glucose levels were significantly higher in the PCOS group (p PCOS group while ADMA levels (1.14 ± 0.6 vs. 3.37 ± 6.4, p = 0.004) were significantly higher in the PCOS group. However, there was no significant difference in PAF-AH activity among the groups. Decreased PON1-HTLase and increased ADMA levels might be a relevant marker for the development of future atherosclerotic heart disease (AHD) in non-obese PCOS patients. Further studies are needed to confirm our results.

  17. Circulating asymmetric dimethylarginine and the risk of preeclampsia: a meta-analysis based on 1338 participants.

    Science.gov (United States)

    Yuan, Jing; Wang, Xinguo; Xie, Yudou; Wang, Yuzhi; Dong, Lei; Li, Hong; Zhu, Tongyu

    2017-07-04

    Patients with preeclampsia have higher circulating asymmetric dimethylarginine (ADMA). However, whether circulating ADMA is elevated before the diagnosis of preeclampsia has not been determined. A meta-analysis of observational studies that reported circulating ADMA level before the onset of preeclampsia was performed. Pubmed and Embase were searched. Standardized mean differences (SMD) with 95% confidence intervals (CI) were used to estimate the differences in circulating ADMA. A random effect model or a fixed effect model was applied depending on the heterogeneity. The predictive efficacy of circulating ADMA for the incidence of preeclampsia was also explored. Eleven comparisons with 1338 pregnant women were included. The pooled results showed that the circulating ADMA was significantly higher in women who subsequently developed preeclampsia as compared with those did not (SMD: 0.71, p preeclampsia, and retrieved moderate predictive efficacy. Circulating ADMA is elevated before the development of preeclampsia. Studies are needed to evaluate the predictive efficacy of ADMA for the incidence of preeclampsia.

  18. Asymmetric dimethylarginine in children with homocystinuria or phenylketonuria.

    Science.gov (United States)

    Kanzelmeyer, Nele; Tsikas, Dimitrios; Chobanyan-Jürgens, Kristine; Beckmann, Bibiana; Vaske, Bernhard; Illsinger, Sabine; Das, Anibh M; Lücke, Thomas

    2012-05-01

    Plasma concentration of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis from L-arginine and a cardiovascular risk factor, was found to be elevated in plasma of homocysteinemic adults. Enhanced cardiovascular risk due to homocystinuria and impaired renal function has been found in patients with phenylketonuria (PKU) on protein-restricted diet. However, it is still unknown whether ADMA synthesis is also elevated in children with homocystinuria due to cystathionine beta-synthase deficiency (classical homocystinuria), and whether ADMA may play a role in phenylketonuria in childhood. In the present study, we investigated the status of the L-arginine/NO pathway in six young patients with homocystinuria, in 52 young phenylketonuria patients on natural protein-restricted diet, and in age- and gender-matched healthy children serving as controls. ADMA in plasma and urine was determined by GC-MS/MS. The NO metabolites nitrate and nitrite in plasma and urine, and urinary dimethylamine (DMA), the dimethylarginine dimethylaminohydrolase (DDAH) metabolite of ADMA, were measured by GC-MS. Unlike urine ADMA excretion, plasma ADMA concentration in patients with homocystinuria was significantly higher than in controls (660±158 vs. 475±77 nM, P=0.035). DMA excretion rate was considerably higher in children with homocystinuria as compared to controls (62.2±24.5 vs. 6.5±2.9 μmol/mmol creatinine, P=0.068), indicating enhanced DDAH activity in this disease. In contrast and unexpectedly, phenylketonuria patients had significantly lower ADMA plasma concentrations compared to controls (512±136 vs. 585±125 nM, P=0.009). Phenylketonuria patients and controls had similar L-arginine/ADMA molar ratios in plasma. Urinary nitrite excretion was significantly higher in phenylketonuria as compared to healthy controls (1.7±1.7 vs. 0.7±1.2 μmol/mmol creatinine, P=0.003). Our study shows that the L-arginine/NO pathway is differently altered in children

  19. Roles of Nitric Oxide and Asymmetric Dimethylarginine in Pregnancy and Fetal Programming

    Directory of Open Access Journals (Sweden)

    You-Lin Tain

    2012-11-01

    Full Text Available Nitric oxide (NO regulates placental blood flow and actively participates in trophoblast invasion and placental development. Asymmetric dimethylarginine (ADMA can inhibit NO synthase, which generates NO. ADMA has been associated with uterine artery flow disturbances such as preeclampsia. Substantial experimental evidence has reliably supported the hypothesis that an adverse in utero environment plays a role in postnatal physiological and pathophysiological programming. Growing evidence suggests that the placental nitrergic system is involved in epigenetic fetal programming. In this review, we discuss the roles of NO and ADMA in normal and compromised pregnancies as well as the link between placental insufficiency and epigenetic fetal programming.

  20. Asymmetric dimethylarginine, oxidative stress, and vascular nitric oxide synthase in essential hypertension

    DEFF Research Database (Denmark)

    Wang, Dan; Strandgaard, Svend; Iversen, Jens

    2009-01-01

    that the patients in this study have increased circulating levels of the cNOS inhibitor, asymmetric dimethylarginine (ADMA), or the lipid peroxidation product of linoleic acid, 13-hydroxyoctadecadienoic acid (HODE), which is a marker of reactive oxygen species. Patients had significantly (P ... and hypertensive subjects, the individual values for plasma levels of ADMA and HODE were both significantly (P inversely correlated with microvascular EDRF/NO and positively correlated with mean blood pressure. In conclusion, elevated levels of ADMA and oxidative stress in a group of hypertensive...

  1. The dimethylarginine (ADMA)/nitric oxide pathway in the brain and periphery of rats with thioacetamide-induced acute liver failure: Modulation by histidine.

    Science.gov (United States)

    Milewski, Krzysztof; Hilgier, Wojciech; Albrecht, Jan; Zielińska, Magdalena

    2015-09-01

    Hepatic encephalopathy (HE) is related to variations in the nitric oxide (NO) synthesis and oxidative/nitrosative stress (ONS), and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthases (NOSs). In the present study we compared the effects of acute liver failure (ALF) in the rat TAA model on ADMA concentration in plasma and cerebral cortex, and on the activity and expression of the ADMA degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH), in brain and liver. ALF increased blood and brain ADMA, and the increase was correlated with decreased DDAH activity in both brain and liver. An i.p. administration of histidine (His), an amino acid reported to alleviate oxidative stress associated with HE (100 mg/kg b.w.), reversed the increase of brain ADMA, which was accompanied by the recovery of brain DDAH activity (determined ex vivo), and with an increase of the total NOS activity. His also activated DDAH ex vivo in brain homogenates derived from control and TAA rats. ALF in this model was also accompanied by increases of blood cyclooxygenase activity and blood and brain TNF-α content, markers of the inflammatory response in the periphery, but these changes were not affected by His, except for the reduction of TNF-α mRNA transcript in the brain. His increased the total antioxidant capacity of the brain cortex, but not of the blood, further documenting its direct neuroprotective power. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Elevated levels of plasma homocyst(e)ine and asymmetric dimethylarginine in elderly patients with stroke.

    Science.gov (United States)

    Yoo, J H; Lee, S C

    2001-10-01

    Cerebrovascular risk factors, including hypertension, smoking, diabetes mellitus, aging, dyslipidemia, and hyperhomocyst(e)inemia are linked to endothelial dysfunction. Endothelial-derived nitric oxide (NO) has inhibitory effects on key processes in atherothrombosis. Although asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is associated with atherosclerotic disease, there has been no report on association of ADMA with ischemic stroke. Here we investigated the relation of plasma ADMA, stroke, and homocyst(e)inemia in the elderly. Plasma ADMA and homocyst(e)ine concentration was determined using high-performance liquid chromatography and fluorescence detection. Patients with ischemic stroke had significantly higher concentrations of plasma ADMA than controls (1.85+/-1.32 vs. 0.93+/-0.32 micromol/l, P=0.0001). After adjustment for risk factors, elevated ADMA levels, above 90th percentile of normal controls (> or =1.43 micromol/l) was associated with stroke (OR=6.05, 95% CI; 2.77-13.3, P=0.02). ADMA plasma levels were positively correlated to homocyst(e)ine levels (r=0.43, P=0.01). Multiple logistic regression analysis revealed that hyperhomocyst(e)inemia (plasma homocyst(e)ine concentration > or =15.0 micromol/l) was a significant predictor of elevated ADMA level. Altogether, findings indicate that elevated ADMA concentrations are at increased risk for ischemic stroke in the elderly, and may account for increased risk of stroke in patients with hyperhomocyst(e)inemia.

  3. Increased asymmetric dimethylarginine in severe falciparum malaria: association with impaired nitric oxide bioavailability and fatal outcome.

    Directory of Open Access Journals (Sweden)

    Tsin W Yeo

    2010-04-01

    Full Text Available Asymmetrical dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase (NOS, is a predictor of mortality in critical illness. Severe malaria (SM is associated with decreased NO bioavailability, but the contribution of ADMA to the pathogenesis of impaired NO bioavailability and adverse outcomes in malaria is unknown. In adults with and without falciparum malaria, we tested the hypotheses that plasma ADMA would be: 1 increased in proportion to disease severity, 2 associated with impaired vascular and pulmonary NO bioavailability and 3 independently associated with increased mortality. We assessed plasma dimethylarginines, exhaled NO concentrations and endothelial function in 49 patients with SM, 78 with moderately severe malaria (MSM and 19 healthy controls (HC. Repeat ADMA and endothelial function measurements were performed in patients with SM. Multivariable regression was used to assess the effect of ADMA on mortality and NO bioavailability. Plasma ADMA was increased in SM patients (0.85 microM; 95% CI 0.74-0.96 compared to those with MSM (0.54 microM; 95%CI 0.5-0.56 and HCs (0.64 microM; 95%CI 0.58-0.70; p<0.001. ADMA was an independent predictor of mortality in SM patients with each micromolar elevation increasing the odds of death 18 fold (95% CI 2.0-181; p = 0.01. ADMA was independently associated with decreased exhaled NO (r(s = -0.31 and endothelial function (r(s = -0.32 in all malaria patients, and with reduced exhaled NO (r(s = -0.72 in those with SM. ADMA is increased in SM and associated with decreased vascular and pulmonary NO bioavailability. Inhibition of NOS by ADMA may contribute to increased mortality in severe malaria.

  4. Cardiovascular disease markers in women with polycystic ovary syndrome with emphasis on asymmetric dimethylarginine and homocysteine

    OpenAIRE

    Mohamadin, Ahmed M.; Habib, Fawzia A.; Al-Saggaf, Abdulrahman A.

    2010-01-01

    BACKGROUND AND OBJECTIVES: Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Little is known about cardiovascular risk factors in patients with PCOS. We investigated plasma markers of cardiovascular disease in Saudi women with PCOS, with an emphasis on asymmetric dimethylarginine (ADMA) and total homocysteine (tHcy). PATIENTS AND METHODS: Fifty Saudi women with PCOS diagnosed by the Rotterdam criteria (mean age [SD...

  5. Comparison of Three Sample Preparation Procedures for the Quantification of L-Arginine, Asymmetric Dimethylarginine, and Symmetric Dimethylarginine in Human Plasma Using HPLC-FLD

    Science.gov (United States)

    Schou-Pedersen, Anne Marie Voigt

    2018-01-01

    Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were compared regarding the quantification of L-arginine and ADMA in human plasma: (A) protein precipitation (PP) based on aqueous trichloroacetic acid (TCA), (B) PP using a mixture of ammonia and acetonitrile, and (C) solid-phase extraction (SPE). The samples were analysed by using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The analytical performance of (A) was comparable with that of (C), demonstrating recoveries of >90%, coefficient of variations (CVs, %) of 0.994), precision (sample preparation of human plasma samples before HPLC-FLD in providing important information regarding elevated ADMA concentrations. PMID:29484214

  6. Flow-Mediated Dilatation and Asymmetric Dimethylarginine Do Not Predict Mortality in Peritoneal Dialysis Patients

    Directory of Open Access Journals (Sweden)

    Sami Uzun

    2017-09-01

    Full Text Available Aim: Asymmetric dimethylarginine (ADMA is associated with increased coronary artery disease risk through endothelial dysfunction in dialysis patients. We aimed to investigate the role of flow-mediated dilatation (FMD, a non-invasive indicator of endothelial function, and ADMA in mortality in peritoneal dialysis (PD patients. Methods: PD patients aged 18-80 years; with dialysis duration of at least three months were included. FMD measurement and ADMA levels were recorded. Outcome of the patients on the third year were analyzed with binary logistic analyses. Results: The mean age of the 55 patients was 53±15 years and the mean follow-up duration was 36 months. Mean FMD and ADMA levels were 10.6±6.4% and 81.8±48.0 mol/L, respectively. Eighteen patients died during follow-up. Age, presence of diabetes mellitus and ischemic heart disease, ultrafiltration amount and serum albumin level were related with mortality while gender, weekly Kt/V and ADMA levels were not. There was no significant relationship between ADMA level and FMD (p=0.873. FMD was negatively correlated with systolic and diastolic blood pressures (p=0.001, p<0.001, respectively. Hypertension was found to be the most important single factor determining FMD (p=0.037. Conclusion: Estimating endothelial function by FMD or measuring serum ADMA levels may not be useful for predicting mortality in PD patients.

  7. The correlation of serum asymmetric dimethylarginine and anti-Müllerian hormone in primary dysmenorrhea

    Directory of Open Access Journals (Sweden)

    Nermin Akdemir

    2016-08-01

    Full Text Available In this study, we aimed to investigate the association of serum asymmetric dimethylarginine (ADMA and anti-Müllerian hormone (AMH levels in primary dysmenorrhea patients. The study employed a cross-sectional design. Eighty-nine female university students with primary dysmenorrhea were included in the study. All patients underwent complete clinical and laboratory investigations, including serum ADMA, AMH levels, pelvic ultrasonography, electrocardiography, and echocardiography. Pearson correlation and linear regression analysis were used to evaluate associations between continuous data. Categorical associations were evaluated using χ2 test. Correlation analysis between serum ADMA and AMH levels in the study group showed a highly significant positive relationship (Pearson correlation = 0.978, p = 0.01. Our study has shown a significant positive correlation between serum ADMA and AMH levels in primary dysmenorrhea. Serum ADMA levels may have the potential to demonstrate ovarian reserve.

  8. Correlation between Interleukin-6 (IL-6, High Sensitivity C-Reactive Protein (hsCRP, Endothelin-1 (ET-1, Asymmetric Dimethylarginine (ADMA and Insulin Resistance (HOMA-IR in Central Obese Men

    Directory of Open Access Journals (Sweden)

    Andri Hidayat

    2011-04-01

    Full Text Available BACKGROUND: Many studies have shown that obesity was closely related to insulin resistance via several pathways such as inflammation, oxidative stress, lipolysis, and endothelial dysfunction. This study was carried out to observe the correlation between inflammation (IL-6 and hsCRP, lipolysis process (ET-1, and endothelial dysfunction (ADMA and insulin resistance (HOMA-IR in centrally obese men. METHODS: This was a cross sectional study on 62 male subjects aged 30–60 years old with waist circumference (WC >90 cm. IL-6, ET-1 and ADMA levels were measured using ELISA method, while hsCRP and insulin were measured using chemiluminescence method. All blood testings were conducted in Prodia Clinical Laboratory. RESULTS: The results showed that WC was significantly correlated with hsCRP (r=0.294, p=0.022, ET-1 (r=0.257, p=0.047 and ADMA (r=0.338, p=0.009. We also found a significant correlation between hsCRP with HOMA-IR (r=0.324, p=0.021, ADMA with HOMA-IR (r=0.280, p=0.045 and IL-6 with hsCRP (r=0.437, p=0.003. CONCLUSIONS: hsCRP and ADMA have significant correlation with HOMA-IR in centrally obese men. HOMA-IR significantly increases in subjects with ADMA above median and either IL-6 or hsCRP above median, as compared to those in the other groups. Inflammation and endothelial dysfunction are important causal pathways of insulin resistance state in centrally obese men. KEYWORDS: obesity, IL-6, hsCRP, ET-1, ADMA, HOMA-IR.

  9. Asymmetric Dimethylarginine Plasma Levels and Endothelial Function in Newly Diagnosed Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Francesco Perticone

    2012-10-01

    Full Text Available It is now well established that major risk factors for cardiovascular diseases (CVD impact upon endothelial function by decreasing nitric oxide (NO bioavailability. Asymmetric dimethylarginine (ADMA, an endogenous analog of l-arginine, is able to inhibit the activity of endothelial-NO synthase, promoting endothelial dysfunction. Type 2 diabetes (T2D is characterized by a reduced endothelium-dependent vasodilation and increased ADMA levels and ADMA is strongly associated with micro- and macrovascular diabetic complications. However, there are not a lot of data about the role of ADMA on endothelial function in newly diagnosed T2D patients without cardiovascular (CV complications. For this aim, we have enrolled forty-five newly diagnosed T2D patients, evaluated by a oral glucose tolerance test, and thirty normal subjects. Endothelium-dependent and -independent vasodilatation was investigated by intra-arterial infusion of increasing doses of acetylcholine (ACh and sodium nitroprusside. ADMA was measured by high-performance liquid chromatography and insulin resistance (IR by HOMA. Newly diagnosed T2D patients showed higher ADMA and l-arginine mean values in comparison with normal subjects and a significantly reduced ACh-stimulated forearm blood flow (FBF. In T2D patients FBF was significantly and inversely correlated with ADMA (r = −0.524, p < 0.0001 and in a multivariate regression analysis, ADMA resulted the stronger predictor of FBF, explaining the 27.5% of variability (p < 0.0001. In conclusion, ADMA was strongly related to endothelial dysfunction also in patients with newly diagnosed T2D, without clinically manifest vascular complications. This field is of great interest for understanding the mechanisms underlying the pathogenesis of diabetic disease and its CV complications.

  10. Homocyst(e)ine-lowering therapy does not affect plasma asymmetrical dimethylarginine concentrations in patients with peripheral artery disease.

    Science.gov (United States)

    Ziegler, Sophie; Mittermayer, Friedrich; Plank, Christina; Minar, Erich; Wolzt, Michael; Schernthaner, Gerit-Holger

    2005-04-01

    Elevated plasma asymmetrical dimethylarginine (ADMA) is suggested to contribute to hyperhomocyst(e)ine-related vascular dysfunction in patients with peripheral artery disease (PAD). The present trial investigated whether homocyst(e)ine (Hcy)-lowering therapy with vitamin-B (vit-B) and folic acid affects plasma concentrations of ADMA in patients with PAD and hyperhomocyst(e)inemia. Forty-nine subjects (15 women, 34 men) with PAD and fasting plasma total Hcy concentrations greater than 15 micromol/liter were randomized to receive either oral vit-B and folic acid therapy (n = 27) or placebo (n = 22) for 6 wk. Fasting venous blood samples were monitored for plasma total Hcy, vit-B12 and folate, ADMA, symmetric dimethylarginine, L-arginine, and high-sensitivity C-reactive protein. After 6 wk, plasma Hcy concentrations were decreased, and concentrations of vit-B12 and folate were elevated in patients with vitamin supplementation (all P < 0.05 vs. baseline) and unchanged in the placebo group. Dimethylarginine plasma concentrations were not affected by treatment. High-sensitivity C-reactive protein correlated with ADMA plasma concentrations (r = 0.29; P < 0.01). The lack of vit-B and folic acid therapy on plasma concentrations of ADMA renders a role of extracellular methylarginines unlikely to be involved in the pathophysiology of hyperhomocyst(e)inemia and its complications.

  11. Impact of Catheter Arteriography on the Serum Level of Asymmetric Dimethylarginine, an Endogenous Inhibitor of Nitric Oxide Synthase

    International Nuclear Information System (INIS)

    Bozlar, Ugur; Ugurel, Mehmet Sahin; Ozcan, Omer; Cakir, Erdinc; Ustunsoz, Bahri; Ucoz, Taner; Bilgi, Cumhur; Somuncu, Ibrahim

    2008-01-01

    The purpose of this study was to investigate the instantaneous impact of catheter arteriography on blood asymmetric dimethylarginine (ADMA) levels in accordance with patient- and procedure-related variables. Sixty-eight patients (16 women, 52 men; mean age, 45.6 ± 20.1 years; range, 20-79 years) referred for cerebral or peripheral catheter arteriography were recruited for the study. Pre- and postarteriography arterial blood ADMA levels were determined by high-performance liquid chromatographic technique. Type of nonionic iodinated contrast media used, duration of procedure, patient gender, and patient age were noted and evaluated as possible factors that could influence serum ADMA levels in arteriography procedures. Prearteriography ADMA levels decreased significantly after arteriography in general (pre, 1.16 ± 0.96 μmol/L; post, 1.08 ± 0.80 μmol/L; p = 0.002). Males tended to have lower postarteriography serum ADMA levels (p = 0.005). Serum ADMA levels tended to get lower after peripheral arteriography procedures (p = 0.005) and when iohexol, 350 mg I/ml, was used as the contrast agent (p = 0.017). In conclusion, ADMA level does not seem to be subject to acute elevation after catheter arteriography; on the contrary, its level may decrease in general. Moreover, a reduction in serum ADMA level may be expected, especially in male patients, in patients who undergo a peripheral arteriography procedure, or when iohexol, 350 mg I/ml, is used as the contrast agent

  12. High plasma concentrations of asymmetric dimethylarginine inhibit ischemic cardioprotection in hypercholesterolemic rats

    International Nuclear Information System (INIS)

    Landim, M.B.P.; Dourado, P.M.M.; Casella-Filho, A.; Chagas, A.C.P.; Luz, P.L. da

    2013-01-01

    A low concentration of nitric oxide associated with a high concentration of asymmetric dimethylarginine (ADMA) can explain the lack of ischemic cardioprotection observed in the presence of hypercholesterolemia. The objective of the present study was to evaluate the effect of hypercholesterolemia on ischemic pre- and postconditioning and its correlation with plasma concentrations of ADMA. Male Wistar rats (6-8 weeks old) fed a 2% cholesterol diet (n = 21) for 8 weeks were compared to controls (n = 25) and were subjected to experimental myocardial infarction and reperfusion, with ischemic pre- and postconditioning. Total cholesterol and ADMA were measured in plasma before the experimental infarct and the infarct area was quantified. Weight, total cholesterol and plasma ADMA (means ± SE; 1.20 ± 0.06, 1.27 ± 0.08 and 1.20 ± 0.08 vs 0.97 ± 0.04, 0.93 ± 0.05 and 0.97 ± 0.04 µM) were higher in animals on the hypercholesterolemic diet than in controls, respectively. Cardioprotection did not reduce infarct size in the hypercholesterolemic animals (pre: 13.55% and post: 8% compared to 7.95% observed in the group subjected only to ischemia and reperfusion), whereas infarct size was reduced in the animals on a normocholesterolemic diet (pre: 8.25% and post: 6.10% compared to 12.31%). Hypercholesterolemia elevated ADMA and eliminated the cardioprotective effects of ischemic pre- and postconditioning in rats

  13. High plasma concentrations of asymmetric dimethylarginine inhibit ischemic cardioprotection in hypercholesterolemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Landim, M.B.P.; Dourado, P.M.M.; Casella-Filho, A.; Chagas, A.C.P.; Luz, P.L. da [Unidade de Aterosclerose, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2013-05-10

    A low concentration of nitric oxide associated with a high concentration of asymmetric dimethylarginine (ADMA) can explain the lack of ischemic cardioprotection observed in the presence of hypercholesterolemia. The objective of the present study was to evaluate the effect of hypercholesterolemia on ischemic pre- and postconditioning and its correlation with plasma concentrations of ADMA. Male Wistar rats (6-8 weeks old) fed a 2% cholesterol diet (n = 21) for 8 weeks were compared to controls (n = 25) and were subjected to experimental myocardial infarction and reperfusion, with ischemic pre- and postconditioning. Total cholesterol and ADMA were measured in plasma before the experimental infarct and the infarct area was quantified. Weight, total cholesterol and plasma ADMA (means ± SE; 1.20 ± 0.06, 1.27 ± 0.08 and 1.20 ± 0.08 vs 0.97 ± 0.04, 0.93 ± 0.05 and 0.97 ± 0.04 µM) were higher in animals on the hypercholesterolemic diet than in controls, respectively. Cardioprotection did not reduce infarct size in the hypercholesterolemic animals (pre: 13.55% and post: 8% compared to 7.95% observed in the group subjected only to ischemia and reperfusion), whereas infarct size was reduced in the animals on a normocholesterolemic diet (pre: 8.25% and post: 6.10% compared to 12.31%). Hypercholesterolemia elevated ADMA and eliminated the cardioprotective effects of ischemic pre- and postconditioning in rats.

  14. Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis

    Science.gov (United States)

    Segarra, Gloria; Cortina, Belén; Mauricio, María Dolores; Novella, Susana; Lluch, Paloma; Navarrete-Navarro, Javier; Noguera, Inmaculada; Medina, Pascual

    2016-01-01

    AIM To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats. METHODS Rat renal arteries from Sham (n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10-6-10-3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10-9-3 × 10-6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein expression and activity of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme that catabolizes ADMA. RESULTS In renal arteries precontracted with norepinephrine, ADMA caused endothelium-dependent contractions. The pD2 values to ADMA were similar in the Sham and PPVL groups (4.20 ± 0.08 and 4.11 ± 0.09, P > 0.05, respectively), but were lower than those of the BDL group (4.79 ± 0.16, P < 0.05). Acetylcholine-induced endothelium-dependent relaxation that did not differ, in terms of pD2 and maximal relaxation, among the 3 groups studied. Treatment with ADMA (3 × 10-4 mol/L) inhibited acetylcholine-induced relaxation in the 3 groups, but the inhibition was higher (P < 0.05) in the BDL group compared with that for the Sham and PPVL groups. The mRNA and protein expression of DDAH-1 were similar in kidneys from the three groups. Conversely, DDAH-2 expression was increased (P < 0.05) in PPVL and further enhanced (P < 0.05) in the BDL group. However, renal DDAH activity was significantly decreased in the BDL group. CONCLUSION Cirrhosis increased the inhibitory effect of ADMA on basal- and induced-release of NO in renal arteries, and decreased DDAH activity in the kidney. PMID:28082806

  15. Long-Term Intermittent Exposure to High Altitude Elevates Asymmetric Dimethylarginine in First Exposed Young Adults.

    Science.gov (United States)

    Lüneburg, Nicole; Siques, Patricia; Brito, Julio; De La Cruz, Juan José; León-Velarde, Fabiola; Hannemann, Juliane; Ibanez, Cristian; Böger, Rainer H

    2017-09-01

    Lüneburg, Nicole, Patricia Siques, Julio Brito, Juan José De La Cruz, Fabiola León-Velarde, Juliane Hannemann, Cristian Ibanez, and Rainer Böger. Long-term intermittent exposure to high altitude elevates asymmetric dimethylarginine in first exposed young adults. High Alt Med Biol. 18:226-233, 2017.-Hypoxia-induced dysregulation of pulmonary and cerebral circulation may be related to an impaired nitric oxide (NO) pathway. We investigated the effect of chronic intermittent hypobaric hypoxia (CIH) on metabolites of the NO pathway. We measured asymmetric and symmetric dimethylarginine (ADMA and SDMA) and monomethyl-L-arginine (L-NMMA) and assessed their associations with acclimatization in male draftees (n = 72) undergoing CIH shifts at altitude (3550 m) during 3 months. Sixteen Andean natives living at altitude (3675 m) (chronic hypobaric hypoxia [CH]) were included for comparison. In CIH, ADMA and L-NMMA plasma concentrations increased from 1.14 ± 0.04 to 1.95 ± 0.09 μmol/L (mean ± SE) and from 0.22 ± 0.07 to 0.39 ± 0.03 μmol/L, respectively, (p < 0.001 for both) after 3 months, whereas SDMA did not change. The concentrations of ADMA and L-NMMA were higher in CH (3.48 ± 0.07, 0.53 ± 0.08 μmol/L; p < 0.001) as compared with CIH. In both CIH and CH, ADMA correlated with hematocrit (r 2  = 0.07, p < 0.05; r 2  = 0.26; p < 0.01). In CIH, an association of ADMA levels with poor acclimatization status was observed. We conclude that the endogenous NO synthase inhibitors, ADMA and L-NMMA, are elevated in hypoxia. This may contribute to impaired NO production at altitude and may also be predictive of altitude-associated health impairment.

  16. Effect of vildagliptin add-on treatment to metformin on plasma asymmetric dimethylarginine in type 2 diabetes mellitus patients

    Directory of Open Access Journals (Sweden)

    Cakirca M

    2014-02-01

    Full Text Available Mustafa Cakirca,1 Cumali Karatoprak,1 Mehmet Zorlu,1 Muharrem Kiskac,1 Mustafa Kanat,2 Mehmet Ali Cikrikcioglu,1 Pinar Soysal,3 Mehmet Hursitoglu,4 Ahmet Adil Camli,1 Reha Erkoc,1 Muhammad Abdul-Ghani5 1Internal Medicine Clinic, Faculty of Medicine, Bezmialem Vakif University, 2Department of Internal Medicine, Medical Faculty, Istanbul Medipol University, 3Department of Geriatric Medicine, Medical Faculty, Dokuz Eylül University, 4Department of Internal Medicine, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey; 5Division of Medicine – Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA Aims: A close association has been demonstrated between increased cardiovascular risk and high asymmetric dimethylarginine (ADMA levels in type 2 diabetes mellitus (DM patients. We planned to measure serum ADMA levels in type 2 DM patients using vildagliptin, a dipeptidyl peptidase-4 (DPP-4 inhibitor. Materials and methods: A total of 68 type 2 DM patients who were on metformin were enrolled in the study. Based on the glycemic levels of patients, vildagliptin was added on to treatment in 33 patients. Patients were followed for 6 months. Serum ADMA, C-reactive protein, and fibrinogen levels were compared in groups of patients using metformin or metformin + vildagliptin, after 6 months. Results: Serum ADMA levels were found to be significantly lower in the group using vildagliptin compared to the group using metformin + vildagliptin (P<0.001. However, serum C-reactive protein and fibrinogen levels were statistically similar in the two study groups (P=0.34 and P=0.23, respectively. Conclusion: Metformin + vildagliptin treatment was observed to lower serum ADMA levels in type 2 DM patients. Our findings notwithstanding, large-scale prospective randomized controlled studies are warranted to conclude that vildagliptin provides cardiovascular protection along with diabetes regulation. Keywords: asymmetric

  17. The farnesoid X receptor agonist obeticholic acid upregulates biliary excretion of asymmetric dimethylarginine via MATE-1 during hepatic ischemia/reperfusion injury

    Science.gov (United States)

    Berardo, Clarissa; Siciliano, Veronica; Rizzo, Vittoria; Adorini, Luciano; Richelmi, Plinio

    2018-01-01

    Background We previously showed that increased asymmetric dimethylarginine (ADMA) biliary excretion occurs during hepatic ischemia/reperfusion (I/R), prompting us to study the effects of the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) on bile, serum and tissue levels of ADMA after I/R. Material and methods Male Wistar rats were orally administered 10mg/kg/day of OCA or vehicle for 5 days and were subjected to 60 min partial hepatic ischemia or sham-operated. After a 60 min reperfusion, serum, tissue and bile ADMA levels, liver mRNA and protein expression of ADMA transporters (CAT-1, CAT-2A, CAT-2B, OCT-1, MATE-1), and enzymes involved in ADMA synthesis (protein-arginine-N-methyltransferase-1, PRMT-1) and metabolism (dimethylarginine-dimethylaminohydrolase-1, DDAH-1) were measured. Results OCA administration induced a further increase in biliary ADMA levels both in sham and I/R groups, with no significant changes in hepatic ADMA content. A reduction in CAT-1, CAT-2A or CAT-2B transcripts was found in OCA-treated sham-operated rats compared with vehicle. Conversely, OCA administration did not change CAT-1, CAT-2A or CAT-2B expression, already reduced by I/R. However, a marked decrease in OCT-1 and increase in MATE-1 expression was observed. A similar trend occurred with protein expression. Conclusion The reduced mRNA expression of hepatic CAT transporters suggests that the increase in serum ADMA levels is probably due to decreased liver uptake of ADMA from the systemic circulation. Conversely, the mechanism involved in further increasing biliary ADMA levels in sham and I/R groups treated with OCA appears to be MATE-1-dependent. PMID:29346429

  18. The Effect of Nebivolol versus Metoprolol Succinate Extended Release on Asymmetric Dimethylarginine in Hypertension

    Science.gov (United States)

    Kandavar, Ramprasad; Higashi, Yusuke; Chen, Wei; Blackstock, Christopher; Vaughn, Charlotte; Sukhanov, Sergiy; Sander, Gary E.; Roffidal, Louise E.; Delafontaine, Patrice; Giles, Thomas D.

    2011-01-01

    Objectives This study sought to determine if metoprolol succinate ER (MET), and nebivolol (NEB), a β1-AR with increased bioavailability of nitric oxide (NO), would have differing effects on plasma asymmetric dimethylarginine concentration in hypertensives. Background It was hypothesized that NEB, a β1-AR antagonist and β3-AR agonist with NO- releasing properties and MET, only a β1-AR antagonist, would have different effects on plasma ADMA concentration. Methods Forty-one hypertensive subjects randomly received either 50 mg of MET (n = 19) or 5 mg of NEB (n = 22) for 4 weeks followed by 100 mg MET and 10 mg NEB for 4 weeks. ADMA and IGF-1 were measured by ELISA kit; endothelial progenitor cells were estimated using fluorescein-labeled monoclonal antibody to KDR and CD133 receptors; arterial augmentation index was measured by radial tonometry. Results Baseline systolic/diastolic blood pressure was 155.1 ± 18.7/85.3 ± 12.5 mm Hg for MET subjects and 157.6 ± 20.7/87.1 ± 14.0 mm Hg for NEB subjects. Baseline ADMA was 0.32 ± 0.123 μmol/L in the MET group and 0.4035 ± 0.1378 in the NEB group. ADMA increased 44.78% and 72% in the MET group at weeks 4 and 8 (p < 0.05 for both), respectively, without increase in the NEB group. At week 8 augmentation index was increased in the MET group (p<0.05). IGF-1 and EPC were unchanged by treatment. Conclusions Plasma ADMA and augmentation index are increased in a dose-dependent fashion by MET but not with NEB. PMID:21251896

  19. Activities of asymmetric dimethylarginine-related enzymes in white adipose tissue are associated with circulating lipid biomarkers

    Directory of Open Access Journals (Sweden)

    Iwasaki Hiroaki

    2012-04-01

    Full Text Available Abstract Background Asymmetric NG,NG-dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase, is regulated by the enzymatic participants of synthetic and metabolic processes, i.e., type I protein N-arginine methyltransferase (PRMT and dimethylarginine dimethylaminohydrolase (DDAH. Previous reports have demonstrated that circulating ADMA levels can vary in patients with type 1 and type 2 diabetes mellitus (T2DM. White adipose tissue expresses the full enzymatic machinery necessary for ADMA production and metabolism; however, modulation of the activities of adipose ADMA-related enzymes in T2DM remains to be determined. Methods A rodent model of T2DM using 11- and 20-week old Goto-Kakizaki (GK rats was used. The expression and catalytic activity of PRMT1 and DDAH1 and 2 in the white adipose tissues (periepididymal, visceral and subcutaneous fats and femur skeletal muscle tissue were determined by immunoblotting, in vitro methyltransferase and in vitro citrulline assays. Results Non-obese diabetic GK rats showed low expression and activity of adipose PRMT1 compared to age-matched Wistar controls. Adipose tissues from the periepididymal, visceral and subcutaneous fats of GK rats had high DDAH1 expression and total DDAH activity, whereas the DDAH2 expression was lowered below the control value. This dynamic of ADMA-related enzymes in white adipose tissues was distinct from that of skeletal muscle tissue. GK rats had lower levels of serum non-esterified fatty acids (NEFA and triglycerides (TG than the control rats. In all subjects the adipose PRMT1 and DDAH activities were statistically correlated with the levels of serum NEFA and TG. Conclusion Activities of PRMT1 and DDAH in white adipose tissues were altered in diabetic GK rats in an organ-specific manner, which was reflected in the serum levels of NEFA and TG. Changes in adipose ADMA-related enzymes might play a part in the function of white adipose tissue.

  20. Asymmetric and Symmetric Dimethylarginines are Markers of Delayed Cerebral Ischemia and Neurological Outcome in Patients with Subarachnoid Hemorrhage.

    Science.gov (United States)

    Appel, Daniel; Seeberger, Miriam; Schwedhelm, Edzard; Czorlich, Patrick; Goetz, Alwin E; Böger, Rainer H; Hannemann, Juliane

    2018-03-20

    Delayed cerebral ischemia (DCI) is the major cause of lethality and neuronal damage in patients who survived the primary subarachnoid hemorrhage (SAH). Asymmetric and symmetric dimethylarginines (ADMA and SDMA) inhibit nitric oxide production from L-arginine via distinct mechanisms. Elevated ADMA levels are associated with vasospasm after SAH. We aimed to study the time course of ADMA and SDMA in plasma and ventricular cerebrospinal fluid (CSF) and their associations with DCI and outcome. We measured ADMA and SDMA in 34 SAH patients with an external ventricular drain at admission and on days 3, 6, 8, 12, and 15 and followed them up for clinical status and neurological outcome until 30 days post-discharge. DCI was defined as the appearance of new infarctions on cerebral computed tomography or magnetic resonance imaging. ADMA and SDMA plasma concentrations did not differ significantly at baseline between patients who suffered DCI (N = 14; 41%) and not; however, plasma ADMA reached a peak on days 8 and 15 after hemorrhage in patients with DCI (0.81-0.91 µmol/l). Baseline plasma L-arginine/ADMA ratio was significantly lower in patients with DCI (57.1 [34.3; 70.8] vs. 68.7 [55.7; 96.2]; p < 0.05). ADMA and SDMA concentrations in CSF were significantly higher in patients with DCI than without. In multivariable-adjusted linear regression models, CSF ADMA was negatively associated with the incidence of DCI (OR 0.03 [0.02-0.70]; p = 0.04), whereas CSF SDMA on the day of hemorrhage predicted poor neurological outcome until 30 days after discharge (OR 22.4 [1.21-416.02]; p = 0.04). Our study shows that ADMA and the L-arginine/ADMA ratio are associated with the incidence of DCI after SAH. By contrast, SDMA was associated with initial neuronal damage and poor neurological outcome after SAH. These data support the hypothesis that ADMA and L-arginine affect the pathophysiology of cerebral ischemia after SAH, while SDMA is a biomarker of neurological outcome after SAH.

  1. Low plasma arginine:asymmetric dimethyl arginine ratios predict mortality after intracranial aneurysm rupture

    DEFF Research Database (Denmark)

    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels

    2013-01-01

    Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, predicts mortality in cardiovascular disease and has been linked to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). In this prospective study, we assessed whether circulating ADMA, arginine...

  2. Effect of vildagliptin add-on treatment to metformin on plasma asymmetric dimethylarginine in type 2 diabetes mellitus patients.

    Science.gov (United States)

    Cakirca, Mustafa; Karatoprak, Cumali; Zorlu, Mehmet; Kiskac, Muharrem; Kanat, Mustafa; Cikrikcioglu, Mehmet Ali; Soysal, Pinar; Hursitoglu, Mehmet; Camli, Ahmet Adil; Erkoc, Reha; Abdul-Ghani, Muhammad

    2014-01-01

    A close association has been demonstrated between increased cardiovascular risk and high asymmetric dimethylarginine (ADMA) levels in type 2 diabetes mellitus (DM) patients. We planned to measure serum ADMA levels in type 2 DM patients using vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor. A total of 68 type 2 DM patients who were on metformin were enrolled in the study. Based on the glycemic levels of patients, vildagliptin was added on to treatment in 33 patients. Patients were followed for 6 months. Serum ADMA, C-reactive protein, and fibrinogen levels were compared in groups of patients using metformin or metformin + vildagliptin, after 6 months. Serum ADMA levels were found to be significantly lower in the group using vildagliptin compared to the group using metformin + vildagliptin (Pvildagliptin treatment was observed to lower serum ADMA levels in type 2 DM patients. Our findings notwithstanding, large-scale prospective randomized controlled studies are warranted to conclude that vildagliptin provides cardiovascular protection along with diabetes regulation.

  3. Blood pressure from childhood to adolescence in obese youths in relation to insulin resistance and asymmetric dimethylarginine.

    Science.gov (United States)

    de Giorgis, T; Marcovecchio, M L; Giannini, C; Chiavaroli, V; Chiarelli, F; Mohn, A

    2016-02-01

    Hypertension is the most important cardiovascular complication of obesity, even during childhood. Several studies have demonstrated that there is a natural progression of hypertension from childhood to adulthood. However, there are no data reporting a potential worsening in blood pressure (BP) already moving from the pre-pubertal to the pubertal period in obese youths. The aim of this study was to evaluate early change in BP and its relation to insulin resistance (IR) and asymmetric dimethylarginine (ADMA). Thirty obese children underwent a first assessment when they were pre-pubertal (visit_1) and were re-evaluated after a mean of 4.5 years (visit_2). At both visits, anthropometric parameters were assessed, blood samples were collected for measurement of insulin, glucose and ADMA and a 24-h ambulatory BP monitoring was performed. At visit_2, the study participants presented increased HOMA-IR and ADMA compared to visit_1 (HOMA-IR: 3.6 ± 2.8 vs 2.8 ± 1.4, p = 0.01; ADMA: 1.57 ± 0.78 vs 0.77 ± 0.52 μmol/l, p childhood to adolescence (p obese children, and modifications in insulin resistance and ADMA seem to be implicated in this early progression in BP.

  4. Correlation of Neopterin and TNF-alpha with Asymmetric Dimethylarginine in Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Dedeh Yuniarty

    2011-12-01

    Full Text Available BACKGROUND: A large number of obesity in the community increases the incidence of Metabolic Syndrome (MetS that can increase the risks of heart disease, diabetes, and stroke. One of the possible causes of stroke is atherosclerosis. Atherosclerosis is initiated by the incidence of inflammation and endothelial dysfuction. Atherosclerosis is involved in an ongoing inflammatory response. At the beginning of atherosclerosis, when the endothel become inflamed, it expresses adhesion molecules  that attract monocytes. The monocytes then migrate into the intima due to endothelial dysfunction. Activation of macrophage occurs in the process of inflammation as the earliest type of lesion of atherosclerosis. In this study, monocyte/macrophage activation is marked by Neopterin. In other process of atherosclerosis, vascular nitric oxide (NO activity has a role as a potent endogenous vasodilator. In regulating the vascular tone, NO has a role to suppress vascular smooth muscle proliferation, inhibit platelet adhesion and aggregation, and interferes with the leukocyte-endothelial cell interaction. In MetS, hypercholesterolemia decreases NO activity. Asymmetric Dimethylarginine (ADMA has been characterized as an endogenous, competitive inhibitor of NO synthase. In this study, the incidence of endothelial dysfunction is marked by ADMA. The aim of this study was to discover the role of Neopterin in MetS patients by evaluating the correlation between Neopterin and ADMA in MetS through tumor necrosis factor (TNF-α or direct line. METHODS: The study was cross sectional on 64 males with MetS aged 30-65 years. The measurements of TNF-α concentrations was done, respectively. RESULTS: Neopterin concentration correlated with Log TNF-α concentration (r=0.311, p=0.012. There is no significant correlation between Neopterin and ADMA (r=0.012, p=0.930; ADMA and Log TNF-α (r=0.029, p=0.821. CONCLUSIONS: There is no significant correlation between Neopterin and ADMA through

  5. Asymmetric dimethylarginine may mediate increased heat pain threshold in experimental chronic kidney disease.

    Science.gov (United States)

    Kielstein, Jan T; Suntharalingam, Mayuren; Perthel, Ronny; Rong, Song; Martens-Lobenhoffer, Jens; Jäger, Kristin; Bode-Böger, Stefanie M; Nave, Heike

    2012-03-01

    Thermal sensitivity in uraemia is decreased. Non-selective synthetic nitric oxide synthase (NOS) inhibitors significantly attenuate thermal hyperalgesia in preclinical models. The aim of our study was to evaluate the effect of experimental uraemia, which is associated with an increase of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), on thermal sensitivity in rats. Furthermore, we intended to study the effect of chronic ADMA infusion alone on thermal sensitivity. Male Sprague-Dawley rats (n = 54), 10 weeks old, weight 370-430 g, were randomly assigned to three groups receiving either (i) isotonic saline or (ii) ADMA via osmotic mini pumps or (iii) underwent 5/6 nephrectomy (Nx). After 14 days, 50% of all animals from all groups underwent thermal sensitivity testing and terminal blood draw. After 28 days, the remaining animals underwent the same procedures. Thermal sensitivity examination was performed by the hot-plate test, measuring time from heat exposition to first paw licking or jumping of the animal. While the median [interquartile range] latency time between heat exposition to first paw licking or jumping of the animal in the NaCl infusion group remained unchanged between Day 14 (8.4 [6.75-11.50] s) and Day 28 (7.35 [6.10-7.90] s) both, ADMA infusion and 5/6 nephrectomy tended to increase the thermal pain threshold at Day 14 (9.25 [6.55-12.18] s) and (9.50 [5.8 ± 11.0] s), respectively, compared to NaCl on Day 14 (8.4 [6.75-11.50] s). This difference became statistical significant at Day 28 where the median latency time in the ADMA group (13.10 [11.85-15.95] s) and in the 5/6 Nx group (13.50 [10.85-17.55] s) were significantly higher than in the NaCl group (7.35 [6.10-7.90] s). Induction of progressive renal failure in rats by 5/6 nephrectomy, which is accompanied by a marked increase of the serum levels of the endogenous NOS inhibitor ADMA, leads to a significantly increased heat pain threshold at 28 days. The sole infusion of ADMA into

  6. Effect of acute variations of insulin and glucose on plasma concentrations of asymmetric dimethylarginine in young people with type 1 diabetes

    OpenAIRE

    Marcovecchio , M. Loredana; Widmer , Barry; Dunger , David B.; Dalton , R. Neil

    2008-01-01

    Abstract Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is considered a major risk factor for cardiovascular disease and progression of renal disease. In the present study we aim to investigate the effect of acute variations in plasma glucose and insulin on plasma ADMA levels in young people with type 1 diabetes (T1D). Fifteen young patients (10 males) with T1D, median age 18.3 (13.2-24.4) years, HbA1c 9% (6.4-13.6), underwent an overnight...

  7. Symmetric and asymmetric dimethylarginine as risk markers of cardiovascular disease, all-cause mortality and deterioration in kidney function in persons with type 2 diabetes and microalbuminuria

    DEFF Research Database (Denmark)

    Zobel, Emilie H; von Scholten, Bernt Johan; Reinhard, Henrik

    2017-01-01

    IDI). C statistic (area under the curve) quantifies the model's improved ability to discriminate events from non-events. rIDI quantifies the increase in separation of events and non-events on a relative scale. RESULTS: Higher SDMA was associated with increased risk of all three endpoints (unadjusted: p......BACKGROUND: To evaluate symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) as risk markers of cardiovascular disease, all-cause mortality and deterioration in renal function in a well characterised type 2 diabetic population with microalbuminuria and without symptoms...... of coronary artery disease. METHODS: 200 participants followed for 6.1 years. SDMA and ADMA were measured at baseline. Endpoints included (1) composite cardiovascular endpoint (n = 40); (2) all-cause mortality (n = 26); and (3) decline in eGFR of >30% (n = 42). Cox models were unadjusted and adjusted...

  8. Cardiovascular disease markers in women with polycystic ovary syndrome with emphasis on asymmetric dimethylarginine and homocysteine.

    Science.gov (United States)

    Mohamadin, Ahmed M; Habib, Fawzia A; Al-Saggaf, Abdulrahman A

    2010-01-01

    Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Little is known about cardiovascular risk factors in patients with PCOS. We investigated plasma markers of cardiovascular disease in Saudi women with PCOS, with an emphasis on asymmetric dimethylarginine (ADMA) and total homocysteine (tHcy). Fifty Saudi women with PCOS diagnosed by the Rotterdam criteria (mean age [SD] 30.2 [3.0] years) and 40 controls without PCOS (mean age 29.3 [2.5] years) had measyrements taken of clinical, metabolic, and hormonal parameters, including plasma ADMA, tHcy, lipoprotein (a) ([Lp(a)], and serum high sensitivity C-reactive protein (hs-CRP), nitric oxid, and fibrinogen. Insulin resistance was calculated by the homeostasis model assessment (HOMA-IR). Women with PCOS had significantly higher fasting insulin, HOMA-IR, and luteinizing hormone (LH) levels than healthy controls (P P P CONCLUSION: Our study revealed that Saudi women with PCOS had a significantly different levels of plasma markers of cardiovascular disease compared with normal controls. Therefore, clinicians who manage women with PCOS should follow up on these markers to reduce the risk of cardiovascular disease.

  9. Nitric Oxide Metabolites and Asymmetric Dimethylarginine Concentrations in Breast Milk

    Directory of Open Access Journals (Sweden)

    Hakan Öztürk

    2017-04-01

    Full Text Available Objective: Nitric oxide plays a preventive role in the development of necrotizing enterocolitis. Oral nitrite and nitrate intake has gained importance with the discovery of the conversion of nitrite to nitric oxide in acidic medium out of the synthesis of nitric oxide from L-arginine. Objective of this study was to examine the breast milk concentrations of nitric oxide and asymmetric dimethylarginine which is a competitive inhibitor of nitric oxide and to compare these concentrations in terms of gestational age and maturity of breast milk. Study Design: Forty-one women were included in the study. Milk samples were collected from 3 groups of mothers as term, late preterm and preterm on the postpartum days 3, 7 and 28. Results: When breast milk concentrations of nitric oxide were compared according to the postnatal day of the milk independently from gestational age; nitric oxide concentration was higher in the colostrum than in the transition milk and mature milk (p=0,035; p=0,001; respectively. For the comparison of asymmetric dimethylarginine concentrations among these groups and days; no statistically significant difference was observed in terms of gestational age and maturity of the milk (p=0.865, p=0.115; respectively. Conclusion: The highest nitric oxide concentration was found in the colostrum, suggesting that colostrum is a valuable food for newborns. Plasma concentrations of asymmetric dimethylarginine were negatively correlated with nitric oxide and did not show a correlation with breast milk, suggesting that asymmetric dimethylargininedoesn’t make nitric oxide inhibition in breast milk.

  10. Detection and quantification of α-keto-δ-(N(G),N(G)-dimethylguanidino)valeric acid: a metabolite of asymmetric dimethylarginine.

    Science.gov (United States)

    Martens-Lobenhoffer, Jens; Rodionov, Roman N; Drust, Andreas; Bode-Böger, Stefanie M

    2011-12-15

    Nitric oxide is an ubiquitary cell signaling substance. Its enzymatic production rate by nitric oxide synthase is regulated by the concentrations of the substrate L-arginine and the competitive inhibitor asymmetric dimethylarginine (ADMA). A newly recognized elimination pathway for ADMA is the transamination to α-keto-δ-(N(G),N(G)-dimethylguanidino)valeric acid (DMGV) by the enzyme alanine-glyoxylate aminotransferase 2 (AGXT2). This pathway has been proven to be relevant for nitric oxide regulation, but up to now no method exists for the determination of DMGV in biological fluids. We have developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of DMGV. D(6)-DMGV was used as internal standard. Samples were purified online by column switching, and separation was achieved on a porous graphitic carbon column. The calibration was linear over ranges of 10 to 200 nmol/L for plasma and 0.1 to 20 μmol/L for urine. The intra- and interday accuracies and precisions in plasma and urine were better than 10%. In plasma samples, DMGV was present in concentrations between 19.1 and 77.5 nmol/L. In urine samples, concentrations between 0.0114 and 1.03 μmol/mmol creatinine were found. This method can be used as a tool for the scientific investigation of the ADMA conversion to DMGV via the enzyme AGXT2. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Development of RI protein chip system for measurement of ADMA as risk factor of liver disease, cardiovascular disease and diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gil Hong; An, Sin Ae; Choi, Hyun Mi; Cheong, Kyung Ah; Chang, Yeon Soo [Korea University, Seoul (Korea, Republic of)

    2010-05-15

    ADMA (asymmetric dimethylarginine) is an endogenous competitive NOS (nitric oxide synthase) inhibitor. Elevation of ADMA level in body fluid is related to various diseases including diabetes mellitus, atherosclerosis, hypercholesterolemia, chronic heart failure, and hypertension. Our goal was to elucidate the role for ADMA and protein arginine methylation in the pathogenesis of diabetes and develop RI protein chip system for easy determination of ADMA levels in blood or tissues. As a result, ADMA regulated by protein arginine methylation, DDAH1, and NOS was demonstrated to play some role in the pathogenesis of diabetes mellitus, and arginine methylation of some proteins indicated their possible involvement in the change in ADMA levels. The concept of the RI protein chip system was devised such that firstly, ADMA was acylated by radio-labelled succinic acid, and followed by binding of the complex to anti-acyl ADMA-specific antibody coated on chip. Acylation condition of ADMA with radio-labelled succinic acid was established

  12. Development of RI protein chip system for measurement of ADMA as risk factor of liver disease, cardiovascular disease and diabetes

    International Nuclear Information System (INIS)

    Park, Gil Hong; An, Sin Ae; Choi, Hyun Mi; Cheong, Kyung Ah; Chang, Yeon Soo

    2010-05-01

    ADMA (asymmetric dimethylarginine) is an endogenous competitive NOS (nitric oxide synthase) inhibitor. Elevation of ADMA level in body fluid is related to various diseases including diabetes mellitus, atherosclerosis, hypercholesterolemia, chronic heart failure, and hypertension. Our goal was to elucidate the role for ADMA and protein arginine methylation in the pathogenesis of diabetes and develop RI protein chip system for easy determination of ADMA levels in blood or tissues. As a result, ADMA regulated by protein arginine methylation, DDAH1, and NOS was demonstrated to play some role in the pathogenesis of diabetes mellitus, and arginine methylation of some proteins indicated their possible involvement in the change in ADMA levels. The concept of the RI protein chip system was devised such that firstly, ADMA was acylated by radio-labelled succinic acid, and followed by binding of the complex to anti-acyl ADMA-specific antibody coated on chip. Acylation condition of ADMA with radio-labelled succinic acid was established

  13. Dimethylarginine Dimethylaminohydrolase Overexpression enhances Insulin Sensitivity

    Science.gov (United States)

    Sydow, Karsten; Mondon, Carl E.; Schrader, Joerg; Konishi, Hakuoh; Cooke, John P.

