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Sample records for cilnidipine suppresses podocyte

  1. Preparation and evaluation of cilnidipine microemulsion

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    Hemal Tandel

    2012-01-01

    Full Text Available Cilnidipine, a calcium channel blocker having neuroprotective action and BCS Class II drug, hence formulating in Microemulsion will increase solubility, absorption and bioavailability. The formulation was prepared using titration method by tocotrienol, tween 20 and transcutol HP as oil, surfactant and co-surfactant and characterized for dilutability, dye solubility, assay (98.39±0.06, pH (6.6±1.5, Viscosity (98±1.0 cps and Conductivity (0.2±0.09 μS/cm. The formulation was optimized on basis of percentage transmittance (99.269±0.23 at 700 nm, Globule size (13.31±4.3 nm and zeta potential (-11.4±2.3 mV. Cilnidipine microemulsion was found to be stable for 3 months.

  2. Stressed podocytes

    DEFF Research Database (Denmark)

    Svenningsen, Per

    2015-01-01

    conditions and in response to injury induced by endoplasmatic reticulum (ER) stress (Golubinskaya et al., 2015). Their report shed light on the complex regulation of Best3 in podocytes and will help pave the way for future studies on the pathogenesis of kidneys diseases with podocyte injury. This article is...

  3. Cilnidipine lowered psychological stress-induced increase in blood pressure in a hypertensive man: a case report

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    Tsuji Sadatoshi

    2007-09-01

    Full Text Available Abstract Background In some hypertensive patients, psychological stress makes blood pressure difficult to control and causes physical symptoms such as headache or dizziness. We report the case of a hypertensive man whose psychological stress-induced increase in blood pressure was attenuated by cilnidipine. Case Presentation The patient (a 72-year-old man had hypertension and was on antihypertensive therapy. When mentally concentrating, he experienced occipital headaches and dizziness, and despite thorough testing, no abnormality was found. He was subsequently referred to our department. The mirror drawing test (MDT, a psychological stress test, increased blood pressure by about 40 mmHg, and the patient described occipital headache. Plasma noradrenaline level also increased from 212 to 548 pg/ml. We therefore switched the patient from nifedipine, an L-type calcium (Ca channel blocker, to cilnidipine, an L-type/N-type Ca channel blocker with suppressive effects on sympathetic activity. Cilnipidine attenuated MDT-induced an increase in blood pressure and plasma noradrenaline level and prevented the development of headache during testing. Conclusion These findings suggest that cilnidipine is a useful antihypertensive agent for hypertensive patients in whom psychological stress causes marked fluctuations in blood pressure.

  4. FTIR SPECTROSCOPIC METHOD FOR QUANTITATIVE ANALYSIS OF CILNIDIPINE IN TABLET DOSAGE FORM

    OpenAIRE

    Ashish Patel; Arti Panchal; Viral Patel; Akhil Nagar

    2015-01-01

    A Fourier transform infrared (FT-IR) spectrometric method was developed for the rapid and direct measurement of Cilnidipine in pharmaceutical drugs. Cilnidipine is newly discovered and very effective antihypertensive drug. Cilnidipine can be determined by various methods and now we are adding a new one that uses a Fourier transform infrared spectrophotometric technique. The method involves the measurement of absorbance of carbonyl group (C=O) peak at 1697 cm-1. The proposed method was validat...

  5. Progenitor Cells and Podocyte Regeneration

    OpenAIRE

    Shankland, Stuart J.; Pippin, Jeffrey W.; Duffield, Jeremy S.

    2014-01-01

    The very limited ability of adult podocytes to proliferate in vivo is clinically significant because: podocytes form a vascular barrier which is functionally critical to the nephron; podocyte hypoplasia is a characteristic of disease; and inadequate regeneration of podocytes is a major cause of persistent podocyte hypoplasia. Excessive podocyte loss or inadequate replacement leads to glomerulosclerosis in many progressive kidney diseases. Thus, restoration of podocyte cell density is almost c...

  6. The fourth-generation Calcium channel blocker: Cilnidipine

    OpenAIRE

    Chandra, K. Sarat; Ramesh, G.

    2013-01-01

    Several classes of antihypertensive agents have been in clinical use, including diuretics, α-blockers, β-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II type 1 receptor blockers (ARB), and organic calcium channel blockers (CCBs). All these drugs are being currently used in the treatment of Hypertension & various disease conditions of the heart either alone or in combination. Cilnidipine is a new antihypertensive drug distinguished from other L-type Ca2+ channel blocke...

  7. Podocyte injury and its consequences.

    Science.gov (United States)

    Nagata, Michio

    2016-06-01

    Podocytes maintain the glomerular filtration barrier, and the stability of this barrier depends on their highly differentiated postmitotic phenotype, which also defines the particular vulnerability of the glomerulus. Recent podocyte biology and gene disruption studies in vivo indicate a causal relationship between abnormalities of single podocyte molecules and proteinuria and glomerulosclerosis. Podocytes live under various stresses and pathological stimuli. They adapt to maintain homeostasis, but excessive stress leads to maladaptation with complex biological changes including loss of integrity and dysregulation of cellular metabolism. Podocyte injury causes proteinuria and detachment from the glomerular basement membrane. In addition to "sick" podocytes and their detachment, our understanding of glomerular responses following podocyte loss needs to address the pathways from podocyte injury to sclerosis. Studies have found a variety of glomerular responses to podocyte dysfunction in vivo, such as disruption of podocyte-endothelial cross talk and activation of podocyte-parietal cell interactions, all of which help us to understand the complex scenario of podocyte injury and its consequences. This review focuses on the cellular aspects of podocyte dysfunction and the adaptive or maladaptive glomerular responses to podocyte injury that lead to its major consequence, glomerulosclerosis. PMID:27165817

  8. Progenitor Cells and Podocyte Regeneration

    Science.gov (United States)

    Shankland, Stuart J.; Pippin, Jeffrey W.; Duffield, Jeremy S.

    2014-01-01

    The very limited ability of adult podocytes to proliferate in vivo is clinically significant because: podocytes form a vascular barrier which is functionally critical to the nephron; podocyte hypoplasia is a characteristic of disease; and inadequate regeneration of podocytes is a major cause of persistent podocyte hypoplasia. Excessive podocyte loss or inadequate replacement leads to glomerulosclerosis in many progressive kidney diseases. Thus, restoration of podocyte cell density is almost certainly reliant on regeneration by podocyte progenitors. However such putative progenitors have remained elusive until recently. In this review we describe the developmental processes leading to podocyte and parietal epithelial cell (PEC) formation during glomerulogenesis. We compare evidence that in normal human kidneys PECs expressing ‘progenitor’ markers CD133 and CD24 can differentiate into podocytes in vitro and in vivo with evidence from animal models suggesting a more limited role of PEC-capacity to serve as podocyte progenitors in adults. We will highlight tantalizing new evidence that specialized vascular wall cells of afferent arterioles including those which produce renin in healthy kidney, provide a novel local progenitor source of new PECs and podocytes in response to podocyte hypoplasia in the adult, and draw comparisons with glomerulogenesis. PMID:25217270

  9. Antihypertensive Efficiency and Safety of L- & N- type Ca2+ Antagonists -cilnidipine

    Institute of Scientific and Technical Information of China (English)

    张向阳; 刘国树

    2003-01-01

    Objectives To evaluate antihypertensive efficiency and safety of a new domesticof L - & N - type Ca2+ antagonist - cilnidipine withimidapril as a positive control. Methods After 2weeks' placebo washingout, 22 patients were treatedwith cilnidipine 5 mg daily and 27 patients were treatedwith imidapril 5 mg daily. 4 weeks later, if patient'ssitting diastolic blood pressure is over 90 mmHg, his/her dosage was doubled for another 4 weeks, the othersmeasuring up remained their dosage unchanged foranother 4 weeks. Blood pressure, heart rate, blood andurine routine examination, serum glucose, serumchemical examination including total cholesterol,triglyceride, HDL, LDL, transaminase, creatine etcand side reactions were recorded before and after thetrial. Data were analyzed statistically. Results After8 weeks' treatment, blood pressure was significantlydecreased (P < 0.05) in both groups, and the twomedicines had similar antihypertensive effects. Fur-thermore, the reducing of heart rate was statisticallysignificant compared with baseline ( P < 0.01 ) in thecilnidipine group, but not in the imidapril group. Thenegative chronotropic effect of cilnidipine had little ef-fect on continuing the therapy. There were no changeson blood and urine routine examination and serumlipid, serum glucose, creatine, transaminase and etcin both groups. Their side reactions were mild and well-tolerated. Conclusions Cilnidipine has a con-vincing antihypertensive effect similar to that of imi-dapril. Especially cilnidipine may be administered topatients with relatively mild tachycardia.