    2011-01-01

    Objective Previous studies suggest that nitric oxide (NO) may modulate insulin-induced uptake of glucose in insulin-sensitive tissues. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase (NOS). We hypothesized that a reduction in endogenous ADMA would increase NO synthesis and thereby enhance insulin sensitivity. Methods and Results To test this hypothesis we employed a transgenic mouse in which we overexpressed human dimethylarginine dimethylaminohydrolase (DDAH-I). The DDAH-I mice had lower plasma ADMA at all ages (22–70 weeks) by comparison to wild-type (WT) littermates. With a glucose challenge, WT mice showed a prompt increase in ADMA, whereas DDAH-I mice had a blunted response. Furthermore, DDAH-I mice had a blunted increase in plasma insulin and glucose levels after glucose challenge, with a 50% reduction in the insulin resistence index, consistent with enhanced sensitivity to insulin. In liver, we observed an increased Akt phosphorylation in the DDAH-I mice after i.p. glucose challenge. Incubation of skeletal muscle from WT mice ex vivo with ADMA (2μM) markedly suppressed insulin-induced glycogen synthesis in fast-twitch but not slow-twitch muscle. Conclusions These findings suggest that the endogenous NOS inhibitor ADMA reduces insulin sensitivity, consistent with previous observations that NO plays a role in insulin sensitivity. PMID:18239148

  14. Effects of Pioglitazone on Asymmetric Dimethylarginine and Components of the Metabolic Syndrome in Nondiabetic Patients (EPICAMP Study: A Double-Blind, Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Pedram Shokouh

    2013-01-01

    Full Text Available The present trial aimed to investigate the effects of pioglitazone on the serum level of asymmetric dimethylarginine (ADMA, a marker of endothelial function, and some indices of inflammation and glucose and lipid metabolism in nondiabetic metabolic syndrome patients. 104 eligible participants (57% female; age between 20 and 70 were enrolled in a double-blind placebo-controlled trial and were randomized to receive either pioglitazone (uptitrated to 30 mg/day or matching placebo for 24 weeks. Participants were clinically examined and a blood sample was obtained at baseline and at the end of the trial. Pioglitazone significantly improved C-reactive protein level irrespective of changes in insulin sensitivity. Compared with the placebo group, alanine and aspartate transaminases were decreased and high-density lipoprotein cholesterol was increased after treatment with pioglitazone. A considerably greater weight gain was also recorded in the intervention group. We failed to observe any significant changes in serum ADMA in either group and between groups with and without adjustment for age, sex, and components of the metabolic syndrome. In a nutshell, pioglitazone seems to have positive effects on lipid profile, liver transaminases, and systemic inflammation. However, its previously demonstrated endothelial function-improving properties do not seem to be mediated by ADMA.

  15. The Analysis of Asymetric Dimethylarginine and Homocysteine in Patients with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Tetty Hendrawati

    2009-08-01

    Full Text Available BACKGROUND: Asymmetric dimethylarginine (ADMA is a competitive inhibitor of nitric oxide synthase (NOS. ADMA reduces NO synthesis when its concentration elevates. ADMA is a novel risk factor for cardiovascular disease. Plasma ADMA accumulates in patients with endstage renal disease, due to reduced renal clearance. Hyperhomocysteinemia is often found in patients with chronic kidney disease (CKD. Homocysteine may cause ADMA to accumulate; however, the mechanism by which ADMA level elevates in hyperhomocysteinemia is still unclear. Objective of this study was to analyze the concentrations of homocysteine and ADMA and to assess the correlation between homocysteine and ADMA concentrations with the severity of chronic kidney disease. METHODS: This was a cross-sectional study on 75 patients with CKD, comprising men and women aged 40-70 years. Assessments were done on the concentrations of creatinine, homocysteine, ADMA, fasting blood glucose, cholesterol HDL and triglyceride. RESULTS: In later stage of CKD there was significantly higher tHcy concentration as compared with the earlier stage of CKD (p=0.0000. In CKD stage 2 to 4 there was a tendency for ADMA concentration to increase to a significant average (p=0.210, but ADMA concentration was lower at stage 5. There was increased ADMA along with increased tHcy concentration of around 20μ mol/L, and this then decreased. The inverse correlation between tHcy and ADMA concentrations started to appear in CKD stage 4, but this correlation was statistically insignificant (r2=0.19; p=0.499. CONCLUSIONS: This study showed there was a correlation between homocysteine and ADMA concentrations in patients with CKD stage 2 to 5, although statistically not significant. KEYWORDS: asymmetric dimethylarginine, homocysteine, chronic kidney disease.

  16. Simvastatin and asymmetric dimethylarginine-homocysteine metabolic pathways in patients with newly detected severe hypercholesterolemia.

    Science.gov (United States)

    Vladimirova-Kitova, Ludmila G; Deneva, Tania I

    2010-01-01

    The idea that statin therapy decreases asymmetric dimethylarginine through lowering low-density lipoprotein cholesterol levels seems logic. However, controversy exists in the literature concerning this issue. This study compares the effect of moderate (40 mg) to high (80 mg) simvastatin doses on asymmetric dimethylarginine levels in patients with newly detected severe hypercholesterolemia (after targeted LDL levels of or = 7.5 mmol/L and low-density lipoprotein cholesterol > or = 4.9 mmol/L). Asymmetric dimethylarginine levels were determined by enzyme-linked immunosorbent assay, total homocystein by the high performance liquid chromatography method. A statistically significant decrease exists in total cholesterol, triglycerides, low-density lipoprotein cholesterol and apolipoprotein-B levels as well as apolipoprotein-B/apolipoprotein-A1 index following one month of 40 mg simvastatin therapy (P homocystein levels were also decreased but the difference was not significant (p = 0.571; p = 0.569). A dose-dependent effect was established comparing the influence of moderate (40 mg) to high (80 mg) simvastatin doses on the tested atherogenic biomarkers (lipid profile, apolipoprotein-A1, apolipoprotein-B). Asymmetric dimethylarginine and total homocystein levels showed a statistically significant decrease with 80 mg simvastatin (p homocysteine in contrast to high dose (80 mg) after targeted LDL of < or = 2.6 mmol/L levels are reached in patients with newly detected severe hypercholesterolemia.

  17. Effects of ADMA upon gene expression: an insight into the pathophysiological significance of raised plasma ADMA.

    Directory of Open Access Journals (Sweden)

    Caroline L Smith

    2005-10-01

    Full Text Available Asymmetric dimethylarginine (ADMA is a naturally occurring inhibitor of nitric oxide synthesis that accumulates in a wide range of diseases associated with endothelial dysfunction and enhanced atherosclerosis. Clinical studies implicate plasma ADMA as a major novel cardiovascular risk factor, but the mechanisms by which low concentrations of ADMA produce adverse effects on the cardiovascular system are unclear.We treated human coronary artery endothelial cells with pathophysiological concentrations of ADMA and assessed the effects on gene expression using U133A GeneChips (Affymetrix. Changes in several genes, including bone morphogenetic protein 2 inducible kinase (BMP2K, SMA-related protein 5 (Smad5, bone morphogenetic protein receptor 1A, and protein arginine methyltransferase 3 (PRMT3; also known as HRMT1L3, were confirmed by Northern blotting, quantitative PCR, and in some instances Western blotting analysis to detect changes in protein expression. To determine whether these changes also occurred in vivo, tissue from gene deletion mice with raised ADMA levels was examined. More than 50 genes were significantly altered in endothelial cells after treatment with pathophysiological concentrations of ADMA (2 microM. We detected specific patterns of changes that identify pathways involved in processes relevant to cardiovascular risk and pulmonary hypertension. Changes in BMP2K and PRMT3 were confirmed at mRNA and protein levels, in vitro and in vivo.Pathophysiological concentrations of ADMA are sufficient to elicit significant changes in coronary artery endothelial cell gene expression. Changes in bone morphogenetic protein signalling, and in enzymes involved in arginine methylation, may be particularly relevant to understanding the pathophysiological significance of raised ADMA levels. This study identifies the mechanisms by which increased ADMA may contribute to common cardiovascular diseases and thereby indicates possible targets for therapies.

  18. Pilot study of the association of the DDAH2 -449G polymorphism with asymmetric dimethylarginine and hemodynamic shock in pediatric sepsis.

    Directory of Open Access Journals (Sweden)

    Scott L Weiss

    Full Text Available Genetic variability in the regulation of the nitric oxide (NO pathway may influence hemodynamic changes in pediatric sepsis. We sought to determine whether functional polymorphisms in DDAH2, which metabolizes the NO synthase inhibitor asymmetric dimethylarginine (ADMA, are associated with susceptibility to sepsis, plasma ADMA, distinct hemodynamic states, and vasopressor requirements in pediatric septic shock.In a prospective study, blood and buccal swabs were obtained from 82 patients ≤ 18 years (29 with severe sepsis/septic shock plus 27 febrile and 26 healthy controls. Plasma ADMA was measured using tandem mass spectrometry. DDAH2 gene was partially sequenced to determine the -871 6g/7 g insertion/deletion and -449G/C single nucleotide polymorphisms. Shock type ("warm" versus "cold" was characterized by clinical assessment. The -871 7g allele was more common in septic (17% then febrile (4% and healthy (8% patients, though this was not significant after controlling for sex and race (p = 0.96. ADMA did not differ between -871 6g/7 g genotypes. While genotype frequencies also did not vary between groups for the -449G/C SNP (p = 0.75, septic patients with at least one -449G allele had lower ADMA (median, IQR 0.36, 0.30-0.41 µmol/L than patients with the -449CC genotype (0.55, 0.49-0.64 µmol/L, p = 0.008 and exhibited a higher incidence of "cold" shock (45% versus 0%, p = 0.01. However, after controlling for race, the association with shock type became non-significant (p = 0.32. Neither polymorphism was associated with inotrope score or vasoactive infusion duration.The -449G polymorphism in the DDAH2 gene was associated with both low plasma ADMA and an increased likelihood of presenting with "cold" shock in pediatric sepsis, but not with vasopressor requirement. Race, however, was an important confounder. These results support and justify the need for larger studies in racially homogenous populations to further examine whether genotypic

  19. ADMA induces monocyte adhesion via activation of chemokine receptors in cultured THP-1 cells.

    Science.gov (United States)

    Chen, Meifang; Li, Yuanjian; Yang, Tianlun; Wang, Yongjin; Bai, Yongping; Xie, Xiumei

    2008-08-01

    Asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, is also an important inflammatory factor contributing to the development of atherosclerosis (AS). The present study was to test the effect of ADMA on angiotensin (Ang) II-induced monocytic adhesion. Human monocytoid cells (THP-1) or isolated peripheral blood monocyte cells (PBMCs) were incubated with Ang II (10(-6)M) or exogenous ADMA (30 microM) for 4 or 24h in the absence or presence of losartan or antioxidant PDTC. In cultured THP-1 cells, Ang II (10(-6)M) for 24h elevated the level of ADMA in the medium, upregulated the protein expression of protein arginine methyltransferase (PRMT) and decreased the activity of dimethylarginine dimethylaminohydrolase (DDAH). Both of Ang II and ADMA increased monocytic adhesion to human umbilical vein endothelial cells (HUVECs), elevated the levels of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha and upregulated CCR(2) and CXCR(2) mRNA expression, concomitantly with increase in reactive oxygen species (ROS) generation and activation of nuclear factor (NF)-kappaB. Pretreatment with losartan (10 microM) or PDTC (10 microM) abolished the effects mediated by Ang II or ADMA. In isolated PBMCs from healthy individuals, ADMA upregulated the expression of CXCR(2) mRNA, which was attenuated by losartan (10 microM), however, ADMA had no effect on surface protein expression of CCR(2). The present results suggest that ADMA may be involved in monocytic adhesion induced by Ang II via activation of chemokine receptors by ROS/NF-kappaB pathway.

  20. Asymmetric dimethylarginine as a prognostic marker for cardiovascular complications in hypertensive patients

    Directory of Open Access Journals (Sweden)

    Osama Tayeh

    2011-06-01

    Conclusions: ADMA is elevated in hypertensive patients. Elevated ADMA concentrations are associated with impaired endothelium functions, which are demonstrated by NO reduction in the sera of hypertensive patients. ADMA is correlated positively with the traditional cardiovascular risk factors. Also there was a strong significant negative correlation between NO and ADMA levels in the whole hypertensive groups.

  1. Plasma Levels of Dimethylarginines in Preterm Very Low Birth Weight Neonates: Its Relation with Perinatal Factors and Short-Term Outcome

    Directory of Open Access Journals (Sweden)

    Rob M. Moonen

    2014-12-01

    Full Text Available Endogenously produced inhibitors of nitric oxide (NO synthase, in particular asymmetric dimethylarginine (ADMA, are currently considered of importance in various disease states characterized by reduced NO availability. We investigated the association between plasma levels of ADMA, symmetric dimethylarginine (SDMA, l-arginine, and citrulline and perinatal factors and outcome in 130 preterm (gestational age ≤30 weeks very low birth weight (VLBW, <1500 g infants. Plasma samples were collected 6–12 h after birth. We did not find significant correlations between ADMA, SDMA, l-arginine, and citrulline levels and gestational age or birth weight. However, the arginine:ADMA ratio (AAR, a better indicator of NO availability than either arginine or ADMA separately was positively correlated with gestational age. ADMA and arginine levels were not significantly different between males and females but males showed a negative correlation between ADMA levels and gestational age. Perinatal factors such as preeclampsia, chrorioamnionitis, prolonged rupture of membranes, or form of delivery did not significantly alter dimethylarginine levels or AAR. In contrast, the AAR was significantly reduced in the infants with respiratory distress, mechanical ventilation, and systemic hypotension Therefore, our data suggest that altered NO availability may play a role in the respiratory and cardiovascular adaptation in preterm VLBW infants.

  2. Asymmetric dimethylarginine in somatically healthy schizophrenia patients treated with atypical antipsychotics

    DEFF Research Database (Denmark)

    Jørgensen, Anders; Knorr, Ulla Benedichte Søsted; Soendergaard, Mia Greisen

    2015-01-01

    ratio are positively correlated to measures of oxidative stress. METHODS: We included 40 schizophrenia patients treated with AAP, but without somatic disease or drug abuse, and 40 healthy controls. Plasma concentrations of ADMA and L-arginine were determined by high-performance liquid chromatography...... in a range of cardiovascular disorders. Increased ADMA levels may also lead to increased oxidative stress. We hypothesized that ADMA and the L-arginine:ADMA ratio are increased in somatically healthy schizophrenia patients treated with atypical antipsychotics (AAP), and that the ADMA and the L-arginine: ADMA....... Data were related to markers of systemic oxidative stress on DNA, RNA and lipids, as well as measures of medication load, duration of disease and current symptomatology. RESULTS: Plasma ADMA and the L-arginine:ADMA ratio did not differ between schizophrenia patients and controls. Furthermore, ADMA...

  3. N-Acetylcysteine Prevents Hypertension via Regulation of the ADMA-DDAH Pathway in Young Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Nai-Chia Fan

    2013-01-01

    Full Text Available Asymmetric dimethylarginine (ADMA reduces nitric oxide (NO, thus causing hypertension. ADMA is metabolized by dimethylarginine dimethylaminohydrolase (DDAH, which can be inhibited by oxidative stress. N-Acetylcysteine (NAC, an antioxidant, can facilitate glutathione (GSH synthesis. We aimed to determine whether NAC can prevent hypertension by regulating the ADMA-DDAH pathway in spontaneously hypertensive rats (SHR. Rats aged 4 weeks were assigned into 3 groups (n=8/group: control Wistar Kyoto rats (WKY, SHR, and SHR receiving 2% NAC in drinking water. All rats were sacrificed at 12 weeks of age. SHR had higher blood pressure than WKY, whereas NAC-treated animals did not. SHR had elevated plasma ADMA levels, which was prevented by NAC therapy. SHR had lower renal DDAH activity than WKY, whereas NAC-treated animals did not. Renal superoxide production was higher in SHR than in WKY, whereas NAC therapy prevented it. NAC therapy was also associated with higher GSH-to-oxidized GSH ratio in SHR kidneys. Moreover, NAC reduced oxidative stress damage in SHR. The observed antihypertensive effects of NAC in young SHR might be due to restoration of DDAH activity to reduce ADMA, leading to attenuation of oxidative stress. Our findings highlight the impact of NAC on the development of hypertension by regulating ADMA-DDAH pathway.

  4. HPLC determination of plasma dimethylarginines: method validation and preliminary clinical application.

    Science.gov (United States)

    Ivanova, Mariela; Artusi, Carlo; Boffa, Giovanni Maria; Zaninotto, Martina; Plebani, Mario

    2010-11-11

    Asymmetric dimethylarginine (ADMA) has been suggested as a possible marker of endothelial dysfunction, and interest in its use in clinical practice is increasing. However, the potential role of symmetric dimethylarginine (SDMA) as an endogenous marker of renal function, has been less widely investigated. The aims of the present study were therefore to determine reference values for dimethylarginines in plasma after method validation, and to ascertain ADMA plasma concentrations in patients with disorders characterized by endothelial dysfunction; a further end-point was to investigate the relationship between SDMA plasma concentrations and estimated GFR (eGFR) as well as plasmatic creatinine in patients with chronic kidney disease (CKD). HPLC with fluorescence detection was used for the determination of plasma dimethylarginines. To verify the clinical usefulness of ADMA and SDMA, values from 4 groups of patients at a high risk of cardiovascular complications as well renal dysfunction (chronic heart failure n=126; type II diabetes n=43; pulmonary arterial hypertension n=17; chronic kidney disease n=42) were evaluated, and compared with the reference values, obtained from 225 blood donors. The intra- and inter-assay CVs (peadiatric populations, for which the use of eGFR is not recommended. 2010 Elsevier B.V. All rights reserved.

  5. Reduction of plasma asymmetric dimethylarginine in obese patients with chronic kidney disease after three years of a low-protein diet supplemented with keto-amino acids: a randomized controlled trial.

    Science.gov (United States)

    Teplan, Vladimir; Schück, Otto; Racek, Jaroslav; Mareckova, Olga; Stollova, Milena; Hanzal, Vladimir; Malý, Jan

    2008-01-01

    Levels of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are elevated in chronic kidney disease (CKD) and may contribute to vascular complications. In this study we tested the hypothesis that elevated ADMA can be reduced in obese CKD patients by long-term administration of a low-protein diet supplemented with keto-amino acids. In a long-term prospective double-blind placebo-controlled randomized trial, we evaluated for a period of 36 months a total of 111 CKD patients (54 men, 57 women) aged 22-76 years with obesity (BMI >or= 30 kg/m(2)) and an inulin clearance rate (C(in)) of 22-40 ml/min/1.73 m(2). All patients were on a low-protein diet containing 0.6 g protein/kg BW per day and 120-125 kJ/kg BW per day. The diet was randomly supplemented with keto-amino acids at a dosage of 100 mg/kg BW per day (66 patients, Group I); 65 patients received placebo (Group II). During the study period, the glomerular filtration rate decreased slightly in Group I (C(in) from 32.4 +/- 12.6 to 29.8 +/- 8.6 ml/min/1.73 m(2)) and more markedly in Group II (from 33.2 +/- 12.6 to 23.2 +/- 98.4 ml/min/1.73 m(2), P diet and keto-amino acids in CKD patients with obesity led to decreases of ADMA, visceral body fat and proteinuria. Concomitant decreases of glycated hemoglobin, LDL-cholesterol and pentosidine may also contribute to the delay in progression of renal failure.

  6. The ADMA/DDAH/NO pathway in human vein endothelial cells exposed to arsenite.

    Science.gov (United States)

    Osorio-Yáñez, Citlalli; Chin-Chan, Miguel; Sánchez-Peña, Luz C; Atzatzi-Aguilar, Octavio G; Olivares-Reyes, Jesus A; Segovia, José; Del Razo, Luz M

    2017-08-01

    Inorganic arsenic (iAs) exposure is related to cardiovascular disease, which is characterized by endothelial dysfunction and nitric oxide (NO) depletion. The mechanisms underlying NO depletion as related to iAs exposure are not fully understood. The endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine (ADMA), might be a molecular target of iAs. ADMA concentrations are regulated by proteins involved in its synthesis (arginine methyl transferase 1 [PRMT-1]) and degradation (dimethylarginine dimethylaminohydrolase [DDAH]). Both, ADMA and NO are susceptible to oxidative stress. We aimed to determine the ADMA/DDAH/NO pathway in human vein endothelial cells (HUVEC-CS) exposed to arsenite. We exposed HUVEC-CS cells to 1, 2.5 and 5μM of arsenite for 24h. We proved that arsenite at 5μM was able to decrease NO levels with an associated increase in ADMA and depletion of l-arginine in HUVEC-CS cells. We also found a decrease in DDAH-1 protein expression with 5μM of arsenite compared to the control group. However, we did not observe significant differences in PRMT-1 protein expression at any of the concentrations of arsenite employed. Finally, arsenite (2.5 and 5μM) increased NADPH oxidase 4 protein levels compared with the control group. We conclude that ADMA, l-arginine and DDAH are involved in NO depletion produced by arsenite, and that the mechanism is related to oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Asymmetric dimethylarginine and lipid peroxidation products in early autosomal dominant polycystic kidney disease

    DEFF Research Database (Denmark)

    Wang, Dan; Strandgaard, S.; Borresen, M.L.

    2008-01-01

    academic medical center. Factor: Patients with ADPKD versus controls. Outcomes & Measurement: Plasma (P) levels, urinary (U) excretion, and urinary clearance (C) of ADMA and HODE. Because of multiple comparisons, P for significance is considered less than 0.0167. Results: Patients with ADPKD had......-sectional nature of study, and limited number of markers of oxidative stress. Conclusions: P-ADMA and P-HODE levels are increased in patients with early ADPKD. Increased P-ADMA level is related to decreased CADMA and is accompanied by oxidative stress. Am J Kidney Dis 51:184-191. (c) 2008 by the National Kidney...

  8. Serum Asymmetric Dimethylarginine, and Adiponectin as Predictors of Atherosclerotic Risk among Obese Egyptian Children

    Directory of Open Access Journals (Sweden)

    Enas R. Abdel Hameed

    2014-06-01

    CONCLUSIONS: Our results revealed that ADMA, Adiponectin and lipid profile can be considered as predictive biomarkers in prediction and prevention of atherosclerotic risk in the future among overweight and obese Egyptian children.

  9. Urinary NGAL and hematic ADMA levels: an early sign of cardio-renal syndrome in young adults born preterm?

    Science.gov (United States)

    Bassareo, Pier Paolo; Fanos, Vassilios; Mussap, Michele; Flore, Giovanna; Noto, Antonio; Puddu, Melania; Saba, Luca; Mercuro, Giuseppe

    2013-10-01

    Prematurity at birth is a known risk factor for the development of an early chronic renal disease. Urinary neutrophil gelatinase-associated lipocalin (NGAL) is a well established biomarker of kidney injury, while high blood levels of asymmetric dimethylarginine (ADMA) are associated with the future development of adverse cardiovascular events and cardiac death. (1) to verify the presence of statistically significant differences between urinary NGAL and hematic ADMA levels in young adults born preterm at extremely low birth weight (<1000 g; ex-ELBW) and those of a control group of healthy adults born at term (C) (2) to seek correlations between NGAL and ADMA levels, which would indicate the presence of an early cardio-renal involvement in ex-ELBW. Twelve ex-ELBW subjects (six males and six female, mean age: 23.9 ± 3.2 years) were compared with 12 C (six males and six female). Urinary NGAL and hematic ADMA levels were assessed. Urinary NGAL levels were higher in ex- ELBW subjects compared to C (p < 0.05), as well as hematic ADMA concentrations (p < 0.05). A statistically significant correlation was found between urinary NGAL and ADMA (r = -0.60, p < 0.04). Our preliminary findings support the hypothesis that in ex-ELBW subjects the development of an early chronic kidney disease contributes towards inducing an increase in the atherosclerotic process and in the risk of future adverse cardiovascular events.

  10. The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine

    Directory of Open Access Journals (Sweden)

    Saskia J. H. Brinkmann

    2015-05-01

    Full Text Available Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS and thereby nitric oxide (NO, respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9, standard rabbit chow plus atorvastatin (group S, n = 8, standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8 or standard rabbit chow (group C, n = 9 as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques.

  11. Asymmetric dimethyl-L-arginine (ADMA): a possible link between homocyst(e)ine and endothelial dysfunction.

    Science.gov (United States)

    Stühlinger, Markus C; Stanger, Olaf

    2005-02-01

    Hyperhomocyst(e)inemia is associated with an increased risk for atherosclerotic disease and venous thromboembolism. The impact of elevated plasma homocysteine levels seems to be clinically relevant, since the total cardiovascular risk of hyperhomocyst(e)inemia is comparable to the risk associated with hyperlipidemia or smoking. There is substantial evidence for impairment of endothelial function in human and animal models of atherosclerosis, occurring even before development of overt plaques. Interestingly endothelial dysfunction appears to be a sensitive indicator of the process of atherosclerotic lesion development and predicts future vascular events. NO is the most potent endogenous vasodilator known. It is released by the endothelium, and reduced NO bioavailability is responsible for impaired endothelium-dependent vasorelaxation in hyperhomocyst(e)inemia and other metabolic disorders associated with vascular disease. Substances leading to impaired endothelial function as a consequence of reduced NO generation are endogenous NO synthase inhibitors such as ADMA. Indeed there is accumulating evidence from animal and human studies that ADMA, endothelial function and homocyst(e)ine might be closely interrelated. Specifically elevations of ADMA associated with impaired endothelium-dependent relaxation were found in chronic hyperhomocyst(e)inemia, as well as after acute elevation of plasma homocyst(e)ine following oral methionine intake. The postulated mechanisms for ADMA accumulation are increased methylation of arginine residues within proteins, as well as reduced metabolism of ADMA by the enzyme DDAH, but they still need to be confirmed to be operative in vivo. Hyperhomocyst(e)inemia, as well as subsequent endothelial dysfunction can be successfully treated by application of folate and B vitamins. Since ADMA seems to play a central role in homocyst(e)ine-induced endothelial dysfunction, another way of preventing vascular disease in patients with elevated homocyst

  12. Asymmetric dimethylarginine regulates the lipopolysaccharide-induced nitric oxide production in macrophages by suppressing the activation of NF-kappaB and iNOS expression

    Czech Academy of Sciences Publication Activity Database

    Pekarová, Michaela; Kubala, Lukáš; Martíšková, Hana; Binó, Lucia; Twarogová, M.; Klinke, A.; Rudolph, T.K.; Kuchtová, Z.; Kolářová, Hana; Ambrožová, Gabriela; Kuchta, R.; Kadlec, J.; Lojek, Antonín

    2013-01-01

    Roč. 713, 1-3 (2013), s. 68-77 ISSN 0014-2999 R&D Projects: GA ČR(CZ) GP13-40882P Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : Macrophage * Methylarginine * Asymmetric dimethylarginine Subject RIV: BO - Biophysics Impact factor: 2.684, year: 2013

  13. Effect of resistance training on plasma nitric oxide and asymmetric dimethylarginine concentrations in type I diabetic rats

    Directory of Open Access Journals (Sweden)

    Parivash Shekarchizadeh Esfahani

    2013-01-01

    Conclusion: Elevated ADMA level in diabetic animals can normalize during resistance exercise. Reduced ADMA level and increased NO level following resistance training might improve cardiovascular risk in diabetic subjects.

  14. Impaired endothelial function after aneurysmal subarachnoid haemorrhage correlates with arginine:asymmetric dimethylarginine ratio

    DEFF Research Database (Denmark)

    Bergström, A; Staalsø, J M; Romner, B

    2014-01-01

    BACKGROUND: Endothelial dysfunction might be involved in the development of cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH). METHODS: This prospective observational study of 48 SAH subjects and 23 control subjects examined associations between reactive hyperaemia index (RHI....... Five consecutive measurements were obtained at days 0-2, 3-5, 6-8, 9-11, and 12-15. RESULTS: RHI was 1.67 (0.46) at days 0-2 after SAH but increased at days 3-15 to the same levels as in controls (P... and arginine:ADMA ratio (r=0.43, P

  15. How does spa treatment affect cardiovascular function and vascular endothelium in patients with generalized osteoarthritis? A pilot study through plasma asymmetric di-methyl arginine (ADMA) and L-arginine/ADMA ratio

    Science.gov (United States)

    Karaarslan, Fatih; Ozkuk, Kagan; Seringec Karabulut, Serap; Bekpinar, Seldag; Karagulle, Mufit Zeki; Erdogan, Nergis

    2018-05-01

    The study aims to investigate the effect of spa treatment on vascular endothelium and clinical symptoms of generalized osteoarthritis. Forty generalized osteoarthritis (GOA) patients referred to a government spa hospital, and 40 GOA patients followed on university hospital locomotor system disease ambulatory clinics were included as study and control groups, respectively. Study group received spa treatment including thermal water baths, physical therapy modalities, and exercises. Control group was followed with home exercises for 15 days. Plasma ADMA, L-arginine, L-arginine/ADMA ratio, routine blood analyses, 6-min walking test, including fingertip O2 saturation, systolic/diastolic blood pressure, and pulse rate, were measured at the beginning and at the end of treatment. Groups were evaluated with VAS pain, patient, and physician global assessment; HAQ; and WOMAC at the beginning, at the end, and after 1 month of treatment. In study group, L-arginine and L-arginine/ADMA ratio showed statistically significant increase after treatment. Plasma ADMA levels did not change. There is no significant difference in intergroup comparison. Study group displayed statistically significant improvements in all clinical parameters. The study showed that spa treatment does not cause any harm to the vascular endothelium through ADMA. Significant increase in plasma L-arginine and L-arginine/ADMA ratio suggests that balneotherapy may play a preventive role on cardiovascular diseases. Balneotherapy provides meaningful improvements on clinical parameters of GOA.

  16. How does spa treatment affect cardiovascular function and vascular endothelium in patients with generalized osteoarthritis? A pilot study through plasma asymmetric di-methyl arginine (ADMA) and L-arginine/ADMA ratio

    Science.gov (United States)

    Karaarslan, Fatih; Ozkuk, Kagan; Seringec Karabulut, Serap; Bekpinar, Seldag; Karagulle, Mufit Zeki; Erdogan, Nergis

    2017-12-01

    The study aims to investigate the effect of spa treatment on vascular endothelium and clinical symptoms of generalized osteoarthritis. Forty generalized osteoarthritis (GOA) patients referred to a government spa hospital, and 40 GOA patients followed on university hospital locomotor system disease ambulatory clinics were included as study and control groups, respectively. Study group received spa treatment including thermal water baths, physical therapy modalities, and exercises. Control group was followed with home exercises for 15 days. Plasma ADMA, L-arginine, L-arginine/ADMA ratio, routine blood analyses, 6-min walking test, including fingertip O2 saturation, systolic/diastolic blood pressure, and pulse rate, were measured at the beginning and at the end of treatment. Groups were evaluated with VAS pain, patient, and physician global assessment; HAQ; and WOMAC at the beginning, at the end, and after 1 month of treatment. In study group, L-arginine and L-arginine/ADMA ratio showed statistically significant increase after treatment. Plasma ADMA levels did not change. There is no significant difference in intergroup comparison. Study group displayed statistically significant improvements in all clinical parameters. The study showed that spa treatment does not cause any harm to the vascular endothelium through ADMA. Significant increase in plasma L-arginine and L-arginine/ADMA ratio suggests that balneotherapy may play a preventive role on cardiovascular diseases. Balneotherapy provides meaningful improvements on clinical parameters of GOA.

  17. Dimethylarginines, blood glucose, and C-reactive protein in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Aurélie Gudjoncik

    2016-04-01

    Conclusion: Our study showed that in patients with acute MI, SDMA, and only weakly ADMA, are associated with admission blood glucose, beyond traditional dimethylarginine determinants and may therefore have biological activity beyond renal function.

  18. Diagnostical significance of dimethylarginine in the development of hepatorenal syndrome in patients with alcoholic liver cirrhosis

    Directory of Open Access Journals (Sweden)

    Ničković Vanja

    2012-01-01

    Full Text Available Background/Aim. Chronic consumption of alcohol during a longer period of time leads to the development of cirrhosis with the reduction in metabolic liver function and disorders in arginine metabolism. Hepatorenal syndrome (HRS is the most severe complication of alcoholic liver cirrhosis. The aim of the study was to analyze disorders in arginine metabolism by monitoring concentrations of asymmetric dimethylarginine (ADMA and symmetric dimethylarginine (SDMA in patients with liver cirrhosis and HRS. Methods. The study included three groups of subjects: a group of patients with cirrhosis and HRS (24 patients, a group of patients with cirrhosis without HRS (18 patients and a control group composed of 42 healthy voluntary blood donors. Concentrations of ADMA, SDMA and L-arginine in plasma were measured in all groups using the high pressure liquid chromatography (HPLC method. Results. The concentration of SDMA was significantly higher in the patients with HRS compared to the patients without HRS and it was also higher than the values obtained from the healthy participants (1.76 ± 0.3 μmol/L; 1.01 ± 0.32 and 0.520 ± 0.18 μmol/L, respectively; p < 0.01. The concentrations of ADMA were higher in the cirrhotic patients with HRS than in those without this serious complication of cirrhosis. The concentration of ADMA in all the examined cirrhotic patients was higher than those obtained from healthy volunteers (1.35 ± 0.27 μmol/L, 1.05 ± 0.35 μmol/L and 0.76 ± 0.21 μmol/L, respectively. In the patients with terminal alcoholic liver cirrhosis, the concentrations of ADMA and SDMA correlated with the progress of cirrhosis as well as with the development of cirrhosis complications. In the patients with HRS there was a positive correlation between creatinine and SDMA in plasma (r2 = 0.0756, p < 0.001 which was not found between creatinine and ADMA. Conclusion. The obtained results demonstrate that the increase in SDMA concentration is proportionate to

  19. Inhibitors of the Hydrolytic Enzyme Dimethylarginine Dimethylaminohydrolase (DDAH: Discovery, Synthesis and Development

    Directory of Open Access Journals (Sweden)

    Rhys B. Murphy

    2016-05-01

    Full Text Available Dimethylarginine dimethylaminohydrolase (DDAH is a highly conserved hydrolytic enzyme found in numerous species, including bacteria, rodents, and humans. In humans, the DDAH-1 isoform is known to metabolize endogenous asymmetric dimethylarginine (ADMA and monomethyl arginine (l-NMMA, with ADMA proposed to be a putative marker of cardiovascular disease. Current literature reports identify the DDAH family of enzymes as a potential therapeutic target in the regulation of nitric oxide (NO production, mediated via its biochemical interaction with the nitric oxide synthase (NOS family of enzymes. Increased DDAH expression and NO production have been linked to multiple pathological conditions, specifically, cancer, neurodegenerative disorders, and septic shock. As such, the discovery, chemical synthesis, and development of DDAH inhibitors as potential drug candidates represent a growing field of interest. This review article summarizes the current knowledge on DDAH inhibition and the derived pharmacokinetic parameters of the main DDAH inhibitors reported in the literature. Furthermore, current methods of development and chemical synthetic pathways are discussed.

  20. Impact of ADMA, endothelial progenitor cells and traditional cardiovascular risk factors on pulse wave velocity among prediabetic individuals

    Directory of Open Access Journals (Sweden)

    Protopsaltis Ioannis

    2012-11-01

    Full Text Available Abstract Background Central arterial stiffness represents a well-established predictor of cardiovascular disease. Decreased circulating endothelial progenitor cells (EPCs, increased asymmetric dimethyl-arginine (ADMA levels, traditional cardiovascular risk factors and insulin resistance have all been associated with increased arterial stiffness. The correlations of novel and traditional cardiovascular risk factors with central arterial stiffness in prediabetic individuals were investigated in the present study. Methods The study population consisted of 53 prediabetic individuals. Individuals were divided into groups of isolated impaired fasting glucose (IFG, isolated impaired glucose tolerance (IGT and combined IGT-IFG. Age, sex, family history of diabetes, smoking history, body mass index (BMI, waist to hip ratio (WHR, waist circumference (WC, blood pressure, lipid profile, levels of high sensitive C-reactive protein (hsCRP, glomerular filtration rate (GFR, and history of antihypertensive or statin therapy were obtained from all participants. Insulin resistance was evaluated using the Homeostatic Model Assessment (HOMA-IR. Carotid -femoral pulse wave velocity was used as an index of arterial stiffness. Circulating EPC count and ADMA serum levels were also determined. Results Among studied individuals 30 (56.6% subjects were diagnosed with isolated IFG, 9 (17% with isolated IGT (17% and 14 with combined IFG-IGT (26.4%. In univariate analysis age, mean blood pressure, fasting glucose, total cholesterol, LDL cholesterol, and ADMA levels positively correlated with pulse-wave velocity while exercise and GFR correlated negatively. EPC count did not correlate with PWV. In multivariate stepwise regression analysis PWV correlated independently and positively with LDL-Cholesterol (low density lipoprotein and ADMA levels and negatively with exercise. Conclusions Elevated ADMA and LDL-C levels are strongly associated with increased arterial stiffness among

  1. A single nucleotide polymorphism in the dimethylarginine dimethylaminohydrolase gene is associated with lower risk of pulmonary hypertension in bronchopulmonary dysplasia

    Science.gov (United States)

    Trittmann, JK; Gastier-Foster, JM; Zmuda, EJ; Frick, J; Rogers, LK; Vieland, VJ; Chicoine, LG; Nelin, LD

    2016-01-01

    Aim Pulmonary hypertension (PH) develops in 25–40% of bronchopulmonary dysplasia (BPD) patients, substantially increasing mortality. We have previously found that asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) production, is elevated in patients with BPD-associated PH. ADMA is metabolized by NG,NG- dimethylarginine dimethylaminohydrolase (DDAH). Presently, we test the hypothesis that there are single nucleotide polymorphisms (SNPs) in DDAH1 and/or DDAH2 associated with the development of PH in BPD patients. Methods BPD patients were enrolled (n=98) at Nationwide Children’s Hospital. Clinical characteristics and 36 SNPs in DDAH1 and DDAH2 were compared between BPD-associated PH patients (cases) and BPD-alone patients (controls). Results In BPD patients, 25 (26%) had echocardiographic evidence of PH (cases). In this cohort, DDAH1 wildtype rs480414 was 92% sensitive and 53% specific for PH in BPD, and the DDAH1 SNP rs480414 decreased the risk of PH in an additive model of inheritance (OR=0.39; 95% CI [0.18–0.88], p=0.01). Conclusion The rs480414 SNP in DDAH1 may be protective against the development of PH in patients with BPD. Furthermore, the DDAH1 rs480414 may be a useful biomarker in developing predictive models for PH in patients with BPD. PMID:26663142

  2. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis.

    Science.gov (United States)

    Kirkby, Nicholas S; Tesfai, Abel; Ahmetaj-Shala, Blerina; Gashaw, Hime H; Sampaio, Walkyria; Etelvino, Gisele; Leão, Nádia Miricéia; Santos, Robson A; Mitchell, Jane A

    2016-12-01

    Nonsteroidal antiinflammatory drugs, including ibuprofen, are among the most commonly used medications and produce their antiinflammatory effects by blocking cyclooxygenase (COX)-2. Their use is associated with increased risk of heart attacks caused by blocking COX-2 in the vasculature and/or kidney, with our recent work implicating the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), a cardiotoxic hormone whose effects can be prevented by l-arginine. The ibuprofen salt ibuprofen arginate (Spididol) was created to increase solubility but we suggest that it could also augment the NO pathway through codelivery of arginine. Here we investigated the idea that ibuprofen arginate can act to simultaneously inhibit COX-2 and preserve the NO pathway. Ibuprofen arginate functioned similarly to ibuprofen sodium for inhibition of mouse/human COX-2, but only ibuprofen arginate served as a substrate for NOS. Ibuprofen arginate but not ibuprofen sodium also reversed the inhibitory effects of ADMA and N G -nitro-l-arginine methyl ester on inducible NOS (macrophages) and endothelial NOS in vitro (aorta) and in vivo (blood pressure). These observations show that ibuprofen arginate provides, in one preparation, a COX-2 inhibitor and NOS substrate that could act to negate the harmful cardiovascular consequences mediated by blocking renal COX-2 and increased ADMA. While remarkably simple, our findings are potentially game-changing in the nonsteroidal antiinflammatory drug arena.-Kirkby, N. S., Tesfai, A., Ahmetaj-Shala, B., Gashaw, H. H., Sampaio, W., Etelvino, G., Leão, N. M., Santos, R. A., Mitchell, J. A. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis. © The Author(s).

  3. The L-arginine/asymmetric dimethylarginine ratio is improved by anti-tumor necrosis factor-α therapy in inflammatory arthropathies. Associations with aortic stiffness.

    Science.gov (United States)

    Angel, Kristin; Provan, Sella Aarrestad; Mowinckel, Petter; Seljeflot, Ingebjørg; Kvien, Tore Kristian; Atar, Dan

    2012-11-01

    Anti-Tumor Necrosis Factor (TNF)-α therapy improves vascular pathology in inflammatory arthropathies such as rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis. The l-arginine/ADMA ratio is important for modulation of the nitric oxide synthase activity. We examined the effect of TNF-α antagonists on ADMA and l-arginine/ADMA, and associations between ADMA, L-arginine/ADMA, aortic stiffness and carotid intima media thickness (CIMT) in patients with inflammatory arthropathies. Forty-eight patients who started with anti-TNF-α therapy were compared with a non-treated group of 32 patients. Plasma ADMA and L-arginine were assessed at baseline, 3 and 12 months. In a subgroup of 55 patients, aortic pulse wave velocity (aPWV) was measured at baseline, 3 and 12 moths, and CIMT was examined at baseline and 12 months. Anti-TNF-α therapy increased the L-arginine/ADMA ratio (mean [SD]) in the treatment group compared to the control group after 3 months (12 [29] vs. -13 [20], P < 0.001) and 12 months (7 [27] vs. -8 [19], P = 0.008), but did not affect ADMA (3 months: 0.00 [0.09] μmol/L vs. 0.02 [0.07] μmol/L, P = 0.42, 12 months: 0.01 [0.08] μmol/L vs. 0.01 [0.09] μmol/L, P = 0.88). Baseline aPWV was associated with ADMA (P = 0.02) and L-arginine/ADMA (P = 0.02) in multiple regression analyses, and the L-arginine/ADMA ratio was continuously associated with aPWV after initiation of anti-TNF-α therapy (P = 0.03). ADMA and L-arginine/ADMA were not correlated with CIMT. Anti-TNF-α therapy improved the L-arginine/ADMA ratio in patients with inflammatory arthropathies. ADMA and the L-arginine/ADMA ratio were associated with aPWV, and might have a mechanistic role in the aortic stiffening observed in these patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Overexpression of dimethylarginine dimethylaminohydrolase 1 attenuates airway inflammation in a mouse model of asthma.

    Directory of Open Access Journals (Sweden)

    Kayla G Kinker

    Full Text Available Levels of asymmetric dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase, are increased in lung, sputum, exhaled breath condensate and plasma samples from asthma patients. ADMA is metabolized primarily by dimethylarginine dimethylaminohydrolase 1 (DDAH1 and DDAH2. We determined the effect of DDAH1 overexpression on development of allergic inflammation in a mouse model of asthma. The expression of DDAH1 and DDAH2 in mouse lungs was determined by RT-quantitative PCR (qPCR. ADMA levels in bronchoalveolar lavage fluid (BALF and serum samples were determined by mass spectrometry. Wild type and DDAH1-transgenic mice were intratracheally challenged with PBS or house dust mite (HDM. Airway inflammation was assessed by bronchoalveolar lavage (BAL total and differential cell counts. The levels of IgE and IgG1 in BALF and serum samples were determined by ELISA. Gene expression in lungs was determined by RNA-Seq and RT-qPCR. Our data showed that the expression of DDAH1 and DDAH2 was decreased in the lungs of mice following HDM exposure, which correlated with increased ADMA levels in BALF and serum. Transgenic overexpression of DDAH1 resulted in decreased BAL total cell and eosinophil numbers following HDM exposure. Total IgE levels in BALF and serum were decreased in HDM-exposed DDAH1-transgenic mice compared to HDM-exposed wild type mice. RNA-Seq results showed downregulation of genes in the inducible nitric oxide synthase (iNOS signaling pathway in PBS-treated DDAH1-transgenic mice versus PBS-treated wild type mice and downregulation of genes in IL-13/FOXA2 signaling pathway in HDM-treated DDAH1-transgenic mice versus HDM-treated wild type mice. Our findings suggest that decreased expression of DDAH1 and DDAH2 in the lungs may contribute to allergic asthma and overexpression of DDAH1 attenuates allergen-induced airway inflammation through modulation of Th2 responses.

  5. Increased Symmetric Dimethylarginine Level Is Associated with Worse Hospital Outcomes through Altered Left Ventricular Ejection Fraction in Patients with Acute Myocardial Infarction.

    Directory of Open Access Journals (Sweden)

    Julie Lorin

    Full Text Available We aimed to investigate whether SDMA- symmetric dimethylarginine -the symmetrical stereoisomer of ADMA- might be a marker of left ventricular function in AMI.Asymmetric dimethylarginine (ADMA has been implicated in the prognosis after acute myocardial infarction (AMI and heart failure (HF.Cross sectional prospective study from 487 consecutive patients hospitalized 2, and death.Patients were analysed based on SDMA tertiles. Sex, diabetes, dyslipidemia, and prior MI were similar for all tertiles. In contrast, age and hypertension increased across the tertiles (p<0.001. From the first to the last tertile, GRACE risk score was elevated while LVEF and eGFR was reduced. The rate of severe HF and death were gradually increased across the SDMA tertiles (from 0.6% to 7.4%, p = 0.006 and from 0.6% to 5.0%, p = 0.034, respectively. Backward logistic multivariate analysis showed that SDMA was an independent estimate of developing severe HF, even when adjusted for confounding (OR(95%CI: 8.2(3.0-22.5, p<0.001. Further, SDMA was associated with mortality, even after adjustment for GRACE risk score (OR(95%CI: 4.56(1.34-15.52, p = 0.015.Our study showed for the first time that SDMA is associated with hospital outcomes, through altered LVEF and may have biological activity beyond renal function.

  6. Evaluation of ADMA, carbonyl groups, CAT and NKA in depressed patients with and without posttraumatic stress disorder.

    Science.gov (United States)

    Ogłodek, Ewa A

    2017-08-01

    It has been shown that asymmetric dimethylarginine (ADMA), carbonyl groups, catalase (CAT) and neurokinin A (NKA) are actively involved in neuronal processes such as depression and posttraumatic stress disorder (PTSD). One of their roles is to protect the body from oxidative damage. This is done by affecting neuronal growth, development and plasticity. The study aimed at assessing the concentrations of ADMA, carbonyl groups, CAT and NKA in patients with varying levels of depression severity, PTSD, and depression concurrent with PTSD. The study covered 460 people. Out of them, 120 suffered from different types of depression. The study groups comprised: 60 subjects with mild depression (MD), 60 subjects with moderate depression (MOD), 60 subjects with severe depression (SeD), 60 subjects with MD and PTSD (MD+PTSD), 60 subjects with MOD and PTSD (MOD+PTSD), 60 subjects with SeD and PTSD (SeD+PTSD), and 60 subjects with PTSD alone. Each group of 60 participants included 30 males and 30 females. The concentrations of all blood parameters were determined at 7 a.m. using the ELISA method. Depressive episodes became more severe as the concentration levels of studied markers increased. ADMA, carbonyl groups, CAT and NKA can be useful markers of chronic stress in both males and females with depression, PTSD, and depression concurrent with PTSD. They can be utilized when making an initial diagnosis and evaluating the severity of disease. Changes in their concentration levels may show a biological response to oxidative stress characteristic of depression. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

  7. Effect of Exercise on ADMA Level in Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Bengur Taşkıran

    2012-03-01

    Full Text Available Objective: The increase in symmetric (SDMA and asymmetric dimethyl arginine (ADMA is associated with endothelial dysfunction. The aim of this study was to evaluate the effect of exercise on ADMA and SDMA levels and related ratios in type 2 DM.Material and Methods: Thirty-six women with type 2 DM and 44 healthy women were recruited to the study. Fourteen and 19 subjects, respectively, attended four-weeks of moderate intensity exercise. Plasma SDMA, ADMA, and L-arginine levels were measured by the HPLC method initially, after the first exercise session, and after one month. Results: All measurements were within the normal range in both groups and did not change significantly immediately after exercise and after the first month. In the healthy group, L-arginine/ADMA and L-arginine/SDMA ratios after one month were significantly higher than the initial values (p<0.022 and p=0.017, respectively. After one month of exercise, L-arginine/ADMA and L-arginine/SDMA ratios increased in diabetics and decreased in healthy subjects when compared to those after the first exercise session (p=0.026 and p=0.037, respectively. Conclusion: We suggest that L-arginine/ADMA and L-arginine/SDMA ratios should be used in spite of absolute values. These molecules have a substantial role in the beneficial effects of exercise in healthy subjects while their role is small in diabetics.

  8. Systemic inflammation is linked to low arginine and high ADMA plasma levels resulting in an unfavourable NOS substrate-to-inhibitor ratio: the Hoorn Study

    NARCIS (Netherlands)

    van der Zwan, L.P.; Scheffer, P.G.; Dekker, J.M.; Stehouwer, C.D.A.; Heine, R.J.; Teerlink, T.

    2011-01-01

    Inflammation is associated with a reduced availability of NO in the vasculature. We investigated the possible involvement of altered levels of the substrate (arginine) and the inhibitor [ADMA (asymmetric ω-N

  9. Online trapping and enrichment ultra performance liquid chromatography–tandem mass spectrometry method for sensitive measurement of “arginine-asymmetric dimethylarginine cycle” biomarkers in human exhaled breath condensate

    International Nuclear Information System (INIS)

    Di Gangi, Iole Maria; Pirillo, Paola; Carraro, Silvia; Gucciardi, Antonina; Naturale, Mauro; Baraldi, Eugenio; Giordano, Giuseppe

    2012-01-01

    Highlights: ► Simultaneous quantification of “arginine-ADMA cycle” metabolites developed in EBC. ► EBC is a non-invasive matrix highly useful in patients with respiratory diseases. ► Method, fast, precise and accurate, is suitable in the pediatric clinical studies. ► Sensitivity is increased using on-line trapping and enrichment-UPLC–MS/MS method. ► EBC measurements in asthmatic adolescents confirm that ADMA is increased in asthma. - Abstract: Background: Exhaled breath condensate (EBC) is a biofluid collected non invasively that, enabling the measurement of several biomarkers, has proven useful in the study of airway inflammatory diseases, including asthma, COPD and cystic fibrosis. To the best of our knowledge, there is no previous report of any analytical method to detect ADMA in EBC. Objectives: Aim of this work was to develop an online sample trapping and enrichment system, coupled with an UPLC–MS/MS method, for simultaneous quantification of seven metabolites related to “Arginine-ADMA cycle”, using the isotopic dilution. Methods: Butylated EBC samples were trapped in an online cartridge, washed before and after each injection with cleanup solution to remove matrix components and switched inline into the high pressure analytical column. Multiple reaction monitoring in positive mode was used for analyte quantification by tandem mass spectrometry. Results: Validation studies were performed in EBC to examine accuracy, precision and robustness of the method. For each compound, the calibration curves showed a coefficient of correlation (r 2 ) greater than 0.992. Accuracy (%Bias) was −1 ), measured in EBC samples of asthmatic adolescents are significantly increased (p < 0.0001) than in normal controls (0.0040 ± 0.0021 vs. 0.0012 ± 0.0005 and 0.0020 ± 0.0015 vs. 0.0002 ± 0.0001, respectively), as well the ADMA/Tyr (0.34 ± 0.09 vs. 0.12 ± 0.02, p < 0.0001) and the SDMA/Tyr ratio (0.10 ± 0.04 vs. 0.015 ± 0.004, p < 0.0001). Conclusions

  10. Dimethylarginine dimethylaminohydrolase 1 is involved in spinal nociceptive plasticity.

    Science.gov (United States)

    DʼMello, Richard; Sand, Claire A; Pezet, Sophie; Leiper, James M; Gaurilcikaite, Egle; McMahon, Stephen B; Dickenson, Anthony H; Nandi, Manasi

    2015-10-01

    Activation of neuronal nitric oxide synthase, and consequent production of nitric oxide (NO), contributes to spinal hyperexcitability and enhanced pain sensation. All NOS isoforms are inhibited endogenously by asymmetric dimethylarginine, which itself is metabolised by dimethylarginine dimethylaminohydrolase (DDAH). Inhibition of DDAH can indirectly attenuate NO production by elevating asymmetric dimethylarginine concentrations. Here, we show that the DDAH-1 isoform is constitutively active in the nervous system, specifically in the spinal dorsal horn. DDAH-1 was found to be expressed in sensory neurons within both the dorsal root ganglia and spinal dorsal horn; L-291 (NG-[2-Methoxyethyl]-L-arginine methyl ester), a DDAH-1 inhibitor, reduced NO synthesis in cultured dorsal root ganglia neurons. Spinal application of L-291 decreased N-methyl-D-aspartate-dependent postdischarge and windup of dorsal horn sensory neurons--2 measures of spinal hyperexcitability. Finally, spinal application of L-291 reduced both neuronal and behavioral measures of formalin-induced central sensitization. Thus, DDAH-1 may be a potential therapeutic target in neuronal disorders, such as chronic pain, where elevated NO is a contributing factor.

  11. Online trapping and enrichment ultra performance liquid chromatography-tandem mass spectrometry method for sensitive measurement of 'arginine-asymmetric dimethylarginine cycle' biomarkers in human exhaled breath condensate

    Energy Technology Data Exchange (ETDEWEB)

    Di Gangi, Iole Maria, E-mail: giordano@pediatria.unipd.it [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Pirillo, Paola [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Carraro, Silvia [Unit of Allergy and Respiratory Diseases, Department of Women' s and Children' s Health, University of Padova (Italy); Gucciardi, Antonina; Naturale, Mauro [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Baraldi, Eugenio [Unit of Allergy and Respiratory Diseases, Department of Women' s and Children' s Health, University of Padova (Italy); Giordano, Giuseppe [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy)

    2012-11-19

    Highlights: Black-Right-Pointing-Pointer Simultaneous quantification of 'arginine-ADMA cycle' metabolites developed in EBC. Black-Right-Pointing-Pointer EBC is a non-invasive matrix highly useful in patients with respiratory diseases. Black-Right-Pointing-Pointer Method, fast, precise and accurate, is suitable in the pediatric clinical studies. Black-Right-Pointing-Pointer Sensitivity is increased using on-line trapping and enrichment-UPLC-MS/MS method. Black-Right-Pointing-Pointer EBC measurements in asthmatic adolescents confirm that ADMA is increased in asthma. - Abstract: Background: Exhaled breath condensate (EBC) is a biofluid collected non invasively that, enabling the measurement of several biomarkers, has proven useful in the study of airway inflammatory diseases, including asthma, COPD and cystic fibrosis. To the best of our knowledge, there is no previous report of any analytical method to detect ADMA in EBC. Objectives: Aim of this work was to develop an online sample trapping and enrichment system, coupled with an UPLC-MS/MS method, for simultaneous quantification of seven metabolites related to 'Arginine-ADMA cycle', using the isotopic dilution. Methods: Butylated EBC samples were trapped in an online cartridge, washed before and after each injection with cleanup solution to remove matrix components and switched inline into the high pressure analytical column. Multiple reaction monitoring in positive mode was used for analyte quantification by tandem mass spectrometry. Results: Validation studies were performed in EBC to examine accuracy, precision and robustness of the method. For each compound, the calibration curves showed a coefficient of correlation (r{sup 2}) greater than 0.992. Accuracy (%Bias) was <3% except for NMMA and H-Arg (<20%), intra- and inter-assay precision (expressed as CV%) were within {+-}20% and recovery ranged from 97.1 to 102.8% for all analytes. Inter-day variability analysis on 20 EBC of adult subjects did

  12. Differences in the association between maternal serum homocysteine and ADMA levels in women with pregnancies complicated by preeclampsia and/or intrauterine growth restriction.

    Science.gov (United States)

    Laskowska, Marzena; Laskowska, Katarzyna; Oleszczuk, Jan

    2013-01-01

    The aim of our study was to investigate the association between homocysteine and asymmetric dimethylarginine in preeclamptic women with and without intrauterine growth restriction compared with normal healthy uncomplicated pregnancies and normotensive pregnancies complicated by idiopathic isolated intrauterine fetal growth restriction. The maternal serum homocysteine and asymmetric dimethylarginine concentrations were determined using a sandwich enzyme-linked immunosorbent assays. A statistically significant positive correlation of maternal serum homocysteine levels with the serum asymmetric dimethylarginine levels was observed in healthy normotensive uncomplicated pregnant women from the control group and in preeclamptic patients with appropriate-for-gestational-age fetuses (R = 0.380079, p-value = 0.002311* and R = 0.455797, p-value = 0.004030* for the control and the P groups, respectively). However, this correlation was not significant in women with pregnancy complicated by intrauterine growth restriction, both isolated and in the course of severe preeclampsia. These findings provide support for the hypothesis that elevated levels of asymmetric dimethylarginine in pregnancy complicated by preeclampsia are associated with elevated homocysteine levels. But our results also demonstrate that in pregnancies complicated by intrauterine growth restriction, this mechanism is important, although not the only one.

  13. Effect of keto amino acids on asymmetric dimethyl arginine, muscle and fat tissue in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Vladimir Teplan

    2012-06-01

    Full Text Available Levels of endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA are elevated in chronic kidney disease (CKD and may contribute to vascular complications. In this study we tested the hypothesis that elevated ADMA can be reduced in CKD patients by long-term administration of low-protein diet (LPD supplemented with keto amino acids (KA. In a long-term prospective double blind placebo controlled randomized trial, we evaluated a total of 120 CKD patients (62/58F aged 22-76 yrs with creatinine clearance 22-40mL/min/1.73m2 for a period of 36 months. All patients were on low-protein diet containing 0.6 protein/kg/IBW/day and 120-125/kJ/kg/IBW/day. LPD was randomly supplemented with KA at dosage of 100 mg/kg/IBW/day (61 patients, Group I while 59 patients (Group II received placebo. During the study period, glomerular filtration rate (GFR slightly decreased (Ccr from 34.2±11.6 to 29.9±9.2 mL/min and 33.5±11.6 to 22.2±10.4 mL/min in Group I and II, respectively; this however was more marked in Group II (p<0.01. Fat in muscle measured by MR spectroscopy (MRS, m.tibialis anterior significantly decreased in Group I and was linked to reduced volume of visceral fat measured by MRI (p<0.01. Reduction of fat in Group II was not significant. In Group I, there was a significant decrease in the plasma level of ADMA (from 2.4±0.4 to 1.2±0.3 μmol/L, p<0.01, but ADMA remained unchanged in Group II. A further remarkable finding was reduction in the plasma concentration of pentosidine (from 486±168 to 325±127 μg/L, p<0.01 and decrease of proteinuria (from 3.7±2.20 to 1.6±1.2 g/24hrs, p<0.01 in Group I. Plasma adiponectin (ADPN in Group I rose (p<0.01. Analysis of lipid spectrum revealed a mild yet significant decrease in total cholesterol and LPD-cholesterol (p<0.01, more pronounced in Group I. In Group I, there was a decrease in plasma triglycerides (from 3.8±1.5 down to 2.3±0.5 mmol/L, p<0.01, whereas glycated hemoglobin (HbAc1

  14. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    International Nuclear Information System (INIS)

    Abdel-Messeih, P.L.

    2012-01-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T 4 were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T 4 as compared to controls. There were significant negative correlations between NO and both ADMA (r 2 = 0.84) and free T 4 (r 2 = 0.95) in overt hypothyroid group while significant positive correlation (r 2 = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females

  15. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Messeih, P. L. [Health Radiation Research Department, National Centre for Radiation Research and Technology, Cairo (Egypt)

    2012-07-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T{sub 4} were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T{sub 4} as compared to controls. There were significant negative correlations between NO and both ADMA (r{sup 2} = 0.84) and free T{sub 4} (r{sup 2} = 0.95) in overt hypothyroid group while significant positive correlation (r{sup 2} = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females.

  16. High Levels of Methylarginines Were Associated With Increased Mortality in Patients With Severe Sepsis

    DEFF Research Database (Denmark)

    Mortensen, Karoline Myglegard; Itenov, Theis Skovsgaard; Haase, Nicolai

    2016-01-01

    Introduction: Nitric oxide (NO) likely plays a pivotal role in the pathogenesis of sepsis. Arginine is a substrate for NO, whereas the methylated arginines—asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA)—are endogenous by-products of proteolysis that inhibit NO production....... We investigated if high-plasma levels of ADMA, SDMA, and arginine/ADMA ratio were associated with 90-day mortality in patients with severe sepsis or septic shock. Methods: We included 267 adult patients admitted to intensive care unit with severe sepsis or septic shock. The patients had previously...... been included in the randomized controlled trial “Scandinavian Starch for Severe Sepsis and Septic Shock (6S).” ADMA, SDMA, and arginine/ADMA ratio were measured in plasma. The risk of death within 90 days was estimated in multivariate Cox regression analyses adjusted for gender, age >=65 years, major...

  17. Symmetric Dimethylarginine in Cats with Hypertrophic Cardiomyopathy and Diabetes Mellitus

    DEFF Research Database (Denmark)

    Langhorn, R.; Kieler, I. N.; Koch, J.

    2018-01-01

    Background: Symmetric dimethylarginine (SDMA) has been increasingly used as a marker of early chronic kidney disease (CKD) in cats, but little is known about the influence of comorbidities on SDMA in this species. Hypothesis: Hypertrophic cardiomyopathy (HCM) and diabetes mellitus (DM), independe......Background: Symmetric dimethylarginine (SDMA) has been increasingly used as a marker of early chronic kidney disease (CKD) in cats, but little is known about the influence of comorbidities on SDMA in this species. Hypothesis: Hypertrophic cardiomyopathy (HCM) and diabetes mellitus (DM......), independently of CKD, are associated with changes in serum SDMA. Animals: Ninety-four cats (17 with CKD, 40 with HCM, 17 with DM, and 20 healthy controls). Methods: Case-control study. Clinical examination, echocardiography, ECG, blood pressure, CBC, biochemistry, thyroxine, and SDMA measurement were performed....... Urinalysis was performed in controls and cats with CKD and DM. Analysis of variance was used to compare overall differences in the log-transformed SDMA data among groups. A random forest algorithm was applied to explore which clinical and other factors influenced serum SDMA. Results: Median (range) serum...

  18. Study of some biochemical and genetic risk factors for ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the relation between asymmetric dimethylarginine (ADMA ), high sensitive C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1) ( both serum levels and the genotypes of the MCP-1 A-2518G polymorphism) with the development of carotid atherosclerosis in systemic ...

  19. Regulation of DDAH1 as a Potential Therapeutic Target for Treating Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Xiaoyu Liu

    2013-01-01

    Full Text Available Asymmetric dimethylarginine (ADMA is an endogenous nitric oxide synthase inhibitor that blocks nitric oxide production, while congestive heart failure is associated with increased plasma and tissue ADMA content. Increased plasma ADMA is a strong and independent predictor of all-cause mortality in the community and the strongest predictor of mortality in patients after myocardial infarction. Recent studies demonstrated that dimethylarginine dimethylaminohydrolase-1 (DDAH1 is the critical enzyme for ADMA degradation and thereby plays an important role in maintaining cardiovascular nitric oxide bioavailability. Interestingly, activation of the farnesoid X receptor (FXR through the bile acid ursodeoxycholic acid (UDCA or synthetic FXR agonists, such as GW4064, can increase DDAH1 expression. Thus, modulating DDAH1 activity through FXR receptor agonists such as UDCA could be a therapeutic target for treating reduced nitric oxide bioavailability in congestive heart failure and other cardiovascular diseases.

  20. Nitro-Oleic Acid Prevents Hypoxia- and Asymmetric Dimethylarginine-Induced Pulmonary Endothelial Dysfunction

    Czech Academy of Sciences Publication Activity Database

    Koudelka, Adolf; Ambrožová, Gabriela; Klinke, A.; Fidlerová, Táňa; Martíšková, Hana; Kuchta, R.; Rudolph, T.K.; Kadlec, J.; Kuchtová, Z.; Woodcock, S.R.; Freeman, B.A.; Kubala, Lukáš; Pekarová, Michaela

    2016-01-01

    Roč. 30, č. 6 (2016), s. 579-586 ISSN 0920-3206 R&D Projects: GA ČR GP13-40824P; GA MŠk(CZ) LD15069 Institutional support: RVO:68081707 Keywords : fatty acids * arterial - hypertension * oxide synthase * murine model Subject RIV: BO - Biophysics Impact factor: 2.820, year: 2016

  1. The L-arginine Pathway in Acute Ischemic Stroke and Severe Carotid Stenosis

    DEFF Research Database (Denmark)

    Molnar, Tihamer; Pusch, Gabriella; Papp, Viktoria

    2014-01-01

    BACKGROUND: Endothelial dysfunction is associated with increased levels of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) resulting in a decreased production of nitric oxide, which regulates the vascular tone. METHODS: Patients with acute ischemic stroke (AIS, n = 55......) and asymptomatic significant carotid stenosis (AsCS, n = 44) were prospectively investigated. L-arginine, ADMA, SDMA, S100 B, and high-sensitivity C-reactive protein (hsCRP) were serially measured within 6 hours after the onset of stroke, at 24 and 72 poststroke hours. All markers were compared with healthy...... subjects (n = 45). The severity of AIS was daily assessed by National Institute of Health Stroke Scale scoring. RESULTS: Even within 6 hours after the onset of stroke, L-arginine, ADMA, and SDMA were significantly higher in patients with AIS compared with both AsCS and healthy subjects. S100 B reflecting...

  2. Nitric Oxide-Related Biological Pathways in Patients with Major Depression.

    Directory of Open Access Journals (Sweden)

    Andreas Baranyi

    Full Text Available Major depression is a well-known risk factor for cardiovascular diseases and increased mortality following myocardial infarction. However, biomarkers of depression and increased cardiovascular risk are still missing. The aim of this prospective study was to evaluate, whether nitric-oxide (NO related factors for endothelial dysfunction, such as global arginine bioavailability, arginase activity, L-arginine/ADMA ratio and the arginine metabolites asymmetric dimethylarginine (ADMA and symmetric dimethylarginine (SDMA might be biomarkers for depression-induced cardiovascular risk.In 71 in-patients with major depression and 48 healthy controls the Global Arginine Bioavailability Ratio (GABR, arginase activity (arginine/ornithine ratio, the L-arginine/ADMA ratio, ADMA, and SDMA were determined by high-pressure liquid chromatography. Psychiatric and laboratory assessments were obtained at baseline at the time of in-patient admittance and at the time of hospital discharge.The ADMA concentrations in patients with major depression were significantly elevated and the SDMA concentrations were significantly decreased in comparison with the healthy controls. Even after a first improvement of depression, ADMA and SDMA levels remained nearly unchanged. In addition, after a first improvement of depression at the time of hospital discharge, a significant decrease in arginase activity, an increased L-arginine/ADMA ratio and a trend for increased global arginine bioavailability were observed.Our study results are evidence that in patients with major depression ADMA and SDMA might be biomarkers to indicate an increased cardiovascular threat due to depression-triggered NO reduction. GABR, the L-arginine/ADMA ratio and arginase activity might be indicators of therapy success and increased NO production after remission.

  3. Efek N-Asetil-L- Sistein (NAC terhadap Kadar Adma Plasma dan Ekspresi Protein Vcam-l pada Disfungsi Endotel Tikus Diabetes

    Directory of Open Access Journals (Sweden)

    Irma Santi

    2016-12-01

    Full Text Available Abstract Endothelial dysfunction is an early state of symptoms in a cardiovascular disease. An elevated oxidative stress plays a key role in the pathogenesis of macrovascular diabetic complication. The present study was design to evaluate the effect of NAC on plasma ADMA level and the expression of VCAM-1 protein on endothelial dysfunction in diabetic rats. Thirty male Sprague–Dawley rats were divided into 5 groups i.e. normal rats, diabetic rats, treatment with NAC 30 mg/kgBW, NAC 56 mg/ kgBW and NAC 100 mg/kgBW. Diabetic rats model was induced by intraperitonial administration of alloxan monohydrate at dose of 150 mg/kgBW, diabetes occurred on 3nd day after alloxan injection and then started treatment of N-acetyl-L-cystein for 28 days. ADMA plasma level was analyzed with Elisa Reader and the expression of VCAM-1 protein was evaluated by immunohistochemistry. Conclusion of this research is that treatment with NAC 30 mg/kgBW, NAC 56 mg/kgBW and NAC 100 mg/kgBW for 28 days may prevent oxidative stress indicated by the decreasing of plasma ADMA level by 45.8%: 55.75% and 65.92%, respectively and the decreasing of the expression of VCAM-1 protein on endothelial dysfunction in diabetic rat by 24%: 31.75% and 58.92%, respectively. Key words : (NAC, Endothelial dysfunction, ADMA, VCAM-1AbstrakDisfungsi endotel merupakan tahap awal pada penyakit kardiovaskular. Peningkatan stres oksidatif berperan penting dalam patogenesis komplikasi makrovaskular pada penyakit diabetes. Penelitian ini bertujuan untuk mengevaluasi efek N-asetil sistein (NAC dalam menurunkan kadar ADMA plasma dan ekspresi protein VCAM-1 pada disfungsi endotel tikus diabetes. 30 tikus jantan strain sprague- Dawley dibagi menjadi 5 kelompok yaitu kelompok normal, kelompok diabetes, kelompok perlakuan NAC pada dosis 30, 56 dan 100 mg/kgBB. Model tikus diabetes diperoleh dengan diinduksi aloksan monohidrat 150 mg/kgBB secara intraperitonial, kondisi diabetes terjadi pada hari ke-3 setelah

  4. Nitric Oxide Manipulation: A Therapeutic Target for Peripheral Arterial Disease?

    Directory of Open Access Journals (Sweden)

    Gareth Williams

    2012-01-01

    Full Text Available Peripheral Arterial Disease (PAD is a cause of significant morbidity and mortality in the Western world. Risk factor modification and endovascular and surgical revascularisation are the main treatment options at present. However, a significant number of patients still require major amputation. There is evidence that nitric oxide (NO and its endogenous inhibitor asymmetric dimethylarginine (ADMA play significant roles in the pathophysiology of PAD. This paper reviews experimental work implicating the ADMA-DDAH-NO pathway in PAD, focussing on both the vascular dysfunction and effects within the ischaemic muscle, and examines the potential of manipulating this pathway as a novel adjunct therapy in PAD.

  5. Pathogenic cycle between the endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine and the leukocyte-derived hemoprotein myeloperoxidase

    Czech Academy of Sciences Publication Activity Database

    von Leitner, E.C.; Klinke, A.; Atzler, D.; Slocum, J.L.; Lund, N.; Kielstein, J.T.; Maas, R.; Schmidt-Haupt, R.; Pekarová, Michaela; Hellwinkel, O.; Tsikas, D.; D'Alecy, L.G.; Lau, D.; Willems, S.; Kubala, Lukáš; Ehmke, H.; Meinertz, T.; Blankenberg, S.; Schwedhelm, E.; Gadegbeku, C.A.; Boger, R.H.; Baldus, S.; Sydow, K.

    2011-01-01

    Roč. 124, č. 4 (2011), s. 2735-U342 ISSN 0009-7322 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : arteriosclerosis * leukocytes * nitric oxide synthase Subject RIV: BO - Biophysics Impact factor: 14.739, year: 2011

  6. Asymmetric collider

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Colestock, P.; Goderre, G.; Johnson, D.; Martin, P.; Holt, J.; Kaplan, D.

    1993-01-01

    The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering

  7. Transsulfuration pathway thiols and methylated arginines: the Hunter Community Study.

    Directory of Open Access Journals (Sweden)

    Arduino A Mangoni

    Full Text Available Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH activity] and with symmetric dimethylarginine (SDMA. We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level.Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS, and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR = 64 (60-70 years].REGRESSION ANALYSIS SHOWED THAT: a age (P = 0.001, gender (P = 0.03, lower estimated glomerular filtration rate (eGFR, P = 0.08, body mass index (P = 0.008, treatment with beta-blockers (P = 0.03, homocysteine (P = 0.02, and glutamylcysteine (P = 0.003 were independently associated with higher ADMA concentrations; and b age (P = 0.001, absence of diabetes (P = 0.001, lower body mass index (P = 0.01, lower eGFR (P<0.001, cysteine (P = 0.007, and glutamylcysteine (P < 0.001 were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations.After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA and/or cationic amino acid transport requires further investigations.

  8. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    that oscillate in certain directions. Reflection or scattering of light favours certain orientations of the electric and magnetic fields over others. This is why polarising sunglasses can filter out the glint of sunlight reflected off a pond. When light scatters through the expanding debris of a supernova, it retains information about the orientation of the scattering layers. If the supernova is spherically symmetric, all orientations will be present equally and will average out, so there will be no net polarisation. If, however, the gas shell is not round, a slight net polarisation will be imprinted on the light. This is what broad-band polarimetry can accomplish. If additional spectral information is available ('spectro-polarimetry'), one can determine whether the asymmetry is in the continuum light or in some spectral lines. In the case of the Type Ia supernovae, the astronomers found that the continuum polarisation is very small so that the overall shape of the explosion is crudely spherical. But the much larger polarization in strongly blue-shifted spectral lines evidences the presence, in the outer regions, of fast moving clumps with peculiar chemical composition. "Our study reveals that explosions of Type Ia supernovae are really three-dimensional phenomena," says Dietrich Baade. "The outer regions of the blast cloud is asymmetric, with different materials found in 'clumps', while the inner regions are smooth." "This study was possible because polarimetry could unfold its full strength thanks to the light-collecting power of the Very Large Telescope and the very precise calibration of the FORS instrument," he adds. The research team first spotted this asymmetry in 2003, as part of the same observational campaign (ESO PR 23/03 and ESO PR Photo 26/05). The new, more extensive results show that the degree of polarisation and, hence, the asphericity, correlates with the intrinsic brightness of the explosion. The brighter the supernova, the smoother, or less clumpy

  9. Packed red blood cells are an abundant and proximate potential source of nitric oxide synthase inhibition.

    Directory of Open Access Journals (Sweden)

    Charles F Zwemer

    Full Text Available We determined, for packed red blood cells (PRBC and fresh frozen plasma, the maximum content, and ability to release the endogenous nitric oxide synthase (NOS inhibitors asymmetric dimethylarginine (ADMA and monomethylarginine (LNMMA.ADMA and LNMMA are near equipotent NOS inhibitors forming blood's total NOS inhibitory content. The balance between removal from, and addition to plasma determines their free concentrations. Removal from plasma is by well-characterized specific hydrolases while formation is restricted to posttranslational protein methylation. When released into plasma they can readily enter endothelial cells and inhibit NOS. Fresh rat and human whole blood contain substantial protein incorporated ADMA however; the maximum content of ADMA and LNMMA in PRBC and fresh frozen plasma has not been determined.We measured total (free and protein incorporated ADMA and LNMMA content in PRBCs and fresh frozen plasma, as well as their incubation induced release, using HPLC with fluorescence detection. We tested the hypothesis that PRBC and fresh frozen plasma contain substantial inhibitory methylarginines that can be released chemically by complete in vitro acid hydrolysis or physiologically at 37°C by enzymatic blood proteolysis.In vitro strong-acid-hydrolysis revealed a large PRBC reservoir of ADMA (54.5 ± 9.7 µM and LNMMA (58.9 ± 28.9 μM that persisted over 42-d at 6° or -80°C. In vitro 5h incubation at 37°C nearly doubled free ADMA and LNMMNA concentration from PRBCs while no change was detected in fresh frozen plasma.The compelling physiological ramifications are that regardless of storage age, 1 PRBCs can rapidly release pathologically relevant quantities of ADMA and LNMMA when incubated and 2 PRBCs have a protein-incorporated inhibitory methylarginines reservoir 100 times that of normal free inhibitory methylarginines in blood and thus could represent a clinically relevant and proximate risk for iatrogenic NOS inhibition upon

  10. Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH in a rat model of sleeping sickness.

    Directory of Open Access Journals (Sweden)

    Donia Amrouni

    2011-03-01

    Full Text Available Involvement of nitric oxide (NO in the pathophysiology of human African trypanosomiasis (HAT was analyzed in a HAT animal model (rat infected with Trypanosoma brucei brucei. With this model, it was previously reported that trypanosomes were capable of limiting trypanocidal properties carried by NO by decreasing its blood concentration. It was also observed that brain NO concentration, contrary to blood, increases throughout the infection process. The present approach analyses the brain impairments occurring in the regulations exerted by arginase and N(G, N(G-dimethylarginine dimethylaminohydrolase (DDAH on NO Synthases (NOS. In this respect: (i cerebral enzymatic activities, mRNA and protein expression of arginase and DDAH were determined; (ii immunohistochemical distribution and morphometric parameters of cells expressing DDAH-1 and DDAH-2 isoforms were examined within the diencephalon; (iii amino acid profiles relating to NOS/arginase/DDAH pathways were established.Arginase and DDAH activities together with mRNA (RT-PCR and protein (western-blot expressions were determined in diencephalic brain structures of healthy or infected rats at various days post-infection (D5, D10, D16, D22. While arginase activity remained constant, that of DDAH increased at D10 (+65% and D16 (+51% in agreement with western-blot and amino acids data (liquid chromatography tandem-mass spectrometry. Only DDAH-2 isoform appeared to be up-regulated at the transcriptional level throughout the infection process. Immunohistochemical staining further revealed that DDAH-1 and DDAH-2 are contained within interneurons and neurons, respectively.In the brain of infected animals, the lack of change observed in arginase activity indicates that polyamine production is not enhanced. Increases in DDAH-2 isoform may contribute to the overproduction of NO. These changes are at variance with those reported in the periphery. As a whole, the above processes may ensure additive protection

  11. Principles of asymmetric synthesis

    CERN Document Server

    Gawley, Robert E; Aube, Jeffrey

    2012-01-01

    The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions...

  12. EVALUATION OF SYMMETRIC DIMETHYLARGININE AS AN EARLY BIOMARKER OF CHRONIC KIDNEY DISEASE IN CAPTIVE CHEETAHS (ACINONYX JUBATUS).

    Science.gov (United States)

    Lamglait, Benjamin; Vandenbunder-Beltrame, Marielle

    2017-09-01

    Symmetric dimethylarginine (SDMA) has been shown to be a valuable biomarker for early detection of chronic kidney disease (CKD) in canine and feline patients. Recognition of early (subclinical) kidney disease would be of value in cheetahs (Acinonyx jubatus) as prevalence of CKD is relatively high in this species in captivity. Fifty-eight banked serum and plasma samples from seven adult cheetahs that died of CKD were analyzed for creatinine, urea, and SDMA. A marked increase in SDMA was noted on five of the tested cheetahs earlier than the rise of serum creatinine and urea (estimated 8-35 mo; mean 21.4 mo; median 22 mo). SDMA appears as an early biomarker to evaluate renal function for the diagnosis of CKD in cheetahs regardless of the cause of this disease.

  13. Quantifying social asymmetric structures.

    Science.gov (United States)

    Solanas, Antonio; Salafranca, Lluís; Riba, Carles; Sierra, Vicenta; Leiva, David

    2006-08-01

    Many social phenomena involve a set of dyadic relations among agents whose actions may be dependent. Although individualistic approaches have frequently been applied to analyze social processes, these are not generally concerned with dyadic relations, nor do they deal with dependency. This article describes a mathematical procedure for analyzing dyadic interactions in a social system. The proposed method consists mainly of decomposing asymmetric data into their symmetric and skew-symmetric parts. A quantification of skew symmetry for a social system can be obtained by dividing the norm of the skew-symmetric matrix by the norm of the asymmetric matrix. This calculation makes available to researchers a quantity related to the amount of dyadic reciprocity. With regard to agents, the procedure enables researchers to identify those whose behavior is asymmetric with respect to all agents. It is also possible to derive symmetric measurements among agents and to use multivariate statistical techniques.

  14. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  15. Asymmetric ion trap

    Science.gov (United States)

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  16. Plasma L-arginine levels distinguish pulmonary arterial hypertension from left ventricular systolic dysfunction.

    Science.gov (United States)

    Sandqvist, Anna; Schneede, Jörn; Kylhammar, David; Henrohn, Dan; Lundgren, Jakob; Hedeland, Mikael; Bondesson, Ulf; Rådegran, Göran; Wikström, Gerhard

    2018-03-01

    Pulmonary arterial hypertension (PAH) is a life-threatening condition, characterized by an imbalance of vasoactive substances and remodeling of pulmonary vasculature. Nitric oxide, formed from L-arginine, is essential for homeostasis and smooth muscle cell relaxation in PAH. Our aim was to compare plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in PAH compared to left ventricular systolic dysfunction (LVSD) and healthy subjects. This was an observational, multicenter study comparing 21 patients with PAH to 14 patients with LVSD and 27 healthy subjects. Physical examinations were obtained and blood samples were collected. Plasma levels of ADMA, SDMA, L-arginine, L-ornithine, and L-citrulline were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma levels of ADMA and SDMA were higher, whereas L-arginine and L-arginine/ADMA ratio were lower in PAH patients compared to healthy subjects (p L-arginine than patients with LVSD (p L-Arginine correlated to 6 min walking distance (6MWD) (r s  = 0.58, p = 0.006) and L-arginine/ADMA correlated to WHO functional class (r s  = -0.46, p = 0.043) in PAH. In conclusion, L-arginine levels were significantly lower in treatment naïve PAH patients compared to patients with LVSD. Furthermore, L-arginine correlated with 6MWD in PAH. L-arginine may provide useful information in differentiating PAH from LVSD.

  17. Amniotic Fluid Arginine from Gestational Weeks 13 to 15 Is a Predictor of Birth Weight, Length, and Head Circumference

    Directory of Open Access Journals (Sweden)

    Astrid Bjørke-Jenssen

    2017-12-01

    Full Text Available Arginine is a constituent of proteins and a precursor for polyamines and nitric oxide, and is essential for placentation, angiogenesis, and growth. Maternal plasma arginine concentrations are found to be lower in pregnancies complicated by fetal growth restriction, and arginine supplementation in later pregnancy is reported to increase birth weight. We measured arginine and the metabolites asymmetric dimethylarginine (ADMA and symmetric dimethylarginine (SDMA in the amniotic fluid obtained in pregnancy weeks 13 to 15 from 363 pregnancies with a documented normal outcome and related the concentrations to birth weight, length, and head circumference. Arginine was higher in the amniotic fluid from female (mean 40.8 (SD 10.6 µmol/L compared to male fetuses (37.4 (SD 11.2 µmol/L, p = 0.003. Despite the gender difference, arginine in the amniotic fluid from gestational weeks 13–15 was the strongest predictor for birth weight, length, and head circumference. ADMA was a strong predictor for birth weight and length, SDMA for birth weight, while Arg/ADMA and Arg/SDMA only predicted head circumference in multiple linear regression models. Due to increased arginine demands, pregnancy is considered a state of relative arginine deficiency. Our findings reflect the importance of a good maternal arginine status in early pregnancy, an observation that should be evaluated in an intervention study.

  18. Effects of acute and chronic stress on the L-arginine nitric oxide pathway in black and white South Africans: the sympathetic activity and ambulatory blood pressure in Africans study.

    Science.gov (United States)

    Reimann, Manja; Hamer, Mark; Malan, Nicolaas T; Schlaich, Markus P; Lambert, Gavin W; Ziemssen, Tjalf; Boeger, Rainer H; Malan, Leoné

    2013-10-01

    This study investigated the impact of stress on effectors of the L-arginine/nitric oxide (NO) system including the endogenous inhibitor asymmetric dimethylarginine (ADMA). Black (n = 168) and white (n = 206) South African teachers were exposed to a mental and a physical stressor for 1 minute, respectively. Serum samples for determination of l-arginine, NO metabolites, ADMA, and symmetric dimethylarginine (SDMA) were obtained at rest and during stress exposure. Perception of task stressfulness was assessed on a 7-point Likert scale, and psychological distress was estimated by the General Health Questionnaire. Black South Africans exhibited higher resting levels of NO metabolites (adjusted mean [standard error of the mean] = 11.3 [1.3] versus 3.9 [1.1] μmol/l, p stress were evident for NO metabolites (blacks versus whites: 5.94 [1.55] versus -0.74 [1.25] μmol/l, p = .004) and SDMA (blacks versus whites: -0.02 [0.01] versus 0.02 [0.01] μmol/l, p = .004). Ethnicity-by-psychological distress interaction for stress responses was found for l-arginine/ADMA ratio (p = .027). The l-arginine/NO system is affected by psychosocial distress with higher susceptibility in black South Africans. This interaction may contribute to the higher cardiovascular disease risk in black South Africans.

  19. How Is Nature Asymmetric?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 6. How Is Nature Asymmetric? - Discrete Symmetries in Particle Physics and their Violation ... Indian Institute of Technology, Chennai. Aligarh Muslim University. University of Rajasthan, Jaipur. Indian Institute of Science, Bangalore 560012, India.

  20. Exploring asymmetric catalytic transformations

    NARCIS (Netherlands)

    Guduguntla, Sureshbabu

    2017-01-01

    In Chapter 2, we report a highly enantioselective synthesis of β-alkyl-substituted alcohols through a one-pot Cu- catalyzed asymmetric allylic alkylation with organolithium reagents followed by reductive ozonolysis. The synthesis of γ-alkyl-substituted alcohols was also achieved through Cu-catalyzed

  1. Associations of Plasma Nitrite, L-Arginine and Asymmetric Dimethylarginine with Morbidity and Mortality in Patients with Necrotizing Soft Tissue Infections

    DEFF Research Database (Denmark)

    Hansen, Marco Bo; Rasmussen, Lars Simon; Garred, Peter

    2017-01-01

    BACKGROUND: The nitric oxide system could play an important role in the pathophysiology related to necrotizing soft tissue infection (NSTI). Accordingly, we investigated the association between plasma nitrite level at admission and the presence of septic shock in patients with NSTI. We also evalu...

  2. Effects of breed, gender, exercise and white-coat effect on markers of endothelial function in dogs

    DEFF Research Database (Denmark)

    Moesgaard, Sophia Gry; Holte, A.V.; Mogensen, T.

    2007-01-01

    This study examines how systemic biomarkers of endothelial function and nitric oxide metabolism are affected by exercise in dogs. Furthermore, breed variation and white-coat effect have been tested by sampling three different dog breeds both in their home and in a clinical setting. Short......-term exercise increased plasma nitrate and nitrite (NOx) and von Willebrand factor (vWf). There was significant difference between Pointers and the small dog breeds Cairn Terriers and Cavalier King Charles Spaniels in the general plasma levels of vWf and asymmetric dimethylarginine (ADMA9. NOx and vWf were...... significantly higher when the sample was taken in the laboratory cf. at home, whereas ADMA and L-arginine were significantly lower. In conclusion, both short-term exercise and white-coat effect influence several plasma markers of endothelial function depending also on the breed and gender of the dogs...

  3. Correlation of the L-Arginine Pathway with Thrombo-Inflammation May Contribute to the Outcome of Acute Ischemic Stroke

    DEFF Research Database (Denmark)

    Molnar, Tihamer; Pusch, Gabriella; Nagy, Lajos

    2016-01-01

    BACKGROUND: Immune responses contribute to secondary injury after acute ischemic stroke (AIS), and metabolites of the L-arginine pathway are associated with stroke outcome. Here, we analyzed the relationship of the L-arginine pathway with thrombo-inflammatory biomarkers in AIS and their additive...... and independent associations to outcome. METHODS: Serial changes in P-selectin, tPA, MCP-1, sCD40L, IL-6, IL-8, L-arginine, and asymmetric and symmetric dimethylarginine (ADMA, SDMA) were investigated in 55 patients with AIS and without infection within 6 and 72 hours after stroke onset. Outcomes were assessed...... as National Institutes of Health Stroke Scale (NIHSS) worsening by 24 hours, poststroke infection, and death by 1 month. RESULTS: Serum levels of L-arginine showed negative correlation, whereas ADMA and SDMA showed positive correlation with thrombo-inflammatory biomarkers in the hyperacute phase. Most...

  4. Multipartite asymmetric quantum cloning

    International Nuclear Information System (INIS)

    Iblisdir, S.; Gisin, N.; Acin, A.; Cerf, N.J.; Filip, R.; Fiurasek, J.

    2005-01-01

    We investigate the optimal distribution of quantum information over multipartite systems in asymmetric settings. We introduce cloning transformations that take N identical replicas of a pure state in any dimension as input and yield a collection of clones with nonidentical fidelities. As an example, if the clones are partitioned into a set of M A clones with fidelity F A and another set of M B clones with fidelity F B , the trade-off between these fidelities is analyzed, and particular cases of optimal N→M A +M B cloning machines are exhibited. We also present an optimal 1→1+1+1 cloning machine, which is an example of a tripartite fully asymmetric cloner. Finally, it is shown how these cloning machines can be optically realized

  5. Asymmetric information and economics

    Science.gov (United States)

    Frieden, B. Roy; Hawkins, Raymond J.

    2010-01-01

    We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.

  6. Asymmetric Evolutionary Games

    Science.gov (United States)

    McAvoy, Alex; Hauert, Christoph

    2015-01-01

    Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner’s Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326

  7. Serum Symmetric Dimethylarginine as an Early Marker of Excretory Dysfunction in Canine Leishmaniosis (L. infantum Induced Nephropathy

    Directory of Open Access Journals (Sweden)

    Esther Torrent

    2018-01-01

    Full Text Available The aims of the study were to determine whether symmetric dimethylarginine (SDMA was increased in dogs with leishmaniosis and to assess its relationship with creatinine concentration and urinary protein : creatinine ratio (UPC to determine its utility as a marker of early excretory dysfunction. Fifty-three dogs with leishmaniosis classified according to the LeishVet clinical staging (stage I, n=5, stage II, n=30; stage III, n=12; stage IV, n=6 were selected and compared with 41 clinically healthy dogs. Thirty-nine dogs with leishmaniosis were also followed up for six months. SDMA concentrations on the day of diagnosis were significantly higher in dogs with leishmaniosis with respect to control dogs and in dogs from LeishVet stage IV when compared with the other stages. Increased UPC (>0.5, SDMA (>19 μg/dL, and creatinine concentrations (≥1.4 mg/dL were found in 47.1%, 15.1%, and 9.4% of dogs with leishmaniosis, respectively. SDMA concentration was increased in 24% of proteinuric dogs, in 7% of nonproteinuric dogs, and in four of five dogs with increased creatinine. SDMA concentration ≥ 25 μg/dL was associated with clinical chronic kidney disease (CKD after six months. Our results did not demonstrate advantages in using SDMA concentration as an early marker of CKD when compared to creatinine and UPC in canine leishmaniosis.

  8. Overexpression of Dimethylarginine Dimethylaminohydrolase Enhances Tumor Hypoxia: An Insight into the Relationship of Hypoxia and Angiogenesis In Vivo

    Directory of Open Access Journals (Sweden)

    Vassiliki Kostourou

    2004-07-01

    Full Text Available The oxygenation status of tumors derived from wild-type C6 glioma cells and clone D27 cells overexpressing dimethylarginine dimethylaminohydrolase (DDAH was assessed in vivo using a variety of direct and indirect assays of hypoxia. Clone D27 tumors exhibit a more aggressive and better-vascularized phenotype compared to wild-type C6 gliomas. Immunohistochemical analyses using the 2-nitroimidazole hypoxia marker pimonidazole, fiber optic OxyLite measurements of tumor pO2, and localized 31P magnetic resonance spectroscopy measurements of tumor bioenergetic status and pH clearly demonstrated that the D27 tumors were more hypoxic compared to C6 wild type. In the tumor extracts, only glucose concentrations were significantly lower in the D27 tumors. Elevated Glut-1 expression, a reliable functional marker for hypoxia-inducible factor-1-mediated metabolic adaptation, was observed in the D27 tumors. Together, the data show that overexpression of DDAH results in C6 gliomas that are more hypoxic compared to wild-type tumors, and point strongly to an inverse relationship of tumor oxygenation and angiogenesis in vivo-a concept now being supported by the enhanced understanding of oxygen sensing at the molecular level.

  9. Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

    Science.gov (United States)

    Nemeth, Balazs; Kiss, Istvan; Jencsik, Timea; Peter, Ivan; Kreska, Zita; Koszegi, Tamas; Miseta, Attila; Kustan, Peter; Boncz, Imre; Laczo, Andrea; Ajtay, Zeno

    2017-01-01

    To study the effect of carbon dioxide (CO 2 ) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Forty-seven hypertensive patients who underwent transcutaneous CO 2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO 2 treatment. Controls did not undergo CO 2 treatment. Plasma ADMA levels were measured by ELISA. ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). The short- and long-term decrease of ADMA levels suggests that CO 2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO 2 treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  10. Asymmetric quantum cloning machines

    International Nuclear Information System (INIS)

    Cerf, N.J.

    1998-01-01

    A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p ' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p ' )-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities p x , p y and p z . The capacity is proven to be vanishing if (√p x , √p y , √p z ) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)

  11. Asymmetric Arginine dimethylation of Epstein-Barr virus nuclear antigen 2 promotes DNA targeting

    International Nuclear Information System (INIS)

    Gross, Henrik; Barth, Stephanie; Palermo, Richard D.; Mamiani, Alfredo; Hennard, Christine; Zimber-Strobl, Ursula; West, Michelle J.; Kremmer, Elisabeth; Graesser, Friedrich A.

    2010-01-01

    The Epstein-Barr virus (EBV) growth-transforms B-lymphocytes. The virus-encoded nuclear antigen 2 (EBNA2) is essential for transformation and activates gene expression by association with DNA-bound transcription factors such as RBPJκ (CSL/CBF1). We have previously shown that EBNA2 contains symmetrically dimethylated Arginine (sDMA) residues. Deletion of the RG-repeat results in a reduced ability of the virus to immortalise B-cells. We now show that the RG repeat also contains asymmetrically dimethylated Arginines (aDMA) but neither non-methylated (NMA) Arginines nor citrulline residues. We demonstrate that only aDMA-containing EBNA2 is found in a complex with DNA-bound RBPJκ in vitro and preferentially associates with the EBNA2-responsive EBV C, LMP1 and LMP2A promoters in vivo. Inhibition of methylation in EBV-infected cells results in reduced expression of the EBNA2-regulated viral gene LMP1, providing additional evidence that methylation is a prerequisite for DNA-binding by EBNA2 via association with the transcription factor RBPJκ.

  12. Cinchona alkaloids in asymmetric organocatalysis

    NARCIS (Netherlands)

    Marcelli, T.; Hiemstra, H.

    2010-01-01

    This article reviews the applications of cinchona alkaloids as asymmetric catalysts. In the last few years, characterized by the resurgence of interest in asymmetric organocatalysis, cinchona derivatives have been shown to catalyze an outstanding array of chemical reactions, often with remarkable

  13. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  14. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  15. Asymmetric Higgsino dark matter.

    Science.gov (United States)

    Blum, Kfir; Efrati, Aielet; Grossman, Yuval; Nir, Yosef; Riotto, Antonio

    2012-08-03

    In the supersymmetric framework, prior to the electroweak phase transition, the existence of a baryon asymmetry implies the existence of a Higgsino asymmetry. We investigate whether the Higgsino could be a viable asymmetric dark matter candidate. We find that this is indeed possible. Thus, supersymmetry can provide the observed dark matter abundance and, furthermore, relate it with the baryon asymmetry, in which case the puzzle of why the baryonic and dark matter mass densities are similar would be explained. To accomplish this task, two conditions are required. First, the gauginos, squarks, and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the Higgsinos. With this spectrum, supersymmetry does not solve the fine-tuning problem. Second, the temperature of the electroweak phase transition must be low, in the (1-10) GeV range. This condition requires an extension of the minimal supersymmetric standard model.

  16. Asymmetric Organocatalytic Cycloadditions

    DEFF Research Database (Denmark)

    Mose, Rasmus

    2016-01-01

    has gained broad recognition as it has found several applications in academia and industry. The [4+2] cycloaddition has also been performed in an enantioselective aminocatalytic fashion which allows the generation of optically active products. In this thesis it is demonstrated how trienamines can......Since the onset of the new millennium the field of organocatalysis has undergone a great expansion led by investigations in the field of aminocatalysis. This thesis will address some recent developments in aminocatalyzed cycloadditions and provide a theoretical background hereto. Cycloadditions...... undergo cascade reactions with different electron deficient dienophiles in Diels Alder – nucleophilic ring closing reactions. This methodology opens up for the direct asymmetric formation of hydroisochromenes and hydroisoquinolines which may possess interesting biological activities. It is also...

  17. Evaluation of cardiovascular biomarkers in patients with age-related wet macular degeneration

    Directory of Open Access Journals (Sweden)

    Keles S

    2014-08-01

    Full Text Available Sadullah Keles,1 Orhan Ates,1 Baki Kartal,2 Hamit Hakan Alp,3 Metin Ekinci,4 Erdinc Ceylan,2 Osman Ondas,5 Eren Arpali,2 Semih Dogan,6 Kenan Yildirim,7 Mevlut Sait Keles8 1Department of Ophthalmology, School of Medicine, Ataturk University, Erzurum, Turkey; 2Department of Ophthalmology, Regional Training and Research Hospital, Erzurum, Turkey; 3Department of Biochemistry, School of Medicine, Yuzuncu Yil University, Van, Turkey; 4Department of Ophthalmology, School of Medicine, Kafkas University, Kars, Turkey; 5Department of Ophthalmology, Erbaa Government Hospital, Tokat, Turkey; 6Department of Ophthalmology, Kolan Hospital, Istanbul, Turkey; 7Department of Ophthalmology, Igdir Government Hospital, Igdir, Turkey; 8Department of Biochemistry, School of Medicine, Ataturk University, Erzurum, Turkey Aim: To evaluate levels of homocysteine, asymmetric dimethylarginine (ADMA, and nitric oxide (NO, as well as activity of endothelial NO synthase (eNOS, in patients with age-related macular degeneration (AMD.Methods: The levels of homocysteine, ADMA, and NO and activity of eNOS in patients who were diagnosed with wet AMD by fundus fluorescein angiography (n=30 were compared to a control group with no retinal pathology (n=30.Results: Levels of homocysteine and ADMA were found to be significantly higher in the wet AMD group than in the control group (P<0.001, whereas NO levels and eNOS activity were higher in the control group (P<0.001. In the wet AMD group, we detected a 2.64- and 0.33-fold increase in the levels of ADMA and homocysteine, respectively, and a 0.49- and 2.41-fold decrease in the eNOS activity and NO level, respectively.Conclusion: Elevated levels of homocysteine and ADMA were observed in patients with wet AMD. Increased ADMA may be responsible for the diminished eNOS activity found in these patients, which in turn contributes to the decrease in NO levels, which likely plays a role in the pathogenesis of AMD. Keywords: age-related macular

  18. Positive Impact of Nutritional Interventions on Serum Symmetric Dimethylarginine and Creatinine Concentrations in Client-Owned Geriatric Cats.

    Directory of Open Access Journals (Sweden)

    Jean A Hall

    Full Text Available A prospective study was conducted in client-owned geriatric cats to evaluate the short- term effects of a test food on serum symmetric dimethylarginine (SDMA and creatinine (Cr concentrations. Test food contained functional lipids (fish oil, antioxidants (vitamins C and E, L-carnitine, botanicals (vegetables, highly bioavailable protein, and amino acid supplements. Cats (n = 80 were fed either test food or owner's-choice foods (non-nutritionally controlled cohort. Cats were included based on age (≥ 9 years, indoor only, neutered, and free of chronic disease. At baseline, all cats had serum Cr concentrations within the reference interval. Renal function biomarkers and urinalysis results at baseline and after consuming test food or owner's-choice foods for 3 and 6 months were evaluated. Cats consuming test food showed significant decreases in serum Cr and BUN concentrations across time. Overall, cats consuming owner's-choice foods showed significant increases in serum SDMA concentrations at 3 and 6 months compared with baseline (P ≤ 0.05, whereas in cats consuming test food serum SDMA concentrations did not change. At baseline or during the 6-month feeding trial, 23 (28.8% cats had increased serum SDMA, but normal serum Cr consistent with IRIS Stage 1 chronic kidney disease. This included 6 cats fed test food and 17 cats fed owner's-choice foods. In the 6 cats fed test food, serum SDMA decreased in 3 cats and remained stable in 1 cat, whereas in the 17 cats fed owner's-choice foods, serum SDMA increased in 13 cats and decreased or remained stable in 4 cats. The increase in serum SDMA concentration was significant (P = 0.02 only for cats fed owner's-choice foods. These results suggest that nonazotemic cats with elevated serum SDMA (early renal insufficiency when fed a food designed to promote healthy aging are more likely to demonstrate stable renal function compared with cats fed owner's-choice foods. Cats fed owner's-choice foods were more

  19. Force on an Asymmetric Capacitor

    National Research Council Canada - National Science Library

    Bahder, Thomas

    2003-01-01

    .... At present, the physical basis for the Biefeld-Brown effect is not understood. The order of magnitude of the net force on the asymmetric capacitor is estimated assuming two different mechanisms of charge conduction between its electrodes...

  20. Asymmetric cation-binding catalysis

    DEFF Research Database (Denmark)

    Oliveira, Maria Teresa; Lee, Jiwoong

    2017-01-01

    The employment of metal salts is quite limited in asymmetric catalysis, although it would provide an additional arsenal of safe and inexpensive reagents to create molecular functions with high optical purity. Cation chelation by polyethers increases the salts' solubility in conventional organic...... solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...... highly enantioselective silylation reactions in polyether-generated chiral environments, and leading to a record-high turnover in asymmetric organocatalysis. This can lead to further applications by the asymmetric use of other inorganic salts in various organic transformations....

  1. Multicatalyst system in asymmetric catalysis

    CERN Document Server

    Zhou, Jian

    2014-01-01

    This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis.  Helps organic chemists perform more efficient catalysis with step-by-step methods  Overviews new concepts and progress for greener and economic catalytic reactions  Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions   Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance

  2. Asymmetric Gepner models (revisited)

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain)] [IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2010-12-11

    We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as the number of families, singlets and mirrors have an interesting tendency towards smaller values as the gauge groups approaches the Standard Model. We compare our results with an analogous class of free fermionic models. This displays similar features, but with less resolution. Finally we present a complete scan of the three family models based on the triply-exceptional combination (1,16{sup *},16{sup *},16{sup *}) identified originally by Gepner. We find 1220 distinct three family spectra in this case, forming 610 mirror pairs. About half of them have the gauge group SU(3)xSU(2){sub L}xSU(2){sub R}xU(1){sup 5}, the theoretical minimum, and many others are trinification models.

  3. The relationship of nitric oxide synthesis capacity, oxidative stress, and albumin-to-creatinine ratio in black and white men: the SABPA study.

    Science.gov (United States)

    Mels, Catharina M C; Huisman, Hugo W; Smith, Wayne; Schutte, Rudolph; Schwedhelm, Edzard; Atzler, Dorothee; Böger, Rainer H; Ware, Lisa J; Schutte, Aletta E

    2016-02-01

    Inadequate substrate availability and increased nitric oxide synthase inhibitor levels attenuate nitric oxide (NO) synthesis, whereas increased vascular oxidative stress may lead to inactivation of NO. We compared markers of NO synthesis capacity and oxidative stress in a bi-ethnic male population. Inter-relationships of ambulatory blood pressure and urinary albumin-to-creatinine ratio with NO synthesis capacity and oxidative stress markers were investigated. NO synthesis capacity markers (L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA)) and oxidative stress markers (serum peroxides, total glutathione, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), and catalase) were measured. Black men displayed higher blood pressure and albumin-to-creatinine ratio (all p creatinine ratio. In white men, albumin-to-creatinine ratio was positively associated with ADMA (R (2) = 0.18; β = 0.39; p creatinine ratio displayed a favorable NO synthesis capacity. This may be counteracted by increased inactivation of NO, although it was not linked to vascular or renal phenotypes. In white men, reduced NO synthesis capacity may lower NO bio-availability, thereby influencing the albumin-to-creatinine ratio.

  4. Maternal Melatonin Therapy Attenuated Maternal High-Fructose Combined with Post-Weaning High-Salt Diets-Induced Hypertension in Adult Male Rat Offspring

    Directory of Open Access Journals (Sweden)

    You-Lin Tain

    2018-04-01

    Full Text Available Consumption of food high in fructose and salt is associated with the epidemic of hypertension. Hypertension can originate from early life. Melatonin, a pleiotropic hormone, regulates blood pressure. We examined whether maternal melatonin therapy can prevent maternal high-fructose combined with post-weaning high-salt diet-induced programmed hypertension in adult offspring. Pregnant Sprague-Dawley rats received either a normal diet (ND or a 60% fructose diet (HF during pregnancy and the lactation period. Male offspring were on either the ND or a high-salt diet (HS, 1% NaCl from weaning to 12 weeks of age and were assigned to five groups (n = 8/group: ND/ND, HF/ND, ND/HS, HF/HS, and HF/HS+melatonin. Melatonin (0.01% in drinking water was administered during pregnancy and lactation. We observed that maternal HF combined with post-weaning HS diets induced hypertension in male adult offspring, which was attenuated by maternal melatonin therapy. The beneficial effects of maternal melatonin therapy on HF/HS-induced hypertension related to regulating several nutrient-sensing signals, including Sirt1, Sirt4, Prkaa2, Prkab2, Pparg, and Ppargc1a. Additionally, melatonin increased protein levels of mammalian targets of rapamycin (mTOR, decreased plasma asymmetric dimethylarginine (ADMA and symmetric dimethylarginine levels, and increased the l-arginine-to-ADMA ratio. The reprogramming effects by which maternal melatonin therapy protects against hypertension of developmental origin awaits further elucidation.

  5. Evaluation of endogenous nitric oxide synthesis in congenital urea cycle enzyme defects.

    Science.gov (United States)

    Nagasaka, Hironori; Tsukahara, Hirokazu; Yorifuji, Tohru; Miida, Takashi; Murayama, Kei; Tsuruoka, Tomoko; Takatani, Tomozumi; Kanazawa, Masaki; Kobayashi, Kunihiko; Okano, Yoshiyuki; Takayanagi, Masaki

    2009-03-01

    Nitric oxide (NO) is synthesized from arginine and O(2) by nitric oxide synthase (NOS). Citrulline, which is formed as a by-product of the NOS reaction, can be recycled to arginine by the 2 enzymes acting in the urea cycle: argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL). Although the complete urea cycle is expressed only in the liver, ASS and ASL are expressed in other organs including the kidney and vascular endothelium. To examine possible alterations of the NO pathway in urea cycle defects, we measured plasma concentrations of arginine and citrulline and serum concentrations of nitrite/nitrate (NOx(-), stable NO metabolites) and asymmetric dimethylarginine (ADMA, an endogenous NOS inhibitor) in patients with congenital urea cycle disorders of 3 types: ornithine transcarbamylase (OTC) deficiency, ASS deficiency, and ASL deficiency. All were receiving oral arginine replacement at the time of this study. The same parameters were also measured in healthy subjects, who participated as controls. The OTC-deficient patients had significantly high NOx(-) and nonsignificantly high ADMA concentrations. Their NOx(-) was significantly positively correlated with arginine. The ASS-deficient patients had significantly low NOx(-) and significantly high ADMA concentrations. The ASL-deficient patients had normal NOx(-) and nonsignificantly high ADMA concentrations. In ASS-deficient and ASL-deficient patients, the NOx(-) was significantly inversely correlated with citrulline. These results suggest that NO synthesis is enhanced in OTC-deficient patients while receiving arginine but that NO synthesis remains low in ASS-deficient patients despite receiving arginine. They also suggest that endogenous NO synthesis is negatively affected by citrulline and ADMA in ASS-deficient and ASL-deficient patients. Although the molecular mechanisms remain poorly understood, we infer that the NO pathway might play a role in the pathophysiology related to congenital urea cycle

  6. Does asymmetric correlation affect portfolio optimization?

    Science.gov (United States)

    Fryd, Lukas

    2017-07-01

    The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

  7. Asymmetric Synthesis via Chiral Aziridines

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Harden, Adrian; Wyatt, Paul

    1996-01-01

    A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the b......A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines...

  8. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  9. Asymmetric Penning trap coherent states

    International Nuclear Information System (INIS)

    Contreras-Astorga, Alonso; Fernandez, David J.

    2010-01-01

    By using a matrix technique, which allows to identify directly the ladder operators, the coherent states of the asymmetric Penning trap are derived as eigenstates of the appropriate annihilation operators. They are compared with those obtained through the displacement operator method.

  10. JET and COMPASS asymmetrical disruptions

    Czech Academy of Sciences Publication Activity Database

    Gerasimov, S.N.; Abreu, P.; Baruzzo, M.; Drozdov, V.; Dvornova, A.; Havlíček, Josef; Hender, T.C.; Hronová-Bilyková, Olena; Kruezi, U.; Li, X.; Markovič, Tomáš; Pánek, Radomír; Rubinacci, G.; Tsalas, M.; Ventre, S.; Villone, F.; Zakharov, L.E.

    2015-01-01

    Roč. 55, č. 11 (2015), s. 113006-113006 ISSN 0029-5515 R&D Projects: GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : tokamak * asymmetrical disruption * JET * COMPASS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.040, year: 2015

  11. HPLC-MS/MS investigation of biochemical markers for the disclosure of erythropoietin abuse in sports

    Science.gov (United States)

    Appolonova, S. A.; Dikunets, M. A.; Rodchenkov, G. M.

    2009-04-01

    The polypeptide hormone erythropoietin (EPO), which is a forbidden doping drug, was determined by high-performance liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS). The hypothesis about the influence of EPO on the asymmetric dimethylarginine (ADMA)-dimethylargininedime-thylaminohydrolase (DDAH)-NO-synthase system was verified. Changes in this system can serve as indirect biochemical markers of the presence of the forbidden EPO drug in the organism. In the test group, the concentrations of biochemical markers varied from 10 to 40 μg/ml for ADMA and symmetrical DMA (SDMA) and from 0.5 to 10 μg/ml for arginine and citrulline. A single intravenous administration of r-HuEPO (Epocrin, 2000 ME/day) for two volunteers reliably increased ADMA, SDMA, arginine, and citrulline concentrations to 40-270 μg/ml, 40-240μg/ml, 10-60 μg/ml, and 12-140 μg/ml, respectively, with respect to the reference values. The simultaneous increase in arginine, methylarginines, and citrulline contents could be an indirect marker of EPO abuse. The method is recommended for fast screening analysis.