  10. FTIR SPECTROSCOPIC METHOD FOR QUANTITATIVE ANALYSIS OF CILNIDIPINE IN TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Ashish Patel

    2015-07-01

    Full Text Available A Fourier transform infrared (FT-IR spectrometric method was developed for the rapid and direct measurement of Cilnidipine in pharmaceutical drugs. Cilnidipine is newly discovered and very effective antihypertensive drug. Cilnidipine can be determined by various methods and now we are adding a new one that uses a Fourier transform infrared spectrophotometric technique. The method involves the measurement of absorbance of carbonyl group (C=O peak at 1697 cm-1. The proposed method was validated for pharmaceuticals in tablet form and %RSD was found to be less than two with recovery levels 99.8-102.5 and 99.8- 101.4 as per absorbance and peak area respectively.

  11. DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR ESTIMATION OF CILNIDIPINE AND METOPROLOL SUCCINATE

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    Mo.Salauddin A Shaikh

    2015-07-01

    Full Text Available A simple, specific, accurate and precise reversed phase high performance liquid chromatographic method was developed and validated for the simultaneous estimation of Cilnidipine and Metoprolol Succinate, using a Cosmosil C18 (250 х 4.6 mm i.d. column and a mobile phase composed of 0.05M potassium dihydrogen phosphate buffer: Methanol (70:30 pH 3.5 adjusted with ophosphoric acid and at flow rate of 1.0 ml/min. The retention times of Cilnidipine and Metoprolol Succinate were found to be 3.493 min and 5.960 min, respectively. Linearity was established for Cilnidipine and Metoprolol Succinate in the range of 12.5-37.5 μg/ml and 2.5-7.5 μg/ml, respectively. The percentage recoveries of Cilnidipine and Metoprolol Succinate were found to be in the range of 100.13-100.40 % and 99.24-100.29 %, respectively. The correlation coefficients for both components were found to be 0.999. The developed methods were validated according to ICH guidelines and values of linearity, accuracy, precision and other analysis were found to be in good accordance with the prescribed values. This method can be successfully employed for simultaneous quantitative analysis of Cilnidipine and Metoprolol Succinate in its dosage form. The developed HPLC method was subjected to stability indicating studies for marketed formulation. Interfering peak from degraded products or solvent did not interfere with estimation of drugs and the developed method was found to be specific for estimation of Cilnidipine and Metoprolol Succinate.

  12. Podocyte Pathology and Nephropathy

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    Sandra eMerscher

    2014-07-01

    Full Text Available Sphingolipids are components of the lipid rafts in plasma membranes, which are important for proper function of podocytes, a key element of the glomerular filtration barrier. Research revealed an essential role of sphingolipids and sphingolipid metabolites in glomerular disorders of genetic and non-genetic origin. The discovery that glucocerebrosides accumulate in Gaucher disease in glomerular cells and are associated with clinical proteinuria initiated intensive research into the function of other sphingolipids in glomerular disorders. The accumulation of sphingolipids in other genetic diseases including Tay-Sachs, Sandhoff, Fabry, hereditary inclusion body myopathy 2, Niemann-Pick and nephrotic syndrome of the Finnish type and its implications with respect to glomerular pathology will be discussed. Similarily, sphingolipid accumulation occurs in glomerular diseases of non-genetic origin including diabetic kidney disease (DKD, HIV-associated nephropathy, focal segmental glomerulosclerosis (FSGS and lupus nephritis. Sphingomyelin metabolites, such as ceramide, sphingosine and sphingosine-1-phosphate have also gained tremendous interest. We recently described that sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b is expressed in podocytes where it modulates acid sphingomyelinase (ASMase activity and acts as a master modulator of danger signaling. Decreased SMPDL3b expression in post-reperfusion kidney biopsies from transplant recipients with idiopathic FSGS correlates with the recurrence of proteinuria in patients and in experimental models of xenotransplantation. Increased SMPDL3b expression is associated with DKD. The consequences of differential SMPDL3b expression in podocytes in these diseases with respect to their pathogenesis will be discussed. Finally, the role of sphingolipids in the formation of lipid rafts in podocytes and their contribution to the maintenance of a functional slit diaphragm in the glomerulus will be discussed.

  13. Dexamethasone-dependent modulation of cyclic GMP synthesis in podocytes.

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    Lewko, Barbara; Waszkiewicz, Anna; Maryn, Anna; Gołos, Magdalena; Latawiec, Elżbieta; Daca, Agnieszka; Witkowski, Jacek M; Angielski, Stefan; Stępiński, Jan

    2015-11-01

    Podocytes may be direct target for glucocorticoid therapy in glomerular proteinuric disease. Permeability of podocytes largely depends on their capacity to migrate which involves the contractile apparatus in their foot processes. In this study, we examined the effect of synthetic glucocorticoid dexamethasone (DEX) on the ability of podocytes to produce cyclic guanosine monophosphate (cGMP) in the presence of vasoactive factors, atrial natriuretic peptide (ANP), nitric oxide (NO), and angiotensin II (Ang II). We investigated also the effects of cGMP and DEX on podocyte motility. Primary rat podocytes and immortalized mouse podocytes were pretreated with 1 µM DEX for 4 or 24 h. Glomerular hypertension was mimicked by subjecting the cells to mechanical stress. Total and subcellular cGMP levels were determined in podocytes incubated with 0.1 µM ANP, 1 µM S-nitroso-N-acetyl penicillamine (SNAP), and 1 µM Ang II. Cell motility was estimated by a wound-healing assay. The ANP-dependent production of cGMP increased after 4 h exposition to DEX, but was attenuated after 24 h. Adversely, a 24-h pretreatment with DEX augmented the NO-dependent cGMP synthesis. Ang II suppressed the ANP-dependent cGMP production and the effect was enhanced by DEX in mechanical stress conditions. Mechanical stress reduced total cGMP production in the presence of all stimulators, whereas extracellular to total cGMP ratio increased. 8-Br cGMP enhanced podocyte migration which was accompanied by F-actin disassembly. In the presence of DEX these effects were prevented. We conclude that DEX modulates the production of cGMP in podocytes stimulated with vasoactive factors such as Ang II, ANP, and NO, and the effect is time-dependent. cGMP increases podocyte motility, which is prevented by DEX. This mechanism may account for the antiproteinuric effect of glucocorticoids. PMID:26272337

  14. The β isoform of GSK3 mediates podocyte autonomous injury in proteinuric glomerulopathy.

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    Li, Changbin; Ge, Yan; Dworkin, Lance; Peng, Ai; Gong, Rujun

    2016-05-01

    Converging evidence points to glycogen synthase kinase (GSK) 3 as a key player in the pathogenesis of podocytopathy and proteinuria. However, it remains unclear if GSK3 is involved in podocyte autonomous injury in glomerular disease. In normal kidneys, the β isoform of GSK3 was found to be the major GSK3 expressed in glomeruli and intensely stained in podocytes. GSK3β expression in podocytes was markedly elevated in experimental or human proteinuric glomerulopathy. Podocyte-specific somatic ablation of GSK3β in adult mice attenuated proteinuria and ameliorated podocyte injury and glomerular damage in experimental adriamycin (ADR) nephropathy. Mechanistically, actin cytoskeleton integrity in podocytes was largely preserved in GSK3β knockout mice following ADR insult, concomitant with a correction of podocyte hypermotility and lessened phosphorylation and activation of paxillin, a focal adhesion-associated adaptor protein. In addition, GSK3β knockout diminished ADR-induced NFκB RelA/p65 phosphorylation selectively at serine 467; suppressed de novo expression by podocytes of NFκB-dependent podocytopathic mediators, including B7-1, cathepsin L, and MCP-1; but barely affected the induction of NFκB target pro-survival factors, such as Bcl-xL. Moreover, the ADR-elicited podocytopenia and podocyte death were significantly attenuated in GSK3β knockout mice, associated with protection against podocyte mitochondrial damage and reduced phosphorylation and activation of cyclophilin F, a structural component of mitochondria permeability transition pores. Overall, our findings suggest that the β isoform of GSK3 mediates autonomous podocyte injury in glomerulopathy by integrating multiple podocytopathic signalling pathways. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26876299