  12. 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.

  13. Melatonin Therapy Prevents Programmed Hypertension and Nitric Oxide Deficiency in Offspring Exposed to Maternal Caloric Restriction

    Directory of Open Access Journals (Sweden)

    You-Lin Tain

    2014-01-01

    Full Text Available Nitric oxide (NO deficiency is involved in the development of hypertension, a condition that can originate early in life. We examined whether NO deficiency contributed to programmed hypertension in offspring from mothers with calorie-restricted diets and whether melatonin therapy prevented this process. We examined 3-month-old male rat offspring from four maternal groups: untreated controls, 50% calorie-restricted (CR rats, controls treated with melatonin (0.01% in drinking water, and CR rats treated with melatonin (CR + M. The effect of melatonin on nephrogenesis was analyzed using next-generation sequencing. The CR group developed hypertension associated with elevated plasma asymmetric dimethylarginine (ADMA, a nitric oxide synthase inhibitor, decreased L-arginine, decreased L-arginine-to-ADMA ratio (AAR, and decreased renal NO production. Maternal melatonin treatment prevented these effects. Melatonin prevented CR-induced renin and prorenin receptor expression. Renal angiotensin-converting enzyme 2 protein levels in the M and CR + M groups were also significantly increased by melatonin therapy. Maternal melatonin therapy had long-term epigenetic effects on global gene expression in the kidneys of offspring. Conclusively, we attributed these protective effects of melatonin on CR-induced programmed hypertension to the reduction of plasma ADMA, restoration of plasma AAR, increase of renal NO level, alteration of renin-angiotensin system, and epigenetic changes in numerous genes.

  14. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Directory of Open Access Journals (Sweden)

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  15. Application of a new procedure for liquid chromatography/mass spectrometry profiling of plasma amino acid-related metabolites and untargeted shotgun proteomics to identify mechanisms and biomarkers of calcific aortic stenosis.

    Science.gov (United States)

    Olkowicz, Mariola; Debski, Janusz; Jablonska, Patrycja; Dadlez, Michal; Smolenski, Ryszard T

    2017-09-29

    Calcific aortic valve stenosis (CAS) increasingly affects our ageing population, but the mechanisms of the disease and its biomarkers are not well established. Recently, plasma amino acid-related metabolite (AA) profiling has attracted attention in studies on pathology and development of biomarkers of cardiovascular diseases, but has not been studied in CAS. To evaluate the potential relationship between CAS and AA metabolome, a new ion-pairing reversed-phase liquid chromatography-tandem mass spectrometry (IP-RPLC-MS/MS) method has been developed and validated for simultaneous determination of 43 AAs in plasma of stenotic patients and age-matched control subjects. Furthermore, untargeted mass spectrometry-based proteomic analysis and confirmatory ELISA assays were performed. The method developed offered high accuracy (intra-assay imprecision averaged 4.4% for all compounds) and sensitivity (LOQ within 0.01-0.5μM). We found that 22 AAs and three AA ratios significantly changed in the CAS group as compared to control. The most pronounced differences were observed in urea cycle-related AAs and branched-chain AA (BCAA)-related AAs. The contents of asymmetric dimethylarginine (ADMA) and its monomethylated derivative (NMMA) were increased by 30-64% with CAS. The arginine/ADMA and Fischer's ratios as well as arginine, homoarginine, ADMA, symmetric dimethylarginine, hydroxyproline, betaine and 3-methylhistidine correlated with cardiac function-related parameters and concomitant systemic factors in the CAS patients. The results of proteomic analysis were consistent with involvement of inflammation, lipid abnormalities, hemostasis and extracellular matrix remodeling in CAS. In conclusion, changes in plasma AA profile and protein pattern that we identified in CAS provide information relevant to pathomechanisms and may deliver new biomarkers of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Skin autofluorescence as a novel marker of vascular damage in children and adolescents with chronic kidney disease.

    Science.gov (United States)

    Makulska, Irena; Szczepańska, Maria; Drożdż, Dorota; Polak-Jonkisz, Dorota; Zwolińska, Danuta

    2015-05-01

    Skin autofluorescence (sAF) was examined as a marker of the accumulation of advanced glycation end products (AGEs) in tissues of children with chronic kidney disease (CKD) in relation to renal function, dialysis modality and markers of endothelial inflammation and dysfunction. A total of 76 children with CKD were enrolled in the study, of whom 20 children were on hemodialysis (HD), 20 were on peritoneal dialysis (PD) and 36 were treated conservatively. A control group of 26 healthy subjects was also included in the study. In all children, sAF intensity, carotid intima-media (cIMT) thickness and plasma concentrations of sE-selectin, matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1), asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and plasminogen activator inhibitor type 1 (PAI-1) were measured. Compared to the controls, children with CKD had significantly elevated sAF levels. sAF in the children with CKD was positively correlated with sE-selectin, MMP-9, TIMP-1, ADMA, SDMA and PAI-1 levels. In the predialysis group (conservative treatment) sAF levels were positively correlated with sE-selectin and ADMA levels and negatively correlated with glomerular filtration rate. Multiple regression analysis showed a significant association of sAF with sE-selectin and MMP-9 in CKD children. The results reveal that AGEs were accumulated in the children with CKD. This accumulation was related to early vascular changes and a number of biochemical vascular risk markers. sAF measurement, as a noninvasive method, may be useful for identification of clinical risk factors of vascular disease in CKD children.

  17. Electron Jet of Asymmetric Reconnection

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Graham, D. B.; Norgren, C.; Eriksson, E.; Li, W.; Johlander, A.; Vaivads, A.; Andre, M.; Pritchett, P. L.; Retino, A.; hide

    2016-01-01

    We present Magnetospheric Multiscale observations of an electron-scale current sheet and electron outflow jet for asymmetric reconnection with guide field at the subsolar magnetopause. The electron jet observed within the reconnection region has an electron Mach number of 0.35 and is associated with electron agyrotropy. The jet is unstable to an electrostatic instability which generates intense waves with E(sub parallel lines) amplitudes reaching up to 300 mV/m and potentials up to 20% of the electron thermal energy. We see evidence of interaction between the waves and the electron beam, leading to quick thermalization of the beam and stabilization of the instability. The wave phase speed is comparable to the ion thermal speed, suggesting that the instability is of Buneman type, and therefore introduces electron-ion drag and leads to braking of the electron flow. Our observations demonstrate that electrostatic turbulence plays an important role in the electron-scale physics of asymmetric reconnection.

  18. Stable walking with asymmetric legs

    International Nuclear Information System (INIS)

    Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

    2011-01-01

    Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

  19. Variable angle asymmetric cut monochromator

    International Nuclear Information System (INIS)

    Smither, R.K.; Fernandez, P.B.

    1993-09-01

    A variable incident angle, asymmetric cut, double crystal monochromator was tested for use on beamlines at the Advanced Photon Source (APS). For both undulator and wiggler beams the monochromator can expand area of footprint of beam on surface of the crystals to 50 times the area of incident beam; this will reduce the slope errors by a factor of 2500. The asymmetric cut allows one to increase the acceptance angle for incident radiation and obtain a better match to the opening angle of the incident beam. This can increase intensity of the diffracted beam by a factor of 2 to 5 and can make the beam more monochromatic, as well. The monochromator consists of two matched, asymmetric cut (18 degrees), silicon crystals mounted so that they can be rotated about three independent axes. Rotation around the first axis controls the Bragg angle. The second rotation axis is perpendicular to the diffraction planes and controls the increase of the area of the footprint of the beam on the crystal surface. Rotation around the third axis controls the angle between the surface of the crystal and the wider, horizontal axis for the beam and can make the footprint a rectangle with a minimum. length for this area. The asymmetric cut is 18 degrees for the matched pair of crystals, which allows one to expand the footprint area by a factor of 50 for Bragg angles up to 19.15 degrees (6 keV for Si[111] planes). This monochromator, with proper cooling, will be useful for analyzing the high intensity x-ray beams produced by both undulators and wigglers at the APS

  20. Asymmetric information and bank runs

    OpenAIRE

    Gu, Chao

    2007-01-01

    It is known that sunspots can trigger panic-based bank runs and that the optimal banking contract can tolerate panic-based runs. The existing literature assumes that these sunspots are based on a publicly observed extrinsic randomizing device. In this paper, I extend the analysis of panic-based runs to include an asymmetric-information, extrinsic randomizing device. Depositors observe different, but correlated, signals on the stability of the bank. I find that if the signals that depositors o...

  1. Asymmetric information and macroeconomic dynamics

    Science.gov (United States)

    Hawkins, Raymond J.; Aoki, Masanao; Roy Frieden, B.

    2010-09-01

    We show how macroeconomic dynamics can be derived from asymmetric information. As an illustration of the utility of this approach we derive the equilibrium density, non-equilibrium densities and the equation of motion for the response to a demand shock for productivity in a simple economy. Novel consequences of this approach include a natural incorporation of time dependence into macroeconomics and a common information-theoretic basis for economics and other fields seeking to link micro-dynamics and macro-observables.

  2. Asymmetric Synthesis of Apratoxin E.

    Science.gov (United States)

    Mao, Zhuo-Ya; Si, Chang-Mei; Liu, Yi-Wen; Dong, Han-Qing; Wei, Bang-Guo; Lin, Guo-Qiang

    2016-10-21

    An efficient method for asymmetric synthesis of apratoxin E 2 is described in this report. The chiral lactone 8, recycled from the degradation of saponin glycosides, was utilized to prepare the non-peptide fragment 6. In addition to this "from nature to nature" strategy, olefin cross-metathesis (CM) was applied as an alternative approach for the formation of the double bond. Moreover, pentafluorophenyl diphenylphosphinate was found to be an efficient condensation reagent for the macrocyclization.

  3. Comprehensive asymmetric dark matter model

    OpenAIRE

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-01-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical...

  4. Synthesis method of asymmetric gold particles.

    Science.gov (United States)

    Jun, Bong-Hyun; Murata, Michael; Hahm, Eunil; Lee, Luke P

    2017-06-07

    Asymmetric particles can exhibit unique properties. However, reported synthesis methods for asymmetric particles hinder their application because these methods have a limited scale and lack the ability to afford particles of varied shapes. Herein, we report a novel synthetic method which has the potential to produce large quantities of asymmetric particles. Asymmetric rose-shaped gold particles were fabricated as a proof of concept experiment. First, silica nanoparticles (NPs) were bound to a hydrophobic micro-sized polymer containing 2-chlorotritylchloride linkers (2-CTC resin). Then, half-planar gold particles with rose-shaped and polyhedral structures were prepared on the silica particles on the 2-CTC resin. Particle size was controlled by the concentration of the gold source. The asymmetric particles were easily cleaved from the resin without aggregation. We confirmed that gold was grown on the silica NPs. This facile method for synthesizing asymmetric particles has great potential for materials science.

  5. LG tools for asymmetric wargaming

    Science.gov (United States)

    Stilman, Boris; Yakhnis, Alex; Yakhnis, Vladimir

    2002-07-01

    Asymmetric operations represent conflict where one of the sides would apply military power to influence the political and civil environment, to facilitate diplomacy, and to interrupt specified illegal activities. This is a special type of conflict where the participants do not initiate full-scale war. Instead, the sides may be engaged in a limited open conflict or one or several sides may covertly engage another side using unconventional or less conventional methods of engagement. They may include peace operations, combating terrorism, counterdrug operations, arms control, support of insurgencies or counterinsurgencies, show of force. An asymmetric conflict can be represented as several concurrent interlinked games of various kinds: military, transportation, economic, political, etc. Thus, various actions of peace violators, terrorists, drug traffickers, etc., can be expressed via moves in different interlinked games. LG tools allow us to fully capture the specificity of asymmetric conflicts employing the major LG concept of hypergame. Hypergame allows modeling concurrent interlinked processes taking place in geographically remote locations at different levels of resolution and time scale. For example, it allows us to model an antiterrorist operation taking place simultaneously in a number of countries around the globe and involving wide range of entities from individuals to combat units to governments. Additionally, LG allows us to model all sides of the conflict at their level of sophistication. Intelligent stakeholders are represented by means of LG generated intelligent strategies. TO generate those strategies, in addition to its own mathematical intelligence, the LG algorithm may incorporate the intelligence of the top-level experts in the respective problem domains. LG models the individual differences between intelligent stakeholders. The LG tools make it possible to incorporate most of the known traits of a stakeholder, i.e., real personalities involved in

  6. Incompressibility of asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan

    2010-01-01

    Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)

  7. Asymmetric effects in customer satisfaction

    DEFF Research Database (Denmark)

    Füller, Johann; Matzler, Kurt; Faullant, Rita

    2006-01-01

    The results of this study on customer satisfaction in snowboard areas show that the relationship between an attribute and overall satisfaction can indeed be asymmetric. A 30-item self-administered survey was completed by snowboarders (n=2526) in 51 areas in Austria, Germany, Switzerland and Italy....... Results show that waiting time is a dissatisfier; it has a significant impact on overall customer satisfaction in the low satisfaction condition and becomes insignificant in the high satisfaction situation. Restaurants and bars are hybrids, i.e. importance does not depend on performance. Slopes, fun...

  8. Asymmetric Formal Synthesis of Azadirachtin.

    Science.gov (United States)

    Mori, Naoki; Kitahara, Takeshi; Mori, Kenji; Watanabe, Hidenori

    2015-12-01

    An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley's synthetic intermediate (longest linear sequence). The synthesis features: 1) rapid access to the optically active right-hand segment starting from the known 5-hydroxymethyl-2-cyclopentenone scaffold; 2) construction of the B and E rings by a key intramolecular tandem radical cyclization; 3) formation of the hemiacetal moiety in the C ring through the α-oxidation of the six-membered lactone followed by methanolysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Spontaneous baryogenesis from asymmetric inflaton

    International Nuclear Information System (INIS)

    Takahashi, Fuminobu

    2015-10-01

    We propose a variant scenario of spontaneous baryogenesis from asymmetric inflaton based on current-current interactions between the inflaton and matter fields with a non-zero B-L charge. When the inflaton starts to oscillate around the minimum after inflation, it may lead to excitation of a CP-odd component, which induces an effective chemical potential for the B-L number through the current-current interactions. We study concrete inflation models and show that the spontaneous baryogenesis scenario can be naturally implemented in the chaotic inflation in supergravity.

  10. Field factors for asymmetric collimators

    International Nuclear Information System (INIS)

    Turner, J.R.; Butler, A.P.H.

    1996-01-01

    In recent years manufacturers have been supplying linear accelerators with either a single pair or a dual pair of collimators. The use of a model to relate off-axis field factors to on-axis field factors obviates the need for repeat measurements whenever the asymmetric collimators are employed. We have investigated the variation of collimator scatter Sc, with distance of the central ray x from the central axis for a variety of non square field sizes. Collimator scatter was measured by in-air measurements with a build-up cap. The Primaty-Off-Centre-Ratio (POCR) was measured in-air by scanning orthogonally across the beam with an ionization chamber. The result of the investigation is the useful prediction of off-axis field factors for a range of rectangular asymmetric fields using the simple product of the on-axis field factor and the POCR in air. The effect of asymmetry on the quality of the beam and hence the percent depth dose will be discussed. (author)

  11. Antiatherogenic effects of oleanolic acid in apolipoprotein E knockout mice

    DEFF Research Database (Denmark)

    Buus, Niels Henrik; Hansson, Nicolaj Christopher; Rodriguez-Rodriguez, Rosalia

    2011-01-01

    were investigated in vitro. Inducible nitric oxide synthase (iNOS) was visualized using immunoblotting. As opposed to WT and fluvastatin- and vehicle-treated mice, OA-fed ApoE(-/-) mice gained no weight during the treatment period. Plasma concentrations of total-cholesterol and triglyceride were...... in combination with OA (100 mg/kg/day), fluvastatin (5 mg/kg/day) or vehicle, with wild type (WT) mice serving as controls. After 8 weeks of treatment atherosclerotic plaque areas in the aortic arch and plasma lipid concentrations were determined. Vasoconstriction and relaxation of the proximal part of aorta...... not significantly reduced by OA- or fluvastatin treatment. Plaque area of vehicle-treated mice was 25%, but only 14% in OA- and 19% in fluvastatin-treated mice. As compared to WT, vasoconstriction to phenylephrine was attenuated in ApoE(-/-) mice. The NOS inhibitor asymmetric dimethylarginine (ADMA) enhanced...

  12. Weight loss and vascular inflammatory markers in overweight women with and without polycystic ovary syndrome.

    Science.gov (United States)

    Moran, Lisa J; Noakes, Manny; Wittert, Gary A; Clifton, Peter M; Norman, Robert J

    2012-11-01

    Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular disease risk. The effect of weight loss on the vascular inflammatory markers plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA), soluble vascular cell adhesion molecule-1 (sVCAM-1) and intracellular adhesion molecule-1 (sICAM-1) is unknown. Overweight women with (n=14) and without (n=13) PCOS of comparable age and body mass index undertook an 8-week weight-loss programme. Women with PCOS had elevated PAI-1, sVCAM-1 and sICAM-1 before and after weight loss compared with the controls. For all women, sVCAM-1 (P=0.026) and sICAM-1 (P=0.04) decreased with weight loss. Women with PCOS have elevated inflammatory markers, which are partially reduced by weight loss. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Brain-natriuretic peptide and cyclic guanosine monophosphate as biomarkers of myxomatous mitral valve disease in dogs

    DEFF Research Database (Denmark)

    Moesgaard, Sophia Gry; Falk, Bo Torkel; Teerlink, Tom

    2011-01-01

    Elevations in the plasma concentrations of natriuretic peptides correlate with increased severity of myxomatous mitral valve disease (MMVD) in dogs. This study correlates the severity of MMVD with the plasma concentrations of the biomarkers N-terminal fragment of the pro-brain-natriuretic peptide...... (NT-proBNP) and its second messenger, cyclic guanosine monophosphate (cGMP). Furthermore, the l-arginine:asymmetric dimethylarginine (ADMA) ratio was measured as an index of nitric oxide availability. The study included 75 dogs sub-divided into five groups based on severity of MMVD as assessed...... by clinical examination and echocardiography. Plasma NT-proBNP and cGMP concentrations increased with increasing valve dysfunction and were significantly elevated in dogs with heart failure. The cGMP:NT-proBNP ratio decreased significantly in dogs with heart failure, suggesting the development of natriuretic...

  14. Asymmetric Frontal Brain Activity and Parental Rejection

    NARCIS (Netherlands)

    Huffmeijer, R.; Alink, L.R.A.; Tops, M.; Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.

    2013-01-01

    Asymmetric frontal brain activity has been widely implicated in reactions to emotional stimuli and is thought to reflect individual differences in approach-withdrawal motivation. Here, we investigate whether asymmetric frontal activity, as a measure of approach-withdrawal motivation, also predicts

  15. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...

  16. Mechanochemistry assisted asymmetric organocatalysis: A sustainable approach

    Directory of Open Access Journals (Sweden)

    Pankaj Chauhan

    2012-12-01

    Full Text Available Ball-milling and pestle and mortar grinding have emerged as powerful methods for the development of environmentally benign chemical transformations. Recently, the use of these mechanochemical techniques in asymmetric organocatalysis has increased. This review highlights the progress in asymmetric organocatalytic reactions assisted by mechanochemical techniques.

  17. Designing asymmetric multiferroics with strong magnetoelectric coupling

    Science.gov (United States)

    Lu, Xuezeng; Xiang, Hongjun; Rondinelli, James; Materials Theory; Design Group Team

    2015-03-01

    Multiferroics offer exciting opportunities for electric-field control of magnetism. Single-phase multiferroics suitable for such applications at room temperature need much more study. Here, we propose the concept of an alternative type of multiferroics, namely, the ``asymmetric multiferroic.'' In asymmetric multiferroics, two locally stable ferroelectric states are not symmetrically equivalent, leading to different magnetic properties between these two states. Furthermore, we predict from first principles that a Fe-Cr-Mo superlattice with the LiNbO3-type structure is such an asymmetric multiferroic. The strong ferrimagnetism, high ferroelectric polarization, and significant dependence of the magnetic transition temperature on polarization make this asymmetric multiferroic an ideal candidate for realizing electric-field control of magnetism at room temperature. Our study suggests that the asymmetric multiferroic may provide an alternative playground for voltage control of magnetism and find its applications in spintronics and quantum computing.

  18. A case of asymmetrical arthrogryposis

    International Nuclear Information System (INIS)

    Hageman, G.; Vette, J.K.; Willemse, J.

    1983-01-01

    Following the introduction of the conception that arthrogryposis is a symptom and not a clinical entity, a case of the very rare asymmetric form of neurogenic arthrogryposis is presented. The asymmetry of congenital contractures and weakness is associated with hemihypotrophy. The value of muscular CT-scanning prior to muscle biopsy is demonstrated. Muscular CT-scanning shows the extension of adipose tissue, which has replaced damaged muscles and therby indicates the exact site for muscle biopsy. Since orthopaedic treatment in arthrogryposis can be unrewarding due to severe muscular degeneration, preoperative scanning may provide additional important information on muscular function and thus be of benefit for surgery. The advantage of muscular CT-scanning in other forms of arthrogryposis requires further determination. The differential diagnosis with Werdnig-Hoffmann disease is discussed. (author)

  19. Comprehensive asymmetric dark matter model

    Science.gov (United States)

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-05-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a Z2 parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilizing the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the C P -violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.

  20. Chaos of several typical asymmetric systems

    International Nuclear Information System (INIS)

    Feng Jingjing; Zhang Qichang; Wang Wei

    2012-01-01

    The threshold for the onset of chaos in asymmetric nonlinear dynamic systems can be determined using an extended Padé method. In this paper, a double-well asymmetric potential system with damping under external periodic excitation is investigated, as well as an asymmetric triple-well potential system under external and parametric excitation. The integrals of Melnikov functions are established to demonstrate that the motion is chaotic. Threshold values are acquired when homoclinic and heteroclinic bifurcations occur. The results of analytical and numerical integration are compared to verify the effectiveness and feasibility of the analytical method.

  1. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....

  2. Modeling of asymmetrical boost converters

    Directory of Open Access Journals (Sweden)

    Eliana Isabel Arango Zuluaga

    2014-01-01

    Full Text Available The asymmetrical interleaved dual boost (AIDB is a fifth-order DC/DC converter designed to interface photovoltaic (PV panels. The AIDB produces small current harmonics to the PV panels, reducing the power losses caused by the converter operation. Moreover, the AIDB provides a large voltage conversion ratio, which is required to step-up the PV voltage to the large dc-link voltage used in grid-connected inverters. To reject irradiance and load disturbances, the AIDB must be operated in a closed-loop and a dynamic model is required. Given that the AIDB converter operates in Discontinuous Conduction Mode (DCM, classical modeling approaches based on Continuous Conduction Mode (CCM are not valid. Moreover, classical DCM modeling techniques are not suitable for the AIDB converter. Therefore, this paper develops a novel mathematical model for the AIDB converter, which is suitable for control-pur-poses. The proposed model is based on the calculation of a diode current that is typically disregarded. Moreover, because the traditional correction to the second duty cycle reported in literature is not effective, a new equation is designed. The model accuracy is contrasted with circuital simulations in time and frequency domains, obtaining satisfactory results. Finally, the usefulness of the model in control applications is illustrated with an application example.

  3. Asymmetric Supercapacitor Electrodes and Devices.

    Science.gov (United States)

    Choudhary, Nitin; Li, Chao; Moore, Julian; Nagaiah, Narasimha; Zhai, Lei; Jung, Yeonwoong; Thomas, Jayan

    2017-06-01

    The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Bioinspired smart asymmetric nanochannel membranes.

    Science.gov (United States)

    Zhang, Zhen; Wen, Liping; Jiang, Lei

    2018-01-22

    Bioinspired smart asymmetric nanochannel membranes (BSANM) have been explored extensively to achieve the delicate ionic transport functions comparable to those of living organisms. The abiotic system exhibits superior stability and robustness, allowing for promising applications in many fields. In view of the abundance of research concerning BSANM in the past decade, herein, we present a systematic overview of the development of the state-of-the-art BSANM system. The discussion is focused on the construction methodologies based on raw materials with diverse dimensions (i.e. 0D, 1D, 2D, and bulk). A generic strategy for the design and construction of the BSANM system is proposed first and put into context with recent developments from homogeneous to heterogeneous nanochannel membranes. Then, the basic properties of the BSANM are introduced including selectivity, gating, and rectification, which are associated with the particular chemical and physical structures. Moreover, we summarized the practical applications of BSANM in energy conversion, biochemical sensing and other areas. In the end, some personal opinions on the future development of the BSANM are briefly illustrated. This review covers most of the related literature reported since 2010 and is intended to build up a broad and deep knowledge base that can provide a solid information source for the scientific community.

  5. Reflection asymmetric shapes in nuclei

    International Nuclear Information System (INIS)

    Ahmad, I.; Carpenter, M.P.; Emling, H.

    1989-01-01

    Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N∼134, Z∼88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin ∼8ℎ. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin ∼7ℎ. The nuclei which exhibit octupole deformation in this mass region are 144 Ba, 146 Ba and 146 Ce; 142 Ba, 148 Ce, 150 Ce and 142 Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab

  6. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  7. Lift production through asymmetric flapping

    Science.gov (United States)

    Jalikop, Shreyas; Sreenivas, K. R.

    2009-11-01

    At present, there is a strong interest in developing Micro Air Vehicles (MAV) for applications like disaster management and aerial surveys. At these small length scales, the flight of insects and small birds suggests that unsteady aerodynamics of flapping wings can offer many advantages over fixed wing flight, such as hovering-flight, high maneuverability and high lift at large angles of attack. Various lift generating mechanims such as delayed stall, wake capture and wing rotation contribute towards our understanding of insect flight. We address the effect of asymmetric flapping of wings on lift production. By visualising the flow around a pair of rectangular wings flapping in a water tank and numerically computing the flow using a discrete vortex method, we demonstrate that net lift can be produced by introducing an asymmetry in the upstroke-to-downstroke velocity profile of the flapping wings. The competition between generation of upstroke and downstroke tip vortices appears to hold the key to understanding this lift generation mechanism.

  8. An efficient catalyst for asymmetric Reformatsky reaction

    Indian Academy of Sciences (India)

    rate enantioselectivity using N,N-dialkylnorephedrines as chiral ligands. ..... temperatures also, there was no product conversion. ... Optimization of reaction conditions for asymmetric Reformatsky reaction between benzaldehyde and α-.

  9. Asymmetric cryptography based on wavefront sensing.

    Science.gov (United States)

    Peng, Xiang; Wei, Hengzheng; Zhang, Peng

    2006-12-15

    A system of asymmetric cryptography based on wavefront sensing (ACWS) is proposed for the first time to our knowledge. One of the most significant features of the asymmetric cryptography is that a trapdoor one-way function is required and constructed by analogy to wavefront sensing, in which the public key may be derived from optical parameters, such as the wavelength or the focal length, while the private key may be obtained from a kind of regular point array. The ciphertext is generated by the encoded wavefront and represented with an irregular array. In such an ACWS system, the encryption key is not identical to the decryption key, which is another important feature of an asymmetric cryptographic system. The processes of asymmetric encryption and decryption are formulized mathematically and demonstrated with a set of numerical experiments.

  10. Asymmetrical Representation of Gender in Amharic1

    African Journals Online (AJOL)

    Administrator

    in its grammar. Gender representation in this language is asymmetrical heavily ..... In dictionaries where. Amharic appears either as the target or the source language, verbs are entered ...... The Dialects of Amharic Revisited. Semitica et.

  11. Beam-beam issues in asymmetric colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  12. Congenital asymmetric crying face: a case report

    Directory of Open Access Journals (Sweden)

    Semra Kara

    2011-12-01

    Full Text Available Congenital asymmetric crying face is an anomalia caused by unilateral absence or weakness of depressor anguli oris muscle The major finding of the disease is the absence or weakness in the outer and lower movement of the commissure during crying. The other expression muscles are normal and the face is symmetric at rest. The asymmetry in congenital asymmetric crying face is most evident during infancy but decreases by age. Congenital asymmetric crying face can be associated with cervicofacial, musclebone, respiratory, genitourinary and central nervous system anomalia. It is diagnosed by physical examination. This paper presents a six days old infant with Congenital asymmetric crying face and discusses the case in terms of diagnosis and disease features.

  13. Asymmetric total synthesis of cladosporin and isocladosporin.

    Science.gov (United States)

    Zheng, Huaiji; Zhao, Changgui; Fang, Bowen; Jing, Peng; Yang, Juan; Xie, Xingang; She, Xuegong

    2012-07-06

    The first asymmetric total syntheses of cladosporin and isocladosporin were accomplished in 8 steps with 8% overall yield and 10 steps with 26% overall yield, respectively. The relative configuration of isocladosporin was determined via this total synthesis.

  14. Magnetically Modified Asymmetric Supercapacitors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle life....

  15. Impact of Secondary Interactions in Asymmetric Catalysis

    OpenAIRE

    Frölander, Anders

    2007-01-01

    This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. An OH–Pd hydrogen bond in Pd(0)–π-olefin complexes of hydroxy-containing oxazoline ligands was identified by density functional theory computations and helped to rationalize the contrasting results obtained emplo...

  16. Engineered Asymmetric Composite Membranes with Rectifying Properties.

    Science.gov (United States)

    Wen, Liping; Xiao, Kai; Sainath, Annadanam V Sesha; Komura, Motonori; Kong, Xiang-Yu; Xie, Ganhua; Zhang, Zhen; Tian, Ye; Iyoda, Tomokazu; Jiang, Lei

    2016-01-27

    Asymmetric composite membranes with rectifying properties are developed by grafting pH-stimulus-responsive materials onto the top layer of the composite structure, which is prepared by two novel block copolymers using a phase-separation technique. This engineered asymmetric composite membrane shows potential applications in sensors, filtration, and nanofluidic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Inclined asymmetric librations in exterior resonances

    Science.gov (United States)

    Voyatzis, G.; Tsiganis, K.; Antoniadou, K. I.

    2018-04-01

    Librational motion in Celestial Mechanics is generally associated with the existence of stable resonant configurations and signified by the existence of stable periodic solutions and oscillation of critical (resonant) angles. When such an oscillation takes place around a value different than 0 or π , the libration is called asymmetric. In the context of the planar circular restricted three-body problem, asymmetric librations have been identified for the exterior mean motion resonances (MMRs) 1:2, 1:3, etc., as well as for co-orbital motion (1:1). In exterior MMRs the massless body is the outer one. In this paper, we study asymmetric librations in the three-dimensional space. We employ the computational approach of Markellos (Mon Not R Astron Soc 184:273-281, https://doi.org/10.1093/mnras/184.2.273, 1978) and compute families of asymmetric periodic orbits and their stability. Stable asymmetric periodic orbits are surrounded in phase space by domains of initial conditions which correspond to stable evolution and librating resonant angles. Our computations were focused on the spatial circular restricted three-body model of the Sun-Neptune-TNO system (TNO = trans-Neptunian object). We compare our results with numerical integrations of observed TNOs, which reveal that some of them perform 1:2 resonant, inclined asymmetric librations. For the stable 1:2 TNO librators, we find that their libration seems to be related to the vertically stable planar asymmetric orbits of our model, rather than the three-dimensional ones found in the present study.

  18. Reversal modes in asymmetric Ni nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Leighton, B.; Pereira, A. [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J., E-mail: jescrigm@gmail.com [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile)

    2012-11-15

    We have investigated the evolution of the magnetization reversal mechanism in asymmetric Ni nanowires as a function of their geometry. Circular nanowires are found to reverse their magnetization by the propagation of a vortex domain wall, while in very asymmetric nanowires the reversal is driven by the propagation of a transverse domain wall. The effect of shape asymmetry of the wire on coercivity and remanence is also studied. Angular dependence of the remanence and coercivity is also addressed. Tailoring the magnetization reversal mechanism in asymmetric nanowires can be useful for magnetic logic and race-track memory, both of which are based on the displacement of magnetic domain walls. Finally, an alternative method to detect the presence of magnetic drops is proposed. - Highlights: Black-Right-Pointing-Pointer Asymmetry strongly modifies the magnetic behavior of a wire. Black-Right-Pointing-Pointer Very asymmetric nanowires reverse their magnetization by a transverse domain wall. Black-Right-Pointing-Pointer An alternative method to detect the presence of magnetic drops is proposed. Black-Right-Pointing-Pointer Tailoring the reversal mode in asymmetric nanowires can be useful for potential applications.

  19. Effect of arginine:lysine and glycine:methionine intake ratios on dyslipidemia and selected biomarkers implicated in cardiovascular disease: A study with hypercholesterolemic rats.

    Science.gov (United States)

    Venkatesh, Ravula; Srinivasan, Krishnapura; Singh, Sridevi Annapurna

    2017-07-01

    The effect of intake ratios of arginine (Arg): lysine (Lys) and glycine (Gly): methionine (Met) on lipid profile and selected cardiovascular disease markers, was studied, in rats maintained on a hypercholesterolemic diet. The rise in blood cholesterol was countered by 32%, 24%, and 49%, respectively, through increased oral supplementation of Arg, Gly, and Arg+Gly; a corresponding increase in plasma phospholipids at the end of the 8-week study was observed. The elevated plasma cholesterol to phospholipids ratio was countered by 27, 40, and 57%, respectively, through oral supplementation of Arg, Gly, and Arg+Gly. The elevation in hepatic cholesterol was lowered by 18, 29, and 51%, respectively, while phospholipids concentration was concomitantly increased by these amino acids. The elevated cholesterol to phospholipids ratio was, thus, significantly countered in the hypercholesterolemic situation by orally supplemented Arg, Gly, and Arg+Gly. Increased plasma asymmetric dimethylarginine (ADMA) levels, under hypercholesterolemic conditions, were lowered by 12, 15 and 34%, respectively, while plasma symmetric dimethylarginine (SDMA) levels were lowered by 14, 10 and 17%, respectively, with orally supplemented Arg, Gly and Arg+Gly. Only Gly and Arg+Gly decreased plasma homocysteine levels. Total nitric oxide (NO) concentration was considerably increased by Gly supplementation in hypercholesterolemic rats. Thus, altered ratios of Arg:Lys or Gly:Met offered beneficial influence on the lipid profile and plasma levels of ADMA, SDMA and homocysteine in hypercholesterolemic rats. Optimal beneficial effects, among ratios tested, was observed when Arg:Lys and Gly:Met ratios were maintained in ratios of 1:1 and 2:1, respectively. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Periodontal treatment in patients with chronic kidney disease: a pilot study.

    Science.gov (United States)

    Almeida, S; Figueredo, C M; Lemos, C; Bregman, R; Fischer, R G

    2017-04-01

    This pilot cohort study evaluated the effect of periodontal treatment on renal function, metabolic markers and asymmetric dimethylarginine (ADMA) in patients with pre-dialysis chronic kidney disease (CKD) presenting chronic periodontitis. Twenty-six patients with CKD and severe chronic periodontitis were selected. Periodontal parameters included plaque index, bleeding on probing, probing pocket depth and clinical attachment level. Estimated glomerular filtration rate (eGFR), triglycerides, total cholesterol, albumin and ADMA levels were evaluated at baseline, 90 and 180 d after periodontal therapy. eGFR was evaluated by the Modification of Diet in Renal Disease equation. All periodontal clinical parameters significantly improved (p periodontal therapy. There was a significant improvement on the median values (25%; 75% percentiles) of eGFR from 34.6 (27; 44.7) mL/min/1.73 m 2 on baseline to 37.6 (29.7; 57) mL/min/1.73 m 2 on day 90, and to 37.6 (28.6; 56) mL/min/1.73 m 2 (p periodontal treatment. No significant differences were observed at the median values of metabolic markers comparing baseline and 180 d after periodontal treatment. The results point to a link of kidney disease with endothelium dysfunction and periodontitis, suggesting that periodontal treatment may be beneficial to the course of CKD. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Anti-Atherogenic Activity of Polyphenol-Rich Extract from Bee Pollen

    Directory of Open Access Journals (Sweden)

    Anna Rzepecka-Stojko

    2017-12-01

    Full Text Available The aim of this study was to determine the effect of polyphenol-rich ethanol extract of bee pollen (EEP on atherosclerosis induced by a high-fat diet in ApoE-knockout mice. EEP was given with feed in two doses of 0.1 and 1 g/kg body mass (BM. The studies have been conducted in a period of 16 weeks. The following factors were estimated: total cholesterol (TC, oxidized low density lipoproteins (ox-LDL, asymmetric dimethylarginine (ADMA, angiotensin-converting enzyme (ACE and angiotensin II (ANG II in the 5th, 10th, 12th, 14th, and 16th week of the experiment. In the last, i.e., 16th week of the studies the development of coronary artery disease (CAD was also estimated histopathologically. Supplementing diet with EEP resulted in decreasing TC level. EEP reduced oxidative stress by lowering the levels of ox-LDL, ADMA, ANG II and ACE. EEP protected coronary arteries by significantly limiting the development of atherosclerosis (the dose of 0.1 g/kg BM or completely preventing its occurrence (the dose of 1 g/kg BM. The obtained results demonstrate that EEP may be useful as a potential anti-atherogenic agent.

  2. Diet in children with phenylketonuria and risk of cardiovascular disease: A narrative overview.

    Science.gov (United States)

    Verduci, E; Banderali, G; Moretti, F; Lassandro, C; Cefalo, G; Radaelli, G; Salvatici, E; Giovannini, M

    2016-03-01

    The aim of this paper is to review the possible relationship of restricted phenylalanine (Phe) diet, a diet primarily comprising low-protein foods and Phe-free protein substitutes, with major cardiovascular risk factors (overweight/obesity, blood lipid profile, plasma levels of homocysteine, adiponectin and free asymmetric dimethylarginine (ADMA), oxidative stress and blood pressure) in PKU children. In PKU children compliant with diet, blood total cholesterol, low-density lipoprotein cholesterol (LDL-C), plasma ADMA levels and diastolic pressure were reported to be lower and plasma adiponectin levels to be higher compared to healthy controls. No difference was observed in overweight prevalence and in high-density lipoprotein cholesterol (HDL-C) levels. Inconsistent results were found for plasma homocysteine levels and antioxidant status. PKU children compliant with diet seem to display non-different cardiovascular risks compared with the healthy population. Well-designed longitudinal studies are required to clarify the potential underlying mechanisms associated with PKU and cardiovascular risk factors. Copyright © 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  3. Single Low-Density Lipoprotein Apheresis Does Not Improve Vascular Endothelial Function in Chronically Treated Hypercholesterolemic Patients

    Directory of Open Access Journals (Sweden)

    Kevin D. Ballard

    2016-01-01

    Full Text Available Objective. To investigate vascular endothelial function (VEF responses to a single low-density lipoprotein (LDL apheresis session in hypercholesterolemic patients undergoing chronic treatment. Methods. We measured brachial artery flow-mediated dilation (FMD, plasma lipids, vitamin E (α- and γ-tocopherol, markers of oxidative/nitrative stress (malondialdehyde (MDA and nitro-γ-tocopherol (NGT, and regulators of NO metabolism (arginine (ARG and asymmetric dimethylarginine (ADMA prior to (Pre and immediately following (Post LDL apheresis and at 1, 3, 7, and 14 d Post in 5 hypercholesterolemic patients (52 ± 11 y. Results. Relative to Pre, total cholesterol (7.8±1.5 mmol/L and LDL-cholesterol (6.2±1.2 mmol/L were 61% and 70% lower (P<0.01, respectively, at Post and returned to Pre levels at 14 d. Brachial FMD responses (6.9 ± 3.6% and plasma MDA, ARG, and ADMA concentrations were unaffected by LDL apheresis. Plasma α-tocopherol, γ-tocopherol, and NGT concentrations were 52–69% lower at Post (P<0.01, and α-tocopherol remained 36% lower at 1 d whereas NGT remained 41% lower at d 3. Conclusions. Acute cholesterol reduction by LDL apheresis does not alter VEF, oxidative stress, or NO homeostasis in patients treated chronically for hypercholesterolemia.

  4. Prediction of Wound Healing in Diabetic Foot Ulcers: an Observational Study in Tertiary Hospital in Indonesia

    Directory of Open Access Journals (Sweden)

    Pradana Soewondo

    2017-04-01

    Full Text Available Aim: to evaluate the role of clinical characteristics, functional markers of vasodilation, inflammatory response, and atherosclerosis in predicting wound healing in diabetic foot ulcer. Methods: a cohort study (February – October 2010 was conducted from 40 subjects with acute diabetic foot ulcer at clinical ward of Dr. Cipto Mangunkusumo National Central General Hospital, Jakarta, Indonesia. Each subject underwent at least two variable measurements, i.e. during inflammatory phase and proliferation phase. The studied variables were clinical characteristics, complete peripheral blood count (CBC and differential count, levels of HbA1c, ureum, creatinine, lipid profile, fasting blood glucose (FBG, marker of endothelial dysfunction (asymmetric dimethylarginine/ADMA, endothelin-1/ET-1, and flow-mediated dilation/FMD of brachial artery, and marker of vascular calcification (osteoprotegerin/OPG. Results: median of time achieving 50% granulation tissue in our study was 21 days. There were nine factors that contribute in the development of 50% granulation tissue, i.e. family history of diabetes mellitus (DM, previous history of wound, wound area, duration of existing wound, captopril and simvastatin medications, levels of ADMA, ET-1, and OPG. There were three out of the nine factors that significantly correlated with wound healing, i.e. wound area, OPG levels, and simvastatin medications. Conclusion: in acute diabetic foot ulcers, wound area and OPG levels had positive correlation with wound healing, whereas simvastatin medications had negative correlation with wound healing.

  5. Prediction of Wound Healing in Diabetic Foot Ulcers: an Observational Study in Tertiary Hospital in Indonesia.

    Science.gov (United States)

    Soewondo, Pradana; Suyono, Slamet; Sastrosuwignyo, Mpu Kanoko; Harahap, Alida R; Sutrisna, Bambang; Makmun, Lukman H

    2017-01-01

    to evaluate the role of clinical characteristics, functional markers of vasodilation, inflammatory response, and atherosclerosis in predicting wound healing in diabetic foot ulcer. a cohort study (February - October 2010) was conducted from 40 subjects with acute diabetic foot ulcer at clinical ward of Dr. Cipto Mangunkusumo National Central General Hospital, Jakarta, Indonesia. Each subject underwent at least two variable measurements, i.e. during inflammatory phase and proliferation phase. The studied variables were clinical characteristics, complete peripheral blood count (CBC) and differential count, levels of HbA1c, ureum, creatinine, lipid profile, fasting blood glucose (FBG), marker of endothelial dysfunction (asymmetric dimethylarginine/ADMA, endothelin-1/ET-1, and flow-mediated dilation/FMD of brachial artery), and marker of vascular calcification (osteoprotegerin/OPG). median of time achieving 50% granulation tissue in our study was 21 days. There were nine factors that contribute in the development of 50% granulation tissue, i.e. family history of diabetes mellitus (DM), previous history of wound, wound area, duration of existing wound, captopril and simvastatin medications, levels of ADMA, ET-1, and OPG. There were three out of the nine factors that significantly correlated with wound healing, i.e. wound area, OPG levels, and simvastatin medications. in acute diabetic foot ulcers, wound area and OPG levels had positive correlation with wound healing, whereas simvastatin medications had negative correlation with wound healing.

  6. Fabrication and characterization of a chemically oxidized-nanostructured porous silicon based biosensor implementing orienting protein A.

    Science.gov (United States)

    Naveas, Nelson; Hernandez-Montelongo, Jacobo; Pulido, Ruth; Torres-Costa, Vicente; Villanueva-Guerrero, Raúl; Predestinación García Ruiz, Josefa; Manso-Silván, Miguel

    2014-03-01

    Nanostructured porous silicon (PSi) elicits as a very attractive material for future biosensing systems due to its high surface area, biocompatibility and well-established fabrication methods. In order to engineer its performance as a biosensor transducer platform, the density of immunoglobulins properly immobilized and oriented onto the surface needs to be optimized. In this work we fabricated and characterized a novel biosensing system focusing on the improvement of the biofunctionalization cascade. The system consists on a chemically oxidized PSi platform derivatized with 3-aminopropyltriethoxysilane (APTS) that is coupled to Staphylococcus protein A (SpA). The chemical oxidation has previously demonstrated to enhance the biofunctionalization process and here "by implementing SpA" a molecularly oriented immunosensor is achieved. The biosensor system is characterized in terms of its chemical composition, wettability and optical reflectance. Finally, this system is successfully exploited to develop a biosensor for detecting asymmetric dimethylarginine (ADMA), an endogenous molecule involved in cardiovascular diseases. Therefore, this work is relevant from the point of view of design and optimization of the biomolecular immobilization cascade on PSi surfaces with the added value of contribution to the development of new assays for detecting ADMA with a view on prevention of cardiovascular diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Renewable resource management under asymmetric information

    DEFF Research Database (Denmark)

    Jensen, Frank; Andersen, Peder; Nielsen, Max

    2013-01-01

    Asymmetric information between fishermen and the regulator is important within fisheries. The regulator may have less information about stock sizes, prices, costs, effort, productivity and catches than fishermen. With asymmetric information, a strong analytical tool is principal-agent analysis....... In this paper, we study asymmetric information about productivity within a principal-agent framework and a tax on fishing effort is considered. It is shown that a second best optimum can be achieved if the effort tax is designed such that low-productivity agents rent is exhausted, while high-productivity agents...... receive an information rent. The information rent is equivalent to the total incentive cost. The incentive costs arise as we want to reveal the agent's type....

  8. Asymmetric synthesis II more methods and applications

    CERN Document Server

    Christmann, Mathias

    2012-01-01

    After the overwhelming success of 'Asymmetric Synthesis - The Essentials', narrating the colorful history of asymmetric synthesis, this is the second edition with latest subjects and authors. While the aim of the first edition was mainly to honor the achievements of the pioneers in asymmetric syntheses, the aim of this new edition was bringing the current developments, especially from younger colleagues, to the attention of students. The format of the book remained unchanged, i.e. short conceptual overviews by young leaders in their field including a short biography of the authors. The growing multidisciplinary research within chemistry is reflected in the selection of topics including metal catalysis, organocatalysis, physical organic chemistry, analytical chemistry, and its applications in total synthesis. The prospective reader of this book is a graduate or undergraduate student of advanced organic chemistry as well as the industrial chemist who wants to get a brief update on the current developments in th...

  9. Targeted metabolomics reveals reduced levels of polyunsaturated choline plasmalogens and a smaller dimethylarginine/arginine ratio in the follicular fluid of patients with a diminished ovarian reserve.

    Science.gov (United States)

    de la Barca, J M Chao; Boueilh, T; Simard, G; Boucret, L; Ferré-L'Hotellier, V; Tessier, L; Gadras, C; Bouet, P E; Descamps, P; Procaccio, V; Reynier, P; May-Panloup, P

    2017-11-01

    least absolute shrinkage and selection operator with logistic regression (LASSO-LR), applied to the ratios and sums of the metabolites. Both multivariate models showed good predictive performances when applied to the validation set. The final penalized model retained the three most significant variables, i.e. the total dimethylarginine-to-arginine ratio (Total DMA/Arginine), the sum of the polyunsaturated choline plasmalogens (PUFA ae), and the patient's age. The negative coefficients of Total DMA/Arginine and PUFA ae indicated that these FF variables had lower values in DOR patients than in NOR patients. N/A. This study presents two limitations. First, with this targeted metabolomics analysis, we have explored only a limited portion of the FF metabolome. Second, although the signature found was highly significant, the mechanism underlying the dysfunction remains undetermined. The understanding of the mechanisms implied in ovarian ageing is essential for providing an adequate response to affected women desiring pregnancy. Our study proposes an incoming signature that may open new paths towards this goal. This study was supported by the University Hospital of Angers, the University of Angers, and the French national research centers, INSERM and the CNRS. There were no competing interests. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  10. Asymmetric acoustic transmission in multiple frequency bands

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Shu-yi [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  11. Asymmetric acoustic transmission in multiple frequency bands

    International Nuclear Information System (INIS)

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-01-01

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices

  12. Standards vs. labels with imperfect competition and asymmetric information

    DEFF Research Database (Denmark)

    Baltzer, Kenneth Thomas

    2012-01-01

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical differentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  13. Standards vs. labels with imperfect competition and asymmetric information

    DEFF Research Database (Denmark)

    Baltzer, Kenneth Thomas

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical dierentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  14. Vortex Dynamics of Asymmetric Heave Plates

    Science.gov (United States)

    Rusch, Curtis; Maurer, Benjamin; Polagye, Brian

    2017-11-01

    Heave plates can be used to provide reaction forces for wave energy converters, which harness the power in ocean surface waves to produce electricity. Heave plate inertia includes both the static mass of the heave plate, as well as the ``added mass'' of surrounding water accelerated with the object. Heave plate geometries may be symmetric or asymmetric, with interest in asymmetric designs driven by the resulting hydrodynamic asymmetry. Limited flow visualization has been previously conducted on symmetric heave plates, but flow visualization of asymmetric designs is needed to understand the origin of observed hydrodynamic asymmetries and their dependence on the Keulegan-Carpenter number. For example, it is hypothesized that the time-varying added mass of asymmetric heave plates is caused by vortex shedding, which is related to oscillation amplitude. Here, using direct flow visualization, we explore the relationship between vortex dynamics and time-varying added mass and drag. These results suggest potential pathways for more advanced heave plate designs that can exploit vortex formation and shedding to achieve more favorable hydrodynamic properties for wave energy converters.

  15. Asymmetric hindwing foldings in rove beetles.

    Science.gov (United States)

    Saito, Kazuya; Yamamoto, Shuhei; Maruyama, Munetoshi; Okabe, Yoji

    2014-11-18

    Foldable wings of insects are the ultimate deployable structures and have attracted the interest of aerospace engineering scientists as well as entomologists. Rove beetles are known to fold their wings in the most sophisticated ways that have right-left asymmetric patterns. However, the specific folding process and the reason for this asymmetry remain unclear. This study reveals how these asymmetric patterns emerge as a result of the folding process of rove beetles. A high-speed camera was used to reveal the details of the wing-folding movement. The results show that these characteristic asymmetrical patterns emerge as a result of simultaneous folding of overlapped wings. The revealed folding mechanisms can achieve not only highly compact wing storage but also immediate deployment. In addition, the right and left crease patterns are interchangeable, and thus each wing internalizes two crease patterns and can be folded in two different ways. This two-way folding gives freedom of choice for the folding direction to a rove beetle. The use of asymmetric patterns and the capability of two-way folding are unique features not found in artificial structures. These features have great potential to extend the design possibilities for all deployable structures, from space structures to articles of daily use.

  16. Mixed gas plasticization phenomena in asymmetric membranes

    NARCIS (Netherlands)

    Visser, Tymen

    2006-01-01

    This thesis describes the thorough investigation of mixed gas transport behavior of asymmetric membranes in the separation of feed streams containing plasticizing gases in order to gain more insights into the complicated behavior of plasticization. To successfully employ gas separation membranes in

  17. Asymmetric conditional volatility in international stock markets

    Science.gov (United States)

    Ferreira, Nuno B.; Menezes, Rui; Mendes, Diana A.

    2007-08-01

    Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the SP 500, FTSE 100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of changes in macroeconomic variables, we find no significant evidence of asymmetric behaviour of the stock market returns. There are some signs that the Portuguese Stock Market tends to show somewhat less market efficiency than other markets since the effect of the shocks appear to take a longer time to dissipate.

  18. MHD stability of vertically asymmetric tokamak equilibria

    International Nuclear Information System (INIS)

    Dalhed, H.E.; Grimm, R.C.; Johnson, J.L.

    1981-03-01

    The ideal MHD stability properties of a special class of vertically asymmetric tokamak equilibria are examined. The calculations confirm that no major new physical effects are introduced and the modifications can be understood by conventional arguments. The results indicate that significant departures from up-down symmetry can be tolerated before the reduction in β becomes important for reactor operation

  19. Catalytic asymmetric synthesis of the alkaloid (+)-myrtine

    NARCIS (Netherlands)

    Pizzuti, Maria Gabriefla; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    A new protocol for the asymmetric synthesis of trans-2,6-disubstituted-4-piperidones has been developed using a catalytic enantioselective conjugate addition reaction in combination with a diastereoselective lithiation-substitution sequence; an efficient synthesis of (+)-myrtine has been achieved

  20. Asymmetric Aminalization via Cation-Binding Catalysis

    DEFF Research Database (Denmark)

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk

    2018-01-01

    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the...

  1. Volume inequalities for asymmetric Wulff shapes

    OpenAIRE

    Schuster, Franz E.; Weberndorfer, Manuel

    2012-01-01

    Sharp reverse affine isoperimetric inequalities for asymmetric Wulff shapes and their polars are established, along with the characterization of all extremals. These new inequalities have as special cases previously obtained simplex inequalities by Ball, Barthe and Lutwak, Yang, and Zhang. In particular, they provide the solution to a problem by Zhang.

  2. Quantum optics of lossy asymmetric beam splitters

    NARCIS (Netherlands)

    Uppu, Ravitej; Wolterink, Tom; Tentrup, Tristan Bernhard Horst; Pinkse, Pepijn Willemszoon Harry

    2016-01-01

    We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2×2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering

  3. Motion in an Asymmetric Double Well

    OpenAIRE

    Brizard, Alain J.; Westland, Melissa C.

    2016-01-01

    The problem of the motion of a particle in an asymmetric double well is solved explicitly in terms of the Weierstrass and Jacobi elliptic functions. While the solution of the orbital motion is expressed simply in terms of the Weierstrass elliptic function, the period of oscillation is more directly expressed in terms of periods of the Jacobi elliptic functions.

  4. Asymmetric output profile of Xe Laser

    NARCIS (Netherlands)

    Blok, F.J.; Rubin, P.L.; Verschuur, Jeroen W.J.; Witteman, W.J.

    2001-01-01

    A new set of asymmetric modes was recently revealed in a Xe slab laser with pronounced lens effects originating from gas heating in the discharge. The appearance of these modes is a threshold effect. Their domain of existence in the Xe laser is discussed. It is shown that mode competition can result

  5. Computing modal dispersion characteristics of radially Asymmetric ...

    African Journals Online (AJOL)

    We developed a matrix theory that applies to with non-circular/circular but concentric layers fibers. And we compute the dispersion characteristics of radially unconventional fiber, known as Asymmetric Bragg fiber. An attempt has been made to determine how the modal characteristics change as circular Bragg fiber is ...

  6. Seasonally asymmetric enhancement of northern vegetation productivity

    Science.gov (United States)

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  7. Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter

    DEFF Research Database (Denmark)

    Masina, Isabella; Sannino, Francesco

    2011-01-01

    The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown...... component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton...... flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric....