  15. Astragaloside IV prevents high glucose-induced podocyte apoptosis via downregulation of TRPC6.

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    Yao, Xing-Mei; Liu, Yu-Jun; Wang, Yun-Man; Wang, Hao; Zhu, Bing-Bing; Liang, Yong-Ping; Yao, Wei-Guo; Yu, Hui; Wang, Nian-Song; Zhang, Xue-Mei; Peng, Wen

    2016-06-01

    Diabetic nephropathy (DN) is one of the most important causes of end‑stage renal disease. Astragaloside IV (AS-IV) is a saponin isolated from Astragalus membranaceus, which possesses various pharmacological activities. AS‑IV prevents podocyte apoptosis and ameliorates renal injury in DN; however, few studies have focused on its effects on ion channels. The transient receptor potential channel 6 (TRPC6) is an important Ca2+‑permeable ion channel in podocytes, which is involved in high glucose (HG)-induced podocyte apoptosis. The aim of the present study was to investigate whether AS‑IV prevented HG‑induced podocyte apoptosis via TRPC6. Cultured podocytes were pre‑treated with 10, 20 or 40 µM AS‑IV for 1 h prior to HG exposure for 24 h. Apoptosis, cell viability, expression of TRPC6, nuclear factor of activated T cells (NFAT2) and B‑cell lymphoma 2‑associated X protein (Bax), as well as the intracellular Ca2+ concentration were subsequently analyzed. The results indicated that HG induced podocyte apoptosis and upregulation of TRPC6, and increased intracellular Ca2+. Furthermore, enhanced NFAT2 and Bax expression was detected. Conversely, AS‑IV protected HG‑induced podocyte apoptosis, downregulated TRPC6 expression and suppressed intracellular Ca2+ in HG-stimulated podocytes. AS‑IV also suppressed NFAT2 and Bax expression. These results suggest that AS‑IV may prevent HG-induced podocyte apoptosis via downregulation of TRPC6, which is possibly mediated via the calcineurin/NFAT signaling pathway. PMID:27109610

  16. 西尼地平的合成工艺研究%Study on the Synthesis Technology of Cilnidipine

    Institute of Scientific and Technical Information of China (English)

    施务务; 李立标

    2014-01-01

    With 2-methoxyethyl acetoacetate and cinnamyl acetoacetate as the starting materials, the cilnidipine can be obtained from 3-Aminocrotonic Cinnamate by Aldol condensation and Hantzsch cyclization. It is a suitable way to produce cilnidipin industrially,which provides the advantage of simplicity and safety.%以乙酰乙酸甲氧基乙基酯、乙酰乙酸肉桂醇酯为起始原料,经中间体3-氨基巴豆酸肉桂醇酯,通过Aldol缩合、Hantzsch环合反应,合成出了钙离子拮抗剂西尼地平。该合成工艺安全可行,操作简单,适合工业化生产。

  17. PINCH1 is transcriptional regulator in podocytes that interacts with WT1 and represses podocalyxin expression.

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    Dan Wang

    Full Text Available BACKGROUND: PINCH1, an adaptor protein containing five LIM domains, plays an important role in regulating the integrin-mediated cell adhesion, migration and epithelial-mesenchymal transition. PINCH1 is induced in the fibrotic kidney after injury, and it primarily localizes at the sites of focal adhesion. Whether it can translocate to the nucleus and directly participate in gene regulation is completely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using cultured glomerular podocytes as a model system, we show that PINCH1 expression was induced by TGF-β1, a fibrogenic cytokine that promotes podocyte dysfunction. Interestingly, increased PINCH1 not only localized at the sites of focal adhesions, but also underwent nuclear translocation after TGF-β1 stimulation. This nuclear translocation of PINCH1 was apparently dependent on the putative nuclear export/localization signals (NES/NLS at its C-terminus, as deletion or site-directed mutations abolished its nuclear shuttling. Co-immunoprecipitation and pull-down experiments revealed that PINCH1 interacted with Wilms tumor 1 protein (WT1, a nuclear transcription factor that is essential for regulating podocyte-specific gene expression in adult kidney. Interaction of PINCH1 and WT1 was mediated by the LIM1 domain of PINCH1 and C-terminal zinc-finger domain of WT1, which led to the suppression of the WT1-mediated podocalyxin expression in podocytes. PINCH1 also repressed podocalyxin gene transcription in a promoter-luciferase reporter assay. CONCLUSION/SIGNIFICANCE: These results indicate that PINCH1 can shuttle into the nucleus from cytoplasm in podocytes, wherein it interacts with WT1 and suppresses podocyte-specific gene expression. Our studies reveal a previously unrecognized, novel function of PINCH1, in which it acts as a transcriptional regulator through controlling specific gene expression.

  18. Heme oxygenase-1 enhances autophagy in podocytes as a protective mechanism against high glucose-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Chenglong [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Zheng, Haining [Department of Hyperbaric Oxygen, Nanjing General Hospital of Nanjing Military Command, Nanjing (China); Huang, Shanshan; You, Na; Xu, Jiarong; Ye, Xiaolong; Zhu, Qun; Feng, Yamin; You, Qiang; Miao, Heng [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Ding, Dafa, E-mail: dingdafa2004@aliyun.com [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China); Lu, Yibing, E-mail: luyibing2004@126.com [Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing (China)

    2015-10-01

    Injury and loss of podocytes play vital roles in diabetic nephropathy progression. Emerging evidence suggests autophagy, which is induced by multiple stressors including hyperglycemia, plays a protective role. Meanwhile, heme oxygenase-1 (HO-1) possesses powerful anti-apoptotic properties. Therefore, we investigated the impact of autophagy on podocyte apoptosis under diabetic conditions and its association with HO-1. Mouse podocytes were cultured in vitro; apoptosis was detected by flow cytometry. Transmission electron microscopy and biochemical autophagic flux assays were used to measure the autophagy markers microtubule-associated protein 1 light chain 3-II (LC3-II) and beclin-1. LC3-II and beclin-1 expression peaked 12–24 h after exposing podocytes to high glucose. Inhibition of autophagy with 3-methyladenine or Beclin-1 siRNAs or Atg 5 siRNAs sensitized cells to apoptosis, suggesting autophagy is a survival mechanism. HO-1 inactivation inhibited autophagy, which aggravated podocyte injury in vitro. Hemin-induced autophagy also protected podocytes from hyperglycemia in vitro and was abrogated by HO-1 siRNA. Adenosine monophosphate-activated protein kinase phosphorylation was higher in hemin-treated and lower in HO-1 siRNA-treated podocytes. Suppression of AMPK activity reversed HO-1-mediated Beclin-1 upregulation and autophagy, indicating HO-1-mediated autophagy is AMPK dependent. These findings suggest HO-1 induction and regulation of autophagy are potential therapeutic targets for diabetic nephropathy. - Highlights: • High glucose leads to increased autophagy in podocytes at an early stage. • The early autophagic response protects against high glucose-induced apoptosis. • Heme oxygenase-1 enhances autophagy and decreases high glucose -mediated apoptosis. • Heme oxygenase-1 induces autophagy through the activation of AMPK.

  19. Heme oxygenase-1 enhances autophagy in podocytes as a protective mechanism against high glucose-induced apoptosis

    International Nuclear Information System (INIS)

    Injury and loss of podocytes play vital roles in diabetic nephropathy progression. Emerging evidence suggests autophagy, which is induced by multiple stressors including hyperglycemia, plays a protective role. Meanwhile, heme oxygenase-1 (HO-1) possesses powerful anti-apoptotic properties. Therefore, we investigated the impact of autophagy on podocyte apoptosis under diabetic conditions and its association with HO-1. Mouse podocytes were cultured in vitro; apoptosis was detected by flow cytometry. Transmission electron microscopy and biochemical autophagic flux assays were used to measure the autophagy markers microtubule-associated protein 1 light chain 3-II (LC3-II) and beclin-1. LC3-II and beclin-1 expression peaked 12–24 h after exposing podocytes to high glucose. Inhibition of autophagy with 3-methyladenine or Beclin-1 siRNAs or Atg 5 siRNAs sensitized cells to apoptosis, suggesting autophagy is a survival mechanism. HO-1 inactivation inhibited autophagy, which aggravated podocyte injury in vitro. Hemin-induced autophagy also protected podocytes from hyperglycemia in vitro and was abrogated by HO-1 siRNA. Adenosine monophosphate-activated protein kinase phosphorylation was higher in hemin-treated and lower in HO-1 siRNA-treated podocytes. Suppression of AMPK activity reversed HO-1-mediated Beclin-1 upregulation and autophagy, indicating HO-1-mediated autophagy is AMPK dependent. These findings suggest HO-1 induction and regulation of autophagy are potential therapeutic targets for diabetic nephropathy. - Highlights: • High glucose leads to increased autophagy in podocytes at an early stage. • The early autophagic response protects against high glucose-induced apoptosis. • Heme oxygenase-1 enhances autophagy and decreases high glucose -mediated apoptosis. • Heme oxygenase-1 induces autophagy through the activation of AMPK