  8. Biocompatible zinc oxide nanocrystals stabilized via hydroxyethyl cellulose for mitigation of diabetic complications.

    Science.gov (United States)

    Hussein, Jihan; El-Banna, Mona; Razik, Tay Abdel; El-Naggar, Mehrez E

    2018-02-01

    The vascular complications of diabetes are the most serious manifestations of the disease. The hyperglycemia can directly promote an inflammatory state where the increase C-reactive (CRP) and cytokines, such as interleukins (IL-1 and IL-6), which contribute to the development of cardiovascular diseases. The current study was aimed to evaluate the role of environmentally-synthesized zinc oxide nanocrystals (ZnO-NPs) in augmentation of hyperglycemia and its complications, as well as the preservation of asymmetrical dimethylarginine (ADMA) level as a specific marker for endothelial dysfunction in streptozotocin (STZ)-induced diabetic rats. ZnO-NPs was chemically-synthesized using environmental benign biodegradable hydroxyl ethyl cellulose (HES) as both a stabilizing and directing agent in the presence of potassium hydroxide. HES is a biomaterial compound used in many biomedical applications due to its biodegradability and biocompatibility in nature. Particle size, morphological structure, purity, and crystallinity of the as-prepared ZnO-NPs were evaluated through different techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy connected to energy-dispersive X-ray spectra (SEM-EDS). Sixty male albino rats were used in this study and divided into four groups: control, ZnO-NPs, diabetic and treated groups; after the experimental period, CRP and interleukin-1 (IL-1α) were determined by ELISA. ADMA was estimated by RP-HPLC using a fluorescence detector. The results obtained indicate that CRP, IL-1α, and ADMA levels increased significantly concomitant with a reduction in NO level in the diabetic group, whereas ZnO-NPs supplementation significantly attenuated these parameters. Based on these encouraging results, the reported approach of environmental synthesis and application has the potential of leading to a new generation of nanometerials for treatment of diabetic complications with considerably enhanced

  9. Determinants of insulin responsiveness in young women: Impact of polycystic ovarian syndrome, nitric oxide, and vitamin D.

    Science.gov (United States)

    Ngo, D T M; Chan, W P; Rajendran, S; Heresztyn, T; Amarasekera, A; Sverdlov, A L; O'Loughlin, P D; Morris, H A; Chirkov, Y Y; Norman, R J; Horowitz, J D

    2011-10-30

    Polycystic ovary syndrome (PCOS) is associated with incremental risk of atherosclerosis and possibly of cardiovascular events. Insulin resistance (IR) occurs frequently in PCOS subjects, which might be one of the mechanisms involved in engendering such risk. We sought to evaluate whether the impact of other factors potentially associated both with PCOS and with IR might differentially modulate degree of IR in women with and without PCOS. We measured body mass index (BMI), hs-CRP, plasma concentrations of asymmetric dimethylarginine (ADMA), vitamin D (25(OH)D3) levels and platelet responsiveness to nitric oxide donor sodium nitroprusside (NO responsiveness) in 47 young women (n=27 with PCOS and n=20 weight-matched controls) without metabolic syndrome, hypertension or overt cardiovascular disease. We performed univariate and multivariate regression analyses to establish correlates of the quantitative insulin-sensitivity check index (QUICKI), as a marker of IR. On univariate analysis, plasma 25(OH)D3 levels and low NO responsiveness tended to be direct correlates with QUICKI in the entire subject group. BMI, hs-CRP, and ADMA levels were significant inverse correlates of QUICKI in PCOS subjects, but not in subjects without PCOS. On multivariate analysis, NO responsiveness, and 25(OH)D3 levels, but not PCOS per se were significant correlates of QUICKI. In the entire cohort of young women, low NO responsiveness and vitamin D deficiency are associated with low QUICKI, while elevated ADMA, inflammatory activation and obesity are selectively associated with low QUICKI in PCOS subjects; this may contribute to the increased cardiovascular risk associated with this syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Endodontic infection and endothelial dysfunction are associated with different mechanisms in men and women.

    Science.gov (United States)

    Cotti, Elisabetta; Zedda, Angela; Deidda, Martino; Piras, Alessandra; Flore, Giovanna; Ideo, Francesca; Madeddu, Clelia; Pau, Valentina Maria; Mercuro, Giuseppe

    2015-05-01

    To investigate the potential link between apical periodontitis (AP) and cardiovascular (CV) function, inflammation markers, endothelial flow reserve (EFR), and levels of asymmetrical dimethylarginine (ADMA), the endogenous inhibitor of nitric oxide synthase (NOS), were measured in young adults with AP aged 20-40 years of both sexes. Forty men and 41 women (31 ± 5.71 years) free from periodontal disease, CV disease, and traditional CV risk factors were enrolled in the study. Twenty men and 21 women had AP; 40 healthy individuals matched for age, sex, and physical characteristics were also recruited as controls. All subjects underwent dental and complete physical examination, electrocardiography, conventional and tissue Doppler imaging echocardiography, and measurement of EFR. Interleukin (IL)-2, tumor necrosis factor alpha, reactive oxygen species (ROS), and ADMA were also assessed. Data were analyzed using the 2-tailed Student t test, the Pearson t test (or the Spearman t test for nonparametric variables), and multivariate linear regression analysis. Echocardiography excluded any morphologic and functional cardiac alteration in all the subjects studied. Patients with AP of both sexes showed a significant reduction in EFR (P < .05) and a significant increase in IL-2 (men: P < .01, women: P < .05), whereas ROS were increased significantly only in women (P < .05). ADMA levels were unchanged in women with AP, but they were significantly increased in men (P < .05). A significant direct correlation between ADMA and IL-2 (r = 0.67, P < .001) and an inverse correlation between ADMA and EFR (r = -0.42, P < .05) in men and a significant inverse correlation between ROS and EFR (r = -0.71, P < .01) in female patients were observed. The presence of chronic inflammation in young adults with AP may cause early endothelial dysfunction documented by the reduced EFR. AP in men may influence the metabolism of NOS, whereas in women it appears to implicate a more direct detrimental

  11. Direct catalytic asymmetric aldol-Tishchenko reaction.

    Science.gov (United States)

    Gnanadesikan, Vijay; Horiuchi, Yoshihiro; Ohshima, Takashi; Shibasaki, Masakatsu

    2004-06-30

    A direct catalytic asymmetric aldol reaction of propionate equivalent was achieved via the aldol-Tishchenko reaction. Coupling an irreversible Tishchenko reaction to a reversible aldol reaction overcame the retro-aldol reaction problem and thereby afforded the products in high enantio and diastereoselectivity using 10 mol % of the asymmetric catalyst. A variety of ketones and aldehydes, including propyl and butyl ketones, were coupled efficiently, yielding the corresponding aldol-Tishchenko products in up to 96% yield and 95% ee. Diastereoselectivity was generally below the detection limit of 1H NMR (>98:2). Preliminary studies performed to clarify the mechanism revealed that the aldol products were racemic with no diastereoselectivity. On the other hand, the Tishchenko products were obtained in a highly enantiocontrolled manner.

  12. Brownian Motion of Asymmetric Boomerang Colloidal Particles

    Science.gov (United States)

    Chakrabarty, Ayan; Konya, Andrew; Wang, Feng; Selinger, Jonathan; Sun, Kai; Wei, Qi-Huo

    2014-03-01

    We used video microscopy and single particle tracking to study the diffusion and local behaviors of asymmetric boomerang particles in a quasi-two dimensional geometry. The motion is biased towards the center of hydrodynamic stress (CoH) and the mean square displacements of the particles are linear at short and long times with different diffusion coefficients and in the crossover regime it is sub-diffusive. Our model based on Langevin theory shows that these behaviors arise from the non-coincidence of the CoH with the center of the body. Since asymmetric boomerangs represent a class of rigid bodies of more generals shape, therefore our findings are generic and true for any non-skewed particle in two dimensions. Both experimental and theoretical results will be discussed.

  13. Dynamics of asymmetric kinetic Ising systems revisited

    International Nuclear Information System (INIS)

    Huang, Haiping; Kabashima, Yoshiyuki

    2014-01-01

    The dynamics of an asymmetric kinetic Ising model is studied. Two schemes for improving the existing mean-field description are proposed. In the first scheme, we derive the formulas for instantaneous magnetization, equal-time correlation, and time-delayed correlation, considering the correlation between different local fields. To derive the time-delayed correlation, we emphasize that the small-correlation assumption adopted in previous work (Mézard and Sakellariou, 2011 J. Stat. Mech. L07001) is in fact not required. To confirm the prediction efficiency of our method, we perform extensive simulations on single instances with either temporally constant external driving fields or sinusoidal external fields. In the second scheme, we develop an improved mean-field theory for instantaneous magnetization prediction utilizing the notion of the cavity system in conjunction with a perturbative expansion approach. Its efficiency is numerically confirmed by comparison with the existing mean-field theory when partially asymmetric couplings are present. (paper)

  14. Bianisotropic metamaterials based on twisted asymmetric crosses

    International Nuclear Information System (INIS)

    Reyes-Avendaño, J A; Sampedro, M P; Juárez-Ruiz, E; Pérez-Rodríguez, F

    2014-01-01

    The effective bianisotropic response of 3D periodic metal-dielectric structures, composed of crosses with asymmetrically-cut wires, is investigated within a general homogenization theory using the Fourier formalism and the form-factor division approach. It is found that the frequency dependence of the effective permittivity for a system of periodically-repeated layers of metal crosses exhibits two strong resonances, whose separation is due to the cross asymmetry. Besides, bianisotropic metamaterials, having a base of four twisted asymmetric crosses, are proposed. The designed metamaterials possess negative refractive index at frequencies determined by the cross asymmetry, the gap between the arms of adjacent crosses lying on the same plane, and the type of Bravais lattice. (papers)

  15. Improved DFIG Capability during Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...... the natural component of the Doubly-Fed Induction Generator (DFIG) stator flux during the fault period, their effects on the rotor voltage can be investigated. It is concluded that the phase-to-phase fault has the worst scenario due to its highest introduction of the negative stator flux. Afterwards......, the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility....

  16. Asymmetric volatility connectedness on the forex market

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2017-01-01

    Roč. 77, č. 1 (2017), s. 39-56 ISSN 0261-5606 R&D Projects: GA ČR(CZ) GA16-14179S Institutional support: RVO:67985556 Keywords : volatility * connectedness * asymmetric effects Subject RIV: AH - Economics OBOR OECD: Finance Impact factor: 1.853, year: 2016 http://library.utia.cas.cz/separaty/2017/E/barunik-0478477.pdf

  17. Magnetic properties of strongly asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Kutschera, M.; Wojcik, W.

    1988-01-01

    We investigate stability of neutron matter containing a small proton admixture with respect to spin fluctuations. We establish conditions under which strongly asymmetric nuclear matter could acquire a permanent magnetization. It is shown that if the protons are localized, the system becomes unstable to spin fluctuations for arbitrarily weak proton-neutron spin interactions. For non-localized protons there exists a threshold value of the spin interaction above which the system can develop a spontaneous polarization. 12 refs., 2 figs. (author)

  18. Isospin dependent properties of asymmetric nuclear matter

    OpenAIRE

    Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

    2009-01-01

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic de...

  19. Asymmetric flow events in a VEER 1000

    International Nuclear Information System (INIS)

    Horak, W.C.; Kennett, R.J.; Shier, W.; Guppy, J.G.

    1992-07-01

    This paper describes the simulation of asymmetric loss of flow events in Russian designed VVER-1000 reactors using the RETRAN-02 Mod4 computer code. VVER-1000 reactors have significant differences from United States pressurized water reactors including multi-level emergency response systems and plant operation at reduced power levels with one or more main circulation pumps inoperable. The results of these simulations are compared to similar analyses done by the designers for the Rovno plant

  20. Two particle states in an asymmetric box

    OpenAIRE

    Li, Xin; Liu, Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by L\\"uscher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these f...

  1. Symmetric vs. asymmetric punishment regimes for bribery

    OpenAIRE

    Engel, Christoph; Goerg, Sebastian J.; Yu, Gaoneng

    2012-01-01

    In major legal orders such as UK, the U.S., Germany, and France, bribers and recipients face equally severe criminal sanctions. In contrast, countries like China, Russia, and Japan treat the briber more mildly. Given these differences between symmetric and asymmetric punishment regimes for bribery, one may wonder which punishment strategy is more effective in curbing corruption. For this purpose, we designed and ran a lab experiment in Bonn (Germany) and Shanghai (China) with exactly the same...

  2. Predicting tensorial electrophoretic effects in asymmetric colloids

    Science.gov (United States)

    Mowitz, Aaron J.; Witten, T. A.

    2017-12-01

    We formulate a numerical method for predicting the tensorial linear response of a rigid, asymmetrically charged body to an applied electric field. This prediction requires calculating the response of the fluid to the Stokes drag forces on the moving body and on the countercharges near its surface. To determine the fluid's motion, we represent both the body and the countercharges using many point sources of drag known as Stokeslets. Finding the correct flow field amounts to finding the set of drag forces on the Stokeslets that is consistent with the relative velocities experienced by each Stokeslet. The method rigorously satisfies the condition that the object moves with no transfer of momentum to the fluid. We demonstrate that a sphere represented by 1999 well-separated Stokeslets on its surface produces flow and drag force like a solid sphere to 1% accuracy. We show that a uniformly charged sphere with 3998 body and countercharge Stokeslets obeys the Smoluchowski prediction [F. Morrison, J. Colloid Interface Sci. 34, 210 (1970), 10.1016/0021-9797(70)90171-2] for electrophoretic mobility when the countercharges lie close to the sphere. Spheres with dipolar and quadrupolar charge distributions rotate and translate as predicted analytically to 4% accuracy or better. We describe how the method can treat general asymmetric shapes and charge distributions. This method offers promise as a way to characterize and manipulate asymmetrically charged colloid-scale objects from biology (e.g., viruses) and technology (e.g., self-assembled clusters).

  3. Asymmetric threat data mining and knowledge discovery

    Science.gov (United States)

    Gilmore, John F.; Pagels, Michael A.; Palk, Justin

    2001-03-01

    Asymmetric threats differ from the conventional force-on- force military encounters that the Defense Department has historically been trained to engage. Terrorism by its nature is now an operational activity that is neither easily detected or countered as its very existence depends on small covert attacks exploiting the element of surprise. But terrorism does have defined forms, motivations, tactics and organizational structure. Exploiting a terrorism taxonomy provides the opportunity to discover and assess knowledge of terrorist operations. This paper describes the Asymmetric Threat Terrorist Assessment, Countering, and Knowledge (ATTACK) system. ATTACK has been developed to (a) data mine open source intelligence (OSINT) information from web-based newspaper sources, video news web casts, and actual terrorist web sites, (b) evaluate this information against a terrorism taxonomy, (c) exploit country/region specific social, economic, political, and religious knowledge, and (d) discover and predict potential terrorist activities and association links. Details of the asymmetric threat structure and the ATTACK system architecture are presented with results of an actual terrorist data mining and knowledge discovery test case shown.

  4. Diagnostic implications of asymmetrical mammographic patterns

    International Nuclear Information System (INIS)

    Asenjo, M.; Ania, B.J.

    1997-01-01

    To analyze the effect of asymmetrical mammographic patterns of the diagnosis of breast cancer. In a series of 6, 476 patients referred to a Breast Imaging Diagnosis Unit, we excluded males, women with previous breast surgery, and cases in which mammography was not performed, which left 5,203 women included. Each breast was classified according to one of four patterns of mammographic parenchymal density. Asymmetry was considered to exist when a patient's breasts had different patterns. Breast cancer was confirmed histologically in 282 (5.4%) women. The mammographic pattern was asymmetrical in 8% of the women with cancer and in 2% of the women without cancer (p<0.001). Fine-needle aspiration biopsy was performed in 78% and 96% (p=0.04), respectively, of the women with and without mammographic asymmetry who had neoplasms, and in 33% and 22% (p=0.02), respectively, of the women with and without mammographic asymmetry who did not have neoplasms. Asymmetrical mammographic pattern was four times more frequent in the women with breast cancer. This asymmetry decreased the frequency of needle biopsy in women with cancer, but increased the frequency of needle biopsy in women without cancer. (Author) 11 refs

  5. Hadron scattering in an asymmetric box

    International Nuclear Information System (INIS)

    Li Xin; Chen Ying; Meng Guozhan; Feng Xu; Gong Ming; He Song; Li Gang; Liu Chuan; Liu Yubin; Ma Jianping; Meng Xiangfei; Shen Yan; Zhang Jianbo

    2007-01-01

    We propose to study hadron-hadron scattering using lattice QCD in an asymmetric box which allows one to access more non-degenerate low-momentum modes for a given volume. The conventional Luescher's formula applicable in a symmetric box is modified accordingly. To illustrate the feasibility of this approach, pion-pion elastic scattering phase shifts in the I = 2, J = 0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. After the chiral and continuum extrapolation, we find that our quenched results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. Agreement is also found when compared with previous theoretical results from lattice and other means. Moreover, with the usage of asymmetric volume, we are able to compute the scattering phases in the low-momentum range (pion three momentum less than about 350MeV in the center of mass frame) for over a dozen values of the pion three-momenta, much more than using the conventional symmetric box with comparable volume

  6. Simulation of Phenix EOL Asymmetric Test

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kwi Seok; Lee, Kwi Lim; Choi, Chi Woong; Kang, Seok Hun; Chang, Won Pyo; Jeong, Hae Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The asymmetric test of End-Of-Life (EOL) tests on the Phenix plant was used for the evaluation of the MARS-LMR in the Generation IV frame as a part of the code validation. The purpose of the test is to evaluate the ability of the system code to describe asymmetric situations and to identify important phenomena during asymmetrical transient such as a three dimensional effect, buoyancy influence, and thermal stratification in the hot and cold pools. 3-dimensional sodium coolant mixing in the pools has different characteristics from the one dimensional full instantaneous mixing. The velocities and temperatures at the core outlet level differ at each sub-assembly and the temperature in the center of the hot pool may be high because the driver fuels are located at the center region. The temperatures in the hot pool are not the same in the radial and axial locations due to the buoyancy effect. The temperatures in the cold pool also differ along with the elevations and azimuthal directions due to the outlet location of IHX and the thermal stratification

  7. Flatfish: an asymmetric perspective on metamorphosis.

    Science.gov (United States)

    Schreiber, Alexander M

    2013-01-01

    The most asymmetrically shaped and behaviorally lateralized of all the vertebrates, the flatfishes are an endless source of fascination to all fortunate enough to study them. Although all vertebrates undergo left-right asymmetric internal organ placement during embryogenesis, flatfish are unusual in that they experience an additional period of postembryonic asymmetric remodeling during metamorphosis, and thus deviate from a bilaterally symmetrical body plan more than other vertebrates. As with amphibian metamorphosis, all the developmental programs of flatfish metamorphosis are ultimately under the control of thyroid hormone. At least one gene pathway involved in embryonic organ lateralization (nodal-lefty-pitx2) is re-expressed in the larval stage during flatfish metamorphosis. Aspects of modern flatfish ontogeny, such as the gradual translocation of one eye to the opposite side of the head and the appearance of key neurocranial elements during metamorphosis, seem to elegantly recapitulate flatfish phylogeny. This chapter highlights the current state of knowledge of the developmental biology of flatfish metamorphosis with emphases on the genetic, morphological, behavioral, and evolutionary origins of flatfish asymmetry. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Observation of asymmetric electromagnetic field profiles in chiral metamaterials

    Science.gov (United States)

    Hisamoto, Nobuyuki; Ueda, Tetsuya; Sawada, Kei; Tomita, Satoshi

    2018-02-01

    We experimentally observe asymmetric electromagnetic field profiles along two-dimensional chiral metamaterials. The asymmetric field profiles depending on the chirality and the operation frequency have been reproduced well by the numerical simulation. Around a chiral meta-atom, distribution of a Poynting vector is found to be shifted asymmetrically. These results are explained in terms of an analogy with the side-jump mechanism in the electronic anomalous Hall systems.

  9. Asymmetric forecasting and commitment policy in a robust control problem

    OpenAIRE

    Taro Ikeda

    2013-01-01

    This paper provides a piece of results regarding asymmetric forecasting and commitment monetary policy with a robust control algorithm. Previous studies provide no clarification of the connection between asymmetric preference and robust commitment policy. Three results emerge from general equilibrium modeling with asymmetric preference: (i) the condition for system stability implies an average inflation bias with respect to asymmetry (ii) the effect of asymmetry can be mitigated if policy mak...

  10. Asymmetric acoustic transmission in graded beam

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li, E-mail: lj94172350@hotmail.com [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Jiu Hui, E-mail: ejhwu@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Guan, Dong; Lu, Kuan [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Gao, Nansha [School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Songhua, Cao [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  11. OFFICER AND COMMANDER IN ASYMMETRIC WARFARE OPERATIONS

    Directory of Open Access Journals (Sweden)

    Giuseppe CAFORIO

    2013-01-01

    Full Text Available Starting from the data of a field research conducted among soldiers with asymmetric warfare experiences from nine different countries, the author seeks to identify and shed light on the various problems that officers with command responsibilities had to face during their missions. A picture emerges of feelings and experiences relating to their first impression upon arriving in the theatre, relations with local armed forces, relations with the local population and local authorities, relations with NGOs, relations with other armies, the impact of the rules of engagement (ROEs, training and education, and operational experiences. The paper ends with a discussion of the lessons learned.

  12. Nanotribology of Symmetric and Asymmetric Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Shinji Yamada

    2010-03-01

    Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.

  13. Asymmetric Total Synthesis of Ieodomycin B

    Directory of Open Access Journals (Sweden)

    Shuangjie Lin

    2017-01-01

    Full Text Available Ieodomycin B, which shows in vitro antimicrobial activity, was isolated from a marine Bacillus species. A novel asymmetric total synthetic approach to ieodomycin B using commercially available geraniol was achieved. The approach involves the generation of 1,3-trans-dihydroxyl at C-3 and C-5 positions via a Crimmins-modified Evans aldol reaction and a chelation-controlled Mukaiyama aldol reaction of a p-methoxybenzyl-protected aldehyde, as well as the generation of a lactone ring in a deprotection–lactonization one-pot reaction.

  14. The Asymmetric Effects of Investor Sentiment

    DEFF Research Database (Denmark)

    Lutz, Chandler

    2016-01-01

    We use the returns on lottery-like stocks and a dynamic factor model to construct a novel index of investor sentiment. This new measure is highly correlated with other behavioral indicators, but more closely tracks speculative episodes. Our main new finding is that the effects of sentiment...... are asymmetric: During peak-to-trough periods of investor sentiment (sentiment contractions), high sentiment predicts low future returns for the cross section of speculative stocks and for the market overall, whereas the relationship between sentiment and future returns is positive but relatively weak during...... trough-to-peak episodes (sentiment expansions). Overall, these results match theories and anecdotal accounts of investor sentiment....

  15. On asymmetric causal relationships in Petropolitics

    Directory of Open Access Journals (Sweden)

    Balan Feyza

    2016-01-01

    Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.

  16. Asymmetric nuclear matter and neutron star properties

    International Nuclear Information System (INIS)

    Engvik, L.; Hjorth-Jensen, M.; Osnes, E.; Bao, G.; Oestgaard, E.

    1994-06-01

    Properties of neutron stars such as mass and radius, using a relativistic Dirac-Brueckner-Hartree-Fock approach, are calculated. Modern meson-exchange potential models are used to evaluate the G-matrix for asymmetric nuclear matter. For pure neutron matter the maximum mass is found to be M max ∼ 2.4M for a radius R ∼ 12 km. With a proton fraction of 30% the result is M max ∼ 2.1M for a radius R ∼ 10.5 km, close to the experimental values. The implications are discussed. 20 refs., 3 figs

  17. Two particle states in an asymmetric box

    International Nuclear Information System (INIS)

    Li Xin; Liu Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by Luescher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these formulae are also discussed

  18. Asymmetrical Capacitors for Propulsion and the ISR Asymmetrical Capacitator Thruster, Experimental Results and Improved Designs

    Science.gov (United States)

    Canning, Francis; Winet, Ed; Ice, Bob; Melcher, Cory; Pesavento, Phil; Holmes, Alan; Butler, Carey; Cole, John; Campbell, Jonathan

    2004-01-01

    The outline of this viewgraph presentation on asymmetrical capacitor thruster development includes: 1) Test apparatus; 2) Devices tested; 3) Circuits used; 4) Data collected (Time averaged, Time resolved); 5) Patterns observed; 6) Force calculation; 7) Electrostatic modeling; 8) Understand it all.

  19. Chiral ferrocenes in asymmetric catalysis: synthesis and applications

    National Research Council Canada - National Science Library

    Dai, Li-Xin; Hou, Xue-Long

    2010-01-01

    .... It provides a thorough overview of the synthesis and characterization of different types of chiral ferrocene ligands, their application to various catalytic asymmetric reactions, and versatile chiral...

  20. [Asymmetric hypertrophy of the masticatory muscles].

    Science.gov (United States)

    Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

    2012-06-01

    Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  1. Asymmetric Uncertainty Expression for High Gradient Aerodynamics

    Science.gov (United States)

    Pinier, Jeremy T

    2012-01-01

    When the physics of the flow around an aircraft changes very abruptly either in time or space (e.g., flow separation/reattachment, boundary layer transition, unsteadiness, shocks, etc), the measurements that are performed in a simulated environment like a wind tunnel test or a computational simulation will most likely incorrectly predict the exact location of where (or when) the change in physics happens. There are many reasons for this, includ- ing the error introduced by simulating a real system at a smaller scale and at non-ideal conditions, or the error due to turbulence models in a computational simulation. The un- certainty analysis principles that have been developed and are being implemented today do not fully account for uncertainty in the knowledge of the location of abrupt physics changes or sharp gradients, leading to a potentially underestimated uncertainty in those areas. To address this problem, a new asymmetric aerodynamic uncertainty expression containing an extra term to account for a phase-uncertainty, the magnitude of which is emphasized in the high-gradient aerodynamic regions is proposed in this paper. Additionally, based on previous work, a method for dispersing aerodynamic data within asymmetric uncer- tainty bounds in a more realistic way has been developed for use within Monte Carlo-type analyses.

  2. D mesons in asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Mishra, Amruta; Mazumdar, Arindam

    2009-01-01

    We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures

  3. On the Collisionless Asymmetric Magnetic Reconnection Rate

    Science.gov (United States)

    Liu, Yi-Hsin; Hesse, M.; Cassak, P. A.; Shay, M. A.; Wang, S.; Chen, L.-J.

    2018-04-01

    A prediction of the steady state reconnection electric field in asymmetric reconnection is obtained by maximizing the reconnection rate as a function of the opening angle made by the upstream magnetic field on the weak magnetic field (magnetosheath) side. The prediction is within a factor of 2 of the widely examined asymmetric reconnection model (Cassak & Shay, 2007, https://doi.org/10.1063/1.2795630) in the collisionless limit, and they scale the same over a wide parameter regime. The previous model had the effective aspect ratio of the diffusion region as a free parameter, which simulations and observations suggest is on the order of 0.1, but the present model has no free parameters. In conjunction with the symmetric case (Liu et al., 2017, https://doi.org/10.1103/PhysRevLett.118.085101), this work further suggests that this nearly universal number 0.1, essentially the normalized fast-reconnection rate, is a geometrical factor arising from maximizing the reconnection rate within magnetohydrodynamic-scale constraints.

  4. Evolutionary stability in the asymmetric volunteer's dilemma.

    Directory of Open Access Journals (Sweden)

    Jun-Zhou He

    Full Text Available It is often assumed that in public goods games, contributors are either strong or weak players and each individual has an equal probability of exhibiting cooperation. It is difficult to explain why the public good is produced by strong individuals in some cooperation systems, and by weak individuals in others. Viewing the asymmetric volunteer's dilemma game as an evolutionary game, we find that whether the strong or the weak players produce the public good depends on the initial condition (i.e., phenotype or initial strategy of individuals. These different evolutionarily stable strategies (ESS associated with different initial conditions, can be interpreted as the production modes of public goods of different cooperation systems. A further analysis revealed that the strong player adopts a pure strategy but mixed strategies for the weak players to produce the public good, and that the probability of volunteering by weak players decreases with increasing group size or decreasing cost-benefit ratio. Our model shows that the defection probability of a "strong" player is greater than the "weak" players in the model of Diekmann (1993. This contradicts Selten's (1980 model that public goods can only be produced by a strong player, is not an evolutionarily stable strategy, and will therefore disappear over evolutionary time. Our public good model with ESS has thus extended previous interpretations that the public good can only be produced by strong players in an asymmetric game.

  5. An asymmetric B factory based on PEP

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e{sup +}e{sup {minus}} collider capable of achieving a luminosity of L = 3 {times} 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings.

  6. An asymmetric B factory based on PEP

    International Nuclear Information System (INIS)

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e + e - collider capable of achieving a luminosity of L = 3 x 10 33 cm -2 s -1 . The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings

  7. Particle identification at an asymmetric B Factory

    International Nuclear Information System (INIS)

    Coyle, P.; Eigen, G.; Hitlin, D.; Oddone, P.; Ratcliff, B.; Roe, N.; Va'vra, J.; Ypsilantis, T.

    1991-09-01

    Particle identification systems are an important component of any detector at a high-luminosity, asymmetric B Factory. In particular, excellent hadron identification is required to probe CP violation in B 0 decays to CP eigenstates. The particle identification systems discussed below also provide help in separating leptons from hadrons at low momenta. We begin this chapter with a discussion of the physics motivation for providing particle identification, the inherent limitations due to interactions and decays in flight, and the requirements for hermiticity and angular coverage. A special feature of an asymmetric B Factory is the resulting asymmetry in the momentum distribution as a function of polar angle; this will also be quantified and discussed. In the next section the three primary candidates, time-of-flight (TOF), energy loss (dE/dx), and Cerenkov counters, both ring-imaging and threshold, will be briefly described and evaluated. Following this, one of the candidates, a long-drift Cerenkov ring-imaging device, is described in detail to provide a reference design. Design considerations for a fast RICH are then described. A detailed discussion of aerogel threshold counter designs and associated R ampersand D conclude the chapter. 56 refs., 64 figs., 13 tabs

  8. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    Science.gov (United States)

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  9. A new convenient asymmetric approach to herbarumin Ⅲ

    Institute of Scientific and Technical Information of China (English)

    Xue Song Chen; Shi Jun Da; Li Hong Yang; Bo Yan Xu; Zhi Xiang Xie; Ying Li

    2007-01-01

    The asymmetric total synthesis of herbarumin Ⅲ 3, a naturally occurred phytotoxin, along with 8-epi-herbarumin Ⅲ 22, was succeeded in 12 steps from n-butyraldehyde based on Brown's asymmetric allylation, taking modified Julia olefination and Yamaguchi's macro-lactonization as key steps.

  10. Appropriate quantization of asymmetric games with continuous strategies

    International Nuclear Information System (INIS)

    Qin Gan; Chen Xi; Sun Min; Zhou Xianyi; Du Jiangfeng

    2005-01-01

    We establish a new quantization scheme to study the asymmetric Bertrand duopoly with differentiated products. This scheme is more efficient than the previous symmetric one because it can exactly make the optimal cooperative payoffs at quantum Nash equilibrium. It is also a necessary condition for general asymmetric games with continuous strategies to reach such payoffs

  11. An Evolving Asymmetric Game for Modeling Interdictor-Smuggler Problems

    Science.gov (United States)

    2016-06-01

    ASYMMETRIC GAME FOR MODELING INTERDICTOR-SMUGGLER PROBLEMS by Richard J. Allain June 2016 Thesis Advisor: David L. Alderson Second Reader: W...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE AN EVOLVING ASYMMETRIC GAME FOR MODELING INTERDICTOR- SMUGGLER PROBLEMS 5. FUNDING NUMBERS 6...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited AN EVOLVING

  12. Decrease in back strength in asymmetric trunk postures

    NARCIS (Netherlands)

    Vink, P.; Daanen, H. A M; Meijst, W. J.; Ligteringen, J.

    1992-01-01

    The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry

  13. Subcopula-based measure of asymmetric association for contingency tables.

    Science.gov (United States)

    Wei, Zheng; Kim, Daeyoung

    2017-10-30

    For the analysis of a two-way contingency table, a new asymmetric association measure is developed. The proposed method uses the subcopula-based regression between the discrete variables to measure the asymmetric predictive powers of the variables of interest. Unlike the existing measures of asymmetric association, the subcopula-based measure is insensitive to the number of categories in a variable, and thus, the magnitude of the proposed measure can be interpreted as the degree of asymmetric association in the contingency table. The theoretical properties of the proposed subcopula-based asymmetric association measure are investigated. We illustrate the performance and advantages of the proposed measure using simulation studies and real data examples. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Asymmetric double Langmuir probe: Small signal application

    International Nuclear Information System (INIS)

    Uckan, T.

    1987-11-01

    We discuss the asymmetric double Langmuir probe (ADLP) and demonstrate the possibility of using it to measure plasma temperature T/sub e/ and density n when it is operated in the region of small signal response. The area of one of the ADLP collectors is considerably larger than the other. This probe can be operated at a relatively low applied voltage, eV/sub a/T/sub e/ < 1, and still provides sufficient information to determine the plasma T/sub e/ and n. There is no need for a direct measurement of the ion saturation current, which can be on the order of a few amperes in large fusion devices. This reduces the requirements on the probe power supply. 6 refs., 6 figs

  15. Do Daily Retail Gasoline Prices adjust Asymmetrically?

    Energy Technology Data Exchange (ETDEWEB)

    Bettendorf, L. [Tinbergen Instituut, Amsterdam/Rotterdam (Netherlands); Van der Geest, S. [Erasmus Universiteit, Rotterdam (Netherlands); Kuper, G. [University of Groningen, Groningen (Netherlands)

    2005-04-15

    This paper analyzes adjustments in the Dutch retail gasoline prices. We estimate an error correction model on changes in the daily retail price for gasoline (taxes excluded) for the period 1996-2004 taking care of volatility clustering by estimating an EGARCH model. It turns out the volatility process is asymmetrical: an unexpected increase in the producer price has a larger effect on the variance of the producer price than an unexpected decrease. We do not find strong evidence for amount asymmetry. However, there is a faster reaction to upward changes in spot prices than to downward changes in spot prices. This implies timing or pattern asymmetry. This asymmetry starts three days after the change in the spot price and lasts for four days.

  16. Isospin dependent properties of asymmetric nuclear matter

    Science.gov (United States)

    Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

    2009-07-01

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and isovector components of the density dependent M3Y interaction. The incompressibility K∞ for the symmetric nuclear matter, the isospin dependent part Kasy of the isobaric incompressibility, and the slope L are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei, and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions and validates the important empirical constraints obtained from recent experimental data.

  17. Asymmetric Spatial Processing Under Cognitive Load.

    Science.gov (United States)

    Naert, Lien; Bonato, Mario; Fias, Wim

    2018-01-01

    Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right) hemispace under high verbal working memory (WM) load are discussed.

  18. Baryon destruction by asymmetric dark matter

    International Nuclear Information System (INIS)

    Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

    2011-01-01

    We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause induced nucleon decay by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10 29 -10 32 yrs in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter-induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

  19. Asymmetric Dark Matter and Dark Radiation

    CERN Document Server

    Blennow, Mattias; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, pre...

  20. PEP-II: An asymmetric B factory

    International Nuclear Information System (INIS)

    1993-06-01

    In this report, the authors have described an updated conceptual design for the high-luminosity Asymmetric B Factory (PEP-II) to be built in the PEP tunnel culmination of more than four years of effort aimed at the design and construction of an asymmetric e + e - collider capable of achieving a luminosity of L = 3 x 10 33 cm -2 s -1 . All aspects of the conceptual design were scrutinized in March 1991 by a DOE technical review committee chaired by Dr. L. Edward Temple. The design was deemed feasible and capable of achieving its physics goals. Furthermore, the cost estimate, schedule, and management plan for the project were fully endorsed by the committee. This updated conceptual design report captures the technical progress since the March 1991 review and reflects the lower cost estimate corresponding to the improved design. Although the PEP-II design has continued to evolve, no technical scope changes have been made that invalidate the conclusion of the DOE review. The configuration adopted utilizes two storage rings, an electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of PEP-II. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two PEP-II storage rings

  1. The asymmetric total synthesis of (+)- and (-)-trypargine via Noyori asymmetric transfer hydrogenation

    International Nuclear Information System (INIS)

    Pilli, Ronaldo A.; Rodrigues Junior, Manoel Trindade

    2009-01-01

    A concise and efficient total synthesis of (+)- and (-)-trypargine (6 steps and 38% overall yield), a 1-substituted β-carboline guanidine alkaloid isolated from the skin of the African frog K. senegalensis, was developed based on the construction of the b-carboline moiety via Bischler-Napieralski reaction and the enantioselective reduction of the dihydro-β-carboline intermediate via an asymmetric transfer hydrogenation reaction using Noyori's protocol. (author)

  2. Asymmetric dominance and asymmetric mate choice oppose premating isolation after allopatric divergence.

    Science.gov (United States)

    Sefc, Kristina M; Hermann, Caroline M; Steinwender, Bernd; Brindl, Hanna; Zimmermann, Holger; Mattersdorfer, Karin; Postl, Lisbeth; Makasa, Lawrence; Sturmbauer, Christian; Koblmüller, Stephan

    2015-04-01

    Assortative mating promotes reproductive isolation and allows allopatric speciation processes to continue in secondary contact. As mating patterns are determined by mate preferences and intrasexual competition, we investigated male-male competition and behavioral isolation in simulated secondary contact among allopatric populations. Three allopatric color morphs of the cichlid fish Tropheus were tested against each other. Dyadic male-male contests revealed dominance of red males over bluish and yellow-blotch males. Reproductive isolation in the presence of male-male competition was assessed from genetic parentage in experimental ponds and was highly asymmetric among pairs of color morphs. Red females mated only with red males, whereas the other females performed variable degrees of heteromorphic mating. Discrepancies between mating patterns in ponds and female preferences in a competition-free, two-way choice paradigm suggested that the dominance of red males interfered with positive assortative mating of females of the subordinate morphs and provoked asymmetric hybridization. Between the nonred morphs, a significant excess of negative assortative mating by yellow-blotch females with bluish males did not coincide with asymmetric dominance among males. Hence, both negative assortative mating preferences and interference of male-male competition with positive assortative preferences forestall premating isolation, the latter especially in environments unsupportive of competition-driven spatial segregation.

  3. Effect of vitamin D on aortic remodeling in streptozotocin-induced diabetes

    Directory of Open Access Journals (Sweden)

    Salum Erik

    2012-07-01

    Full Text Available Abstract Background Diabetes mellitus is associated with micro- and macrovascular complications and increased cardiovascular risk. Elevated levels of serum asymmetric dimethylarginine (ADMA may be responsible for endothelial dysfunction associated with diabetes-induced vascular impairment. Vitamin D may have potential protective effects against arterial stiffening. This study aimed to examine both the effects of diabetes on the functional/structural properties of the aorta and the endothelial function and the effects of vitamin D supplementation. Methods Male Wistar rats (n = 30 were randomly assigned to control untreated, diabetic untreated, and diabetic + cholecalciferol groups. Diabetes was induced by intraperitoneal injection of streptozotocin, followed by oral administration of cholecalciferol (500 IU/kg for 10 weeks in the treatment group. Aortic pulse wave velocity (PWV was recorded over a mean arterial pressure (MAP range of 50 to 200 mmHg using a dual pressure sensor catheter. Intravenous infusion of phenylephrine and nitroglycerine was used to increase and decrease MAP, respectively. Serum 25-hydroxyvitamin D [25(OHD] levels were measured using a radioimmune assay. ADMA levels in serum were measured by enzyme-linked immunoassay. Aortic samples were collected for histomorphometrical analysis. Results PWV up to MAP 170 mmHg did not reveal any significant differences between all groups, but in diabetic rats, PWV was significantly elevated across MAP range between 170 and 200 mmHg. Isobaric PWV was similar between the treated and untreated diabetic groups, despite significant differences in the levels of serum 25(OHD (493 ± 125 nmol/L vs 108 ± 38 nmol/L, respectively. Serum levels of ADMA were similarly increased in the treated and untreated diabetic groups, compared to the control group. The concentration and integrity of the elastic lamellae in the medial layer of the aorta was impaired in untreated

  4. Survey of beta-particle interaction experiments with asymmetric matter

    Science.gov (United States)

    Van Horn, J. David; Wu, Fei

    2018-05-01

    Asymmetry is a basic property found at multiple scales in the universe. Asymmetric molecular interactions are fundamental to the operation of biological systems in both signaling and structural roles. Other aspects of asymmetry are observed and useful in many areas of science and engineering, and have been studied since the discovery of chirality in tartrate salts. The observation of parity violation in beta decay provided some impetus for later experiments using asymmetric particles. Here we survey historical work and experiments related to electron (e-) or positron (e+) polarimetry and their interactions with asymmetric materials in gas, liquid and solid forms. Asymmetric interactions may be classified as: 1) stereorecognition, 2) stereoselection and 3) stereoinduction. These three facets of physical stereochemistry are unique but interrelated; and examples from chemistry and materials science illustrate these aspects. Experimental positron and electron interactions with asymmetric materials may be classified in like manner. Thus, a qualitative assessment of helical and polarized positron experiments with different forms of asymmetric matter from the past 40 years is presented, as well as recent experiments with left-hand and right-hand single crystal quartz and organic compounds. The purpose of this classification and review is to evaluate the field for potential new experiments and directions for positron (or electron) studies with asymmetric materials.

  5. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2012-10-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these {eta}-parameterized asymmetric dark matter ({eta}ADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry {eta} close to the baryon asymmetry {eta}{sub B}. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain {eta}ADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an {eta}-asymmetry with a value in the interval 10{sup -12}-10{sup -10}, would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological {eta}ADM scenarios that we discuss have a relic dark matter density {Omega}h {sup 2} and baryon asymmetry {eta}{sub B} in agreement with

  6. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    International Nuclear Information System (INIS)

    Lopes, Ilídio; Silk, Joseph

    2012-01-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these η-parameterized asymmetric dark matter (ηADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry η close to the baryon asymmetry η B . Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain ηADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an η-asymmetry with a value in the interval 10 –12 -10 –10 , would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological ηADM scenarios that we discuss have a relic dark matter density Ωh 2 and baryon asymmetry η B in agreement with the current WMAP measured values, Ω DM h 2 = 0

  7. Role of alpha-lipoic acid in the management of anemia in patients with chronic renal failure undergoing hemodialysis

    Directory of Open Access Journals (Sweden)

    El-Nakib GA

    2013-08-01

    Full Text Available Gehad A El-Nakib,1 Tarek M Mostafa,2 Tarek M Abbas,4 Mamdouh M El-Shishtawy,3 Mokhtar M Mabrouk,2 Mohammed A Sobh41Mansoura University Hospitals, Mansoura, Egypt; 2Faculty of Pharmacy, Tanta University, Tanta, Egypt; 3Faculty of Pharmacy, Mansoura University, Mansoura, Egypt; 4Urology and Nephrology Centre, Faculty of Medicine, Mansoura University, Mansoura, EgyptIntroduction: Anemia associated with chronic kidney disease is a serious complication necessitating expenditure of huge medical efforts and resources. This study investigates the role of alpha-lipoic acid (ALA in end stage renal disease patients undergoing hemodialysis. By the virtue of its antioxidative effects, ALA is expected to act as an erythropoietin (EPO adjuvant, and also has extended beneficial effects on endothelial dysfunction.Methods: Forty-four patients undergoing hemodialysis and receiving EPO were randomized into two groups: the first group received ALA 600 mg once daily for 3 months; while the other group represented the control group. Parameters measured at baseline and at end of study were hemoglobin, EPO doses, EPO resistance index (ERI, iron store indices, malondialdehyde, oxidized low-density lipoprotein (ox-LDL, interleukin-6 (IL-6, tumor necrosis factor-α (TNF-α, and asymmetric dimethylarginine (ADMA, as well as routine laboratory follow-up.Results: EPO doses and ERI were significantly decreased in the treatment group, while they did not change in the control group. Hemoglobin, iron store indices, malondialdehyde, oxidized ox-LDL, IL-6, TNF-α, and ADMA were similar in both treatment and control groups at baseline, and did not change by the end of study period. Likewise, routine laboratory measures were not affected by the treatment.Conclusion: ALA could be used in hemodialysis patients to reduce requirements for EPO. However, larger and longer term studies are required to clarify the exact role of ALA in hemodialysis as well as in pre-hemodialysis patients

  8. Asymmetric quantum well broadband thyristor laser

    Science.gov (United States)

    Liu, Zhen; Wang, Jiaqi; Yu, Hongyan; Zhou, Xuliang; Chen, Weixi; Li, Zhaosong; Wang, Wei; Ding, Ying; Pan, Jiaoqing

    2017-11-01

    A broadband thyristor laser based on InGaAs/GaAs asymmetric quantum well (AQW) is fabricated by metal organic chemical vapor deposition (MOCVD). The 3-μm-wide Fabry-Perot (FP) ridge-waveguide laser shows an S-shape I-V characteristic and exhibits a flat-topped broadband optical spectrum coverage of ~27 nm (Δ-10 dB) at a center wavelength of ~1090 nm with a total output power of 137 mW under pulsed operation. The AQW structure was carefully designed to establish multiple energy states within, in order to broaden the gain spectrum. An obvious blue shift emission, which is not generally acquired in QW laser diodes, is observed in the broadening process of the optical spectrum as the injection current increases. This blue shift spectrum broadening is considered to result from the prominent band-filling effect enhanced by the multiple energy states of the AQW structure, as well as the optical feedback effect contributed by the thyristor laser structure. Project supported by the National Natural Science Foundation of China (Nos. 61604144, 61504137). Zhen Liu and Jiaqi Wang contributed equally to this work.

  9. Asymmetric Cherenkov acoustic reverse in topological insulators

    Science.gov (United States)

    Smirnov, Sergey

    2014-09-01

    A general phenomenon of the Cherenkov radiation known in optics or acoustics of conventional materials is a formation of a forward cone of, respectively, photons or phonons emitted by a particle accelerated above the speed of light or sound in those materials. Here we suggest three-dimensional topological insulators as a unique platform to fundamentally explore and practically exploit the acoustic aspect of the Cherenkov effect. We demonstrate that by applying an in-plane magnetic field to a surface of a three-dimensional topological insulator one may suppress the forward Cherenkov sound up to zero at a critical magnetic field. Above the critical field the Cherenkov sound acquires pure backward nature with the polar distribution differing from the forward one generated below the critical field. Potential applications of this asymmetric Cherenkov reverse are in the design of low energy electronic devices such as acoustic ratchets or, in general, in low power design of electronic circuits with a magnetic field control of the direction and magnitude of the Cherenkov dissipation.

  10. Asymmetric Spatial Processing Under Cognitive Load

    Directory of Open Access Journals (Sweden)

    Lien Naert

    2018-04-01

    Full Text Available Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right hemispace under high verbal working memory (WM load are discussed.

  11. Collaborative hierarchy maintains cooperation in asymmetric games.

    Science.gov (United States)

    Antonioni, Alberto; Pereda, María; Cronin, Katherine A; Tomassini, Marco; Sánchez, Angel

    2018-03-29

    The interplay of social structure and cooperative behavior is under much scrutiny lately as behavior in social contexts becomes increasingly relevant for everyday life. Earlier experimental work showed that the existence of a social hierarchy, earned through competition, was detrimental for the evolution of cooperative behaviors. Here, we study the case in which individuals are ranked in a hierarchical structure based on their performance in a collective effort by having them play a Public Goods Game. In the first treatment, participants are ranked according to group earnings while, in the second treatment, their rankings are based on individual earnings. Subsequently, participants play asymmetric Prisoner's Dilemma games where higher-ranked players gain more than lower ones. Our experiments show that there are no detrimental effects of the hierarchy formed based on group performance, yet when ranking is assigned individually we observe a decrease in cooperation. Our results show that different levels of cooperation arise from the fact that subjects are interpreting rankings as a reputation which carries information about which subjects were cooperators in the previous phase. Our results demonstrate that noting the manner in which a hierarchy is established is essential for understanding its effects on cooperation.

  12. Climate policy, asymmetric information and firm survival

    International Nuclear Information System (INIS)

    Hagem, C.

    2001-02-01

    The purpose of this paper is to compare the effect of different domestic climate policy instruments under asymmetric information when the regulator wants to secure the survival of a specific firm. It is a well-known result from economic theory that emission taxes lead to a cost-effective distribution of abatement across polluters. However, if the regulator wants to ensure the survival of a specific firm, it may need to design policy instruments that reduce the firm's cost of complying with an emission tax regime. The climate policy instruments considered in this paper are tradable emission permits with distribution of free permits, emission taxes in combination with a fixed subsidy, and two types of voluntary agreements. It demonstrates first that if distributing free tradable permits shall have a preventing effect, the allocation of permits has to be made contingent on production. It further shows that a voluntary agreement where a specific abatement target is set by the regulator can prevent a shutdown but leads to lower welfare than the use of emission taxes in combination with a fixed subsidy. And finally it illustrates that a voluntary agreement designed as a menu of abatement contracts increases social welfare compared to an emission tax regime

  13. Performance of an AGATA asymmetric detector

    Energy Technology Data Exchange (ETDEWEB)

    Boston, A.J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)], E-mail: ajboston@liv.ac.uk; Dimmock, M.R.; Unsworth, C.; Boston, H.C.; Cooper, R.J.; Grint, A.N.; Harkness, L.J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.H. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Jones, M.; Nolan, P.J.; Oxley, D.C. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Slee, M. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2009-06-01

    High-resolution gamma-ray detectors based on high-purity germanium crystals (HPGe) are one of the key workhorses of experimental nuclear science. The technical development of such detector technology has been dramatic in recent years. Large volume, high-granularity, electrically segmented HPGe detectors have been realised and a methodology to improve position sensitivity using pulse-shape analysis coupled with the novel technique of gamma-ray tracking has been developed. Collaborations have been established in Europe (Advanced GAmma Tracking Array (AGATA)) [J. Simpson, Acta Phys. Pol. B 36 (2005) 1383] and the USA (GRETA/GRETINA) [C.W. Beausang, Nucl. Instr. and Meth. B 204 (2003)] to build gamma-ray tracking spectrometers. This paper discusses the performance of the first AGATA asymmetric detector that has been tested at the University of Liverpool. The use of a fully digital data acquisition system has allowed detector charge pulse shapes from a selection of well-defined photon interaction positions to be analysed, yielding important information on the position sensitivity of the detector.

  14. Asymmetric Dark Matter and Dark Radiation

    International Nuclear Information System (INIS)

    Blennow, Mattias; Martinez, Enrique Fernandez; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, precise measurements of the number of relativistic species, such as those expected from the Planck satellite, can provide information on the structure of the dark sector. We also discuss the constraints of the interactions between DM and Dark Radiation from their imprint in the matter power spectrum

  15. Asymmetric adaptations to energy price changes

    International Nuclear Information System (INIS)

    Kuper, G.H.; Van Soest, D.P.

    1999-01-01

    The effectiveness of policies to reduce the use of energy depend on the elasticity of substitution between the various inputs and on the rate of technological progress. This paper presents a theoretical model emphasising energy investment characteristics of uncertainty and irreversibility that result in testable hypotheses concerning the relative values of substitution parameters and rates of technological change in periods of high and increasing energy prices and in periods of low prices. Estimation results for a panel of sectors of the Dutch economy show that the elasticity of substitution between energy and other inputs is low in periods of low energy prices, whereas it is significantly higher in the preceding period of high and increasing energy prices. Furthermore, energy-saving technological progress in periods of high and increasing energy prices is also significantly higher than if energy prices are low and falling. The regression results suggest that, due this asymmetric response of firms to changes in energy prices, taxing energy in the current period of low energy prices will not yield substantial reductions in energy use of Dutch industry. 21 refs

  16. Trade Credit Insurance and Asymmetric Information Problem

    Directory of Open Access Journals (Sweden)

    Sokolovska Olena

    2017-03-01

    Full Text Available The presence of different risk factors in international trade gives evidence of the necessity of support in gaps that may affect exporters’ activity. To maximize the trade volumes and in the same time to minimize the exporters’ risks the stakeholders use trade credit insurance. The paper provides analysis of conceptual background of the trade credit insurance in the world. We analyzed briefly the problems, arising in insurance markets due to asymmetric information, such as adverse selection and moral hazard. Also we discuss the main stages of development of trade credit insurance in countries worldwide. Using comparative and graphical analysis we provide a brief evaluation of the dynamics of claims and recoveries for different forms of trade credit insurance. We found that the claims related to the commercial risk for medium and long trade credits in recent years exceed the recoveries, while with the political risk the reverse trend holds. And we originally consider these findings in terms of information asymmetry in the trade credit insurance differentiated by type of risk.

  17. Asymmetric sensory reweighting in human upright stance.

    Directory of Open Access Journals (Sweden)

    David Logan

    Full Text Available To investigate sensory reweighting as a fundamental property of sensor fusion during standing, we probed postural control with simultaneous rotations of the visual scene and surface of support. Nineteen subjects were presented with pseudo-random pitch rotations of visual scene and platform at the ankle to test for amplitude dependencies in the following conditions: low amplitude vision: high amplitude platform, low amplitude vision: low amplitude platform, and high amplitude vision: low amplitude platform. Gain and phase of frequency response functions (FRFs to each stimulus were computed for two body sway angles and a single weighted EMG signal recorded from seven muscles. When platform stimulus amplitude was increased while visual stimulus amplitude remained constant, gain to vision increased, providing strong evidence for inter-modal reweighting between vision and somatosensation during standing. Intra-modal reweighting of vision was also observed as gains to vision decreased as visual stimulus amplitude increased. Such intra-modal and inter-modal amplitude dependent changes in gain were also observed in muscular activity. Gains of leg segment angle and muscular activity relative to the platform, on the other hand, showed only intra-modal reweighting. That is, changing platform motion amplitude altered the responses to both visual and support surface motion whereas changing visual scene motion amplitude did not significantly affect responses to support surface motion, indicating that the sensory integration scheme between somatosensation (at the support surface and vision is asymmetric.

  18. Micromagnetic simulation of Fe asymmetric nanorings

    International Nuclear Information System (INIS)

    Palma, J.L.; Morales-Concha, C.; Leighton, B.; Altbir, D.; Escrig, J.

    2012-01-01

    During the last decade several methods to control the vortex chirality in nanodots have been proposed. One of them, the introduction of asymmetry in the geometry of the dots, originates interesting effects on the magnetic behavior of the particle. However, asymmetry in core-free structures is also interesting to investigate because of the reproducibility of their magnetic properties. In this work we report systematic changes in the coercivity and remanence in asymmetric nanorings. The angular dependence is also addressed. For specific geometries and magnetic field direction newly reversal modes appear associated with important changes in the coercivity and remanence of the rings. - Highlights: → We report that the existence of asymmetry strongly influences the coercivity and the remanence. → Magnetization reversal is driven by the nucleation of a C state and propagation of a vortex state. → We also conclude that the lack of a core contributes to the stability of the vortex state. → Asymmetry can be useful for tailoring specific magnetic characteristics of these systems.