  20. Podocytes degrade endocytosed albumin primarily in lysosomes.

    Science.gov (United States)

    Carson, John M; Okamura, Kayo; Wakashin, Hidefumi; McFann, Kim; Dobrinskikh, Evgenia; Kopp, Jeffrey B; Blaine, Judith

    2014-01-01

    Albuminuria is a strong, independent predictor of chronic kidney disease progression. We hypothesize that podocyte processing of albumin via the lysosome may be an important determinant of podocyte injury and loss. A human urine derived podocyte-like epithelial cell (HUPEC) line was used for in vitro experiments. Albumin uptake was quantified by Western blot after loading HUPECs with fluorescein-labeled (FITC) albumin. Co-localization of albumin with lysosomes was determined by confocal microscopy. Albumin degradation was measured by quantifying FITC-albumin abundance in HUPEC lysates by Western blot. Degradation experiments were repeated using HUPECs treated with chloroquine, a lysosome inhibitor, or MG-132, a proteasome inhibitor. Lysosome activity was measured by fluorescence recovery after photo bleaching (FRAP). Cytokine production was measured by ELISA. Cell death was determined by trypan blue staining. In vivo, staining with lysosome-associated membrane protein-1 (LAMP-1) was performed on tissue from a Denys-Drash trangenic mouse model of nephrotic syndrome. HUPECs endocytosed albumin, which co-localized with lysosomes. Choloroquine, but not MG-132, inhibited albumin degradation, indicating that degradation occurs in lysosomes. Cathepsin B activity, measured by FRAP, significantly decreased in HUPECs exposed to albumin (12.5% of activity in controls) and chloroquine (12.8%), and declined further with exposure to albumin plus chloroquine (8.2%, p<0.05). Cytokine production and cell death were significantly increased in HUPECs exposed to albumin and chloroquine alone, and these effects were potentiated by exposure to albumin plus chloroquine. Compared to wild-type mice, glomerular staining of LAMP-1 was significantly increased in Denys-Drash mice and appeared to be most prominent in podocytes. These data suggest lysosomes are involved in the processing of endocytosed albumin in podocytes, and lysosomal dysfunction may contribute to podocyte injury and

  1. Loss of the Podocyte-Expressed Transcription Factor Tcf21/Pod1 Results in Podocyte Differentiation Defects and FSGS

    OpenAIRE

    Maezawa, Yoshiro; Onay, Tuncer; Scott, Rizaldy P.; Keir, Lindsay S.; Dimke, Henrik; Li, Chengjin; Eremina, Vera; Maezawa, Yuko; Jeansson, Marie; Shan, Jingdong; Binnie, Matthew; Lewin, Moshe; Ghosh, Asish; Miner, Jeffrey H.; Vainio, Seppo J.

    2014-01-01

    Podocytes are terminally differentiated cells with an elaborate cytoskeleton and are critical components of the glomerular barrier. We identified a bHLH transcription factor, Tcf21, that is highly expressed in developing and mature podocytes. Because conventional Tcf21 knockout mice die in the perinatal period with major cardiopulmonary defects, we generated a conditional Tcf21 knockout mouse to explore the role of this transcription factor in podocytes in vivo. Tcf21 was deleted from podocyt...

  2. Cell Biology and Pathology of Podocytes

    Science.gov (United States)

    Greka, Anna; Mundel, Peter

    2013-01-01

    As an integral member of the filtration barrier in the kidney glomerulus, the podocyte is in a unique geographical position: It is exposed to chemical signals from the urinary space (Bowman’s capsule), it receives and transmits chemical and mechanical signals to/from the glomerular basement membrane upon which it elaborates, and it receives chemical and mechanical signals from the vascular space with which it also communicates. As with every cell, the ability of the podocyte to receive signals from the surrounding environment and to translate them to the intracellular milieu is dependent largely on molecules residing on the cell membrane. These molecules are the first-line soldiers in the ongoing battle to sense the environment, to respond to friendly signals, and to defend against injurious foes. In this review, we take a membrane biologist’s view of the podocyte, examining the many membrane receptors, channels, and other signaling molecules that have been implicated in podocyte biology. Although we attempt to be comprehensive, our goal is not to capture every membrane-mediated pathway but rather to emphasize that this approach may be fruitful in understanding the podocyte and its unique properties. PMID:22054238

  3. Development and Characterization of Solid Self-emulsifying Drug Delivery System of Cilnidipine.

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    Bakhle, Suparna Sacchit; Avari, Jasmine Gev

    2015-01-01

    The present investigations highlight the development of solid self-emulsifying drug delivery system (solid-SEDDS) for improved oral delivery of the poorly water-soluble drug; cilnidipine. Liquid SEDDS of the drug were formulated using Capryol 90 as the oil phase, Tween 80 as the surfactant, and Transcutol HP as the co-surfactant after screening various vehicles. The prepared systems were characterized for self-emulsification time, robustness to dilution, % transmittance, globule size, drug release, and thermodynamic stability. Ternary phase diagrams were plotted to identify the area of microemulsification. The optimized liquid SEDDS was transformed into a free-flowing powder using Neusilin US2 as the adsorbent. Solid self-emulsifying powder retained the self-emulsifying property of the liquid SEDDS. Differential scanning calorimetric, X-ray powder diffraction studies revealed the possibility of transformation of the crystalline form of the drug to the amorphous form in the SEDDS prepared with the carrier. The morphology of solid-SEDDS from scanning electron microscopy studies demonstrated the presence of spherical, granular particles indicating good flowing ability. Dissolution studies revealed enhanced dissolution of the drug from the solid system compared with the pure drug and its marketed formulation. Similarly, the in vitro absorption profile of the drug from the formulated SEDDS was significantly higher compared with pure drug. Thus it can be concluded that solid-SEDDS, amenable for development of solid dosage form, can be successfully developed using Neusilin US2 with the potential of enhancing the solubility, dissolution rate, and bioavailability of the drug. PMID:26027464

  4. The Expression Profile of Complement Components in Podocytes.

    Science.gov (United States)

    Li, Xuejuan; Ding, Fangrui; Zhang, Xiaoyan; Li, Baihong; Ding, Jie

    2016-01-01

    Podocytes are critical for maintaining the glomerular filtration barrier and are injured in many renal diseases, especially proteinuric kidney diseases. Recently, reports suggested that podocytes are among the renal cells that synthesize complement components that mediate glomerular diseases. Nevertheless, the profile and extent of complement component expression in podocytes remain unclear. This study examined the expression profile of complement in podocytes under physiological conditions and in abnormal podocytes induced by multiple stimuli. In total, 23/32 complement component components were detected in podocyte by conventional RT-PCR. Both primary cultured podocytes and immortalized podocytes expressed the complement factors C1q, C1r, C2, C3, C7, MASP, CFI, DAF, CD59, C4bp, CD46, Protein S, CR2, C1qR, C3aR, C5aR, and Crry (17/32), whereas C4, CFB, CFD, C5, C6, C8, C9, MBL1, and MBL2 (9/32) complement factors were not expressed. C3, Crry, and C1q-binding protein were detected by tandem mass spectrometry. Podocyte complement gene expression was affected by several factors (puromycin aminonucleoside (PAN), angiotensin II (Ang II), interleukin-6 (IL-6), and transforming growth factor-β (TGF-β)). Representative complement components were detected using fluorescence confocal microscopy. In conclusion, primary podocytes express various complement components at the mRNA and protein levels. The complement gene expressions were affected by several podocyte injury factors. PMID:27043537

  5. The Expression Profile of Complement Components in Podocytes

    Directory of Open Access Journals (Sweden)

    Xuejuan Li

    2016-03-01

    Full Text Available Podocytes are critical for maintaining the glomerular filtration barrier and are injured in many renal diseases, especially proteinuric kidney diseases. Recently, reports suggested that podocytes are among the renal cells that synthesize complement components that mediate glomerular diseases. Nevertheless, the profile and extent of complement component expression in podocytes remain unclear. This study examined the expression profile of complement in podocytes under physiological conditions and in abnormal podocytes induced by multiple stimuli. In total, 23/32 complement component components were detected in podocyte by conventional RT-PCR. Both primary cultured podocytes and immortalized podocytes expressed the complement factors C1q, C1r, C2, C3, C7, MASP, CFI, DAF, CD59, C4bp, CD46, Protein S, CR2, C1qR, C3aR, C5aR, and Crry (17/32, whereas C4, CFB, CFD, C5, C6, C8, C9, MBL1, and MBL2 (9/32 complement factors were not expressed. C3, Crry, and C1q-binding protein were detected by tandem mass spectrometry. Podocyte complement gene expression was affected by several factors (puromycin aminonucleoside (PAN, angiotensin II (Ang II, interleukin-6 (IL-6, and transforming growth factor-β (TGF-β. Representative complement components were detected using fluorescence confocal microscopy. In conclusion, primary podocytes express various complement components at the mRNA and protein levels. The complement gene expressions were affected by several podocyte injury factors.

  6. Podocyte-Specific Deletion of Murine CXADR Does Not Impair Podocyte Development, Function or Stress Response.

    Science.gov (United States)

    Schell, Christoph; Kretz, Oliver; Bregenzer, Andreas; Rogg, Manuel; Helmstädter, Martin; Lisewski, Ulrike; Gotthardt, Michael; Tharaux, Pierre-Louis; Huber, Tobias B; Grahammer, Florian

    2015-01-01

    The coxsackie- and adenovirus receptor (CXADR) is a member of the immunoglobulin protein superfamily, present in various epithelial cells including glomerular epithelial cells. Beside its known function as a virus receptor, it also constitutes an integral part of cell-junctions. Previous studies in the zebrafish pronephros postulated a potential role of CXADR for the terminal differentiation of glomerular podocytes and correct patterning of the elaborated foot process architecture. However, due to early embryonic lethality of constitutive Cxadr knockout mice, mammalian data on kidney epithelial cells have been lacking. Interestingly, Cxadr is robustly expressed during podocyte development and in adulthood in response to glomerular injury. We therefore used a conditional transgenic approach to elucidate the function of Cxadr for podocyte development and stress response. Surprisingly, we could not discern a developmental phenotype in podocyte specific Cxadr knock-out mice. In addition, despite a significant up regulation of CXADR during toxic, genetic and immunologic podocyte injury, we could not detect any impact of Cxadr on these injury models. Thus these data indicate that in contrast to lower vertebrate models, mammalian podocytes have acquired molecular programs to compensate for the loss of Cxadr. PMID:26076477

  7. Podocyte-Specific Deletion of Murine CXADR Does Not Impair Podocyte Development, Function or Stress Response.

    Directory of Open Access Journals (Sweden)

    Christoph Schell

    Full Text Available The coxsackie- and adenovirus receptor (CXADR is a member of the immunoglobulin protein superfamily, present in various epithelial cells including glomerular epithelial cells. Beside its known function as a virus receptor, it also constitutes an integral part of cell-junctions. Previous studies in the zebrafish pronephros postulated a potential role of CXADR for the terminal differentiation of glomerular podocytes and correct patterning of the elaborated foot process architecture. However, due to early embryonic lethality of constitutive Cxadr knockout mice, mammalian data on kidney epithelial cells have been lacking. Interestingly, Cxadr is robustly expressed during podocyte development and in adulthood in response to glomerular injury. We therefore used a conditional transgenic approach to elucidate the function of Cxadr for podocyte development and stress response. Surprisingly, we could not discern a developmental phenotype in podocyte specific Cxadr knock-out mice. In addition, despite a significant up regulation of CXADR during toxic, genetic and immunologic podocyte injury, we could not detect any impact of Cxadr on these injury models. Thus these data indicate that in contrast to lower vertebrate models, mammalian podocytes have acquired molecular programs to compensate for the loss of Cxadr.

  8. Curcumin attenuates high glucose-induced podocyte apoptosis by regulating functional connections between caveolin-1 phosphorylation and ROS

    Science.gov (United States)

    Sun, Li-na; Liu, Xiang-chun; Chen, Xiang-jun; Guan, Guang-ju; Liu, Gang

    2016-01-01

    Aim: Caveolin-1 (cav-1) is a major multifunctional scaffolding protein of caveolae. Cav-1 is primarily expressed in mesangial cells, renal proximal tubule cells and podocytes in kidneys. Recent evidence shows that the functional connections between cav-1 and ROS play a key role in many diseases. In this study we investigated whether regulating the functional connections between cav-1 and ROS in kidneys contributed to the beneficial effects of curcumin in treating diabetic nephropathy in vitro and in vivo. Methods: Cultured mouse podocytes (mpc5) were incubated in a high glucose (HG, 30 mmol/L) medium for 24, 48 or 72 h. Male rats were injected with STZ (60 mg/kg, ip) to induce diabetes. ROS generation, SOD activity, MDA content and caspase-3 activity in the cultured cells and kidney cortex homogenate were determined. Apoptotic proteins and cav-1 phosphorylation were analyzed using Western blot analyses. Results: Incubation in HG-containing medium time-dependently increased ROS production, oxidative stress, apoptosis, and cav-1 phosphorylation in podocytes. Pretreatment with curcumin (1, 5, and 10 μmol/L) dose-dependently attenuated these abnormalities in HG-treated podocytes. Furthermore, in HG-containing medium, the podocytes transfected with a recombinant plasmid GFP-cav-1 Y14F (mutation at a cav-1 phosphorylation site) exhibited significantly decreased ROS production and apoptosis compared with the cells transfected with empty vector. In diabetic rats, administration of curcumin (100 or 200 mg/kg body weight per day, ig, for 8 weeks) not only significantly improved the renal function, but also suppressed ROS levels, oxidative stress, apoptosis and cav-1 phosphorylation in the kidneys. Conclusion: Curcumin attenuates high glucose-induced podocyte apoptosis in vitro and diabetic nephropathy in vivo partly through regulating the functional connections between cav-1 phosphorylation and ROS. PMID:26838071

  9. Morphine Induces Albuminuria by Compromising Podocyte Integrity

    OpenAIRE

    Lan, Xiqian; Rai, Partab; Chandel, Nirupama; Cheng, Kang; Lederman, Rivka; Saleem, Moin A; Mathieson, Peter W.; Husain, Mohammad; Crosson, John T.; Gupta, Kalpna; Malhotra, Ashwani; Singhal, Pravin C.

    2013-01-01

    Morphine has been reported to accelerate the progression of chronic kidney disease. However, whether morphine affects slit diaphragm (SD), the major constituent of glomerular filtration barrier, is still unclear. In the present study, we examined the effect of morphine on glomerular filtration barrier in general and podocyte integrity in particular. Mice were administered either normal saline or morphine for 72 h, then urine samples were collected and kidneys were subsequently isolated for im...

  10. Erythropoietin ameliorates podocyte injury in advanced diabetic nephropathy in the db/db mouse.

    Science.gov (United States)

    Loeffler, Ivonne; Rüster, Christiane; Franke, Sybille; Liebisch, Marita; Wolf, Gunter

    2013-09-15

    Podocyte damage and accumulation of advanced glycation end products (AGEs) are characteristics of diabetic nephropathy (DN). The pathophysiology of AGE-challenged podocytes, such as hypertrophy, apoptosis, and reduced cell migration, is closely related to the induction of the cell cycle inhibitor p27(Kip1) and to the inhibition of neuropilin 1 (NRP1). We have previously demonstrated that treatment with erythropoietin is associated with protective effects for podocytes in vitro. db/db mice with overt DN aged 15-16 wk were treated with either placebo, epoetin-β, or continuous erythropoietin receptor activator (CERA) for 2 wk. db/db mice compared with nondiabetic db/m control mice revealed the expected increases in body weight, blood glucose, albumin-to-creatinine ratio, and AGE accumulation. Whereas there were no differences in body weight, hyperglycemia and AGEs were observed among diabetic mice that received epoetin-β compared with CERA and placebo treatment, indicating that epoetin-β/CERA treatment does not interfere with the development of diabetes in this model. However, the albumin-to-creatinine ratio was significantly lower in db/db mice treated with epoetin-β or CERA. Furthermore, kidney weights in db/db mice were increased compared with db/m control mice, indicating renal hypertrophy, whereas the increase in renal weight in epoetin-β- or CERA-treated db/db mice was significantly lower than in placebo-treated control mice. Induction of p27(Kip1) and suppression of NRP1 were significantly reduced in the epoetin-β treatment group versus the CERA treatment group. Furthermore, erythropoietin treatment diminished the diabetes-induced podocyte loss. Together, independently from hematopoetic effects, epoetin-β or CERA treatment was associated with protective changes in DN, especially that NRP1 and p27(Kip1) expressions as well as numbers of podocytes returned to normal levels. Our data show, for the first time, that medication of overt DN with erythropoietin