  19. Optimal multicopy asymmetric Gaussian cloning of coherent states

    Science.gov (United States)

    Fiurášek, Jaromír; Cerf, Nicolas J.

    2007-05-01

    We investigate the asymmetric Gaussian cloning of coherent states which produces M copies from N input replicas in such a way that the fidelity of each copy may be different. We show that the optimal asymmetric Gaussian cloning can be performed with a single phase-insensitive amplifier and an array of beam splitters. We obtain a simple analytical expression characterizing the set of optimal asymmetric Gaussian cloning machines and prove the optimality of these cloners using the formalism of Gaussian completely positive maps and semidefinite programming techniques. We also present an alternative implementation of the asymmetric cloning machine where the phase-insensitive amplifier is replaced with a beam splitter, heterodyne detector, and feedforward.

  20. Asymmetrical Polymer Vesicles for Drug delivery and Other Applications

    Directory of Open Access Journals (Sweden)

    Yi Zhao

    2017-06-01

    Full Text Available Scientists have been attracted by polymersomes as versatile drug delivery systems since the last two decades. Polymersomes have the potential to be versatile drug delivery systems because of their tunable membrane formulations, stabilities in vivo, various physicochemical properties, controlled release mechanisms, targeting abilities, and capacities to encapsulate a wide range of drugs and other molecules. Asymmetrical polymersomes are nano- to micro-sized polymeric capsules with asymmetrical membranes, which means, they have different outer and inner coronas so that they can exhibit better endocytosis rate and endosomal escape ability than other polymeric systems with symmetrical membranes. Hence, asymmetrical polymersomes are highly promising as self-assembled nano-delivery systems in the future for in vivo therapeutics delivery and diagnostic imaging applications. In this review, we prepared a summary about recent research progresses of asymmetrical polymersomes in the following aspects: synthesis, preparation, applications in drug delivery and others.

  1. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra; Wang, Ruiqi; Alshareef, Husam N.

    2015-01-01

    electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid

  2. Outage Analysis of Asymmetric RF-FSO Systems

    KAUST Repository

    Ansari, Imran Shafique; Abdallah, Mohamed M.; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

    2017-01-01

    In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channels cascaded with free-space optical (FSO) links is presented. The RF links are modeled by the Rayleigh fading

  3. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    KAUST Repository

    Zhao, Yujun; Lim, XiaoZhi; Pan, Yuanhang; Zong, Lili; Feng, Wei; Tan, Choonhong; Huang, Kuo-Wei

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction's stereoselectivity. © 2012 The Royal Society of Chemistry.

  4. Polarization dependent switching of asymmetric nanorings with a circular field

    Directory of Open Access Journals (Sweden)

    Nihar R. Pradhan

    2016-01-01

    Full Text Available We experimentally investigated the switching from onion to vortex states in asymmetric cobalt nanorings by an applied circular field. An in-plane field is applied along the symmetric or asymmetric axis of the ring to establish domain walls (DWs with symmetric or asymmetric polarization. A circular field is then applied to switch from the onion state to the vortex state, moving the DWs in the process. The asymmetry of the ring leads to different switching fields depending on the location of the DWs and direction of applied field. For polarization along the asymmetric axis, the field required to move the DWs to the narrow side of the ring is smaller than the field required to move the DWs to the larger side of the ring. For polarization along the symmetric axis, establishing one DW in the narrow side and one on the wide side, the field required to switch to the vortex state is an intermediate value.

  5. Optimal multicopy asymmetric Gaussian cloning of coherent states

    International Nuclear Information System (INIS)

    Fiurasek, Jaromir; Cerf, Nicolas J.

    2007-01-01

    We investigate the asymmetric Gaussian cloning of coherent states which produces M copies from N input replicas in such a way that the fidelity of each copy may be different. We show that the optimal asymmetric Gaussian cloning can be performed with a single phase-insensitive amplifier and an array of beam splitters. We obtain a simple analytical expression characterizing the set of optimal asymmetric Gaussian cloning machines and prove the optimality of these cloners using the formalism of Gaussian completely positive maps and semidefinite programming techniques. We also present an alternative implementation of the asymmetric cloning machine where the phase-insensitive amplifier is replaced with a beam splitter, heterodyne detector, and feedforward

  6. Asymmetric continuum extreme processes in solids and fluids

    CERN Document Server

    Teisseyre, Roman

    2014-01-01

    This book deals with a class of basic deformations in asymmetric continuum theory. It describes molecular deformations and transport velocities in fluids, strain deformations in solids as well as the molecular transport, important in fracture processes.

  7. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    KAUST Repository

    Zhao, Yujun

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction\\'s stereoselectivity. © 2012 The Royal Society of Chemistry.

  8. Index profile measurement of asymmetrical elliptical preforms or fibers

    NARCIS (Netherlands)

    Blitterswijk, van W.; Smit, M.K.

    1987-01-01

    An extension of the beam-deflection method to the case of elliptical preforms with eccentric core (asymmetrical elliptical preforms) is presented, which can be easily implemented on automatic measurement equipment

  9. Pseudo-Goldstone modes in isospin-asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Cohen, T.D.; Broniowski, W.

    1995-01-01

    The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter

  10. Subglottic cysts and asymmetrical subglottic narrowing on neck radiograph

    International Nuclear Information System (INIS)

    Holinger, L.D.; Torium, D.M.; Anandappa, E.C.

    1988-01-01

    The congenital subglottic hemangioma typically appears as an asymmetric subglottic narrowing or mass on frontal neck radiograph. Therefore, soft tissue neck radiography has been advocated as a definitive non-operative approach for diagnosing these lesions. However, we have noted similar asymmetric subglottic narrowing in patients with acquired subglottic cysts. These retention cysts occur following long-term intubation in the neonate. The mechanism probably involves subglottic fibrosis which obstructs glands with subsequent cyst formation. Acquired subglottic cysts typically appear as an asymmetric narrowing on frontal or lateral soft tissue neck radiographs. These lesions may produce airway compromise but are effectively treated by forceps or laser removal. Acquired subglottic cysts must be included in the differential diagnosis of asymmetric subglottic narrowing. The definitive diagnosis is made by direct laryngoscopy, not soft tissue neck radiograph. (orig.)

  11. Asymmetric periflexural exanthema: A report in an adult patient

    Directory of Open Access Journals (Sweden)

    Zawar V

    2003-11-01

    Full Text Available Asymmetric periflexural exanthem (APE is a distinctive exanthem, probably viral in origin. It is largely a disease of childhood and is uncommon in adults. We report an adult man presenting with the typical clinical findings of APE.

  12. Fourier synthesis of asymmetrical optical potentials for atoms

    International Nuclear Information System (INIS)

    Ritt, G.

    2007-01-01

    In this work a dissipationless asymmetrical optical potential for cold atoms was produced. In a first step a new type of optical lattice was generated, whose spatial periodicity only corresponds to a quarter of the wavelength of the light used for the generation. This corresponds to the half of the periodicity of a conventional optical lattice, which is formed by the light of the same wavelength. The generation of this new type of optical lattice was reached by the use of two degenerated raman transitions. Virtual processes occur, in which four photons are involved. In conventional optical lattices however virtual two-photon processes occur. By spatially superimposing this optical lattice with a conventional optical lattice an asymmetrical optical potential could be formed. By diffraction of a Bose Einstein condensate of rubidium atoms at the transient activated asymmetrical potential the asymmetrical structure was proven. (orig.)

  13. Kinematics and Dynamics of an Asymmetrical Parallel Robotic Wrist

    DEFF Research Database (Denmark)

    Wu, Guanglei

    2014-01-01

    This paper introduces an asymmetrical parallel robotic wrist, which can generate a decoupled unlimited-torsion motion and achieve high positioning accuracy. The kinematics, dexterity, and singularities of the manipulator are investigated to visualize the performance contours of the manipulator...

  14. Salt supply to and significance of asymmetric salt diapirs

    DEFF Research Database (Denmark)

    Koyi, H.; Burliga, S.; Chemia, Zurab

    2012-01-01

    Salt diapirs can be asymmetric both internally and externally reflecting their evolution history. As such, this asymmetry bear a significant amount of information about the differential loading (± lateral forces) and in turn the salt supply that have shaped the diapir. In two dimensions......, In this study we compare results of analogue and numerical models of diapirs with two natural salt diapris (Klodawa and Gorleben diapirs) to explain their salt supply and asymmetric evolution. In a NW-SE section, the Gorleben salt diapir possesses an asymmetric external geometry represented by a large...... southeastern overhang due to salt extrusion during Middle Cretaceous followed by its burial in Tertiary. This external asymmetry is also reflected in the internal configuration of the diapir which shows different rates of salt flow on the two halves of the structure. The asymmetric external and internal...

  15. Vertical Control and Parallel Trade under Asymmetric Information

    Directory of Open Access Journals (Sweden)

    Alessandro Avenali

    2015-05-01

    profits from the manufacturer to the wholesaler. Therefore, in R&D-intensive industries, such as pharmaceuticals, policy makers should anticipate the likely consequences of PT under asymmetric information on the long-run incentives to innovate.

  16. A method of the asymmetric Abel's inversion in plasma diagnosis

    International Nuclear Information System (INIS)

    Matoba, Tohru; Funahashi, Akimasa

    1975-09-01

    In the case of a noncylindrical plasma, axis symmetric components are drawn from observed projected intensities of physical quantities, assuming an asymmetric form. And the radial intensity distribution is determined by Abel's inversion method. The best fitting curve is obtained analytically from measured values by the least-square estimation of nonlinear parameters. The cylindrical symmetric Abel's inversion code ( ABELIC ) and the asymmetric Abel's inversion code ( ABELILSENP 2 ) are described. (auth.)

  17. Fluorescent nanohybrids based on asymmetrical cyanine dyes decorated carbon nanotubes

    OpenAIRE

    Çavuşlar, Özge; Cavuslar, Ozge

    2015-01-01

    In this thesis, we focused on imparting new optical properties to carbon nanotubes (CNTs) to allow their optical detection and visualization in biomedical applications. We investigated the interactions of CNTs and DNA wrapped CNTs with asymmetrical cyanine dye molecules to study the applicability of resulting hybrid materials to fluorescent based systems. When CNTs interacted with asymmetrical cyanine dyes, they constructed a light absorbing nanoarray. However, the fluorescence emission of th...

  18. Asymmetric Effects on Escape Rates of Bistable System

    International Nuclear Information System (INIS)

    Wang Canjun; Mei Dongcheng; Dai Zucheng

    2011-01-01

    The asymmetric effects on the escape rates from the stable states x ± in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x ± of bistable. However, the asymmetric parameter r enhances the particle escape from stable state x + , and holds back the particle escape from stable state x - . (general)

  19. Method development of damage detection in asymmetric buildings

    Science.gov (United States)

    Wang, Yi; Thambiratnam, David P.; Chan, Tommy H. T.; Nguyen, Andy

    2018-01-01

    Aesthetics and functionality requirements have caused most buildings to be asymmetric in recent times. Such buildings exhibit complex vibration characteristics under dynamic loads as there is coupling between the lateral and torsional components of vibration, and are referred to as torsionally coupled buildings. These buildings require three dimensional modelling and analysis. In spite of much recent research and some successful applications of vibration based damage detection methods to civil structures in recent years, the applications to asymmetric buildings has been a challenging task for structural engineers. There has been relatively little research on detecting and locating damage specific to torsionally coupled asymmetric buildings. This paper aims to compare the difference in vibration behaviour between symmetric and asymmetric buildings and then use the vibration characteristics for predicting damage in them. The need for developing a special method to detect damage in asymmetric buildings thus becomes evident. Towards this end, this paper modifies the traditional modal strain energy based damage index by decomposing the mode shapes into their lateral and vertical components and to form component specific damage indices. The improved approach is then developed by combining the modified strain energy based damage indices with the modal flexibility method which was modified to suit three dimensional structures to form a new damage indicator. The procedure is illustrated through numerical studies conducted on three dimensional five-story symmetric and asymmetric frame structures with the same layout, after validating the modelling techniques through experimental testing of a laboratory scale asymmetric building model. Vibration parameters obtained from finite element analysis of the intact and damaged building models are then applied into the proposed algorithms for detecting and locating the single and multiple damages in these buildings. The results

  20. Asymmetric Price Transmission in Indonesia's Wheat Flour Market

    OpenAIRE

    Varela, Gonzalo J.; Taniguchi, Kiyoshi

    2014-01-01

    Data indicate that its domestic price in Indonesia has been increasing regardless of movements in the international price of wheat. A test for asymmetric price transmission from international wheat to domestic wheat flour markets is conducted using an error correction model and find the presence of asymmetric price transmission. The upward adjustment in the domestic price of wheat flour is much faster than its adjustment downward when it deviates from long-run equilibrium. Our results are rob...

  1. Project financing versus corporate financing under asymmetric information

    OpenAIRE

    Anton Miglo

    2008-01-01

    In recent years financing through the creation of an independent project company or financing by non-recourse debt has become an important part of corporate decisions. Shah and Thakor (JET, 1987) argue that project financing can be optimal when asymmetric information exists between firm's insiders and market participants. In contrast to that paper, we provide an asymmetric information argument for project financing without relying on corporate taxes, costly information production or an assump...

  2. Asymmetric Shaped-Pattern Synthesis for Planar Antenna Arrays

    Directory of Open Access Journals (Sweden)

    T. M. Bruintjes

    2016-01-01

    Full Text Available A procedure to synthesize asymmetrically shaped beam patterns is developed for planar antenna arrays. As it is based on the quasi-analytical method of collapsed distributions, the main advantage of this procedure is the ability to realize a shaped (null-free region with very low ripple. Smooth and asymmetrically shaped regions can be used for Direction-of-Arrival estimation and subsequently for efficient tracking with a single output (fully analog beamformer.

  3. Asymmetric strand segregation: epigenetic costs of genetic fidelity?

    Directory of Open Access Journals (Sweden)

    Diane P Genereux

    2009-06-01

    Full Text Available Asymmetric strand segregation has been proposed as a mechanism to minimize effective mutation rates in epithelial tissues. Under asymmetric strand segregation, the double-stranded molecule that contains the oldest DNA strand is preferentially targeted to the somatic stem cell after each round of DNA replication. This oldest DNA strand is expected to have fewer errors than younger strands because some of the errors that arise on daughter strands during their synthesis fail to be repaired. Empirical findings suggest the possibility of asymmetric strand segregation in a subset of mammalian cell lineages, indicating that it may indeed function to increase genetic fidelity. However, the implications of asymmetric strand segregation for the fidelity of epigenetic information remain unexplored. Here, I explore the impact of strand-segregation dynamics on epigenetic fidelity using a mathematical-modelling approach that draws on the known molecular mechanisms of DNA methylation and existing rate estimates from empirical methylation data. I find that, for a wide range of starting methylation densities, asymmetric -- but not symmetric -- strand segregation leads to systematic increases in methylation levels if parent strands are subject to de novo methylation events. I found that epigenetic fidelity can be compromised when enhanced genetic fidelity is achieved through asymmetric strand segregation. Strand segregation dynamics could thus explain the increased DNA methylation densities that are observed in structured cellular populations during aging and in disease.

  4. Orientation- and position-controlled alignment of asymmetric silicon microrod on a substrate with asymmetric electrodes

    Science.gov (United States)

    Shibata, Akihide; Watanabe, Keiji; Sato, Takuya; Kotaki, Hiroshi; Schuele, Paul J.; Crowder, Mark A.; Zhan, Changqing; Hartzell, John W.; Nakatani, Ryoichi

    2014-03-01

    In this paper, we demonstrate the orientation-controlled alignment of asymmetric Si microrods on a glass substrate with an asymmetric pair of electrodes. The Si microrods have the shape of a paddle with a blade and a shaft part, and the pair of electrodes consists of a narrow electrode and a wide electrode. By applying AC bias to the electrodes, the Si microrods suspended in a fluid align in such a way to settle across the electrode pair, and over 80% of the aligned Si microrods have an orientation with the blade and the shaft of the paddle on the wide and the narrow electrodes, respectively. When Si microrods have a shell of dielectric film and its thickness on the top face is thicker than that on the bottom face, 97.8% of the Si microrods are aligned with the top face facing upwards. This technique is useful for orientation-controlled alignment of nano- and microsized devices that have polarity or a distinction between the top and bottom faces.

  5. Asymmetric Facial Bone Fragmentation Mirrors Asymmetric Distribution of Cranial Neuromasts in Blind Mexican Cavefish

    Directory of Open Access Journals (Sweden)

    Joshua B. Gross

    2016-10-01

    Full Text Available Craniofacial asymmetry is a convergent trait widely distributed across animals that colonize the extreme cave environment. Although craniofacial asymmetry can be discerned easily, other complex phenotypes (such as sensory organ position and numerical variation are challenging to score and compare. Certain bones of the craniofacial complex demonstrate substantial asymmetry, and co-localize to regions harboring dramatically expanded numbers of mechanosensory neuromasts. To determine if a relationship exists between this expansion and bone fragmentation in cavefish, we developed a quantitative measure of positional symmetry across the left-right axis. We found that three different cave-dwelling populations were significantly more asymmetric compared to surface-dwelling fish. Moreover, cave populations did not differ in the degree of neuromast asymmetry. This work establishes a method for quantifying symmetry of a complex phenotype, and demonstrates that facial bone fragmentation mirrors the asymmetric distribution of neuromasts in different cavefish populations. Further developmental studies will provide a clearer picture of the developmental and cellular changes that accompany this extreme phenotype, and help illuminate the genetic basis for facial asymmetry in vertebrates.

  6. Chilly dark sectors and asymmetric reheating

    International Nuclear Information System (INIS)

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-01-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  7. Chilly dark sectors and asymmetric reheating

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States); Cui, Yanou [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Maryland Center for Fundamental Physics, University of Maryland,College Park, MD 20742 (United States); Shelton, Jessie [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States)

    2016-06-06

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N{sub eff}, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  8. Asymmetric inhibitory treatment effects in multilingual aphasia.

    Science.gov (United States)

    Goral, Mira; Naghibolhosseini, Maryam; Conner, Peggy S

    2013-01-01

    Findings from recent psycholinguistic studies of bilingual processing support the hypothesis that both languages of a bilingual are always active and that bilinguals continually engage in processes of language selection. This view aligns with the convergence hypothesis of bilingual language representation. Furthermore, it is hypothesized that when bilinguals perform a task in one language they need to inhibit their other, nontarget language(s) and that stronger inhibition is required when the task is performed in the weaker language than in the stronger one. The study of multilingual individuals who acquire aphasia resulting from a focal brain lesion offers a unique opportunity to test the convergence hypothesis and the inhibition asymmetry. We report on a trilingual person with chronic nonfluent aphasia who at the time of testing demonstrated greater impairment in her first acquired language (Persian) than in her third, later learned language (English). She received treatment in English followed by treatment in Persian. An examination of her connected language production revealed improvement in her grammatical skills in each language following intervention in that language, but decreased grammatical accuracy in English following treatment in Persian. The increased error rate was evident in structures that are used differently in the two languages (e.g., auxiliary verbs). The results support the prediction that greater inhibition is applied to the stronger language than to the weaker language, regardless of their age of acquisition. We interpret the findings as consistent with convergence theories that posit overlapping neuronal representation and simultaneous activation of multiple languages and with proficiency-dependent asymmetric inhibition in multilinguals.

  9. Chilly dark sectors and asymmetric reheating

    Science.gov (United States)

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-06-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  10. Asymmetric Planetary Nebulae VI: the conference summary

    Science.gov (United States)

    De Marco, O.

    2014-04-01

    The Asymmetric Planetary Nebulae conference series, now in its sixth edition, aims to resolve the shaping mechanism of PN. Eighty percent of PN have non spherical shapes and during this conference the last nails in the coffin of single stars models for non spherical PN have been put. Binary theories abound but observational tests are lagging. The highlight of APN6 has been the arrival of ALMA which allowed us to measure magnetic fields on AGB stars systematically. AGB star halos, with their spiral patterns are now connected to PPN and PN halos. New models give us hope that binary parameters may be decoded from these images. In the post-AGB and pre-PN evolutionary phase the naked post-AGB stars present us with an increasingly curious puzzle as complexity is added to the phenomenologies of objects in transition between the AGB and the central star regimes. Binary central stars continue to be detected, including the first detection of longer period binaries, however a binary fraction is still at large. Hydro models of binary interactions still fail to give us results, if we make an exception for the wider types of binary interactions. More promise is shown by analytical considerations and models driven by simpler, 1D simulations such as those carried out with the code MESA. Large community efforts have given us more homogeneous datasets which will yield results for years to come. Examples are the ChanPlaN and HerPlaNe collaborations that have been working with the Chandra and Herschel space telescopes, respectively. Finally, the new kid in town is the intermediate-luminosity optical transient, a new class of events that may have contributed to forming several peculiar PN and pre-PN.

  11. Asymmetric explosion of core-collapse supernovae

    International Nuclear Information System (INIS)

    Kazeroni, Remi

    2016-01-01

    A core-collapse supernova represents the ultimate stage of the evolution of massive stars.The iron core contraction may be followed by a gigantic explosion which gives birth to a neutron star.The multidimensional dynamics of the innermost region, during the first hundreds milliseconds, plays a decisive role on the explosion success because hydrodynamical instabilities are able to break the spherical symmetry of the collapse. Large scale transverse motions generated by two instabilities, the neutrino-driven convection and the Standing Accretion Shock Instability (SASI),increase the heating efficiency up to the point of launching an asymmetric explosion and influencing the birth properties of the neutron star. In this thesis, hydrodynamical instabilities are studied using numerical simulations of simplified models. These models enable a wide exploration of the parameter space and a better physical understanding of the instabilities, generally inaccessible to realistic models.The non-linear regime of SASI is analysed to characterize the conditions under which a spiral mode prevails and to assess its ability to redistribute angular momentum radially.The influence of rotation on the shock dynamics is also addressed. For fast enough rotation rates, a corotation instability overlaps with SASI and greatly impacts the dynamics. The simulations enable to better constrain the effect of non-axisymmetric modes on the angular momentum budget of the iron core collapsing into a neutron star. SASI may under specific conditions spin up or down the pulsar born during the explosion. Finally, an idealised model of the heating region is studied to characterize the non-linear onset of convection by perturbations such as those produced by SASI or pre-collapse combustion inhomogeneities. The dimensionality issue is examined to stress the beneficial consequences of the three-dimensional dynamics on the onset of the explosion. (author) [fr

  12. Affective privilege: Asymmetric interference by emotional distracters

    Directory of Open Access Journals (Sweden)

    Crystal eReeck

    2011-09-01

    Full Text Available Numerous theories posit that affectively salient stimuli are privileged in their capacity to capture attention and disrupt ongoing cognition. Two underlying assumptions in this theoretical position are that the potency of affective stimuli transcends task boundaries (i.e., emotional distracters do not have to belong to a current task-set to disrupt processing and that there is an asymmetry between emotional and cognitive processing (i.e., emotional distracters disrupt cognitive processing, but not vice versa. These assumptions have remained largely untested, as common experimental probes of emotion-cognition interaction rarely manipulate task-relevance and only examine one side of the presumed asymmetry of interference. To test these propositions directly, a face-word Stroop protocol was adapted to independently manipulate (a the congruency between target and distracter stimulus features, (b the affective salience of distracter features, and (c the task-relevance of emotional compared to non-emotional target features. A three-way interaction revealed interdependent effects of distracter relevance, congruence, and affective salience. Compared to task-irrelevant distracters, task-relevant congruent distracters facilitated performance and task-relevant incongruent distracters impaired performance, but the latter effect depended on the nature of the target feature and task. Specifically, task-irrelevant emotional distracters resulted in equivalent performance costs as task-relevant non-emotional distracters, whereas task-irrelevant non-emotional distracters did not produce performance costs comparable to those generated by task-relevant emotional distracters. These results document asymmetric cross-task interference effects for affectively salient stimuli, supporting the notion of affective prioritization in human information processing.

  13. Parallel coupling of symmetric and asymmetric exclusion processes

    International Nuclear Information System (INIS)

    Tsekouras, K; Kolomeisky, A B

    2008-01-01

    A system consisting of two parallel coupled channels where particles in one of them follow the rules of totally asymmetric exclusion processes (TASEP) and in another one move as in symmetric simple exclusion processes (SSEP) is investigated theoretically. Particles interact with each other via hard-core exclusion potential, and in the asymmetric channel they can only hop in one direction, while on the symmetric lattice particles jump in both directions with equal probabilities. Inter-channel transitions are also allowed at every site of both lattices. Stationary state properties of the system are solved exactly in the limit of strong couplings between the channels. It is shown that strong symmetric couplings between totally asymmetric and symmetric channels lead to an effective partially asymmetric simple exclusion process (PASEP) and properties of both channels become almost identical. However, strong asymmetric couplings between symmetric and asymmetric channels yield an effective TASEP with nonzero particle flux in the asymmetric channel and zero flux on the symmetric lattice. For intermediate strength of couplings between the lattices a vertical-cluster mean-field method is developed. This approximate approach treats exactly particle dynamics during the vertical transitions between the channels and it neglects the correlations along the channels. Our calculations show that in all cases there are three stationary phases defined by particle dynamics at entrances, at exits or in the bulk of the system, while phase boundaries depend on the strength and symmetry of couplings between the channels. Extensive Monte Carlo computer simulations strongly support our theoretical predictions. Theoretical calculations and computer simulations predict that inter-channel couplings have a strong effect on stationary properties. It is also argued that our results might be relevant for understanding multi-particle dynamics of motor proteins

  14. Supplementation of a γ-tocopherol-rich mixture of tocopherols in healthy men protects against vascular endothelial dysfunction induced by postprandial hyperglycemia.

    Science.gov (United States)

    Mah, Eunice; Noh, Sang K; Ballard, Kevin D; Park, Hea Jin; Volek, Jeff S; Bruno, Richard S

    2013-01-01

    Postprandial hyperglycemia induces oxidative stress responses, impairs vascular endothelial function (VEF) and increases the risk of cardiovascular disease. We hypothesized that the antioxidant and anti-inflammatory activities of a γ-tocopherol-rich mixture of tocopherols (γ-TmT) would protect against vascular dysfunction that is otherwise caused by postprandial hyperglycemia by decreasing oxidative stress and proinflammatory responses, and improving nitric oxide (NO•) homeostasis. In a randomized, crossover study, healthy men (n=15; 21.8 ± 0.8 years) completed a fasting oral glucose challenge (75 g) with or without prior supplementation of γ-TmT (5 days). Brachial artery flow-mediated dilation (FMD), plasma glucose, insulin, antioxidants, malondialdehyde (MDA), inflammatory proteins, arginine and asymmetric dimethylarginine (ADMA) were measured at regular intervals during a 3-h postprandial period. Supplementation of γ-TmT increased (P.05). Postprandial FMD decreased 30%-44% (P<.05) following glucose ingestion, but was maintained with γ-TmT. Supplementation of γ-TmT also attenuated postprandial increases in MDA that occurred following glucose ingestion. Plasma arginine decreased (P<.05) in both trials to a similar extent regardless of γ-TmT supplementation. However, the ratio of ADMA/arginine increased time-dependently in both trials (P<.05), but to a lesser extent following γ-TmT supplementation (P<.05). Inflammatory proteins were unaffected by glucose ingestion or γ-TmT. Collectively, these findings support that short-term supplementation of γ-TmT maintains VEF during postprandial hyperglycemia possibly by attenuating lipid peroxidation and disruptions in NO• homeostasis, independent of inflammation. Published by Elsevier Inc.

  15. Correlation between serum Hcy content and coronary atherosclerosis severity in patients with H-type hypertension and coronary heart disease

    Directory of Open Access Journals (Sweden)

    Xiao-Mei Li

    2017-03-01

    Full Text Available Objective: To analyze the correlation between serum Hcy content and coronary atherosclerosis severity in patients with H-type hypertension and coronary heart disease. Methods: 48 patients with H-type hypertension and coronary heart disease were selected as observation group, and 57 patients with normal hypertension and coronary heart disease were selected as control group. Echocardiography was used to determine coronary lesion parameters, enzymelinked immunosorbent assay (ELISA was used to determine serum levels of homocysteine (Hcy and coronary heart disease-related indexes, and the correlation between Hcy levels and coronary heart disease was further analyzed. Results: Serum Hcy level of observation group was higher than that of control group (P<0.05, absolute GLPSS value and E/A value under echocardiography were less than those of control group while E-DT and E/e value were higher than those of control group (P<0.05; serum adiponectin (APN level was lower than that of control group while P-selectin, asymmetric dimethylarginine (ADMA, oxidized high-density lipoprotein (OX-HDL, MMP-2, MMP-9, lipoprotein-associated phospholipase A2 (Lp-PLA2 and Resistin levels were higher than those of control group (P<0.05; Hcy was negatively correlated with absolute GLPSS value, E/A value and APN level, and was positively correlated with E-DT value, E/e value as well as P-selectin, ADMA, OX-HDL, MMP-2, MMP-9, Lp- PLA2 and Resistin levels (P<0.05. Conclusions: There is direct correlation between serum Hcy levels and the severity of coronary heart disease in patients with H-type hypertension and coronary heart disease, it can be a reliable way to early screen for coronary heart disease and evaluate the illness, and it is also a new target of coronary heart disease intervention.

  16. A glutamate/aspartate switch controls product specificity in a protein arginine methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Debler, Erik W.; Jain, Kanishk; Warmack, Rebeccah A.; Feng, You; Clarke, Steven G.; Blobel, Günter; Stavropoulos, Pete

    2016-02-08

    Trypanosoma brucei PRMT7 (TbPRMT7) is a protein arginine methyltransferase (PRMT) that strictly monomethylates various substrates, thus classifying it as a type III PRMT. However, the molecular basis of its unique product specificity has remained elusive. Here, we present the structure of TbPRMT7 in complex with its cofactor product S-adenosyl-L-homocysteine (AdoHcy) at 2.8 Å resolution and identify a glutamate residue critical for its monomethylation behavior. TbPRMT7 comprises the conserved methyltransferase and β-barrel domains, an N-terminal extension, and a dimerization arm. The active site at the interface of the N-terminal extension, methyltransferase, and β-barrel domains is stabilized by the dimerization arm of the neighboring protomer, providing a structural basis for dimerization as a prerequisite for catalytic activity. Mutagenesis of active-site residues highlights the importance of Glu181, the second of the two invariant glutamate residues of the double E loop that coordinate the target arginine in substrate peptides/proteins and that increase its nucleophilicity. Strikingly, mutation of Glu181 to aspartate converts TbPRMT7 into a type I PRMT, producing asymmetric dimethylarginine (ADMA). Isothermal titration calorimetry (ITC) using a histone H4 peptide showed that the Glu181Asp mutant has markedly increased affinity for monomethylated peptide with respect to the WT, suggesting that the enlarged active site can favorably accommodate monomethylated peptide and provide sufficient space for ADMA formation. In conclusion, these findings yield valuable insights into the product specificity and the catalytic mechanism of protein arginine methyltransferases and have important implications for the rational (re)design of PRMTs.

  17. Restoration of impaired nitric oxide production in MELAS syndrome with citrulline and arginine supplementation.

    Science.gov (United States)

    El-Hattab, Ayman W; Hsu, Jean W; Emrick, Lisa T; Wong, Lee-Jun C; Craigen, William J; Jahoor, Farook; Scaglia, Fernando

    2012-04-01

    Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most common mitochondrial disorders. Although the pathogenesis of stroke-like episodes remains unclear, it has been suggested that mitochondrial proliferation may result in endothelial dysfunction and decreased nitric oxide (NO) availability leading to cerebral ischemic events. This study aimed to assess NO production in subjects with MELAS syndrome and the effect of the NO precursors arginine and citrulline. Using stable isotope infusion techniques, we assessed arginine, citrulline, and NO metabolism in control subjects and subjects with MELAS syndrome before and after arginine or citrulline supplementation. The results showed that subjects with MELAS had lower NO synthesis rate associated with reduced citrulline flux, de novo arginine synthesis rate, and plasma arginine and citrulline concentrations, and higher plasma asymmetric dimethylarginine (ADMA) concentration and arginine clearance. We conclude that the observed impaired NO production is due to multiple factors including elevated ADMA, higher arginine clearance, and, most importantly, decreased de novo arginine synthesis secondary to decreased citrulline availability. Arginine and, to a greater extent, citrulline supplementation increased the de novo arginine synthesis rate, the plasma concentrations and flux of arginine and citrulline, and NO production. De novo arginine synthesis increased markedly with citrulline supplementation, explaining the superior efficacy of citrulline in increasing NO production. The improvement in NO production with arginine or citrulline supplementation supports their use in MELAS and suggests that citrulline may have a better therapeutic effect than arginine. These findings can have a broader relevance for other disorders marked by perturbations in NO metabolism. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Metabolomic Profiling in Individuals with a Failing Kidney Allograft.

    Directory of Open Access Journals (Sweden)

    Roberto Bassi

    Full Text Available Alteration of certain metabolites may play a role in the pathophysiology of renal allograft disease.To explore metabolomic abnormalities in individuals with a failing kidney allograft, we analyzed by liquid chromatography-mass spectrometry (LC-MS/MS; for ex vivo profiling of serum and urine and two dimensional correlated spectroscopy (2D COSY; for in vivo study of the kidney graft 40 subjects with varying degrees of chronic allograft dysfunction stratified by tertiles of glomerular filtration rate (GFR; T1, T2, T3. Ten healthy non-allograft individuals were chosen as controls.LC-MS/MS analysis revealed a dose-response association between GFR and serum concentration of tryptophan, glutamine, dimethylarginine isomers (asymmetric [A]DMA and symmetric [S]DMA and short-chain acylcarnitines (C4 and C12, (test for trend: T1-T3 = p<0.05; p = 0.01; p<0.001; p = 0.01; p = 0.01; p<0.05, respectively. The same association was found between GFR and urinary levels of histidine, DOPA, dopamine, carnosine, SDMA and ADMA (test for trend: T1-T3 = p<0.05; p<0.01; p = 0.001; p<0.05; p = 0.001; p<0.001; p<0.01, respectively. In vivo 2D COSY of the kidney allograft revealed significant reduction in the parenchymal content of choline, creatine, taurine and threonine (all: p<0.05 in individuals with lower GFR levels.We report an association between renal function and altered metabolomic profile in renal transplant individuals with different degrees of kidney graft function.

  19. Asymmetrical reinforcement and Wolbachia infection in Drosophila.

    Directory of Open Access Journals (Sweden)

    John Jaenike

    2006-10-01

    Full Text Available Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquinaria and males of D. recens result in high levels of offspring mortality, due to interspecific cytoplasmic incompatibility caused by Wolbachia infection of D. recens. Such hybrid inviability is not manifested in matings between D. recens females and D. subquinaria males. Here we ask whether the asymmetrical hybrid inviability is associated with a corresponding asymmetry in the level of reinforcement. The geographic ranges of D. recens and D. subquinaria were found to overlap across a broad belt of boreal forest in central Canada. Females of D. subquinaria from the zone of sympatry exhibit much stronger levels of discrimination against males of D. recens than do females from allopatric populations. In contrast, such reproductive character displacement is not evident in D. recens, consistent with the expected effects of unidirectional cytoplasmic incompatibility. Furthermore, there is substantial behavioral isolation within D. subquinaria, because females from populations sympatric with D. recens discriminate against allopatric conspecific males, whereas females from populations allopatric with D. recens show no discrimination against any conspecific males. Patterns of general genetic differentiation among populations are not consistent with patterns of behavioral discrimination, which suggests that the behavioral isolation within D. subquinaria results from selection against mating with Wolbachia-infected D. recens. Interspecific cytoplasmic incompatibility may contribute not only to post-mating isolation, an effect already widely recognized, but also to

  20. Performance of JPEG Image Transmission Using Proposed Asymmetric Turbo Code

    Directory of Open Access Journals (Sweden)

    Siddiqi Mohammad Umar

    2007-01-01

    Full Text Available This paper gives the results of a simulation study on the performance of JPEG image transmission over AWGN and Rayleigh fading channels using typical and proposed asymmetric turbo codes for error control coding. The baseline JPEG algorithm is used to compress a QCIF ( "Suzie" image. The recursive systematic convolutional (RSC encoder with generator polynomials , that is, (13/11 in decimal, and 3G interleaver are used for the typical WCDMA and CDMA2000 turbo codes. The proposed asymmetric turbo code uses generator polynomials , that is, (13/11; 13/9 in decimal, and a code-matched interleaver. The effect of interleaver in the proposed asymmetric turbo code is studied using weight distribution and simulation. The simulation results and performance bound for proposed asymmetric turbo code for the frame length , code rate with Log-MAP decoder over AWGN channel are compared with the typical system. From the simulation results, it is observed that the image transmission using proposed asymmetric turbo code performs better than that with the typical system.

  1. Success Factors of Asymmetric Connections - Example of Large Slovenian Enterprises

    Directory of Open Access Journals (Sweden)

    Viktor Vračar

    2014-11-01

    Full Text Available More and more companies realize the fact that networking or partner collaborations, which are based on partner relations between companies, are essential for their long-term existence. In today’s global competitive environment each company is included at least in some different connections. Very common connections occur between large and smaller enterprises, where the so called asymmetric connections occur, which may be understood as the ability of one organisation to establish power, influence and control over the other organisation and its resources. According to numerous statements, the connections between enterprises are very frequently uneffectivenessful, with opinions on the optimal nature of asymmetric connections being quite common as well, whereby it is, as a rule, a synergic complementing of missing content for both partners. To verify the thesis, that companies achieve more competitiveness and effectiveness through connections, whereby the so called asymmetric connections are common, a structural model of the evolution of asymmetric connection has been developed, which connects the theoretically identified factors and all dependent concepts of competitiveness, efficiency and effectiveness. The empirical research also attempts to further expose the factors of asymmetric connections, which affect efficiency and effectiveness of the connected enterprises.

  2. Time-Dependent-Asymmetric-Linear-Parsimonious Ancestral State Reconstruction.

    Science.gov (United States)

    Didier, Gilles

    2017-10-01

    The time-dependent-asymmetric-linear parsimony is an ancestral state reconstruction method which extends the standard linear parsimony (a.k.a. Wagner parsimony) approach by taking into account both branch lengths and asymmetric evolutionary costs for reconstructing quantitative characters (asymmetric costs amount to assuming an evolutionary trend toward the direction with the lowest cost). A formal study of the influence of the asymmetry parameter shows that the time-dependent-asymmetric-linear parsimony infers states which are all taken among the known states, except for some degenerate cases corresponding to special values of the asymmetry parameter. This remarkable property holds in particular for the Wagner parsimony. This study leads to a polynomial algorithm which determines, and provides a compact representation of, the parametric reconstruction of a phylogenetic tree, that is for all the unknown nodes, the set of all the possible reconstructed states associated with the asymmetry parameters leading to them. The time-dependent-asymmetric-linear parsimony is finally illustrated with the parametric reconstruction of the body size of cetaceans.

  3. Gravity-induced asymmetric distribution of a plant growth hormone

    Science.gov (United States)

    Bandurski, R. S.; Schulze, A.; Momonoki, Y.

    1984-01-01

    Dolk (1936) demonstrated that gravistimulation induced an asymmetric distribution of auxin in a horizontally-placed shoot. An attempt is made to determine where and how that asymmetry arises, and to demonstrate that the endogenous auxin, indole-3-acetic acid, becomes asymmetrically distributed in the cortical cells of the Zea mays mesocotyl during 3 min of geostimulation. Further, indole-3-acetic acid derived by hydrolysis of an applied transport form of the hormone, indole-3-acetyl-myo-inositol, becomes asymmetrically distributed within 15 min of geostimulus time. From these and prior data is developed a working theory that the gravitational stimulus induces a selective leakage, or secretion, of the hormone from the vascular tissue to the cortical cells of the mesocotyl.

  4. Best Speed Fit EDF Scheduling for Performance Asymmetric Multiprocessors

    Directory of Open Access Journals (Sweden)

    Peng Wu

    2017-01-01

    Full Text Available In order to improve the performance of a real-time system, asymmetric multiprocessors have been proposed. The benefits of improved system performance and reduced power consumption from such architectures cannot be fully exploited unless suitable task scheduling and task allocation approaches are implemented at the operating system level. Unfortunately, most of the previous research on scheduling algorithms for performance asymmetric multiprocessors is focused on task priority assignment. They simply assign the highest priority task to the fastest processor. In this paper, we propose BSF-EDF (best speed fit for earliest deadline first for performance asymmetric multiprocessor scheduling. This approach chooses a suitable processor rather than the fastest one, when allocating tasks. With this proposed BSF-EDF scheduling, we also derive an effective schedulability test.

  5. Lower Bounds in the Asymmetric External Memory Model

    DEFF Research Database (Denmark)

    Jacob, Riko; Sitchinava, Nodari

    2017-01-01

    Motivated by the asymmetric read and write costs of emerging non-volatile memory technologies, we study lower bounds for the problems of sorting, permuting and multiplying a sparse matrix by a dense vector in the asymmetric external memory model (AEM). Given an AEM with internal (symmetric) memory...... of size M, transfers between symmetric and asymmetric memory in blocks of size B and the ratio ω between write and read costs, we show Ω(min (N, ωN/B logω M/B N/B) lower bound for the cost of permuting N input elements. This lower bound also applies to the problem of sorting N elements. This proves...

  6. Electromagnetic resonance in the asymmetric terahertz metamaterials with triangle microstructure

    Science.gov (United States)

    Xing, Yuanyuan; Zhang, Xiaoyu; Zhang, Qiang; Gu, Yanping; Qian, Yunan; Lin, Xingyue; Tang, Yunhai; Cheng, Xinli; Qin, Changfa; Shen, Jiaoyan; Zang, Taocheng; Ma, Chunlan

    2018-05-01

    We investigate terahertz transmission properties and electromagnetic resonance modes in the asymmetric triangle structures with the change of asymmetric distance and the direction of electric field. When the THz electric field is perpendicular to the split gap of triangle, the electric field can better excite the THz absorption in the triangle structures. Importantly, electromagnetically induced transparency (EIT) characteristics are observed in the triangle structures due to the destructive interference of the different excited modes. The distributions of electric field and surface current density simulated by finite difference time domain indicate that the bright mode is excited by the side of triangle structures and dark mode is excited by the gap-side of triangle. The present study is helpful to understand the electromagnetic resonance in the asymmetric triangular metamaterials.

  7. Tourist Demand Reactions: Symmetric or Asymmetric across the Business Cycle?

    Science.gov (United States)

    Bronner, Fred; de Hoog, Robert

    2017-09-01

    Economizing and spending priorities on different types of vacations are investigated during two periods: an economic downturn and returning prosperity. Two nation-wide samples of vacationers are used: one during a downturn, the other one at the start of the recovery period. Through comparing the results, conclusions can be drawn about symmetric or asymmetric tourist demand across the business cycle. The main summer holiday has an asymmetric profile: being fairly crisis-resistant during a recession and showing considerable growth during an expansion. This does not apply to short vacations and day trips, each having a symmetric profile: during a recession they experience substantial reductions and during expansion comparable growth. So when talking about tourist demand in general , one cannot say that it is symmetric or asymmetric across the business cycle: it depends on the type of vacation. Differences in tourist demand are best explained by the role of Quality-of-Life for vacationers.

  8. Two-channel totally asymmetric simple exclusion processes

    International Nuclear Information System (INIS)

    Pronina, Ekaterina; Kolomeisky, Anatoly B

    2004-01-01

    Totally asymmetric simple exclusion processes, consisting of two coupled parallel lattice chains with particles interacting with hard-core exclusion and moving along the channels and between them, are considered. In the limit of strong coupling between the channels, the particle currents, density profiles and a phase diagram are calculated exactly by mapping the system into an effective one-channel totally asymmetric exclusion model. For intermediate couplings, a simple approximate theory, that describes the particle dynamics in vertical clusters of two corresponding parallel sites exactly and neglects the correlations between different vertical clusters, is developed. It is found that, similarly to the case of one-channel totally asymmetric simple exclusion processes, there are three stationary state phases, although the phase boundaries and stationary properties strongly depend on inter-channel coupling. Extensive computer Monte Carlo simulations fully support the theoretical predictions

  9. Controllable asymmetric transmission via gap-tunable acoustic metasurface

    Science.gov (United States)

    Liu, Bingyi; Jiang, Yongyuan

    2018-04-01

    In this work, we utilize the acoustic gradient metasurface (AGM) of a bilayer configuration to realize the controllable asymmetric transmission. Relying on the adjustable gap between the two composing layers, the metasurface could switch from symmetric transmission to asymmetric transmission at a certain gap value. The underlying mechanism is attributed to the interference between the forward diffracted waves scattered by the surface bound waves at two air-AGM interfaces, which is apparently influenced by the interlayer distance. We further utilize the hybrid acoustic elements to construct the desired gradient metasurface with a tunable gap and validate the controllable asymmetric transmission with full-wave simulations. Our work provides the solution for actively controlling the transmission property of an acoustic element, which shows potential application in acoustic communication as a dynamic tunable acoustic diode.

  10. Asymmetric adsorption of alanine by quartz powder from ethanol solution

    Energy Technology Data Exchange (ETDEWEB)

    Furuyama, Shozo; Sawada, Michio; Hachiya, Kinji; Morimoto, Tetsuo (Okayama Univ. (Japan). Faculty of Science)

    1982-11-01

    The asymmetric adsorption of the racemic alanine by the optically active quartz from ethanol solution at 8/sup 0/C was studied by the /sup 14/C-tracer method and the newly developed /sup 14/C-tracer ninhydrin-colorimetry combination method. The preferential adsorption of L-alanine by levorotatory quartz (l-quartz) and D-alanine by dextrorotatory quartz (d-quartz) was confirmed. The asymmetric adsorptivity (Asub(s)) falls in the range of 1.1 - 1.3, which is comparable with the value determined at - 80/sup 0/C in the previous paper. The effects of water content in the ethanol solution and of the adsorption temperature upon the adsorption affinity of alanine to quartz were also measured. The cause for the asymmetric adsorption is discussed from the crystallographic point of view.

  11. Dynamic JUNQ inclusion bodies are asymmetrically inherited in mammalian cell lines through the asymmetric partitioning of vimentin.

    Science.gov (United States)

    Ogrodnik, Mikołaj; Salmonowicz, Hanna; Brown, Rachel; Turkowska, Joanna; Średniawa, Władysław; Pattabiraman, Sundararaghavan; Amen, Triana; Abraham, Ayelet-chen; Eichler, Noam; Lyakhovetsky, Roman; Kaganovich, Daniel

    2014-06-03

    Aging is associated with the accumulation of several types of damage: in particular, damage to the proteome. Recent work points to a conserved replicative rejuvenation mechanism that works by preventing the inheritance of damaged and misfolded proteins by specific cells during division. Asymmetric inheritance of misfolded and aggregated proteins has been shown in bacteria and yeast, but relatively little evidence exists for a similar mechanism in mammalian cells. Here, we demonstrate, using long-term 4D imaging, that the vimentin intermediate filament establishes mitotic polarity in mammalian cell lines and mediates the asymmetric partitioning of damaged proteins. We show that mammalian JUNQ inclusion bodies containing soluble misfolded proteins are inherited asymmetrically, similarly to JUNQ quality-control inclusions observed in yeast. Mammalian IPOD-like inclusion bodies, meanwhile, are not always inherited by the same cell as the JUNQ. Our study suggests that the mammalian cytoskeleton and intermediate filaments provide the physical scaffold for asymmetric inheritance of dynamic quality-control JUNQ inclusions. Mammalian IPOD inclusions containing amyloidogenic proteins are not partitioned as effectively during mitosis as their counterparts in yeast. These findings provide a valuable mechanistic basis for studying the process of asymmetric inheritance in mammalian cells, including cells potentially undergoing polar divisions, such as differentiating stem cells and cancer cells.

  12. The rationality of EIA forecasts under symmetric and asymmetric loss

    International Nuclear Information System (INIS)

    Auffhammer, Maximilian

    2007-01-01

    The United States Energy Information Administration publishes annual forecasts of nationally aggregated energy consumption, production, prices, intensity and GDP. These government issued forecasts often serve as reference cases in the calibration of simulation and econometric models, which climate and energy policy are based on. This study tests for rationality of published EIA forecasts under symmetric and asymmetric loss. We find strong empirical evidence of asymmetric loss for oil, coal and electricity prices as well as natural gas consumption, electricity sales, GDP and energy intensity. (author)

  13. Data analysis of asymmetric structures advanced approaches in computational statistics

    CERN Document Server

    Saito, Takayuki

    2004-01-01

    Data Analysis of Asymmetric Structures provides a comprehensive presentation of a variety of models and theories for the analysis of asymmetry and its applications and provides a wealth of new approaches in every section. It meets both the practical and theoretical needs of research professionals across a wide range of disciplines and  considers data analysis in fields such as psychology, sociology, social science, ecology, and marketing. In seven comprehensive chapters this guide details theories, methods, and models for the analysis of asymmetric structures in a variety of disciplines and presents future opportunities and challenges affecting research developments and business applications.

  14. Current drive by asymmetrical heating in a toroidal plasma

    International Nuclear Information System (INIS)

    Gahl, J.M.

    1986-01-01

    This report describes the first experimental observation of current generation by asymmetrical heating of ions. A unidirectional fast Alfven wave launched by a slow-wave antenna inside the Texas Tech Tokamak, asymmetrically heated the ions. Measurements of the asymmetry of the toroidal plasma current with probes at the top and bottom of the toroidal plasma column confirmed the current generation indirectly. Current generation, obtained in a one-species, hydrogen plasma, is a phenomenon which had not been predicted previously. Calculations of the dispersion relation for the fast Alfven wave near the fundamental cyclotron resonance in a one-species, hydrogen plasma, using warm plasma theory, support the experimental results

  15. Climate agreements under limited participation, asymmetric information and market imperfections

    Energy Technology Data Exchange (ETDEWEB)

    Hagem, Cathrine

    1996-12-31

    This thesis relates to climate agreements and cost efficiency by analysing the formation of a system of quota leading to distributed discharge of emissions between countries. Main fields concerned are the greenhouse effect, the political process, efficient and cost-effective climate agreements, and climate agreements under limited participation, asymmetric information and market imperfections covering fields like limited participation in climate agreements, limited participation and indirect impact on non-participating countries` emissions, limited participation and direct impact on non-participating countries` emissions under asymmetric information, and non-competitive market for tradeable quotas. 166 refs., 7 tabs.

  16. Experimental research on photovoltaic module for asymmetrical compound parabolic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jinshe; Wang, Mingyue [Chongqing Normal University, Chongqing (China). Department of Physics; Yang, Changmin [Xian University of Technology, Xian (China). Department of Applied Physics

    2008-07-01

    The photovoltaic module for the use of fixed asymmetrical CPC concentrator was designed and fabricated based on the performance of polycrystalline-silicon solar cells with back surface field (BSF) structure. The performance of the combination of the module and asymmetrical CPC concentrator was investigated. The results show its effective concentration ratio to be 2.46 and the output power of the PV-a-CPC system to be increased by 2.13 times compared with that of the module approximately. (orig.)

  17. Asymptotic behavior of observables in the asymmetric quantum Rabi model

    Science.gov (United States)

    Semple, J.; Kollar, M.

    2018-01-01

    The asymmetric quantum Rabi model with broken parity invariance shows spectral degeneracies in the integer case, that is when the asymmetry parameter equals an integer multiple of half the oscillator frequency, thus hinting at a hidden symmetry and accompanying integrability of the model. We study the expectation values of spin observables for each eigenstate and observe characteristic differences between the integer and noninteger cases for the asymptotics in the deep strong coupling regime, which can be understood from a perturbative expansion in the qubit splitting. We also construct a parent Hamiltonian whose exact eigenstates possess the same symmetries as the perturbative eigenstates of the asymmetric quantum Rabi model in the integer case.

  18. Testing for asymmetric pricing in the Canadian retail gasoline market

    International Nuclear Information System (INIS)

    Godby, R.; Lintner, A.M.; Stengos, T.; Wandschneider, B.

    2000-01-01

    This paper applies a Threshold Regression model to test for asymmetric pricing in the retail gasoline market in Canada, using weekly data for the period January 1990 to December 1996. We present results for 13 Canadian cities for both premium and regular gasoline. Within the context of an error correction model we test for the presence of asymmetric price behaviour using average changes in crude prices as well as various lags for the change in crude as possible thresholds. We are unable to find any evidence to support this view. 23 refs

  19. Decoding Pure Rotational Molecular Spectra for Asymmetric Molecules

    Directory of Open Access Journals (Sweden)

    S. A. Cooke

    2013-01-01

    Full Text Available Rotational spectroscopy can provide insights of unparalleled precision with respect to the wavefunctions of molecular systems that have relevance in fields as diverse as astronomy and biology. In this paper, we demonstrate how asymmetric molecular pure rotational spectra may be analyzed “pictorially” and with simple formulae. It is shown that the interpretation of such spectra relies heavily upon pattern recognition. The presentation of some common spectral line positions in near-prolate asymmetric rotational spectra provides a means by which spectral assignment, and approximate rotational constant determination, may be usefully explored. To aid in this endeavor we have created a supporting, free, web page and mobile web page.

  20. Ideal MHD beta-limits of poloidally asymmetric equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Todd, A.M.M.; Miller, A.E.; Grimm, R.C.; Okabayashi, M.; Dalhed, H.E. Jr.

    1981-05-01

    The ideal MHD stability of poloidally asymmetric equilibria, which are typical of a tokamak reactor design with a single-null poloidal divertor is examined. As with symmetric equilibria, stability to non-axisymmetric modes improves with increasing triangularity and ellipticity, and with lower edge safety factor. Pressure profiles optimized with respect to ballooning stability are obtained for an asymmetric shape, resulting in ..beta../sub critical/ approx. = 5.7%. The corresponding value for an equivalent symmetric shape is ..beta../sub critical/ approx. = 6.5%.

  1. Axisymmetric stability of vertically asymmetric tokamaks at large beta poloidal

    International Nuclear Information System (INIS)

    Yamazaki, K.; Fishman, H.; Okabayashi, M.; Todd, A.M.M.

    1981-09-01

    The stability of high-β vertically asymmetric tokamak equilibria to rigid displacements is investigated analytically. It is found that vertical stability at large beta poloidal is mainly determined by a coupling between the shape of the plasma surface and the Shafranov shift of the magnetic axis. To the lowest order, symmetric components of the plasma surface shape are found to be the critical destabilizing elements. Asymmetric components have little effect. The inclusion of higher order terms in the high β tokamak expansion leads to further destabilization. Qualitative agreement between these analytic results and numerical stability calculations using the PEST code is demonstrated

  2. Ideal MHD beta-limits of poloidally asymmetric equilibria

    International Nuclear Information System (INIS)

    Todd, A.M.M.; Miller, A.E.; Grimm, R.C.; Okabayashi, M.; Dalhed, H.E. Jr.