  11. Renal Podocyte Injury in a Rat Model of Type 2 Diabetes Is Prevented by Metformin

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    Junghyun Kim

    2012-01-01

    Full Text Available Hyperglycemia promotes oxidative stress and hence generation of reactive oxygen species (ROS, which is known to play a crucial role in the pathogenesis of diabetic nephropathy. Metformin, an oral hypoglycemic drug, possesses antioxidant effects. The aim of this paper is to investigate the protective effects of metformin on the injury of renal podocytes in spontaneously diabetic Torii (SDT rats, a new model for nonobese type 2 diabetes. Metformin (350 mg/kg/day was given to SDT rats for 17 weeks. Blood glucose, glycated haemoglobin (HbA1c, and albuminuria were examined. Kidney histopathology, renal 8-hydroxydeoxyguanosine (8-OHdG levels and apoptosis were examined. In 43-week-old SDT rats, severe hyperglycemia was developed, and albuminuria was markedly increased. Diabetes induced significant alterations in renal glomerular structure. In addition, urinary and renal 8-OHdG levels were highly increased, and podocyte loss was shown through application of the TUNEL and synaptopodin staining. However, treatment of SDT rats with metformin restored all these renal changes. Our data suggested that diabetes-induced podocyte loss in diabetic nephropathy could be suppressed by the antidiabetes drug, metformin, through the repression of oxidative injury.

  12. Loss of the Podocyte-Expressed Transcription Factor Tcf21/Pod1 Results in Podocyte Differentiation Defects and FSGS

    DEFF Research Database (Denmark)

    Maezawa, Yoshiro; Onay, Tuncer; Scott, Rizaldy P;

    2014-01-01

    Podocytes are terminally differentiated cells with an elaborate cytoskeleton and are critical components of the glomerular barrier. We identified a bHLH transcription factor, Tcf21, that is highly expressed in developing and mature podocytes. Because conventional Tcf21 knockout mice die in the pe...

  13. Adriamycin increases podocyte permeability: evidence and molecular mechanism

    Institute of Scientific and Technical Information of China (English)

    李晓忠; 袁海涛; 张学光

    2003-01-01

    Objective To investigate the increased podocyte permeability by evidence of adriamycin (AD) and its molecular mechanism.Methods In this study, we explored the direct effects of AD on cultured mouse podocytes and the potential protection effects of Dexamethasome (Dex).Results After 24-hour AD (5×10-7 mol/L) treatment, albumin passage through podocyte monolayers was increased by 2.27-fold (P<0.01). AD caused a 62% decrease in Zonula Occluden -1 (ZO-1) protein (P<0.05), suggesting that AD might increase podocyte permeability by disrupting tight junctions. Dex (1×10-6 mol/L), co-administered with AD, protected podocytes from AD-induced increased albumin passage. This may be linked with an increased P-cadherin protein level to 1.93 fold of control (P<0.01).Conclusions AD has a direct, detrimental effect on podocyte permeability, probably through disrupting tight junctions; Dex could protect against AD-induced high podocyte permeability by upregulating adherent protein P-cadherin.

  14. Angiotensin II down-regulates nephrin–Akt signaling and induces podocyte injury: roleof c-Abl

    Science.gov (United States)

    Yang, Qian; Ma, Yiqiong; Liu, Yipeng; Liang, Wei; Chen, Xinghua; Ren, Zhilong; Wang, Huiming; Singhal, Pravin C.; Ding, Guohua

    2016-01-01

    Recent studies have shown that nephrin plays a vital role in angiotensin II (Ang II)–induced podocyte injury and thus contributes to the onset of proteinuria and the progression of renal diseases, but its specific mechanism remains unclear. c-Abl is an SH2/SH3 domain–containing nonreceptor tyrosine kinase that is involved in cell survival and regulation of the cytoskeleton. Phosphorylated nephrin is able to interact with molecules containing SH2/SH3 domains, suggesting that c-Abl may be a downstream molecule of nephrin signaling. Here we report that Ang II–infused rats developed proteinuria and podocyte damage accompanied by nephrin dephosphorylation and minimal interaction between nephrin and c-Abl. In vitro, Ang II induced podocyte injury and nephrin and Akt dephosphorylation, which occurred in tandem with minimal interaction between nephrin and c-Abl. Moreover, Ang II promoted c-Abl phosphorylation and interaction between c-Abl and SH2 domain–containing 5′-inositol phosphatase 2 (SHIP2). c-Abl small interfering RNA (siRNA) and STI571 (c-Abl inhibitor) provided protection against Ang II–induced podocyte injury, suppressed the Ang II-induced c-Abl–SHIP2 interaction and SHIP2 phosphorylation, and maintained a stable level of nephrin phosphorylation. These results indicate that c-Abl is a molecular chaperone of nephrin signaling and the SHIP2-Akt pathway and that the released c-Abl contributes to Ang II–induced podocyte injury. PMID:26510503

  15. The directed differentiation of human iPS cells into kidney podocytes.

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    Bi Song

    Full Text Available The loss of glomerular podocytes is a key event in the progression of chronic kidney disease resulting in proteinuria and declining function. Podocytes are slow cycling cells that are considered terminally differentiated. Here we provide the first report of the directed differentiation of induced pluripotent stem (iPS cells to generate kidney cells with podocyte features. The iPS-derived podocytes share a morphological phenotype analogous with cultured human podocytes. Following 10 days of directed differentiation, iPS podocytes had an up-regulated expression of mRNA and protein localization for podocyte markers including synaptopodin, nephrin and Wilm's tumour protein (WT1, combined with a down-regulation of the stem cell marker OCT3/4. In contrast to human podocytes that become quiescent in culture, iPS-derived cells maintain a proliferative capacity suggestive of a more immature phenotype. The transduction of iPS podocytes with fluorescent labeled-talin that were immunostained with podocin showed a cytoplasmic contractile response to angiotensin II (AII. A permeability assay provided functional evidence of albumin uptake in the cytoplasm of iPS podocytes comparable to human podocytes. Moreover, labeled iPS-derived podocytes were found to integrate into reaggregated metanephric kidney explants where they incorporated into developing glomeruli and co-expressed WT1. This study establishes the differentiation of iPS cells to kidney podocytes that will be useful for screening new treatments, understanding podocyte pathogenesis, and offering possibilities for regenerative medicine.

  16. Divergent functions of the Rho GTPases Rac1 and Cdc42 in podocyte injury

    DEFF Research Database (Denmark)

    Blattner, Simone M; Hodgin, Jeffrey B; Nishio, Masashi;

    2013-01-01

    the regulation of actin cytoskeleton dynamics. Here, we employed podocyte-specific Cre-lox technology and found that mice with deletion of Rac1 display normal podocyte morphology without glomerular dysfunction well into adulthood. Using the protamine sulfate model of acute podocyte injury, podocyte...... steady state. However, Rac1 has either beneficial or deleterious effects depending on the context of podocyte impairment. Thus, our study highlights the divergent roles of Rac1 and Cdc42 function in podocyte maintenance and injury.Kidney International advance online publication, 15 May 2013; doi:10...

  17. Cellular Effects of Everolimus and Sirolimus on Podocytes

    OpenAIRE

    Müller-Krebs, Sandra; Weber, Lena; Tsobaneli, Julia; Kihm, Lars P; Reiser, Jochen; Zeier, Martin; Schwenger, Vedat

    2013-01-01

    Everolimus (EVL) and Sirolimus (SRL) are potent immunosuppressant agents belonging to the group of mammalian target of rapamycin (mTOR) inhibitors used to prevent transplant rejection. However, some patients develop proteinuria following a switch from a calcineurin inhibitor regimen to mTOR inhibitors. Whether different mTOR inhibitors show similar effects on podocytes is still unknown. To analyze this, human podocytes were incubated with different doses of EVL and SRL. After incubation with ...

  18. Human podocytes perform polarized, caveolae-dependent albumin endocytosis

    OpenAIRE

    Dobrinskikh, Evgenia; Okamura, Kayo; Jeffrey B Kopp; Doctor, R. Brian; Blaine, Judith

    2014-01-01

    The renal glomerulus forms a selective filtration barrier that allows the passage of water, ions, and small solutes into the urinary space while restricting the passage of cells and macromolecules. The three layers of the glomerular filtration barrier include the vascular endothelium, glomerular basement membrane (GBM), and podocyte epithelium. Podocytes are capable of internalizing albumin and are hypothesized to clear proteins that traverse the GBM. The present study followed the fate of FI...

  19. DC-specific ICAM-3-grabbing nonintegrin mediates internalization of HIV-1 into human podocytes

    OpenAIRE

    J. Mikulak; TEICHBERG, S; Arora, S.; KUMAR, D; Yadav, A.; Salhan, D.; Pullagura, S.; Mathieson, P. W.; Saleem, M A; Singhal, P. C.

    2010-01-01

    Human immunodeficiency virus (HIV)-1 has been demonstrated to contribute to the pathogenesis of HIV-associated nephropathy. In renal biopsy studies, podocytes have been reported to be infected by HIV-1. However, the mechanism involved in HIV-1 internalization into podocytes is not clear. In the present study, we evaluated the occurrence of HIV-1 internalization into conditionally immortalized human podocytes and the mechanism involved. Human podocytes rapidly internalized R5 and X4 HIV-1 prim...

  20. Additive effects of cilnidipine, an L-/N-type calcium channel blocker, and an angiotensin II receptor blocker on reducing cardiorenal damage in Otsuka Long-Evans Tokushima Fatty rats with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Mori Y

    2014-06-01

    Full Text Available Yutaka Mori,1,2 Shizuka Aritomi,3 Kazumi Niinuma,3 Tarou Nakamura,3 Kenichi Matsuura,1 Junichi Yokoyama,1 Kazunori Utsunomiya1 1Division of Diabetes and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Minato-ku, Japan; 2Department of Clinical Research, National Hospital Organization, Utsunomiya National Hospital, Utsunomiya, Japan; 3Research Center, Ajinomoto Pharmaceuticals Co, Ltd, Kanagawa, Japan Abstract: Cilnidipine (Cil, which is an L-/N-type calcium channel blocker (CCB, has been known to provide renal protection by decreasing the activity of the sympathetic nervous system (SNS and the renin–angiotensin system. In this study, we compared the effects of the combination of Cil and amlodipine (Aml, which is an L-type CCB, with an angiotensin (Ang II receptor blocker on diabetic cardiorenal damage in spontaneously type 2 diabetic rats. Seventeen-week-old Otsuka Long-Evans Tokushima Fatty rats were randomly assigned to receive Cil, Aml, valsartan (Val, Cil + Val, Aml + Val, or a vehicle (eight rats per group for 22 weeks. Antihypertensive potencies were nearly equal among the CCB monotherapy groups and the combination therapy groups. The lowering of blood pressure by either treatment did not significantly affect the glycemic variables. However, exacerbations of renal and heart failure were significantly suppressed in rats administered Cil or Val, and additional suppression was observed in those administered Cil + Val. Although Val increased the renin–Ang system, Aml + Val treatment resulted in additional increases in these parameters, while Cil + Val did not show such effects. Furthermore, Cil increased the ratio of Ang-(1–7 to Ang-I, despite the fact that Val and Aml + Val decreased the Ang-(1–7 levels. These actions of Cil + Val might be due to their synergistic inhibitory effect on the activity of the SNS, and on aldosterone secretion through N-type calcium channel antagonism and Ang II

  1. HIV-1 expression induces cyclin D1 expression and pRb phosphorylation in infected podocytes: cell-cycle mechanisms contributing to the proliferative phenotype in HIV-associated nephropathy

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    Husain Mohammad

    2002-09-01

    Full Text Available Abstract Background The aberrant cell-cycle progression of HIV-1-infected kidney cells plays a major role in the pathogenesis of HIV-associated nephropathy, however the mechanisms whereby HIV-1 induces infected glomerular podocytes or infected tubular epithelium to exit quiescence are largely unknown. Here, we ask whether the expression of HIV-1 genes in infected podocytes induces cyclin D1 and phospho-pRb (Ser780 expression, hallmarks of cyclin D1-mediated G1 → S phase progression. Results We assessed cyclin D1 and phospho-pRb (Ser780 expression in two well-characterized models of HIV-associated nephropathy pathogenesis: HIV-1 infection of cultured podocytes and HIV-1 transgenic mice (Tg26. Compared to controls, cultured podocytes expressing HIV-1 genes, and podocytes and tubular epithelium from hyperplastic nephrons in Tg26 kidneys, had increased levels of phospho-pRb (Ser780, a target of active cyclin D1/cyclin-dependent kinase-4/6 known to promote G1 → S phase progression. HIV-1-infected podocytes showed markedly elevated cyclin D1 mRNA and cyclin D1 protein, the latter of which did not down-regulate during cell-cell contact or differentiation, suggesting post-transcriptional stabilization of cyclin D1 protein levels by HIV-1. The selective suppression of HIV-1 transcription by the cyclin-dependent kinase inhibitor, flavopiridol, abrogated cyclin D1 expression, underlying the requirement for HIV-1 encoded products to induce cyclin D1. Indeed, HIV-1 virus deleted of nef failed to induce cyclin D1 mRNA to the level of other single gene mutant viruses. Conclusions HIV-1 expression induces cyclin D1 and phospho-pRb (Ser780 expression in infected podocytes, suggesting that HIV-1 activates cyclin D1-dependent cell-cycle mechanisms to promote proliferation of infected renal epithelium.

  2. One Year of Enzyme Replacement Therapy Reduces Globotriaosylceramide Inclusions in Podocytes in Male Adult Patients with Fabry Disease

    OpenAIRE

    Najafian, Behzad; Tøndel, Camilla; Svarstad, Einar; Sokolovkiy, Alexey; Smith, Kelly; Mauer, Michael

    2016-01-01

    Fabry nephropathy is associated with progressive accumulation of globotriaosylceramide (GL3) in podocytes. Reducing this GL3 burden may reduce podocyte injury. Sensitive methods to quantify podocyte GL3 content may determine whether a given strategy can benefit podocytes in Fabry disease. We developed an unbiased electron microscopic stereological method to estimate the average volume of podocytes and their GL3 inclusions in 6 paired pre- and post-enzyme replacement therapy (ERT) biopsies fro...

  3. Ginseng total saponin modulates the changes of α-actinin-4 in podocytes induced by diabetic conditions

    OpenAIRE

    Ha, Tae-Sun; Choi, Ji-Young; Park, Hye-Young; Nam, Ja-Ae; Seong, Su-Bin

    2014-01-01

    Background The actin cytoskeleton in podocytes is essential for the maintenance of its normal structure and function. Its disruption is a feature of podocyte foot-process effacement and is associated with proteinuria. α-Actinin-4 in podocytes serves as a linker protein binding the actin filaments of the cytoskeleton. Methods To investigate the effect of ginseng total saponin (GTS) on the pathological changes of podocyte α-actinin-4 induced by diabetic conditions, we cultured mouse podocytes u...