    1981-05-01

    The ideal MHD stability of poloidally asymmetric equilibria, which are typical of a tokamak reactor design with a single-null poloidal divertor is examined. As with symmetric equilibria, stability to non-axisymmetric modes improves with increasing triangularity and ellipticity, and with lower edge safety factor. Pressure profiles optimized with respect to ballooning stability are obtained for an asymmetric shape, resulting in β/sub critical/ approx. = 5.7%. The corresponding value for an equivalent symmetric shape is β/sub critical/ approx. = 6.5%

  3. Electron Raman scattering in asymmetrical multiple quantum wells

    International Nuclear Information System (INIS)

    Betancourt-Riera, R; Rosas, R; Marin-Enriquez, I; Riera, R; Marin, J L

    2005-01-01

    Optical properties of asymmetrical multiple quantum wells for the construction of quantum cascade lasers are calculated, and expressions for the electronic states of asymmetrical multiple quantum wells are presented. The gain and differential cross-section for an electron Raman scattering process are obtained. Also, the emission spectra for several scattering configurations are discussed, and the corresponding selection rules for the processes involved are studied; an interpretation of the singularities found in the spectra is given. The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers

  4. Six transformer based asymmetrical embedded Z-source inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Poh Chiang, Loh; Chi, Jin

    2013-01-01

    Embedded/Asymmetrical embedded Z-source inverters were proposed to maintain smooth input current/voltage across the dc source and within the impedance network, remain the shoot-through feature used to boost up the dc-link voltage without adding bulky filter at input side. This paper introduces a ...... a class of transformer based asymmetrical embedded Z-source inverters which keep the smooth input current and voltage while achieving enhanced voltage boost capability. The presented inverters are verified by laboratory prototypes experimentally....

  5. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  6. The rationality of EIA forecasts under symmetric and asymmetric loss

    Energy Technology Data Exchange (ETDEWEB)

    Auffhammer, Maximilian [Department of Agricultural and Resource Economics, University of California, 207 Giannini Hall 3310, Berkeley, CA 94720 (United States)

    2007-05-15

    The United States Energy Information Administration publishes annual forecasts of nationally aggregated energy consumption, production, prices, intensity and GDP. These government issued forecasts often serve as reference cases in the calibration of simulation and econometric models, which climate and energy policy are based on. This study tests for rationality of published EIA forecasts under symmetric and asymmetric loss. We find strong empirical evidence of asymmetric loss for oil, coal and electricity prices as well as natural gas consumption, electricity sales, GDP and energy intensity. (author)

  7. An optical tweezer in asymmetrical vortex Bessel-Gaussian beams

    Energy Technology Data Exchange (ETDEWEB)

    Kotlyar, V. V.; Kovalev, A. A., E-mail: alexeysmr@mail.ru; Porfirev, A. P. [Image Processing Systems Institute, 151 Molodogvardeiskaya St., 443001 Samara (Russian Federation); Department of Technical cybernetics, Samara State Aerospace University, Samara 443086 (Russian Federation)

    2016-07-14

    We study an optical micromanipulation that comprises trapping, rotating, and transporting 5-μm polystyrene microbeads in asymmetric Bessel-Gaussian (BG) laser beams. The beams that carry orbital angular momentum are generated by means of a liquid crystal microdisplay and focused by a microobjective with a numerical aperture of NA = 0.85. We experimentally show that given a constant topological charge, the rate of microparticle motion increases near linearly with increasing asymmetry of the BG beam. Asymmetric BG beams can be used instead of conventional Gaussian beam for trapping and transferring live cells without thermal damage.

  8. Preview-based Asymmetric Load Reduction of Wind Turbines

    DEFF Research Database (Denmark)

    Madsen, Mathias; Filsø, Jakob; Soltani, Mohsen

    2012-01-01

    Controller (MPC) developed is based on a model with individual blade pitching to utilize the LIDAR measurements. The MPC must also maintain a given power reference while satisfying a set of actuator constraints. The designed controller was tested on a 5 MW wind turbine in the FAST simulator and compared......Fatigue loads on wind turbines caused by an asymmetric wind field become an increasing concern when the scale of wind turbines increases. This paper presents a model based predictive approach to reduce asymmetric loads by using Light Detection And Ranging (LIDAR) measurements. The Model Predictive...

  9. Dicer is dispensable for asymmetric RISC loading in mammals.

    Science.gov (United States)

    Betancur, Juan G; Tomari, Yukihide

    2012-01-01

    In flies, asymmetric loading of small RNA duplexes into Argonaute2-containing RNA-induced silencing complex (Ago2-RISC) requires Dicer-2/R2D2 heterodimer, which acts as a protein sensor for the thermodynamic stabilities of the ends of small RNA duplexes. However, the mechanism of small RNA asymmetry sensing in mammalian RISC assembly remains obscure. Here, we quantitatively examined RISC assembly and target silencing activity in the presence or absence of Dicer in mammals. Our data show that, unlike the well-characterized fly Ago2-RISC assembly pathway, mammalian Dicer is dispensable for asymmetric RISC loading in vivo and in vitro.

  10. Effect of rosuvastatin on fasting and postprandial endothelial biomarker levels and microvascular reactivity in patients with type 2 diabetes and dyslipidemia: a preliminary report.

    Science.gov (United States)

    Kim, Kyoung Min; Jung, Kyong Yeun; Yun, Han Mi; Lee, Seo Young; Oh, Tae Jung; Jang, Hak Chul; Lim, Soo

    2017-11-09

    The cardiovascular benefits of statins have been proven, but their effect on circulation in small vessels has not been examined fully. We investigated the effect of 20 mg rosuvastatin on biomarkers, including paraoxonase-1 (PON-1) and asymmetric dimethylarginine (ADMA), and on microvascular reactivity. We enrolled 20 dyslipidemic patients with type 2 diabetes and 20 age- and body mass index (BMI)-matched healthy controls. Rosuvastatin (20 mg/day) was given to the patient group for 12 weeks. Biochemical parameters, including PON-1 and ADMA, were compared between the patient and control groups, and before and after rosuvastatin treatment in the patient group. Fasting and 2 h postprandial levels of PON-1 and ADMA after mixed-meal challenge were also compared. Microvascular reactivity in a peripheral artery was examined using laser Doppler flowmetry. The respective mean ± standard deviation of age and BMI were 50.1 ± 3.8 year and 25.8 ± 3.7 kg/m 2 in the patients and 50.2 ± 3.2 year and 25.4 ± 3.4 kg/m 2 in the controls. The patient group had worse profiles of cardiometabolic biomarkers, including PON-1 and ADMA, than the controls. In the patients treated with 20 mg rosuvastatin, low-density lipoprotein (LDL)-cholesterol decreased from 147.2 ± 26.5 to 68.3 ± 24.5 mg/dL and high-density lipoprotein (HDL)-cholesterol increased from 42.4 ± 5.2 to 44.7 ± 6.2 mg/dL (both P fasting and 2 h postprandial levels of PON-1 increased and those of ADMA decreased after treatment with rosuvastatin for 12 weeks. The changes in postprandial levels of both biomarkers were greater than those after fasting. Microcirculation assessed as reactive hyperemia in the patients after an ischemic challenge increased significantly from 335.3 ± 123.4 to 402.7 ± 133.4% after rosuvastatin treatment. The postprandial changes in the biomarkers were significantly associated with improvement of microvascular reactivity. Rosuvastatin treatment for 12

  11. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    NARCIS (Netherlands)

    van der Linden, Jan Willem; Vrijman, Violette; Al-Saady, Rana; El-Saady, Rana; van der Meulen, Ivanka J.; Mourits, Maarten P.; Lapid-Gortzak, Ruth

    2014-01-01

    To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric multifocal IOL (LS-312

  12. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    NARCIS (Netherlands)

    Linden, J.W.M. van der; Vrijman, V.; El-Saady, R.; Meulen, I.J. van der; Mourits, M.P.; Lapid-Gortzak, R.

    2014-01-01

    PURPOSE: To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). METHODS: This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric

  13. Augmented asymmetrical visual field dependence in asymptomatic diabetics: evidence of subclinical asymmetrical bilateral vestibular dysfunction.

    Science.gov (United States)

    Razzak, Rima Abdul; Bagust, Jeffery; Docherty, Sharon; Hussein, Wiam; Al-Otaibi, Abdullah

    2015-01-01

    Diabetes negatively affects the vestibular system in many ways, with vestibular dysfunction (VD), a co-morbidity with a high prevalence in diabetics. The ability to perceive subjective visual vertical (SVV), as a sign of vestibular dysfunction, and visual field dependence was measured using a computerized rod and frame test (CRAF). Alignment errors recorded from 47 asymptomatic Type II diabetics (no vertigo or falls, without peripheral neuropathy or retinopathy) were compared to 29 healthy age matched (46-69years) controls. Visual field dependence was significantly larger and more asymmetrical in the diabetics than controls. In the absence of any visual references, or when a vertical reference frame was provided, SVV perception was accurate in both groups, with no significant difference between the controls and diabetics. During tilted frame presentations, the proportion of subjects with either SVV deviations, or an asymmetry index, larger than an upper limit derived from the control data was significantly greater in diabetics than controls. These results suggest that the decreased ability to resolve visuo-vestibular conflict in asymptomatic diabetic patients (free of retinopathy and peripheral neuropathy) compared to controls may be related to diabetic complications affecting vestibular structures and thus causing a decompensation of subclinical vestibular asymmetries. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Option Pricing with Asymmetric Heteroskedastic Normal Mixture Models

    DEFF Research Database (Denmark)

    Rombouts, Jeroen V. K; Stentoft, Lars

    2015-01-01

    We propose an asymmetric GARCH in mean mixture model and provide a feasible method for option pricing within this general framework by deriving the appropriate risk neutral dynamics. We forecast the out-of-sample prices of a large sample of options on the S&P 500 index from January 2006 to December...

  15. Reputations in Markets with Asymmetric Information: A Classroom Game

    Science.gov (United States)

    Wolf, James R.; Myerscough, Mark A.

    2007-01-01

    The authors describe a classroom game used to teach students about the impact of reputations in markets with asymmetric information. The game is an extension of Holt and Sherman's lemons market game and simulates a market under three information conditions. In the full information setting, all participants know both the quality and the price of…

  16. DNA-based asymmetric organometallic catalysis in water

    NARCIS (Netherlands)

    Oelerich, Jens; Roelfes, Gerard

    2013-01-01

    Here, the first examples of DNA-based organometallic catalysis in water that give rise to high enantioselectivities are described. Copper complexes of strongly intercalating ligands were found to enable the asymmetric intramolecular cyclopropanation of alpha-diazo-beta-keto sulfones in water. Up to

  17. Bertrand Competition with Asymmetric Costs: A Solution in Pure Strategies

    NARCIS (Netherlands)

    Demuynck, Thomas; Herings, P. Jean-Jacques; Saulle, Riccardo D.; Seel, Christian

    2018-01-01

    We consider two versions of a Bertrand duopoly with asymmetric costs and homogeneous goods. They differ in whether predatory pricing is allowed. For each version, we derive the Myopic Stable Set in pure strategies as introduced by Demuynck, Herings, Saulle, and Seel (2017). We contrast our

  18. Asymmetric block copolymers confined in a thin film

    NARCIS (Netherlands)

    Huinink, HP; Brokken-Zijp, JCM; van Dijk, MA; Sevink, GJA

    2000-01-01

    We have used a dynamic density functional theory (DDFT) for polymeric systems, to simulate the formation of micro phases in a melt of an asymmetric block copolymer, A(n)B(m)(f(A) = 1/3), both in the bulk and in a thin film. In the DDFT model a polymer is represented as a chain of springs and beads.

  19. On the topology defined by Thurston's asymmetric metric

    DEFF Research Database (Denmark)

    Papadopoulos, Athanase; Theret, Guillaume

    2007-01-01

    that the topology that the asymmetric metric L induces on Teichmüller space is the same as the usual topology. Furthermore, we show that L satisfies the axioms of a (not necessarily symmetric) metric in the sense of Busemann and conclude that L is complete in the sense of Busemann....

  20. Economic Dispatch of Demand Response Balancing through Asymmetric Block Offers

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Pinson, Pierre; Madsen, Henrik

    2015-01-01

    This paper proposes a method of describing the load shifting ability of flexible electrical loads in a manner suitable for existing power system dispatch frameworks. The concept of an asymmetric block offer for flexible loads is introduced. This offer structure describes the ability of a flexible...

  1. All Pseudocapacitive MXene-RuO2 Asymmetric Supercapacitors

    KAUST Repository

    Jiang, Qiu

    2018-01-23

    2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, in particular in electrochemical energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, symmetric MXene supercapacitors have a limited voltage window of around 0.6 V due to possible oxidation at high anodic potentials. In this study, the fact that titanium carbide MXene (Ti3C2Tx) can operate at negative potentials in acidic electrolyte is exploited, to design an all-pseudocapacitive asymmetric device by combining it with a ruthenium oxide (RuO2) positive electrode. This asymmetric device operates at a voltage window of 1.5 V, which is about two times wider than the operating voltage window of symmetric MXene supercapacitors, and is the widest voltage window reported to date for MXene-based supercapacitors. The complementary working potential windows of MXene and RuO2, along with proton-induced pseudocapacitance, significantly enhance the device performance. As a result, the asymmetric devices can deliver an energy density of 37 µW h cm−2 at a power density of 40 mW cm−2, with 86% capacitance retention after 20 000 charge–discharge cycles. These results show that pseudocapacitive negative MXene electrodes can potentially replace carbon-based materials in asymmetric electrochemical capacitors, leading to an increased energy density.

  2. Design of activated carbon/activated carbon asymmetric capacitors

    Science.gov (United States)

    Piñeiro-Prado, Isabel; Salinas-Torres, David; Ruiz Rosas, Ramiro; Morallon, Emilia; Cazorla-Amoros, Diego

    2016-03-01

    Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed. In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  3. Investment and Internal Finance: Asymmetric Information or Managerial Discretion?

    NARCIS (Netherlands)

    H. Degryse (Hans); A. de Jong (Abe)

    2001-01-01

    textabstractThis paper examines the relation between cash-flow availability and investment spending in the Netherlands. In particular, we are interested whether managerial discretion and/or asymmetric information drive the positive relation between cash-flow and investment spending. This relation

  4. Non-stationary probabilities for the asymmetric exclusion process on ...

    Indian Academy of Sciences (India)

    rich picture of relaxation processes which provides an extension of notions of equi- librium statistical mechanics such as phase transitions and spontaneous symmetry breaking to the non-equilibrium case. The asymmetric exclusion process (ASEP) is the simplest model of non-equilibrium theory of many interacting particles ...

  5. Non-stationary probabilities for the asymmetric exclusion process

    Indian Academy of Sciences (India)

    A solution of the master equation for a system of interacting particles for finite time and particle density is presented. By using a new form of the Bethe ansatz, the totally asymmetric exclusion process on a ring is solved for arbitrary initial conditions and time intervals.

  6. Linguistic Correlates of Asymmetric Motor Symptom Severity in Parkinson's Disease

    Science.gov (United States)

    Holtgraves, Thomas; McNamara, Patrick; Cappaert, Kevin; Durso, Raymond

    2010-01-01

    Asymmetric motor severity is common in Parkinson's Disease (PD) and provides a method for examining the neurobiologic mechanisms underlying cognitive and linguistic deficits associated with the disorder. In the present research, PD participants (N = 31) were assessed in terms of the asymmetry of their motor symptoms. Interviews with the…

  7. Asymmetric Modeling of the Industrial Heavy Water Plant (PIAP)

    International Nuclear Information System (INIS)

    Teruel, Federico; Aprea, J; Guido Lavalle, German

    2000-01-01

    Software of asymmetric stationary simulation for the Industrial Heavy Water Plant (PIAP) was developed, based on an existing symmetric simulator (Brigitte 2.0).This software allows to turn off some of the isotopic enrichment twin units present in the plant and to simulate them asymmetrically, in other words, with different selection of parameters between twins.Other incorporations were done, such as passing flows between units and entering flows in strategic points of the plant.The iterative system in which the symmetric simulator is based was insufficient to develop the asymmetric simulator, so the system was modeled according to an implicit scheme for the units that form the simulator.This type of resolution resulted in a simulator that supports a big range of boundary conditions and internal parameters.Moreover, the time of calculus is short (∼3 minutes), making it actually useful.The asymmetric simulator is at the PIAP now, for its study and validation. It shows expected tendencies and results according to the symmetric simulator already validated

  8. Proline-catalysed asymmetric ketol cyclizations: The template ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A modified template mechanism based on modelling studies of energy minimised complexes is presented for the asymmetric proline-catalysed cyclization of triketones 1, 2 and 3 to the 2S,3S-ketols. 1a, 2a and 3a respectively. The template model involves a three-point contact as favoured in enzyme– substrate ...

  9. Asymmetric Adjustment in the Ethanol and Grains Markets

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); L.H. Chen (Li-Hsueh); S.M. Hammoudeh (Shawkat); M.J. McAleer (Michael)

    2011-01-01

    textabstractThis paper examines the long- and short-run asymmetric adjustments for nine pairs of spot and futures prices, itemized as three own pairs for three different bio-fuel ethanol types, three own pairs for three related agricultural products, namely corn, soybeans and sugar, and three cross

  10. The catalystic asymmetric synthesis of optically active epoxy ketones

    NARCIS (Netherlands)

    Marsman, Bertha Gerda

    1981-01-01

    In this thesis the use of catalytic asymmetric synthesis to prepare optically active epoxy ketones is described. This means that the auxiliary chirality, necessary to obtain an optically active product, is added in a catalytic quantity . In principle this is a very efficient way to make opticlly

  11. Cell Chirality Drives Left-Right Asymmetric Morphogenesis.

    Science.gov (United States)

    Inaki, Mikiko; Sasamura, Takeshi; Matsuno, Kenji

    2018-01-01

    Most macromolecules found in cells are chiral, meaning that they cannot be superimposed onto their mirror image. However, cells themselves can also be chiral, a subject that has received little attention until very recently. In our studies on the mechanisms of left-right (LR) asymmetric development in Drosophila , we discovered that cells can have an intrinsic chirality to their structure, and that this "cell chirality" is generally responsible for the LR asymmetric development of certain organs in this species. The actin cytoskeleton plays important roles in the formation of cell chirality. In addition, Myosin31DF ( Myo31DF ), which encodes Drosophila Myosin ID, was identified as a molecular switch for cell chirality. In other invertebrate species, including snails and Caenorhabditis elegans , chirality of the blastomeres, another type of cell chirality, determines the LR asymmetry of structures in the body. Thus, chirality at the cellular level may broadly contribute to LR asymmetric development in various invertebrate species. Recently, cell chirality was also reported for various vertebrate cultured cells, and studies suggested that cell chirality is evolutionarily conserved, including the essential role of the actin cytoskeleton. Although the biological roles of cell chirality in vertebrates remain unknown, it may control LR asymmetric development or other morphogenetic events. The investigation of cell chirality has just begun, and this new field should provide valuable new insights in biology and medicine.

  12. Asymmetrical Modulation for Uplink Communication in Cooperative Networks

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    -range links with neighboring mobile devices to form cooperative clusters. So far the physical communication over cellular links and over short-range links are separated in time or in frequency. Beyond this state of the art, we exploit a method, referred to as asymmetrical modulation, where a mobile device...

  13. Review of literature on the asymmetric collapse of vapor bubbles

    International Nuclear Information System (INIS)

    Fremd, R.; Froehlich, G.

    1977-06-01

    This report contains a review of literature on the asymmetric collape of vapor bubbles by cavitation with special consideration to vapor explosions. Two numerical models, which describe the collapse of cavities in the neighbourhood of a solid surface, are presented. Moreover experimental results for this case are provided. Propositions to apply the numerical models to vapor explosions are made. (orig.) [de

  14. Symmetrical and asymmetrical growth restriction in preterm-born children

    NARCIS (Netherlands)

    Bocca-Tjeertes, Inger; Bos, Arend; Kerstjens, Jorien; de Winter, Andrea; Reijneveld, Sijmen

    OBJECTIVE: To determine how symmetric (proportionate; SGR) and asymmetric (disproportionate; AGR) growth restriction influence growth and development in preterms from birth to 4 years. METHODS: This community-based cohort study of 810 children comprised 86 SGR, 61 AGR, and 663 non-growth restricted

  15. Analysis of the asymmetrical shortest two-server queueing model

    NARCIS (Netherlands)

    J.W. Cohen

    1995-01-01

    textabstractThis study presents the analytic solution for the asymmetrical two-server queueing model with arriving customers joining the shorter queue for the case with Poisson arrivals and negative exponentially distributed service times. The bivariate generating function of the stationary joint

  16. New approaches in asymmetric synthesis using γ-alkoxybutenolides

    NARCIS (Netherlands)

    Lange, Ben de; Jansen, Johan F.G.A.; Jong, Johannes C. de; Lubben, Marcel; Faber, Wijnand; Schudde, Ebe P.; Feringa, Bernard

    1992-01-01

    The synthesis of a new class of auxiliary based chiral synthons, γ-alkoxy-2(5H)-furanones, is described. The multifunctional compounds enter a variety of asymmetric transformations leading to acyclic- and cyclic-products with up to four new stereogenic centers in a single operation with

  17. Materials dependence of mixed gas plasticization behavior in asymmetric membranes

    NARCIS (Netherlands)

    Visser, Tymen; Masetto, N.; Wessling, Matthias

    2007-01-01

    The mass transport of asymmetric membranes for the separation of carbon dioxide/methane mixtures is determined by competitive sorption and plasticization. With increasing feed pressure in mixed gas experiments, the selectivity decreases due to both effects. Distinction whether one or the other

  18. Design of activated carbon/activated carbon asymmetric capacitors

    Directory of Open Access Journals (Sweden)

    Isabel ePiñeiro-Prado

    2016-03-01

    Full Text Available Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed.In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  19. Asymmetric electroresistance of cluster glass state in manganites

    KAUST Repository

    Lourembam, James; Ding, Junfeng; Bera, Ashok; Lin, Weinan; Wu, Tao

    2014-01-01

    cluster glass magnetic state emerges at low temperatures with a spin freezing temperature of about 99 K, which is accompanied by the reentrant insulating state with high resistance below 30 K. In the EDLT, we observe bipolar and asymmetric modulation

  20. Clinical characteristics in patients with asymmetric idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Callahan, Sean J; Xia, Meng; Murray, Susan; Flaherty, Kevin R

    2016-10-01

    A group of patients with idiopathic pulmonary fibrosis (IPF) presents with disease affecting one lung markedly more than the other. At this time, it is unclear how this population differs from those who present with more symmetric disease. We sought to explain the characteristics of the asymmetric group and how their disease progresses. In this retrospective case-control study we accessed an interstitial lung disease (ILD) database and identified 14 asymmetric IPF cases via high-resolution computed tomography (HRCT) scoring of each lung lobe's disease severity. We identified 28 symmetric IPF controls from the same database using the same methods, and compared the clinical features of each group. Patients with asymmetric disease exhibited similar demographics as those in the general IPF population; they were predominantly male (64%), elderly (69 years old), and used tobacco (57%). We found a trend toward significantly increased all-cause mortality in the case population two years following diagnosis (p = 0.089). Pulmonary function tests were significantly lower in the case group at the time of diagnosis, then both groups experienced gradual decline. We found no statistically significant differences in number of IPF exacerbations (cases 43%, controls 39%, p = 0.824) and gastro-esophageal reflux (both groups 50%). Patients with asymmetric IPF resemble patients in the general IPF population but may have a lower overall survival rate. Further systemic factors may be studied to identify reasons for disease asymmetry and clinical decline in this population. Published by Elsevier Ltd.

  1. Simulation of seismic signals from asymmetric LANL hydrodynamic calculations

    International Nuclear Information System (INIS)

    Stevens, J.L.; Rimer, N.; Halda, E.J.; Barker, T.G.; Davis, C.G.; Johnson, W.E.

    1993-01-01

    Hydrodynamic calculations of an asymmetric nuclear explosion source were propagated to teleseismic distances to investigate the effects of the asymmetric source on seismic signals. The source is an explosion in a 12 meter long canister with the device at one end of the canister and a metal plate adjacent to the explosion. This produces a strongly asymmetric two-lobed source in the hydrodynamic region. The hydrodynamic source is propagated to the far field using a three-step process. The Eulerian hydrodynamic code SOIL was used by LANL to calculate the material velocity, density, and internal energy up to a time of 8.9 milliseconds after the explosion. These quantities were then transferred to an initial grid for the Lagrangian elastic/plastic finite difference code CRAM, which was used by S-CUBED to propagate the signal through the region of nonlinear deformation into the external elastic region. The cavity size and shape at the time of the overlay were determined by searching for a rapid density change in the SOIL grid, and this interior region was then rezoned into a single zone. The CRAM calculation includes material strength and gravity, and includes the effect of the free surface above the explosion. Finally, far field body waves were calculated by integrating over a closed surface in the elastic region and using the representation theorem. A second calculation was performed using an initially spherical source for comparison with the asymmetric calculation

  2. Novel Cinchona derived organocatalysts: new asymmetric transformations and catalysis

    NARCIS (Netherlands)

    Breman, A.C.

    2014-01-01

    Cinchona alkaloids have a long history as being a powerful medicine against malaria. Since a relative short period (about 50 years) chemist have also used these alkaloids as chiral catalyst for a wide variety of asymmetric transformations. Especially since the beginning of this century, when strong

  3. Stability of asymmetric lipid bilayers assessed by molecular dynamics simulations

    NARCIS (Netherlands)

    Esteban-Martin, Santi; Risselada, H. Jelger; Salgado, Jesus; Marrink, Siewert J.

    2009-01-01

    The asymmetric insertion of amphiphiles into biological membranes compromises the balance between the inner and outer monolayers. As a result, area expansion of the receiving leaflet and curvature strain may lead to membrane permeation, shape changes, or membrane fusion events. We have conducted

  4. Current Topics in the Asymmetric Transfer Hydrogenation of Imines

    Czech Academy of Sciences Publication Activity Database

    Januščák, J.; Václavík, Jiří; Šot, P.; Pecháček, J.; Vilhanová, B.; Kuzma, Marek; Kačer, P.

    2015-01-01

    Roč. 109, č. 7 (2015), s. 492-498 ISSN 0009-2770 R&D Projects: GA ČR GAP106/12/1276; GA MŠk(CZ) LO1509 Institutional support: RVO:61388971 Keywords : asymmetric transfer hydrogenation * ruthenium * isoquinoline Subject RIV: EE - Microbiology, Virology Impact factor: 0.279, year: 2015

  5. Beamwidth for asymmetric and multilayer semiconductor laser structures

    DEFF Research Database (Denmark)

    Buus, Jens

    1981-01-01

    An expression for the far field of the fundamental TE0mode in an asymmetrical dielectric slab waveguide is derived. By using normalized waveguide parameters, universal plots of the beamwidth are presented. These plots include the obliquity factor correction. Experimental results for symmetrical G...

  6. Accelerating foreign-key joins using asymmetric memory channels

    NARCIS (Netherlands)

    Pirk, H.; Manegold, S.; Kersten, M.

    2011-01-01

    Indexed Foreign-Key Joins expose a very asymmetric access pattern: the Foreign-Key Index is sequentially scanned whilst the Primary-Key table is target of many quasi-random lookups which is the dominant cost factor. To reduce the costs of the random lookups the fact-table can be (re-) partitioned at

  7. Ion Motion Stability in Asymmetric Surface Electrode Ion Traps

    Science.gov (United States)

    Shaikh, Fayaz; Ozakin, Arkadas

    2010-03-01

    Many recently developed designs of the surface electrode ion traps for quantum information processing have asymmetry built into their geometries. The asymmetry helps rotate the trap axes to angles with respect to electrode surface that facilitate laser cooling of ions but introduces a relative angle between the RF and DC fields and invalidates the classical stability analysis of the symmetric case for which the equations of motion are decoupled. For asymmetric case the classical motion of a single ion is given by a coupled, multi-dimensional version of Mathieu's equation. In this poster we discuss the stability diagram of asymmetric surface traps by performing an approximate multiple scale perturbation analysis of the coupled Mathieu equations, and validate the results with numerical simulations. After obtaining the stability diagram for the linear fields, we simulate the motion of an ion in a given asymmetric surface trap, utilizing a method-of-moments calculation of the electrode fields. We obtain the stability diagram and compare it with the ideal case to find the region of validity. Finally, we compare the results of our stability analysis to experiments conducted on a microfabricated asymmetric surface trap.

  8. The on-line asymmetric traveling salesman problem

    NARCIS (Netherlands)

    Ausiello, G.; Bonifaci, V.; Laura, L.

    2008-01-01

    We consider two on-line versions of the asymmetric traveling salesman problem with triangle inequality. For the homing version, in which the salesman is required to return in the city where it started from, we give a -competitive algorithm and prove that this is best possible. For the nomadic

  9. Bertrand Competition with an Asymmetric No-Discrimination Constraint

    NARCIS (Netherlands)

    Bouckaert, J.M.C.; Degryse, H.A.; van Dijk, T.

    2012-01-01

    Abstract: We study the competitive and welfare consequences when only one firm must commit to uniform pricing while the competitor’s pricing policy is left unconstrained. The asymmetric no-discrimination constraint prohibits both behaviour-based price discrimination within the competitive segment

  10. Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers

    Directory of Open Access Journals (Sweden)

    Arjunan Govindarajan

    2017-06-01

    Full Text Available We investigate modulational instability (MI in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD. In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores. Following the analytical consideration of the MI, numerical simulations are carried out to explore nonlinear development of the MI, revealing the generation of periodic chains of localized peaks with growing amplitudes, which may transform into arrays of solitons.

  11. QUARTZ: a numerical simulation of an asymmetric electrostatic accelerator

    International Nuclear Information System (INIS)

    Wooten, J.W.; Drooks, L.J.; McCollough, D.H.; McGaffey, R.W.; Whealton, J.H.

    1979-01-01

    The physics and numerical aspects of the development of the computer code QUARTZ are given. This code includes the (1) use of a finite element code to obtain solutions of Poisson's equation in an asymmetric, three-dimensional volume; (2) inclusion of space charge neutralization by electrons; and (3) inclusion of ion space charge through an iterative procedure

  12. Simulation of the longitudinal instabilities of the asymmetric bunches

    International Nuclear Information System (INIS)

    Dai Jianping; Zhao Zhentang

    2002-01-01

    The computational model of the code used to simulate the longitudinal instabilities of the asymmetric bunches was introduced. The growth rates of the longitudinal instabilities of the symmetric bunches got by this code were compared with those got by the code ZAP, and they were almost the same. As an example, the simulation results of the BEPC-II were presented

  13. Asymmetric bipolar membrane: A tool to improve product purity

    NARCIS (Netherlands)

    Balster, J.H.; Sumbharaju, R.; Srikantharajah, S.; Punt, Ineke G.M.; Stamatialis, Dimitrios; Jordan, V.; Wessling, Matthias

    2007-01-01

    Bipolar membranes (BPMs) are catalytic membranes for electro-membrane processes splitting water into protons and hydroxyl ions. To improve selectivity and current efficiency of BPMs, we prepare new asymmetric BPMs with reduced salt leakages. The flux of salt ions across a BPM is determined by the

  14. HIV-infected persons with type 2 diabetes show evidence of endothelial dysfunction and increased inflammation

    DEFF Research Database (Denmark)

    Hove-Skovsgaard, Malene; Gaardbo, Julie Christine; Kolte, Lilian

    2017-01-01

    BACKGROUND: Increased incidence of cardiovascular diseases (CVD) in both HIV infection and type 2 diabetes (T2D) compared to the general population has been described. Little is known about the combined effect of HIV infection and T2D on inflammation and endothelial function, both of which may...... contribute to elevated risk of CVD. METHODS: Cross-sectional study including 50 HIV-infected persons on combination anti-retroviral therapy (cART), with HIV RNA 2D (HIV + T2D+), n = 25 without T2D (HIV + T2D-)) and 50 uninfected persons (n = 22 with T2D (HIV-T2D+) and n = 28...... without T2D (HIV-T2D-)). Groups were matched on age and sex. High sensitive C-reactive protein (hsCRP) was used to determine inflammation (cut-off 3 mg/L). The marker of endothelial dysfunction asymmetric dimethylarginine (ADMA) was measured using high performance liquid chromatography. Trimethylamine...

  15. Effect of high flux hemodialysis on plasma toxin molecule contents and body’s microinflammatory state in patients with uremia

    Directory of Open Access Journals (Sweden)

    Zheng-Nan We

    2016-03-01

    Full Text Available Objective: To analyze the effect of high flux hemodialysis on plasma toxin molecule contents and body’s microinflammatory state in patients with uremia. Methods: A total of 96 cases of patients with uremia receiving inpatient dialysis in our hospital from June 2011 to March 2015 were selected as research subjects and randomly divided into observation group and control group, each group with 48 cases. Control group received low flux hemodialysis (LF-HD, observation group received high flux hemodialysis (HF-HD, and then levels of plasma renal function-related toxins, oxidative stress-related toxins, leptin, intact parathyroid hormone and asymmetric dimethylarginine as well as levels of microinflammatory state-related factors of two groups were compared. Results: Plasma BUN, Scr, UA and β2-MG levels of observation group after dialysis were significantly lower than those of control group; plasma MDA and Cor levels of observation group after dialysis were lower than those of control group, and levels of GSH and SOD were higher than those of control group; plasma Leptin, iPTH and ADMA levels of observation group after 1 time and 5 times of dialysis were significantly lower than those of control group; plasma hs-CRP, IL-6, TNF-α and ASAA levels of observation group after dialysis were significantly lower than those of control group. Conclusion: High flux hemodialysis for patients with uremia can effectively eliminate related toxins in the body and reduce systemic microinflammatory state, and it has active clinical significance.

  16. Apple Peel Supplemented Diet Reduces Parameters of Metabolic Syndrome and Atherogenic Progression in ApoE−/− Mice

    Directory of Open Access Journals (Sweden)

    Jaime Gonzalez

    2015-01-01

    Full Text Available Cardiovascular Diseases (CVD represent about 30% of all causes of death worldwide. The development of CVD is related in many cases with the previous existence of metabolic syndrome (MS. It is known that apple consumption has a cardiovascular protecting effect, containing phenolic compounds with antioxidant effect, which are concentrated in the fruit peel. The objective of this study was to test the effect of apple peel consumption in a murine model of MS and apoE−/− mice. Apple supplemented diets reduced the biochemical parameters (glycaemia, total cholesterol, HDL-cholesterol, LDL-cholesterol, ureic nitrogen, triglycerides, insulin, and asymmetric dimethylarginine (ADMA of MS model in CF1 mice significantly. The model apoE−/− mouse was used to evaluate the capacity of the apple peel to revert the progression of the atherogenesis. FD with HAP reverts cholesterol significantly and slows down the progression of the plate diminishing the cholesterol accumulation area. With these results, it can be concluded that the consumption of apple peel reduces several MS parameters and the atherogenic progression in mice.

  17. A meta-analysis of biomarkers related to oxidative stress and nitric oxide pathway in migraine.

    Science.gov (United States)

    Neri, Monica; Frustaci, Alessandra; Milic, Mirta; Valdiglesias, Vanessa; Fini, Massimo; Bonassi, Stefano; Barbanti, Piero

    2015-09-01

    Oxidative and nitrosative stress are considered key events in the still unclear pathophysiology of migraine. Studies comparing the level of biomarkers related to nitric oxide (NO) pathway/oxidative stress in the blood/urine of migraineurs vs. unaffected controls were extracted from the PubMed database. Summary estimates of mean ratios (MR) were carried out whenever a minimum of three papers were available. Nineteen studies were included in the meta-analyses, accounting for more than 1000 patients and controls, and compared with existing literature. Most studies measuring superoxide dismutase (SOD) showed lower activity in cases, although the meta-analysis in erythrocytes gave null results. On the contrary, plasma levels of thiobarbituric acid reactive substances (TBARS), an aspecific biomarker of oxidative damage, showed a meta-MR of 2.20 (95% CI: 1.65-2.93). As for NOs, no significant results were found in plasma, serum and urine. However, higher levels were shown during attacks, in patients with aura, and an effect of diet was found. The analysis of glutathione precursor homocysteine and asymmetric dimethylarginine (ADMA), an NO synthase inhibitor, gave inconclusive results. The role of the oxidative pathway in migraine is still uncertain. Interesting evidence emerged for TBARS and SOD, and concerning the possible role of diet in the control of NOx levels. © International Headache Society 2015.

  18. Totally Asymmetric Limit for Models of Heat Conduction

    Science.gov (United States)

    De Carlo, Leonardo; Gabrielli, Davide

    2017-08-01

    We consider one dimensional weakly asymmetric boundary driven models of heat conduction. In the cases of a constant diffusion coefficient and of a quadratic mobility we compute the quasi-potential that is a non local functional obtained by the solution of a variational problem. This is done using the dynamic variational approach of the macroscopic fluctuation theory (Bertini et al. in Rev Mod Phys 87:593, 2015). The case of a concave mobility corresponds essentially to the exclusion model that has been discussed in Bertini et al. (J Stat Mech L11001, 2010; Pure Appl Math 64(5):649-696, 2011; Commun Math Phys 289(1):311-334, 2009) and Enaud and Derrida (J Stat Phys 114:537-562, 2004). We consider here the convex case that includes for example the Kipnis-Marchioro-Presutti (KMP) model and its dual (KMPd) (Kipnis et al. in J Stat Phys 27:6574, 1982). This extends to the weakly asymmetric regime the computations in Bertini et al. (J Stat Phys 121(5/6):843-885, 2005). We consider then, both microscopically and macroscopically, the limit of large externalfields. Microscopically we discuss some possible totally asymmetric limits of the KMP model. In one case the totally asymmetric dynamics has a product invariant measure. Another possible limit dynamics has instead a non trivial invariant measure for which we give a duality representation. Macroscopically we show that the quasi-potentials of KMP and KMPd, which are non local for any value of the external field, become local in the limit. Moreover the dependence on one of the external reservoirs disappears. For models having strictly positive quadratic mobilities we obtain instead in the limit a non local functional having a structure similar to the one of the boundary driven asymmetric exclusion process.

  19. Uniform versus asymmetric shading mediates crown recession in conifers.

    Directory of Open Access Journals (Sweden)

    Amanda L Schoonmaker

    Full Text Available In this study we explore the impact of asymmetrical vs. uniform crown shading on the mortality and growth of upper and lower branches within tree crowns, for two conifer species: shade intolerant lodgepole pine (Pinus contorta and shade tolerant white spruce (Picea glauca. We also explore xylem hydraulics, foliar nutrition, and carbohydrate status as drivers for growth and expansion of the lower and upper branches in various types of shading. This study was conducted over a two-year period across 10 regenerating forest sites dominated by lodgepole pine and white spruce, in the lower foothills of Alberta, Canada. Trees were assigned to one of four shading treatments: (1, complete uniform shading of the entire tree, (2 light asymmetric shading where the lower 1/4-1/3 of the tree crown was shaded, (3 heavy asymmetric shading as in (2 except with greater light reduction and (4 control in which no artificial shading occurred and most of the entire crown was exposed to full light. Asymmetrical shading of only the lower crown had a larger negative impact on the bud expansion and growth than did uniform shading, and the effect was stronger in pine relative to spruce. In addition, lower branches in pine also had lower carbon reserves, and reduced xylem-area specific conductivity compared to spruce. For both species, but particularly the pine, the needles of lower branches tended to store less C than upper branches in the asymmetric shade, which could suggest a movement of reserves away from the lower branches. The implications of these findings correspond with the inherent shade tolerance and self-pruning behavior of these conifers and supports a carbon based mechanism for branch mortality--mediated by an asymmetry in light exposure of the crown.

  20. The Impacts of Dry Dynamic Cores on Asymmetric Hurricane Intensification

    Science.gov (United States)

    Guimond, Stephen R.; Reisner, Jon M.; Marras, Simone; Giraldo, Francis X.

    2016-01-01

    The fundamental pathways for tropical cyclone (TC) intensification are explored by considering axisymmetric and asymmetric impulsive thermal perturbations to balanced, TC-like vortices using the dynamic cores of three different nonlinear numerical models. Attempts at reproducing the results of previous work, which used the community WRF Model, revealed a discrepancy with the impacts of purely asymmetric thermal forcing. The current study finds that thermal asymmetries can have an important, largely positive role on the vortex intensification, whereas other studies find that asymmetric impacts are negligible. Analysis of the spectral energetics of each numerical model indicates that the vortex response to asymmetric thermal perturbations is significantly damped in WRF relative to the other models. Spectral kinetic energy budgets show that this anomalous damping is primarily due to the increased removal of kinetic energy from the vertical divergence of the vertical pressure flux, which is related to the flux of inertia-gravity wave energy. The increased kinetic energy in the other two models is shown to originate around the scales of the heating and propagate upscale with time from nonlinear effects. For very large thermal amplitudes (50 K), the anomalous removal of kinetic energy due to inertia-gravity wave activity is much smaller, resulting in good agreement between models. The results of this paper indicate that the numerical treatment of small-scale processes that project strongly onto inertia-gravity wave energy can lead to significant differences in asymmetric TC intensification. Sensitivity tests with different time integration schemes suggest that diffusion entering into the implicit solution procedure is partly responsible for the anomalous damping of energy.

  1. Asymmetric Aldol Additions: A Guided-Inquiry Laboratory Activity on Catalysis

    Science.gov (United States)

    King, Jorge H. Torres; Wang, Hong; Yezierski, Ellen J.

    2018-01-01

    Despite the importance of asymmetric catalysis in both the pharmaceutical and commodity chemicals industries, asymmetric catalysis is under-represented in undergraduate chemistry laboratory curricula. A novel guided-inquiry experiment based on the asymmetric aldol addition was developed. Students conduct lab work to compare the effectiveness of…

  2. Alanine-glyoxylate aminotransferase 2 (AGXT2 polymorphisms have considerable impact on methylarginine and β-aminoisobutyrate metabolism in healthy volunteers.

    Directory of Open Access Journals (Sweden)

    Anja Kittel

    Full Text Available Elevated plasma concentrations of asymmetric (ADMA and symmetric (SDMA dimethylarginine have repeatedly been linked to adverse clinical outcomes. Both methylarginines are substrates of alanine-glyoxylate aminotransferase 2 (AGXT2. It was the aim of the present study to simultaneously investigate the functional relevance and relative contributions of common AGXT2 single nucleotide polymorphisms (SNPs to plasma and urinary concentrations of methylarginines as well as β-aminoisobutyrate (BAIB, a prototypic substrate of AGXT2. In a cohort of 400 healthy volunteers ADMA, SDMA and BAIB concentrations were determined in plasma and urine using HPLC-MS/MS and were related to the coding AGXT2 SNPs rs37369 (p.Val140Ile and rs16899974 (p.Val498Leu. Volunteers heterozygous or homozygous for the AGXT2 SNP rs37369 had higher SDMA plasma concentrations by 5% and 20% (p = 0.002 as well as higher BAIB concentrations by 54% and 146%, respectively, in plasma and 237% and 1661%, respectively, in urine (both p<0.001. ADMA concentrations were not affected by both SNPs. A haplotype analysis revealed that the second investigated AGXT2 SNP rs16899974, which was not significantly linked to the other AGXT2 SNP, further aggravates the effect of rs37369 with respect to BAIB concentrations in plasma and urine. To investigate the impact of the amino acid exchange p.Val140Ile, we established human embryonic kidney cell lines stably overexpressing wild-type or mutant (p.Val140Ile AGXT2 protein and assessed enzyme activity using BAIB and stable-isotope labeled [²H₆]-SDMA as substrate. In vitro, the amino acid exchange of the mutant protein resulted in a significantly lower enzyme activity compared to wild-type AGXT2 (p<0.05. In silico modeling of the SNPs indicated reduced enzyme stability and substrate binding. In conclusion, SNPs of AGXT2 affect plasma as well as urinary BAIB and SDMA concentrations linking methylarginine metabolism to the common genetic trait of hyper

  3. [Prevalence and risk factors of extra-coronary artery disease in patients with diabetes which confirmed atherosclerosis of coronary arteries].

    Science.gov (United States)

    Gracheva, S A; Biragova, M S; Glazunova, A M; Klefortova, I I; Melkozerov, K V; Shamkhalova, M Sh; Dzhavelidze, M I; Soldatova, T V; Il'in, A V; Deev, A D; Shestakova, M V; Tugeeva, E F; Buziashvili, Iu I

    2014-01-01

    To assess prevalence and risk factors of extra-coronary artery disease (peripheral artery (PA) disease (D) of lower extremities (LE), brachiocephalic arterial (BCA) stenosis (S), renal arterial (RA) S in type 1 and 2 (T1 and T2) diabetes (D) patients (P) with confirmed atherosclerosis of coronary arteries (CA). 100 P (48 with T2D, 18 with T1D, 34 without diabetes - PWD), with hemodynamically significant atherosclerosis of CA confirmed by coronary angiography. All patients underwent duplex ultrasonography of PA LE, BCA, RA. Other studies included assessment of clinical characteristics and measurement of the following parameters: profibrogenic cytokines (transforming growth factor [TGF] beta1, matrix metalloproteinase 9 [MMP9], monocyte chemotactic protein-1 [MCP-1], regulated on activation normal T-cell expressed and secreted [RANTES), markers of endothelial dysfunction (von Willebrand factor [VWF], homocystein [HCYST], plasminogen activator inhibitor-1 [PAI-1], vascular cell adhesion molecule [VCAM], soluble intercellular adhesion molecules-1 [sICAM], vascular endothelial growth factor [VEGF], asymmetric dimethylarginine [ADMAD, N-terminal fragment of pro-brain natriuretic peptide (NT-pro BNP), fibroblast growth factor 23 (FGF-23), and fibrinogen. Portions of P with multivessel CA disease were similar in all three groups (T1D - 88.9, T2D - 85.5, WD - 82.3%). Coexistence of atherosclerosis in 2 or more vascular beds was identified in 85.3% of T2D and in 50% of WD P (p = 0.005). In T1D group 61.1 and 11.1% of P had atherosclerosis in 2 and 3 vascular beds, respectively. Levels of profibrogenic cytokines and factors of endothelial activation (RANTES, MMP-9, PAI-I, VCAM, sICAM, ADMA) were significantly higher in P with diabetes vs P WD. P with diabetes and multifocal atherosclerosis demonstrated significant increases of CRP, fibrinogen, NT-proBNP, VWF, PAI-1, ADMA, sICAM, and decrease of GFR compared with P with atherosclerosis in 1 vascular bed. Logistic regression

  4. Cognitive patterns in relation to biomarkers of cerebrovascular disease and vascular risk factors.

    Science.gov (United States)

    Miralbell, Júlia; López-Cancio, Elena; López-Oloriz, Jorge; Arenillas, Juan Francisco; Barrios, Maite; Soriano-Raya, Juan José; Galán, Amparo; Cáceres, Cynthia; Alzamora, Maite; Pera, Guillem; Toran, Pere; Dávalos, Antoni; Mataró, Maria

    2013-01-01

    Risk factors for vascular cognitive impairment (VCI) are the same as traditional risk factors for cerebrovascular disease (CVD). Early identification of subjects at higher risk of VCI is important for the development of effective preventive strategies. In addition to traditional vascular risk factors (VRF), circulating biomarkers have emerged as potential tools for early diagnoses, as they could provide in vivo measures of the underlying pathophysiology. While VRF have been consistently linked to a VCI profile (i.e., deficits in executive functions and processing speed), the cognitive correlates of CVD biomarkers remain unclear. In this population-based study, the aim was to study and compare cognitive patterns in relation to VRF and circulating biomarkers of CVD. The Barcelona-AsIA Neuropsychology Study included 747 subjects older than 50, without a prior history of stroke or coronary disease and with a moderate to high vascular risk (mean age, 66 years; 34.1% women). Three cognitive domains were derived from factoral analysis: visuospatial skills/speed, verbal memory and verbal fluency. Multiple linear regression was used to assess relationships between cognitive performance (multiple domains) and a panel of circulating biomarkers, including indicators of inflammation, C-reactive protein (CRP) and resistin, endothelial dysfunction, asymmetric dimethylarginine (ADMA), thrombosis, plasminogen activator inhibitor 1 (PAI-1), as well as traditional VRF, metabolic syndrome and insulin resistance (homeostatic model assessment for insulin resistance index). Analyses were adjusted for age, gender, years of education and depressive symptoms. Traditional VRF were related to lower performance in verbal fluency, insulin resistance accounted for lower performance in visuospatial skills/speed and the metabolic syndrome predicted lower performance in both cognitive domains. From the biomarkers of CVD, CRP was negatively related to verbal fluency performance and increasing ADMA

  5. Computer simulation of molecular absorption spectra for asymmetric top molecules

    International Nuclear Information System (INIS)

    Bende, A.; Tosa, V.; Cosma, V.

    2001-01-01

    The effective Hamiltonian formalism has been used to develop a model for infrared multiple-photon absorption (IRMPA) process in asymmetric top molecules. Assuming a collisionless regime, the interaction between the molecule and laser field can be described by the time-dependent Schroedinger equation. By using the rotating wave approximation and Laplace transformation, the time-dependent problem reduces to a time-independent eigen problem for an effective Hamiltonian which can be solved only numerically for a real vibrational-rotational structure of polyatomic molecule. The vibrational-rotational structure is assumed to be an anharmonic oscillator coupled to an asymmetric rigid rotor. The main assumptions taken into account for this model are the following: (1) the excitation is coherent, i.e. the collision (if present during the laser pulse) does not influence the excitation; (2) the excitation starts from the ground state and is near resonant to a normal mode, thus, the rotating wave approximation can be applied; (3) after absorbing N photons the vibrational energy of the excited mode leak into a quasicontinuum; (4) the thermal population of the ground state is given by the Maxwell-Boltzmann distribution law. The energy levels of the asymmetric top molecules cannot be represented by an explicit formula analogous to that for the symmetric top, according to quantum mechanics, but we can consider it a deviation from the prolate or oblate case of the symmetric top, and we can find in the same manner the selection rules of the asymmetric case using the selection rules for the symmetric case. The infrared bands of asymmetric top molecules are not resolved, but if the dispersion used is not too small, so that the envelopes of the bands can be distinguished from simple maxima, it is possible to draw conclusions as to the type of the bands. In this case, the simulation of the absorption spectra can give us some important information about the types of these bands. In

  6. Examining Asymmetrical Relationships of Organizational Learning Antecedents: A Theoretical Model

    Directory of Open Access Journals (Sweden)

    Ery Tri Djatmika

    2016-02-01

    Full Text Available Global era is characterized by highly competitive advantage market demand. Responding to the challenge of rapid environmental changes, organizational learning is becoming a strategic way and solution to empower people themselves within the organization in order to create a novelty as valuable positioning source. For research purposes, determining the influential antecedents that affect organizational learning is vital to understand research-based solutions given for practical implications. Accordingly, identification of variables examined by asymmetrical relationships is critical to establish. Possible antecedent variables come from organizational and personal point of views. It is also possible to include a moderating one. A proposed theoretical model of asymmetrical effects of organizational learning and its antecedents is discussed in this article.

  7. Atypical presentation of GNE myopathy with asymmetric hand weakness

    Science.gov (United States)

    de Dios, John Karl L.; Shrader, Joseph A.; Joe, Galen O.; McClean, Jeffrey C.; Williams, Kayla; Evers, Robert; Malicdan, May Christine V.; Ciccone, Carla; Mankodi, Ami; Huizing, Marjan; McKew, John C.; Bluemke, David A.; Gahl, William A.; Carrillo-Carrasco, Nuria

    2014-01-01

    GNE myopathy is a rare autosomal recessive muscle disease caused by mutations in GNE, the gene encoding the rate-limiting enzyme in sialic acid biosynthesis. GNE myopathy usually manifests in early adulthood with distal myopathy that progresses slowly and symmetrically, first involving distal muscles of the lower extremities, followed by proximal muscles with relative sparing of the quadriceps. Upper extremities are typically affected later in the disease. We report a patient with GNE myopathy who presented with asymmetric hand weakness. He had considerably decreased left grip strength, atrophy of the left anterior forearm and fibro-fatty tissue replacement of left forearm flexor muscles on T1-weighted magnetic resonance imaging. The patient was an endoscopist and thus the asymmetric hand involvement may be associated with left hand overuse in daily repetitive pinching and gripping movements, highlighting the possible impact of environmental factors on the progression of genetic muscle conditions. PMID:25182749

  8. Achieving uniform efficient illumination with multiple asymmetric compound parabolic luminaires

    Science.gov (United States)

    Gordon, Jeffrey M.; Kashin, Peter

    1994-01-01

    Luminaire designs based on multiple asymmetric nonimaging compound parabolic reflectors are proposed for 2-D illumination applications that require highly uniform far-field illuminance, while ensuring maximal lighting efficiency and sharp angular cutoffs. The new designs derive from recent advances in nonimaging secondary concentrators for line-focus solar collectors. The light source is not treated as a single entity, but rather is divided into two or more separate adjoining sources. An asymmetric compound parabolic luminaire is then designed around each half-source. Attaining sharp cutoffs requires relatively large reflectors. However, severe truncation of the reflectors renders these devices as compact as many conventional luminaires, at the penalty of a small fraction of the radiation being emitted outside the nominal cutoff. The configurations that maximize the uniformity of far-field illuminance offer significant improvements in flux homogeneity relative to alternative designs to date.

  9. Thomson scattering measurements from asymmetric interpenetrating plasma flows

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J. S., E-mail: ross36@llnl.gov; Moody, J. D.; Fiuza, F.; Ryutov, D.; Divol, L.; Huntington, C. M.; Park, H.-S. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-11-15

    Imaging Thomson scattering measurements of collective ion-acoustic fluctuations have been utilized to determine ion temperature and density from laser produced counter-streaming asymmetric flows. Two foils are heated with 8 laser beams each, 500 J per beam, at the Omega Laser facility. Measurements are made 4 mm from the foil surface using a 60 J 2ω probe laser with a 200 ps pulse length. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the multi-ion species, asymmetric flows theoretical form factor for the ion feature such that the ion temperatures, ion densities, and flow velocities for each plasma flow are determined.

  10. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids

    Science.gov (United States)

    Suzuki, Yumiko

    2018-01-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines. PMID:29861702

  11. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids.

    Science.gov (United States)

    Suzuki, Yumiko

    2018-06-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines.

  12. Asymmetrical Information and Public Failure in the Myriad Decision

    Directory of Open Access Journals (Sweden)

    Reginald Shareef

    2014-09-01

    Full Text Available The Public Value concept is a Public Management normative process that utilizes efficiency and ethics as co-equal determinants to assess organizational outcomes. As such, Public Value represents what Ghoshal calls intellectual pluralism or the utilization of normative management processes in the social sciences to challenge the intellectual absolutism of the Chicago School. One discipline where Public Value can be used to assess normative results is Legal Studies’ antitrust field. This research applies Public Value criteria in evaluating the U.S. Supreme Court’s 2013 ruling in Association for Molecular Pathology v. Myriad Genetics. The conclusions tentatively found the Court’s decision will (a create Public Value at the macro level but (b trigger public failure at the micro level for poor women because of an asymmetrical information network. This outcome fits with Stiglitz’s hypothesis concerning asymmetrical information and market failure. Further empirical research on Myriad’s policy is recommended.

  13. Asymmetric excitation of surface plasmons by dark mode coupling

    KAUST Repository

    Zhang, X.

    2016-02-19

    Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

  14. Spin polarized states in strongly asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Isayev, A.A.; Yang, J.

    2004-01-01

    The possibility of appearance of spin polarized states in strongly asymmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the Skyrme effective interaction. The zero temperature dependence of the neutron and proton spin polarization parameters as functions of density is found for SLy4 and SLy5 effective forces. It is shown that at some critical density strongly asymmetric nuclear matter undergoes a phase transition to the state with the oppositely directed spins of neutrons and protons while the state with the same direction of spins does not appear. In comparison with neutron matter, even small admixture of protons strongly decreases the threshold density of spin instability. It is clarified that protons become totally polarized within a very narrow density domain while the density profile of the neutron spin polarization parameter is characterized by the appearance of long tails near the transition density

  15. Occupation probabilities and fluctuations in the asymmetric simple inclusion process

    Science.gov (United States)

    Reuveni, Shlomi; Hirschberg, Ori; Eliazar, Iddo; Yechiali, Uri

    2014-04-01

    The asymmetric simple inclusion process (ASIP), a lattice-gas model of unidirectional transport and aggregation, was recently proposed as an "inclusion" counterpart of the asymmetric simple exclusion process. In this paper we present an exact closed-form expression for the probability that a given number of particles occupies a given set of consecutive lattice sites. Our results are expressed in terms of the entries of Catalan's trapezoids—number arrays which generalize Catalan's numbers and Catalan's triangle. We further prove that the ASIP is asymptotically governed by the following: (i) an inverse square-root law of occupation, (ii) a square-root law of fluctuation, and (iii) a Rayleigh law for the distribution of interexit times. The universality of these results is discussed.

  16. Aspects of collisionless magnetic reconnection in asymmetric systems

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Michael; Aunai, Nicolas; Kuznetsova, Masha [Heliophysics Science Division, Code 670, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Zenitani, Seiji [National Astronomical Observatory of Japan, Tokyo (Japan); Birn, Joachim [Space Science Institute, Boulder, Colorado 80301 (United States)

    2013-06-15

    Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with nonvanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.

  17. Aspects of collisionless magnetic reconnection in asymmetric systems

    International Nuclear Information System (INIS)

    Hesse, Michael; Aunai, Nicolas; Kuznetsova, Masha; Zenitani, Seiji; Birn, Joachim

    2013-01-01

    Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with nonvanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide

  18. Aspects of Collisionless Magnetic Reconnection in Asymmetric Systems

    Science.gov (United States)

    Hesse, Michael; Aunai, Nicolas; Zeitani, Seiji; Kuznetsova, Masha; Birn, Joachim

    2013-01-01

    Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with non-vanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.

  19. Left-Right Asymmetric Morphogenesis in the Xenopus Digestive System

    Science.gov (United States)

    Muller, Jennifer K.; Prather, D.R.; Nascone-Yoder, N. M.

    2003-01-01

    The morphogenetic mechanisms by which developing organs become left-right asymmetric entities are unknown. To investigate this issue, we compared the roles of the left and right sides of the Xenopus embryo during the development of anatomic asymmetries in the digestive system. Although both sides contribute equivalently to each of the individual digestive organs, during the initial looping of the primitive gut tube, the left side assumes concave topologies where the right side becomes convex. Of interest, the concave surfaces of the gut tube correlate with expression of the LR gene, Pitx2, and ectopic Pitx2 mRNA induces ectopic concavities in a localized manner. A morphometric comparison of the prospective concave and convex surfaces of the gut tube reveals striking disparities in their rate of elongation but no significant differences in cell proliferation. These results provide insight into the nature of symmetry-breaking morphogenetic events during left-right asymmetric organ development. ?? 2003 Wiley-Liss, Inc.

  20. Asymmetric cointegration between exchange rate and trade balance in Nigeria

    Directory of Open Access Journals (Sweden)

    Alhaji Jibrilla Aliyu

    2015-12-01

    Full Text Available This paper empirically examines the long-run pass through of the official exchange rates into trade balance in Nigeria by means of threshold cointegration and asymmetric error correction modeling. The study provides evidence for non-linear cointegration between our variables of interest. The estimated asymmetric error correction models provide new evidence for slower transmission of exchange rate depreciations into the country’s trade balance, which in turn appears to offer partial support for the Dutch disease hypothesis. This finding suggests that policy-makers cannot hope to use currency devaluation to improve the trade balance. It is recommended that policy-makers focus attention on diversification of the economy away from dependence on crude oil exports into productive manufacturing and non-oil exports, which will be vital in making the economy more competitive.

  1. New type of asymmetric fission in proton-rich nuclei

    CERN Document Server

    Andreyev, A N; Huyse, M; Van Duppen, P; Antalic, S; Barzakh, A; Bree, N; Cocolios, T E; Comas, V F; Diriken, J; Fedorov, D; Fedosseev, V; Franchoo, S; Heredia, J A; Ivanov, O; Koster, U; Marsh, B A; Nishio, K; Page, R D; Patronis, N; Seliverstov, M; Tsekhanovich, I; Van den Bergh, P; Van De Walle, J; Venhart, M; Vermote, S; Veselsky, M; Wagemans, C; Ichikawa, T; Iwamoto, A; Moller, P; Sierk, A J

    2010-01-01

    A very exotic process of ${\\beta}$-delayed fission of $^{180}$Tl is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment mass distribution of the post-${\\beta}$-decay daughter nucleus $^{180}$Hg (N/Z=1.25) is asymmetric. This asymmetry is more surprising since a mass-symmetric split of this extremely neutron-deficient nucleus would lead to two $^{90}$Zr fragments, with magic N=50 and semimagic Z=40. This is a new type of asymmetric fission, not caused by large shell effects related to fragment magic proton and neutron numbers, as observed in the actinide region. The newly measured branching ratio for $\\beta$-delayed fission of $^{180}$Tl is 3.6(7)×10$^{-3}$%, approximately 2 orders of magnitude larger than in an earlier study.

  2. Biophysical information in asymmetric and symmetric diurnal bidirectional canopy reflectance

    Science.gov (United States)

    Vanderbilt, Vern C.; Caldwell, William F.; Pettigrew, Rita E.; Ustin, Susan L.; Martens, Scott N.; Rousseau, Robert A.; Berger, Kevin M.; Ganapol, B. D.; Kasischke, Eric S.; Clark, Jenny A.

    1991-01-01

    The authors present a theory for partitioning the information content in diurnal bidirectional reflectance measurements in order to detect differences potentially related to biophysical variables. The theory, which divides the canopy reflectance into asymmetric and symmetric functions of solar azimuth angle, attributes asymmetric variation to diurnal changes in the canopy biphysical properties. The symmetric function is attributed to the effects of sunlight interacting with a hypothetical average canopy which would display the average diurnal properties of the actual canopy. The authors analyzed radiometer data collected diurnally in the Thematic Mapper wavelength bands from two walnut canopies that received differing irrigation treatments. The reflectance of the canopies varied with sun and view angles and across seven bands in the visible, near-infrared, and middle infrared wavelength regions. Although one of the canopies was permanently water stressed and the other was stressed in mid-afternoon each day, no water stress signature was unambiguously evident in the reflectance data.

  3. Dissipation induced asymmetric steering of distant atomic ensembles

    Science.gov (United States)

    Cheng, Guangling; Tan, Huatang; Chen, Aixi

    2018-04-01

    The asymmetric steering effects of separated atomic ensembles denoted by the effective bosonic modes have been explored by the means of quantum reservoir engineering in the setting of the cascaded cavities, in each of which an atomic ensemble is involved. It is shown that the steady-state asymmetric steering of the mesoscopic objects is unconditionally achieved via the dissipation of the cavities, by which the nonlocal interaction occurs between two atomic ensembles, and the direction of steering could be easily controlled through variation of certain tunable system parameters. One advantage of the present scheme is that it could be rather robust against parameter fluctuations, and does not require the accurate control of evolution time and the original state of the system. Furthermore, the double-channel Raman transitions between the long-lived atomic ground states are used and the atomic ensembles act as the quantum network nodes, which makes our scheme insensitive to the collective spontaneous emission of atoms.

  4. Reduction of Asymmetric Information through Corporate Governance Mechanisms

    DEFF Research Database (Denmark)

    Holm, Claus; Schøler, Finn

    Research Question/Issue: Is the reduction of asymmetric information through Corporate Governance mechanisms more important for some listed companies than for others? The purpose of this study is to examine how differences in "ownership dispersion" and "international orientation" affect the partic......Research Question/Issue: Is the reduction of asymmetric information through Corporate Governance mechanisms more important for some listed companies than for others? The purpose of this study is to examine how differences in "ownership dispersion" and "international orientation" affect...... the particular use of the Corporate Governance mechanisms "transparency" and "board independence" in listed companies. Research Findings/Insights: Our findings are based on a Danish dataset which includes 100 listed companies. We find that transparency is a more important Corporate Governance mechanism...

  5. Stark parameters of some asymmetrical Si II lines

    International Nuclear Information System (INIS)

    Ferhat, B; Azzouz, Y; Redon, R; Ripert, M; Lesage, A

    2012-01-01

    Six lines of SiII are experimentally studied in pulsed plasma generated by Nd :Yag laser breakdown on pure solid silicon target. A set of experimental Stark parameters of asymmetrical lines are measured in temperature range from 14 000 K to 18 000 K (using Boltzmann plot). Calculated values of the electron density (using Griem's formula) vary from 1.7 to 6.1 × 10 23 m −3 . Processed spectral lines are 333.982 nm (3s 2 4p -3s 2 6s) and 397.746 nm, 399.177 nm, 399.801 nm, 401.622 nm (3d' 2 F 0 -4f' 4 G) and (3d' 2 F 0 - 4f' 2 G) of astrophysical interest. Asymmetrical line shapes are synthesized by a sum of two semi-Lorentzian distributions. The obtained fit is in good agreement with the measured spectra.

  6. R & D STRATEGIC INVESTMENT IN AN ASYMMETRICAL CASE

    Institute of Scientific and Technical Information of China (English)

    Minggao XUE; Pu GONG

    2006-01-01

    This article analyzes R & D investment decisions in an asymmetrical case. The investment decisions share three important characteristics. First, the investment is completely irreversible. Second,there are two kinds of uncertainties over the future returns from the investment and over technology in R & D process, respectively. Third, there is strategic competition in the asymmetrical case. This article presents the optimal investment threshold values and the optimal investment rule of high-efficient firm (leader), and shows that the investment threshold values are reduced by competition of two firms.Finally, the mixed investment strategies for two firms, the probability that each firm separately exercises the option to invest, and the probability that two firms simultaneously exercise the option are given in the paper.

  7. An intrinsically asymmetric radio galaxy: 0500+630?

    Science.gov (United States)

    Saikia, D. J.; Thomasson, P.; Jackson, N.; Salter, C. J.; Junor, W.

    1996-10-01

    As part of a search for high-luminosity radio galaxies with one-sided structures, the radio galaxy 0500+630 has been imaged with both the VLA and MERLIN and its optical spectrum determined using the Isaac Newton Telescope on La Palma. The galaxy is found to have a redshift of 0.290+/-0.004. The radio observations show the source to be highly asymmetric, with an overall structure which cannot be understood easily by ascribing it either to orientation and relativistic beaming effects or to an asymmetric distribution of gas in the central region. A comparison of this source with objects of similar luminosity suggests that it is one of the best examples yet of a source with possibly an intrinsic asymmetry in either the collimation of its jets or the supply of energy from the central engine to opposite sides.

  8. Search for asymmetric rotors in mass region A∼100

    International Nuclear Information System (INIS)

    Bihari, Chhail; Singh, Yuvraj; Varshney, A.K.; Singh, M.; Gupta, K.K.; Gupta, D.K.

    2009-01-01

    Recently in mass region a∼120-140 xenon and barium nuclei have been studied and the energy systematics have been drawn with excellent correlations in mass coefficient and rotation vibration interaction parameter with product of valance nucleons NpNn using three mass coefficients one each for yrast, odd and even γ-bands within the framework of general asymmetric rotor model. Interestingly in the mass region A ∼ 100 ruthenium nuclei have been dealt using similar approach but only one mass coefficient (B γ = B rot ) was found sufficient to reproduce the striking correlations among various parameters. The purpose of the present work is to study whether one mass coefficient works well in describing the inter band transitions in other nuclei in mass region a ∼ 100. We consider Mo, Ru and Pd nuclei and calculate the B(E2) values using asymmetric rotor model

  9. Asymmetric excitation of surface plasmons by dark mode coupling

    KAUST Repository

    Zhang, X.; Xu, Q.; Li, Q.; Xu, Y.; Gu, J.; Tian, Z.; Ouyang, C.; Liu, Y.; Zhang, S.; Zhang, Xixiang; Han, J.; Zhang, W.

    2016-01-01

    Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

  10. Gamma ray constraints on flavor violating asymmetric dark matter

    DEFF Research Database (Denmark)

    Masina, I.; Panci, P.; Sannino, F.

    2012-01-01

    We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and H.E.S.S.; performing combined fits we...... determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by Fermi for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 Te......V. We find that the Fermi constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies....

  11. Optical-fiber strain sensors with asymmetric etched structures.

    Science.gov (United States)

    Vaziri, M; Chen, C L

    1993-11-01

    Optical-fiber strain gauges with asymmetric etched structures have been analyzed, fabricated, and tested. These sensors are very sensitive with a gauge factor as high as 170 and a flat frequency response to at least 2.7 kHz. The gauge factor depends on the asymmetry of the etched structures and the number of etched sections. To understand the physical principles involved, researchers have used structural analysis programs based on a finite-element method to analyze fibers with asymmetric etched structures under tensile stress. The results show that lateral bends are induced on the etched fibers when they are stretched axially. To relate the lateral bending to the optical attenuation, we have also employed a ray-tracing technique to investigate the dependence of the attenuation on the structural deformation. Based on the structural analysis and the ray-tracing study parameters affecting the sensitivity have been studied. These results agree with the results of experimental investigations.

  12. Asymmetric Hardware Distortions in Receive Diversity Systems: Outage Performance Analysis

    KAUST Repository

    Javed, Sidrah; Amin, Osama; Ikki, Salama S.; Alouini, Mohamed-Slim

    2017-01-01

    This paper studies the impact of asymmetric hardware distortion (HWD) on the performance of receive diversity systems using linear and switched combining receivers. The asymmetric attribute of the proposed model motivates the employment of improper Gaussian signaling (IGS) scheme rather than the traditional proper Gaussian signaling (PGS) scheme. The achievable rate performance is analyzed for the ideal and non-ideal hardware scenarios using PGS and IGS transmission schemes for different combining receivers. In addition, the IGS statistical characteristics are optimized to maximize the achievable rate performance. Moreover, the outage probability performance of the receive diversity systems is analyzed yielding closed form expressions for both PGS and IGS based transmission schemes. HWD systems that employ IGS is proven to efficiently combat the self interference caused by the HWD. Furthermore, the obtained analytic expressions are validated through Monte-Carlo simulations. Eventually, non-ideal hardware transceivers degradation and IGS scheme acquired compensation are quantified through suitable numerical results.

  13. Measuring core inflation in India: An asymmetric trimmed mean approach

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Sharma

    2015-12-01

    Full Text Available The paper seeks to obtain an optimal asymmetric trimmed mean-based core inflation measure in the class of trimmed mean measures when the distribution of price changes is leptokurtic and skewed to the right for any given period. Several estimators based on asymmetric trimmed mean approach are constructed and estimates generated by use of these estimators are evaluated on the basis of certain established empirical criteria. The paper also provides the method of trimmed mean expression “in terms of percentile score.” This study uses 69 monthly price indices which are constituent components of Wholesale Price Index for the period, April 1994 to April 2009, with 1993–1994 as the base year. Results of the study indicate that an optimally trimmed estimator is found when we trim 29.5% from the left-hand tail and 20.5% from the right-hand tail of the distribution of price changes.

  14. Multiband Printed Asymmetric Dipole Antenna for LTE/WLAN Applications

    Directory of Open Access Journals (Sweden)

    Chia-Mei Peng

    2013-01-01

    Full Text Available The ability of a single layer strip fed printed asymmetric dipole antenna, which is composed of top-loading, asymmetric coplanar waveguide (ACPW and stepped-feeding structure, to operate at three wide frequency bands (698~960 MHz, 1710~2620 MHz, and 5150~5850 MHz to cover WLAN and LTE operation has been demonstrated. A prototype of the proposed antenna with 57.5 mm in length, 0.4 mm in thickness, and 5 mm in width is fabricated and experimentally investigated. The experimental results indicate that the VSWR 2.5 : 1 bandwidths achieved were 74.3%, 40.8%, and 18.2% at 700 MHz, 2450 MHz, and 5500 MHz, respectively. Experimental results are shown to verify the validity of theoretical work.

  15. Asymmetric Hardware Distortions in Receive Diversity Systems: Outage Performance Analysis

    KAUST Repository

    Javed, Sidrah

    2017-02-22

    This paper studies the impact of asymmetric hardware distortion (HWD) on the performance of receive diversity systems using linear and switched combining receivers. The asymmetric attribute of the proposed model motivates the employment of improper Gaussian signaling (IGS) scheme rather than the traditional proper Gaussian signaling (PGS) scheme. The achievable rate performance is analyzed for the ideal and non-ideal hardware scenarios using PGS and IGS transmission schemes for different combining receivers. In addition, the IGS statistical characteristics are optimized to maximize the achievable rate performance. Moreover, the outage probability performance of the receive diversity systems is analyzed yielding closed form expressions for both PGS and IGS based transmission schemes. HWD systems that employ IGS is proven to efficiently combat the self interference caused by the HWD. Furthermore, the obtained analytic expressions are validated through Monte-Carlo simulations. Eventually, non-ideal hardware transceivers degradation and IGS scheme acquired compensation are quantified through suitable numerical results.

  16. Axisymmetric stability of vertically asymmetric Tokamaks at large beta poloidal

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, K.; Fishman, H.; Okabayashi, M. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Todd, A.M.M. (Grumman Aerospace Corp., Princeton, NJ (USA))

    1983-11-01

    The rigid-mode stability of high-..beta.. vertically asymmetric Tokamak equilibria with quasi-uniform current profile is investigated analytically using toroidicity-shaping double expansion method. It is found that vertical stability at large beta poloidal is mainly determined by a coupling between the shape of the plasma surface and the Shafranov shift of the magnetic axis. To the lowest order, symmetric components of the plasma surface shape are found to be the critical destabilizing elements. Asymmetric components have little effect. The inclusion of higher order terms in the high-..beta.. Tokamak expansion leads to further destabilization. These analytic insights are qualitatively confirmed by numerical stability calculations using the PEST code with parabolic safety-factor profile.

  17. A highly asymmetric dijet event of the ATLAS experiment

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    A highly asymmetric dijet event, with one jet with ET > 100 GeV and no evident recoiling jet, and with high energy calorimeter cell deposits distributed over a wide azimuthal region. Only tracks with pT > 2.6 GeV are shown, and only calorimeter energy deposits with cell energy ET > 700 MeV in the electromagnetic calorimeter, and E > 1 GeV in the hadronic calorimeter.

  18. A Catalytic, Asymmetric Formal Synthesis of (+)-Hamigeran B

    KAUST Repository

    Mukherjee, Herschel

    2011-03-04

    A concise asymmetric, formal synthesis of (+)-hamigeran B is reported. A Pd-catalyzed, decarboxylative allylic alkylation, employing a trifluoromethylated derivative of t-BuPHOX, is utilized as the enantioselective step to form the critical quaternary carbon center in excellent yield and enantioselectivity. The product is converted in three steps to a late-stage intermediate previously used in the synthesis of hamigeran B.

  19. Airplane automatic control force trimming device for asymmetric engine failures

    Science.gov (United States)

    Stewart, Eric C. (Inventor)

    1987-01-01

    The difference in dynamic pressure in the propeller slipstreams as measured by sensors is divided by the freestream dynamic pressure generating a quantity proportional to the differential thrust coefficient. This quantity is used to command an electric trim motor to change the position of trim tab thereby retrimming the airplane to the new asymmetric power condition. The change in position of the trim tab produced by the electric trim motor is summed with the pilot's input to produce the actual trim tab position.

  20. Asymmetric nuclear matter in a modified quark meson coupling model

    International Nuclear Information System (INIS)

    Mishra, R.N.; Sahoo, H.S.; Panda, P.K.; Barik, N.

    2014-01-01

    In an earlier attempt we have successfully used this model in developing the nuclear equation of state and analysed various other bulk properties of symmetric nuclear matter with the dependence of quark masses. In the present work we want to apply the model to analyze asymmetric nuclear matter with the variation of the asymmetry parameter y p as well as analyze the effects of symmetry energy and the slope of the symmetry energy L

  1. Forecasting Performance of Asymmetric GARCH Stock Market Volatility Models

    Directory of Open Access Journals (Sweden)

    Hojin Lee

    2009-12-01

    Full Text Available We investigate the asymmetry between positive and negative returns in their effect on conditional variance of the stock market index and incorporate the characteristics to form an out-of-sample volatility forecast. Contrary to prior evidence, however, the results in this paper suggest that no asymmetric GARCH model is superior to basic GARCH(1,1 model. It is our prior knowledge that, for equity returns, it is unlikely that positive and negative shocks have the same impact on the volatility. In order to reflect this intuition, we implement three diagnostic tests for volatility models: the Sign Bias Test, the Negative Size Bias Test, and the Positive Size Bias Test and the tests against the alternatives of QGARCH and GJR-GARCH. The asymmetry test results indicate that the sign and the size of the unexpected return shock do not influence current volatility differently which contradicts our presumption that there are asymmetric effects in the stock market volatility. This result is in line with various diagnostic tests which are designed to determine whether the GARCH(1,1 volatility estimates adequately represent the data. The diagnostic tests in section 2 indicate that the GARCH(1,1 model for weekly KOSPI returns is robust to the misspecification test. We also investigate two representative asymmetric GARCH models, QGARCH and GJR-GARCH model, for our out-of-sample forecasting performance. The out-of-sample forecasting ability test reveals that no single model is clearly outperforming. It is seen that the GJR-GARCH and QGARCH model give mixed results in forecasting ability on all four criteria across all forecast horizons considered. Also, the predictive accuracy test of Diebold and Mariano based on both absolute and squared prediction errors suggest that the forecasts from the linear and asymmetric GARCH models need not be significantly different from each other.

  2. Strategic Munitions Planning in Non-Conventional Asymmetric Operations

    Science.gov (United States)

    2010-04-01

    Conventional Asymmetric Operations RTO-MP-SAS-081 16 - 3 with a clearly structured, sized and located military force. The principles of Lanchester ...stockpiles and calculated munitions requirements. REFERENCES [1] Prague Summit Declaration, November 2002. [2] J. Fletcher, The Lanchester Legacy... Lanchester battles, Journal of the Operational Research Society, Vol. 50 No. 3, March 1999. [13] W. Freeman, A Study of Ammunition Consumption, Master of

  3. Modelling of novel light sources based on asymmetric heterostructures

    International Nuclear Information System (INIS)

    Afonenko, A.A.; Kononenko, V.K.; Manak, I.S.

    1995-01-01

    For asymmetric quantum-well heterojunction laser sources, processes of carrier injection into quantum wells are considered. In contrast to ordinary quantum-well light sources, active layers in the novel nanocrystalline systems have different thickness and/or compositions. In addition, wide-band gap barrier layers separating the quantum wells may have a linear or parabolic energy potential profile. For various kinds of the structures, mathematical simulation of dynamic response has been carried out. (author). 8 refs, 5 figs

  4. Asymmetric-cut variable-incident-angle monochromator.

    Science.gov (United States)

    Smither, R K; Graber, T J; Fernandez, P B; Mills, D M

    2012-03-01

    A novel asymmetric-cut variable-incident-angle monochromator was constructed and tested in 1997 at the Advanced Photon Source of Argonne National Laboratory. The monochromator was originally designed as a high heat load monochromator capable of handling 5-10 kW beams from a wiggler source. This was accomplished by spreading the x-ray beam out on the surface an asymmetric-cut crystal and by using liquid metal cooling of the first crystal. The monochromator turned out to be a highly versatile monochromator that could perform many different types of experiments. The monochromator consisted of two 18° asymmetrically cut Si crystals that could be rotated about 3 independent axes. The first stage (Φ) rotates the crystal around an axis perpendicular to the diffraction plane. This rotation changes the angle of the incident beam with the surface of the crystal without changing the Bragg angle. The second rotation (Ψ) is perpendicular to the first and is used to control the shape of the beam footprint on the crystal. The third rotation (Θ) controls the Bragg angle. Besides the high heat load application, the use of asymmetrically cut crystals allows one to increase or decrease the acceptance angle for crystal diffraction of a monochromatic x-ray beam and allows one to increase or decrease the wavelength bandwidth of the diffraction of a continuum source like a bending-magnet beam or a normal x-ray-tube source. When the monochromator is used in the doubly expanding mode, it is possible to expand the vertical size of the double-diffracted beam by a factor of 10-15. When this was combined with a bending magnet source, it was possible to generate an 8 keV area beam, 16 mm wide by 26 mm high with a uniform intensity and parallel to 1.2 arc sec that could be applied in imaging experiments.

  5. Optimal security design under asymmetric information and profit manipulation

    OpenAIRE

    Koufopoulos, Kostas; Kozhan, Roman; Trigilia, Giulio

    2014-01-01

    We consider a model of external financing under ex ante asymmetric information and profit manipulation (non verifability). Contrary to conventional wisdom, the optimal contract is not standard debt, and it is not monotonic. Instead, it resembles a contingent convertible (CoCo) bond. In particular: (i) if the profit manipulation and/or adverse selection are not severe, there exists a unique separating equilibrium in CoCos; (ii) in the intermediate region, if the distribution of earnings is unb...

  6. Instantaneous sediment transport model for asymmetric oscillatory sheet flow.

    Directory of Open Access Journals (Sweden)

    Xin Chen

    Full Text Available On the basis of advanced concentration and velocity profiles above a mobile seabed, an instantaneous analytical model is derived for sediment transport in asymmetric oscillatory flow. The applied concentration profile is obtained from the classical exponential law based on mass conservation, and asymmetric velocity profile is developed following the turbulent boundary layer theory and the asymmetric wave theory. The proposed model includes two parts: the basic part that consists of erosion depth and free stream velocity, and can be simplified to the total Shields parameter power 3/2 in accordance with the classical empirical models, and the extra vital part that consists of phase-lead, boundary layer thickness and erosion depth. The effects of suspended sediment, phase-lag and asymmetric boundary layer development are considered particularly in the model. The observed instantaneous transport rate proportional to different velocity exponents due to phase-lag is unified and summarised by the proposed model. Both instantaneous and half period empirical formulas are compared with the developed model, using extensive data on a wide range of flow and sediment conditions. The synchronous variation in instantaneous transport rate with free stream velocity and its decrement caused by increased sediment size are predicted correctly. Net transport rates, especially offshore transport rates with large phase-lag under velocity skewed flows, which existing instantaneous type formulas failed to predict, are predicted correctly in both direction and magnitude by the proposed model. Net sediment transport rates are affected not only by suspended sediment and phase-lag, but also by the boundary layer difference between onshore and offshore.

  7. Asymmetric photoelectron angular distributions from interfering photoionization processes

    International Nuclear Information System (INIS)

    Yin, Y.; Chen, C.; Elliott, D.S.; Smith, A.V.

    1992-01-01

    We have measured asymmetric photoelectron angular distributions for atomic rubidium. Ionization is induced by a one-photon interaction with 280 nm light and by a two-photon interaction with 560 nm light. Interference between the even- and odd-parity free-electron wave functions allows us to control the direction of maximum electron flux by varying the relative phase of the two laser fields

  8. Gallager error-correcting codes for binary asymmetric channels

    International Nuclear Information System (INIS)

    Neri, I; Skantzos, N S; Bollé, D

    2008-01-01

    We derive critical noise levels for Gallager codes on asymmetric channels as a function of the input bias and the temperature. Using a statistical mechanics approach we study the space of codewords and the entropy in the various decoding regimes. We further discuss the relation of the convergence of the message passing algorithm with the endogenous property and complexity, characterizing solutions of recursive equations of distributions for cavity fields

  9. Numerical investigation on asymmetric bilayer system at integer filling factor

    Czech Academy of Sciences Publication Activity Database

    Nomura, K.; Yoshioka, D.; Jungwirth, Tomáš; MacDonald, A. H.

    2004-01-01

    Roč. 22, - (2004), s. 60-63 ISSN 1386-9477. [International Conference on Electronic Properties of Two-Dimensional Systems /15./. Nara, 14.07.2003-18.07.2003] Institutional research plan: CEZ:AV0Z1010914 Keywords : quantum Hall ferromagnet * asymmetric bilayer systems * anisotropy * stripe states Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.898, year: 2004

  10. Asymmetric information capacities of reciprocal pairs of quantum channels

    Science.gov (United States)

    Rosati, Matteo; Giovannetti, Vittorio

    2018-05-01

    Reciprocal pairs of quantum channels are defined as completely positive transformations which admit a rigid, distance-preserving, yet not completely positive transformation that allows one to reproduce the outcome of one from the corresponding outcome of the other. From a classical perspective these transmission lines should exhibit the same communication efficiency. This is no longer the case in the quantum setting: explicit asymmetric behaviors are reported studying the classical communication capacities of reciprocal pairs of depolarizing and Weyl-covariant channels.

  11. Symmetric vs. asymmetric stem cell divisions: an adaptation against cancer?

    Directory of Open Access Journals (Sweden)

    Leili Shahriyari

    Full Text Available Traditionally, it has been held that a central characteristic of stem cells is their ability to divide asymmetrically. Recent advances in inducible genetic labeling provided ample evidence that symmetric stem cell divisions play an important role in adult mammalian homeostasis. It is well understood that the two types of cell divisions differ in terms of the stem cells' flexibility to expand when needed. On the contrary, the implications of symmetric and asymmetric divisions for mutation accumulation are still poorly understood. In this paper we study a stochastic model of a renewing tissue, and address the optimization problem of tissue architecture in the context of mutant production. Specifically, we study the process of tumor suppressor gene inactivation which usually takes place as a consequence of two "hits", and which is one of the most common patterns in carcinogenesis. We compare and contrast symmetric and asymmetric (and mixed stem cell divisions, and focus on the rate at which double-hit mutants are generated. It turns out that symmetrically-dividing cells generate such mutants at a rate which is significantly lower than that of asymmetrically-dividing cells. This result holds whether single-hit (intermediate mutants are disadvantageous, neutral, or advantageous. It is also independent on whether the carcinogenic double-hit mutants are produced only among the stem cells or also among more specialized cells. We argue that symmetric stem cell divisions in mammals could be an adaptation which helps delay the onset of cancers. We further investigate the question of the optimal fraction of stem cells in the tissue, and quantify the contribution of non-stem cells in mutant production. Our work provides a hypothesis to explain the observation that in mammalian cells, symmetric patterns of stem cell division seem to be very common.

  12. Asymmetric Dark Matter Models and the LHC Diphoton Excess

    DEFF Research Database (Denmark)

    Frandsen, Mads T.; Shoemaker, Ian M.

    2016-01-01

    The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays...... have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances....

  13. Transition-Metal-Free Biomolecule-Based Flexible Asymmetric Supercapacitors.

    Science.gov (United States)

    Yang, Yun; Wang, Hua; Hao, Rui; Guo, Lin

    2016-09-01

    A transition-metal-free asymmetric supercapacitor (ASC) is successfully fabricated based on an earth-abundant biomass derived redox-active biomolecule, named lawsone. Such an ASC exhibits comparable or even higher energy densities than most of the recently reported transition-metal-based ASCs, and this green ASC generation from renewable resources is promising for addressing current issues of electronic hazard processing, high cost, and unsustainability. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Prediction of deformation textures in asymmetric rolling of aluminium alloys

    OpenAIRE

    Shore, Diarmuid; Nguyen-Minh, Tuan; Kestens, Leo; Van Bael, Albert

    2015-01-01

    Asymmetric cold rolling (ASR) has been shown to have potential to improve the formability of aluminium sheet alloys in deep drawing by increasing the normal plastic anisotropy, mainly as a result of the additional shear strains it imposes and the consequent alteration of the crystallographic texture. It is generally found that the process produces shear strains that vary across the sheet thickness, resulting in heterogeneity of the texture and related properties. While it may be a typical des...

  15. A Catalytic, Asymmetric Formal Synthesis of (+)-Hamigeran B

    KAUST Repository

    Mukherjee, Herschel; McDougal, Nolan T.; Virgil, Scott C.; Stoltz, Brian M.

    2011-01-01

    A concise asymmetric, formal synthesis of (+)-hamigeran B is reported. A Pd-catalyzed, decarboxylative allylic alkylation, employing a trifluoromethylated derivative of t-BuPHOX, is utilized as the enantioselective step to form the critical quaternary carbon center in excellent yield and enantioselectivity. The product is converted in three steps to a late-stage intermediate previously used in the synthesis of hamigeran B.

  16. Novel phosphonium salts and bifunctional organocatalysts in asymmetric synthesis

    OpenAIRE

    Moore, Graham

    2013-01-01

    This thesis details the syntheses of catalysts and their applications in asymmetric reactions. Initially, the project focused on phase transfer catalysts; quaternary phosphonium salts derived from diethyl tartrate or from commercially available phosphorus compounds and their use primarily in the alkylation of N,N-diphenyl methylene glycine tert-butyl ester. Although some of the salts showed the ability to catalyse the alkylation reaction, all products obtained were racemic. The project then f...

  17. Exposing asymmetric gray matter vulnerability in amyotrophic lateral sclerosis

    OpenAIRE

    Devine, Matthew S.; Pannek, Kerstin; Coulthard, Alan; McCombe, Pamela A.; Rose, Stephen E.; Henderson, Robert D.

    2015-01-01

    Limb weakness in amyotrophic lateral sclerosis (ALS) is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM) to explore gray matter (GM) asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each und...

  18. An asymmetric B-meson factory at PEP

    International Nuclear Information System (INIS)

    Garren, A.; Chattopadhyay, S.; Chin, Y.; Oddone, P.; Zisman, M.S.; Donald, M.; Feldman, G.; Paterson, J.M.; Rees, J.

    1989-03-01

    A preliminary design for a B-factory has been made using asymmetric collisions between positrons in the PEP storage ring and electrons in a new, log-energy ring. The design utilizes small-aperture, permanent-magnet quadrupoles close to the interaction point (IP). Optimization of optical and beam parameters at the IP will be discussed, as well as the lattice design of the interaction region and of the rings. 7 refs., 3 figs., 2 tabs

  19. Hybridized plasmon in an asymmetric cut-wire-pair structure

    Energy Technology Data Exchange (ETDEWEB)

    Tung, Nguyen Thanh [Vietnamese Military Academy of Science and Technology, Hanoi (Viet Nam); Hanyang University, Seoul (Korea, Republic of); Rhee, Joo Yull [Sungkyunkwan University, Suwon (Korea, Republic of); Park, Jin Woo; Lee, Young Pak [Hanyang University, Seoul (Korea, Republic of)

    2010-12-15

    In this report, we discuss an electromagnetic analog of the molecular-orbital theory for metamaterial structures. We show that the electromagnetic responses of a metamagnetic structure consisting of paired cut-wires can be well understood by using the plasmon-hybridization mechanism. The simulated transmission spectra of the asymmetric cut-wire-pair structure, which were obtained utilizing the transfer-matrix method, strongly support our suggestion.

  20. Asymmetric Information, Tax Evasion and Alternative Instruments of Government Revenue

    OpenAIRE

    Rangan Gupta

    2005-01-01

    Using a pure-exchange overlapping generations model, characterized with tax evasion and information asymmetry between the government (the social planner) and the financial intermediaries, we try and seek for the optimal tax and seigniorage plans, derived from the welfare maximizing objective of the social planner. We show that irrespective of whether the economy is characterized by tax evasion, or asymmetric information, a benevolent social planner, maximizing welfare and simultaneously finan...

  1. Exact results for the one dimensional asymmetric exclusion model

    International Nuclear Information System (INIS)

    Derrida, B.; Evans, M.R.; Pasquier, V.

    1993-01-01

    The asymmetric exclusion model describes a system of particles hopping in a preferred direction with hard core repulsion. These particles can be thought of as charged particles in a field, as steps of an interface, as cars in a queue. Several exact results concerning the steady state of this system have been obtained recently. The solution consists of representing the weights of the configurations in the steady state as products of non-commuting matrices. (author)

  2. Reverse Importing and Asymmetric Trade and FDI: A Networks Explanation

    OpenAIRE

    Theresa Greaney

    2002-01-01

    This paper considers the impact of business and social networks on international trade and foreign direct investment (FDI). I propose that differences in the strength of network effects across countries can produce asymmetric trade and investment flows that may lead to trade friction. This proposition is examined using a model of multi-product producers of a differentiated product. A firm from a country with strong network effects has a cost advantage in selling to buyers from its own country...

  3. Learning and forgetting on asymmetric, diluted neural networks

    International Nuclear Information System (INIS)

    Derrida, B.; Nadal, J.P.

    1987-01-01

    It is possible to construct diluted asymmetric models of neural networks for which the dynamics can be calculated exactly. The authors test several learning schemes, in particular, models for which the values of the synapses remain bounded and depend on the history. Our analytical results on the relative efficiencies of the various learning schemes are qualitatively similar to the corresponding ones obtained numerically on fully connected symmetric networks

  4. Supply Disruptions, Asymmetric Information, and a Backup Production Option

    OpenAIRE

    Zhibin (Ben) Yang; Göker Ayd{\\i}n; Volodymyr Babich; Damian R. Beil

    2009-01-01

    We study a manufacturer that faces a supplier privileged with private information about supply disruptions. We investigate how risk-management strategies of the manufacturer change and examine whether risk-management tools are more or less valuable in the presence of such asymmetric information. We model a supply chain with one manufacturer and one supplier, in which the supplier's reliability is either high or low and is the supplier's private information. On disruption, the supplier chooses...

  5. Market research and complementary advertising under asymmetric information

    OpenAIRE

    Tsuchihashi, Toshihiro

    2008-01-01

    We consider whether market research can always increase a seller's sales under bilateral asymmetric information. If a monopoly seller provides a high quality object, market research cannot increase sales even when the cost is sufficiently low. A low quality seller, on the other hand, can likely benefit from market research. However, this research has shown that market research alone does not improve sales and that advertising complements market research. Thus the high quality seller can incre...

  6. Hierarchical polypyrrole based composites for high performance asymmetric supercapacitors

    Science.gov (United States)

    Chen, Gao-Feng; Liu, Zhao-Qing; Lin, Jia-Ming; Li, Nan; Su, Yu-Zhi

    2015-06-01

    An advanced asymmetric supercapacitor with high energy density, exploiting hierarchical polypyrrole (PPy) based composites as both the anode [three dimensional (3D) chuzzle-like Ni@PPy@MnO2] and (3D cochleate-like Ni@MnO2@PPy) cathode, has been developed. The ultrathin PPy and flower-like MnO2 orderly coating on the high-conductivity 3D-Ni enhance charge storage while the unique 3D chuzzle-like and 3D cochleate-like structures provide storage chambers and fast ion transport pathways for benefiting the transport of electrolyte ions. The 3D cochleate-like Ni@MnO2@PPy possesses excellent pseudocapacitance with a relatively negative voltage window while preserved EDLC and free transmission channels conducive to hold the high power, providing an ideal cathode for the asymmetric supercapacitor. It is the first report of assembling hierarchical PPy based composites as both the anode and cathode for asymmetric supercapacitor, which exhibits wide operation voltage of 1.3-1.5 V with maximum energy and power densities of 59.8 Wh kg-1 and 7500 W kg-1.

  7. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-02-16

    In this study, we report the fabrication of solid-state asymmetric supercapacitors (ASCs) based on conducting polymer electrodes on a plastic substrate. Nanostructured conducting polymers of poly(3,4-ethylenedioxythiophene), PEDOT, and polyaniline (PANI) are deposited electrochemically over Au-coated polyethylene naphthalate (PEN) plastic substrates. Due to the electron donating nature of the oxygen groups in the PEDOT, reduction potentials are higher, allowing it to be used as a negative electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid state supercapacitors with PANI as a positive electrode while employing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte. The ASCs exhibit a maximum power density of 2.8 W cm−3 at an energy density of 9 mW h cm−3, which is superior to the carbonaceous and metal oxide based ASC solid state devices. Furthermore, the tandem configuration of asymmetric supercapacitors is shown to be capable of powering a red light emitting diode for about 1 minute after charging for 10 seconds.

  8. Fault Current Characteristics of the DFIG under Asymmetrical Fault Conditions

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2015-09-01

    Full Text Available During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive and negative sequence components. In these cases, the dynamic response of a rotor-side converter (RSC and the notch filters have a large influence on the fault current characteristics of the DFIG. In this paper, the influence of the notch filters on the proportional integral (PI parameters is discussed and the simplified calculation models of the rotor current are established. Then, the dynamic performance of the stator flux linkage under asymmetrical fault conditions is also analyzed. Based on this, the fault characteristics of the stator current under asymmetrical fault conditions are studied and the corresponding analytical expressions of the stator fault current are obtained. Finally, digital simulation results validate the analytical results. The research results are helpful to meet the requirements of a practical short-circuit calculation and the construction of a relaying protection system for the power grid with penetration of DFIGs.

  9. Fold catastrophe model of dynamic pillar failure in asymmetric mining

    Energy Technology Data Exchange (ETDEWEB)

    Yue Pan; Ai-wu Li; Yun-song Qi [Qingdao Technological University, Qingdao (China). College of Civil Engineering

    2009-01-15

    A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This graph contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions. 11 refs., 8 figs.

  10. Exposing asymmetric gray matter vulnerability in amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Matthew S. Devine

    2015-01-01

    Full Text Available Limb weakness in amyotrophic lateral sclerosis (ALS is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM to explore gray matter (GM asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each underwent a structural MRI sequence, from which GM segmentations were generated. Patterns of GM atrophy were assessed in ALS subjects with first weakness in a right-sided limb (n = 15 or left-sided limb (n = 15. Within each group, a voxelwise comparison was also performed between native and mirror GM images, to identify regions of hemispheric GM asymmetry. Subjects with ALS showed disproportionate atrophy of the dominant (left motor cortex hand area, irrespective of the side of first limb weakness (p < 0.01. Asymmetric atrophy of the left somatosensory cortex and temporal gyri was only observed in ALS subjects with right-sided onset of limb weakness. Our VBM protocol, contrasting native and mirror images, was able to more sensitively detect asymmetric GM pathology in a small cohort, compared with standard methods. These findings indicate particular vulnerability of dominant upper limb representation in ALS, supporting previous clinical studies, and with implications for cortical organisation and selective vulnerability.

  11. Asymmetric Flexible MXene-Reduced Graphene Oxide Micro-Supercapacitor

    KAUST Repository

    Couly, Cedric

    2017-11-27

    Current microfabrication of micro-supercapacitors often involves multistep processing and delicate lithography protocols. In this study, simple fabrication of an asymmetric MXene-based micro-supercapacitor that is flexible, binder-free, and current-collector-free is reported. The interdigitated device architecture is fabricated using a custom-made mask and a scalable spray coating technique onto a flexible, transparent substrate. The electrode materials are comprised of titanium carbide MXene (Ti3C2Tx) and reduced graphene oxide (rGO), which are both 2D layered materials that contribute to the fast ion diffusion in the interdigitated electrode architecture. This MXene-based asymmetric micro-supercapacitor operates at a 1 V voltage window, while retaining 97% of the initial capacitance after ten thousand cycles, and exhibits an energy density of 8.6 mW h cm−3 at a power density of 0.2 W cm−3. Further, these micro-supercapacitors show a high level of flexibility during mechanical bending. Utilizing the ability of Ti3C2Tx-MXene electrodes to operate at negative potentials in aqueous electrolytes, it is shown that using Ti3C2Tx as a negative electrode and rGO as a positive one in asymmetric architectures is a promising strategy for increasing both energy and power densities of micro-supercapacitors.

  12. Asymmetric evolution and domestication in allotetraploid cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    Lei Fang

    2017-04-01

    Full Text Available Polyploidy plays a major role in genome evolution, which corresponds to environmental changes over millions of years. The mechanisms of genome evolution, particularly during the process of domestication, are of broad interest in the fields of plant science and crop breeding. Upland cotton is derived from the hybridization and polyploidization of its ancient A and D diploid ancestors. As a result, cotton is a model for polyploid genome evolution and crop domestication. To explore the genomic mysteries of allopolyploid cotton, we investigated asymmetric evolution and domestication in the A and D subgenomes. Interestingly, more structural rearrangements have been characterized in the A subgenome than in the D subgenome. Correspondingly, more transposable elements, a greater number of lost and disrupted genes, and faster evolution have been identified in the A subgenome. In contrast, the centromeric retroelement (RT-domain related sequence of tetraploid cotton derived from the D subgenome progenitor was found to have invaded the A subgenome centromeres after allotetrapolyploid formation. Although there is no genome-wide expression bias between the subgenomes, as with expression-level alterations, gene expression bias of homoeologous gene pairs is widespread and varies from tissue to tissue. Further, there are more positively selected genes for fiber yield and quality in the A subgenome and more for stress tolerance in the D subgenome, indicating asymmetric domestication. This review highlights the asymmetric subgenomic evolution and domestication of allotetraploid cotton, providing valuable genomic resources for cotton research and enhancing our understanding of the basis of many other allopolyploids.

  13. Symmetric and asymmetric nuclear matter in the relativistic approach

    International Nuclear Information System (INIS)

    Huber, H.; Weber, F.; Weigel, M.K.

    1995-01-01

    Symmetric and asymmetric nuclear matter is studied in the framework of the relativistic Brueckner-Hartree-Fock and in the relativistic version of the so-called Λ 00 approximation. The equations are solved self-consistently in the full Dirac space, so avoiding the ambiguities in the choice of the effective scattering amplitude in matter. The calculations were performed for some modern meson-exchange potentials constructed by Brockmann and Machleidt. In some cases we used also the Groningen potentials. First, we examine the outcome for symmetric matter with respect to other calculations, which restrict themselves to positive-energy states only. The main part is devoted to the properties of asymmetric matter. In this case we obtain additionally to the good agreement with the parameters of symmetric matter, also a quite satisfactory agreement with the semiempirical macroscopic coefficients of asymmetric matter. Furthermore, we tested the assumption of a quadratic dependence of the asymmetry energy for a large range of asymmetries. Included is also the dependence of nucleon self-energies on density and neutron excess. For the purpose of comparison we discuss further the similarities and differences with relativistic Hartree and Hartree-Fock calculations and nonrelativistic Skyrme calculations

  14. Advanced materials for aqueous supercapacitors in the asymmetric design

    Directory of Open Access Journals (Sweden)

    Muniyandi Rajkumar

    2015-12-01

    Full Text Available Supercapacitors have been recognized as one of the promising energy storage devices in the future energy technology. In this perspective, rapid progress is made in the development of fundamental and applied aspects of supercapacitors. Various techniques have been developed specifically to estimate the specific capacitance. Numerous efforts have been made in the literature to increase the specific capacitance of electrode materials. Recently, researchers pay more attention on designing supercapacitors of asymmetric type with extending cell voltage and dissimilar materials with complementary working potentials. Researchers try to increase the specific energy of asymmetric supercapacitors (ASCs. Conversely, it is still a challenge to find a suitable operation conditions for ASCs in various designs, especially for the one with battery type electrode. In this review, we describe our recent research works and other reports on the preparation of various nanostructured electrode materials and the performances of both symmetric and asymmetric supercapacitors. Finally, we demonstrate effects of charge balance on the capacitive performances of ASCs which consist of one electrode material of the battery type and one capacitive material. We also demonstrate how to evaluate the charge capacities of both positive and negative electrode materials for this ASC application.

  15. Stochastic modeling of cell growth with symmetric or asymmetric division

    Science.gov (United States)

    Marantan, Andrew; Amir, Ariel

    2016-07-01

    We consider a class of biologically motivated stochastic processes in which a unicellular organism divides its resources (volume or damaged proteins, in particular) symmetrically or asymmetrically between its progeny. Assuming the final amount of the resource is controlled by a growth policy and subject to additive and multiplicative noise, we derive the recursive integral equation describing the evolution of the resource distribution over subsequent generations and use it to study the properties of stable resource distributions. We find conditions under which a unique stable resource distribution exists and calculate its moments for the class of affine linear growth policies. Moreover, we apply an asymptotic analysis to elucidate the conditions under which the stable distribution (when it exists) has a power-law tail. Finally, we use the results of this asymptotic analysis along with the moment equations to draw a stability phase diagram for the system that reveals the counterintuitive result that asymmetry serves to increase stability while at the same time widening the stable distribution. We also briefly discuss how cells can divide damaged proteins asymmetrically between their progeny as a form of damage control. In the appendixes, motivated by the asymmetric division of cell volume in Saccharomyces cerevisiae, we extend our results to the case wherein mother and daughter cells follow different growth policies.

  16. Feasibility study for an asymmetric B-factory at KEK

    International Nuclear Information System (INIS)

    Ozaki, Hitoshi; Yoshimura, Yoshio

    1990-06-01

    In June, 1989, the study group for exploring the feasibility of B meson physics using an asymmetric energy accelerator was organized. This report is the summary of the results of the works that this study group carried out in nine months, and is the Japanese edition of the report of English edition 'Task Force Report on Asymmetric B-factory at KEK'. The activity plan of the study group was to make up the plan exceeding the preceding CLEO-2 experiment by utilizing the features of an asymmetric B-factory. Under this plan, the activities have been carried out by the study meetings twice every week on the physics side and once every two weeks on the accelerator side. Besides, in two study meetings held in October and December, 1989, several persons who have engaged in the research on B meson physics actually in foreign countries were invited, and the discussion was carried out. At present toward the materialization of the plan, the concrete investigation of accelerators and measuring instruments was begun. The significance of a B-factory and the construction project, the physics of a B-factory, the experimental method and the plan for an accelerator are reported. (K.I.)

  17. The synchronization of asymmetric-structured electric coupling neuronal system

    Science.gov (United States)

    Wang, Guanping; Jin, Wuyin; Liu, Hao; Sun, Wei

    2018-02-01

    Based on the Hindmarsh-Rose (HR) model, the synchronization dynamics of asymmetric-structured electric coupling two neuronal system is investigated in this paper. It is discovered that when the time-delay scope and coupling strength for the synchronization are correlated positively under unequal time delay, the time-delay difference does not make a clear distinction between the two individual inter-spike intervals (ISI) bifurcation diagrams of the two coupled neurons. Therefore, the superficial difference of the system synchronization dynamics is not obvious for the unequal time-delay feedback. In the asymmetrical current incentives under asymmetric electric coupled system, the two neurons can only be almost completely synchronized in specific area of the interval which end-pointed with two discharge modes for a single neuron under different stimuli currents before coupling, but the intervention of time-delay feedback, together with the change of the coupling strength, can make the coupled system not only almost completely synchronized within anywhere in the front area, but also outside of it.

  18. Baseline Testing of the Club Car Carryall With Asymmetric Ultracapacitors

    Science.gov (United States)

    Eichenberg, Dennis J.

    2003-01-01

    The NASA John H. Glenn Research Center initiated baseline testing of the Club Car Carryall with asymmetric ultracapacitors as a way to reduce pollution in industrial settings, reduce fossil fuel consumption, and reduce operating costs for transportation systems. The Club Car Carryall provides an inexpensive approach to advance the state of the art in electric vehicle technology in a practical application. The project transfers space technology to terrestrial use via non-traditional partners, and provides power system data valuable for future space applications. The work was done under the Hybrid Power Management (HPM) Program, which includes the Hybrid Electric Transit Bus (HETB). The Carryall is a state of the art, ground up, electric utility vehicle. A unique aspect of the project was the use of a state of the art, long life ultracapacitor energy storage system. Innovative features, such as regenerative braking through ultracapacitor energy storage, are planned. Regenerative braking recovers much of the kinetic energy of the vehicle during deceleration. The Carryall was tested with the standard lead acid battery energy storage system, as well as with an asymmetric ultracapacitor energy storage system. The report concludes that the Carryall provides excellent performance, and that the implementation of asymmetric ultracapacitors in the power system can provide significant performance improvements.

  19. Asymmetric Distribution of GFAP in Glioma Multipotent Cells

    Science.gov (United States)

    Guichet, Pierre-Olivier; Guelfi, Sophie; Ripoll, Chantal; Teigell, Marisa; Sabourin, Jean-Charles; Bauchet, Luc; Rigau, Valérie; Rothhut, Bernard; Hugnot, Jean-Philippe

    2016-01-01

    Asymmetric division (AD) is a fundamental mechanism whereby unequal inheritance of various cellular compounds during mitosis generates unequal fate in the two daughter cells. Unequal repartitions of transcription factors, receptors as well as mRNA have been abundantly described in AD. In contrast, the involvement of intermediate filaments in this process is still largely unknown. AD occurs in stem cells during development but was also recently observed in cancer stem cells. Here, we demonstrate the asymmetric distribution of the main astrocytic intermediate filament, namely the glial fibrillary acid protein (GFAP), in mitotic glioma multipotent cells isolated from glioblastoma (GBM), the most frequent type of brain tumor. Unequal mitotic repartition of GFAP was also observed in mice non-tumoral neural stem cells indicating that this process occurs across species and is not restricted to cancerous cells. Immunofluorescence and videomicroscopy were used to capture these rare and transient events. Considering the role of intermediate filaments in cytoplasm organization and cell signaling, we propose that asymmetric distribution of GFAP could possibly participate in the regulation of normal and cancerous neural stem cell fate. PMID:26953813

  20. Asymmetric Distribution of GFAP in Glioma Multipotent Cells.

    Directory of Open Access Journals (Sweden)

    Pierre-Olivier Guichet

    Full Text Available Asymmetric division (AD is a fundamental mechanism whereby unequal inheritance of various cellular compounds during mitosis generates unequal fate in the two daughter cells. Unequal repartitions of transcription factors, receptors as well as mRNA have been abundantly described in AD. In contrast, the involvement of intermediate filaments in this process is still largely unknown. AD occurs in stem cells during development but was also recently observed in cancer stem cells. Here, we demonstrate the asymmetric distribution of the main astrocytic intermediate filament, namely the glial fibrillary acid protein (GFAP, in mitotic glioma multipotent cells isolated from glioblastoma (GBM, the most frequent type of brain tumor. Unequal mitotic repartition of GFAP was also observed in mice non-tumoral neural stem cells indicating that this process occurs across species and is not restricted to cancerous cells. Immunofluorescence and videomicroscopy were used to capture these rare and transient events. Considering the role of intermediate filaments in cytoplasm organization and cell signaling, we propose that asymmetric distribution of GFAP could possibly participate in the regulation of normal and cancerous neural stem cell fate.