  4. Podocyte-specific knockout of myosin 1e disrupts glomerular filtration.

    Science.gov (United States)

    Chase, Sharon E; Encina, Christina V; Stolzenburg, Lindsay R; Tatum, Arthur H; Holzman, Lawrence B; Krendel, Mira

    2012-10-01

    Myosin 1e (myo1e) is an actin-dependent molecular motor that plays an important role in kidney functions. Complete knockout of myo1e in mice and Myo1E mutations in humans are associated with nephrotic syndrome and focal segmental glomerulosclerosis. In this paper, we tested the hypothesis that myo1e is necessary for normal functions of glomerular visceral epithelial cells (podocytes) using podocyte-targeted knockout of myo1e. Myo1e was selectively knocked out in podocytes using Cre-mediated recombination controlled by the podocin promoter. Myo1e loss from podocytes resulted in proteinuria, podocyte foot process effacement, and glomerular basement membrane disorganization. Our findings indicate that myo1e expression in podocytes is necessary for normal glomerular filtration and that podocyte defects are likely to represent the primary pathway leading to glomerular disease associated with Myo1E mutations. PMID:22811491

  5. Downregulation of MicroRNA-30 Facilitates Podocyte Injury and Is Prevented by Glucocorticoids

    Science.gov (United States)

    Wu, Junnan; Zheng, Chunxia; Fan, Yun; Zeng, Caihong; Chen, Zhaohong; Qin, Weisong; Zhang, Changming; Zhang, Wanfen; Wang, Xiao; Zhu, Xiaodong; Zhang, Mingchao; Zen, Ke

    2014-01-01

    MicroRNAs (miRNAs) are essential for podocyte homeostasis, and the miR-30 family may be responsible for this action. However, the exact roles and clinical relevance of miR-30s remain unknown. In this study, we examined the expression of the miR-30 family in the podocytes of patients with FSGS and found that all members are downregulated. Treating cultured human podocytes with TGF-β, LPS, or puromycin aminonucleoside (PAN) also downregulated the miR-30 family. Podocyte cytoskeletal damage and apoptosis caused by treatment with TGF-β or PAN were ameliorated by exogenous miR-30 expression and aggravated by miR-30 knockdown. Moreover, we found that miR-30s exert their protective roles by direct inhibition of Notch1 and p53, which mediate podocyte injury. In rats, treatment with PAN substantially downregulated podocyte miR-30s and induced proteinuria and podocyte injury; however, transfer of exogenous miR-30a to podocytes of PAN-treated rats ameliorated proteinuria and podocyte injury and reduced Notch1 activation. Finally, we demonstrated that glucocorticoid treatment maintains miR-30 expression in cultured podocytes treated with TGF-β, LPS, or PAN and in the podocytes of PAN-treated rats. Glucocorticoid-sustained miR-30 expression associated with reduced Notch1 activation and alleviated podocyte damage. Taken together, these findings demonstrate that miR-30s protect podocytes by targeting Notch1 and p53 and that the loss of miR-30s facilitates podocyte injury. In addition, sustained miR-30 expression may be a novel mechanism underlying the therapeutic effectiveness of glucocorticoids in treating podocytopathy. PMID:24029422

  6. Mammalian Target of Rapamycin Regulates Nox4-Mediated Podocyte Depletion in Diabetic Renal Injury

    OpenAIRE

    Eid, Assaad A.; Ford, Bridget M.; Bhandary, Basant; de Cassia Cavaglieri, Rita; Block, Karen; Barnes, Jeffrey L.; Gorin, Yves; Choudhury, Goutam Ghosh; Abboud, Hanna E.

    2013-01-01

    Podocyte apoptosis is a critical mechanism for excessive loss of urinary albumin that eventuates in kidney fibrosis. Pharmacological doses of the mammalian target of rapamycin (mTOR) inhibitor rapamycin reduce albuminuria in diabetes. We explored the hypothesis that mTOR mediates podocyte injury in diabetes. High glucose (HG) induces apoptosis of podocytes, inhibits AMP-activated protein kinase (AMPK) activation, inactivates tuberin, and activates mTOR. HG also increases the levels of Nox4 an...

  7. Ginseng Total Saponin Improves Podocyte Hyperpermeability Induced by High Glucose and Advanced Glycosylation Endproducts

    OpenAIRE

    Ha, Tae-Sun; Choi, Ji-Young; Park, Hye-Young; Lee, Jin-Seok

    2011-01-01

    Early diabetic nephropathy is characterized by glomerular hyperpermeability as a result of impaired glomerular filtration structure caused by hyperglycemia, glycated proteins or irreversible advanced glycosylation endproducts (AGE). To investigate the effect of ginseng total saponin (GTS) on the pathologic changes of podocyte ZO (zonula occludens)-1 protein and podocyte permeability induced by diabetic conditions, we cultured mouse podocytes under: 1) normal glucose (5 mM, = control); 2) high...

  8. Novel Functional Changes during Podocyte Differentiation: Increase of Oxidative Resistance and H-Ferritin Expression

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    Emese Bányai

    2014-01-01

    Full Text Available Podocytes are highly specialized, arborized epithelial cells covering the outer surface of the glomerular tuft in the kidney. Terminally differentiated podocytes are unable to go through cell division and hereby they are lacking a key property for regeneration after a toxic injury. Podocytes are long-lived cells but, to date, little is known about the mechanisms that support their stress resistance. Our aim was to investigate whether the well-known morphological changes during podocyte differentiation are accompanied by changes in oxidative resistance in a manner that could support their long-term survival. We used a conditionally immortalized human podocyte cell line to study the morphological and functional changes during differentiation. We followed the differentiation process for 14 days by time-lapse microscopy. During this period nondifferentiated podocytes gradually transformed into large, nonproliferating, frequently multinucleated cells, with enlarged nuclei and opened chromatin structure. We observed that differentiated podocytes were highly resistant to oxidants such as H2O2 and heme when applied separately or in combination, whereas undifferentiated cells were prone to such challenges. Elevated oxidative resistance of differentiated podocytes was associated with increased activities of antioxidant enzymes and H-ferritin expression. Immunohistochemical analysis of normal human kidney specimens revealed that podocytes highly express H-ferritin in vivo as well.

  9. Proteomic analysis of a podocyte vesicle-enriched fraction from human normal and pathological urine samples.

    Science.gov (United States)

    Lescuyer, Pierre; Pernin, Agnès; Hainard, Alexandre; Bigeire, Caty; Burgess, Jennifer A; Zimmermann-Ivol, Catherine; Sanchez, Jean-Charles; Schifferli, Jürg A; Hochstrasser, Denis F; Moll, Solange

    2008-07-01

    Podocytes (glomerular visceral epithelial cells) release vesicles into urine. Podocyte vesicle-enriched fractions from normal and pathological human urine samples were prepared for proteomic analysis. An immunoadsorption method was applied and enrichment of podocyte vesicles was assessed. We identified 76 unique proteins. One protein, serum paraoxonase/arylesterase 1 (PON-1), was newly identified in normal human urine sample. We confirmed this result and showed PON-1 expression in normal human kidney. These results demonstrated the potential for using the urine samples enriched in podocyte vesicles as a starting material in studies aimed at discovery of biomarkers for diseases. PMID:21136901

  10. Podocyte Purinergic P2X4 Channels Are Mechanotransducers That Mediate Cytoskeletal Disorganization.

    Science.gov (United States)

    Forst, Anna-Lena; Olteanu, Vlad Sorin; Mollet, Géraldine; Wlodkowski, Tanja; Schaefer, Franz; Dietrich, Alexander; Reiser, Jochen; Gudermann, Thomas; Mederos Y Schnitzler, Michael; Storch, Ursula

    2016-03-01

    Podocytes are specialized, highly differentiated epithelial cells in the kidney glomerulus that are exposed to glomerular capillary pressure and possible increases in mechanical load. The proteins sensing mechanical forces in podocytes are unconfirmed, but the classic transient receptor potential channel 6 (TRPC6) interacting with the MEC-2 homolog podocin may form a mechanosensitive ion channel complex in podocytes. Here, we observed that podocytes respond to mechanical stimulation with increased intracellular calcium concentrations and increased inward cation currents. However, TRPC6-deficient podocytes responded in a manner similar to that of control podocytes, and mechanically induced currents were unaffected by genetic inactivation of TRPC1/3/6 or administration of the broad-range TRPC blocker SKF-96365. Instead, mechanically induced currents were significantly decreased by the specific P2X purinoceptor 4 (P2X4) blocker 5-BDBD. Moreover, mechanical P2X4 channel activation depended on cholesterol and podocin and was inhibited by stabilization of the actin cytoskeleton. Because P2X4 channels are not intrinsically mechanosensitive, we investigated whether podocytes release ATP upon mechanical stimulation using a fluorometric approach. Indeed, mechanically induced ATP release from podocytes was observed. Furthermore, 5-BDBD attenuated mechanically induced reorganization of the actin cytoskeleton. Altogether, our findings reveal a TRPC channel-independent role of P2X4 channels as mechanotransducers in podocytes. PMID:26160898

  11. Melanocortin 1 receptor agonist protects podocytes through catalase and RhoA activation.

    Science.gov (United States)

    Elvin, Johannes; Buvall, Lisa; Lindskog Jonsson, Annika; Granqvist, Anna; Lassén, Emelie; Bergwall, Lovisa; Nyström, Jenny; Haraldsson, Börje

    2016-05-01

    Drugs containing adrenocorticotropic hormone have been used as therapy for patients with nephrotic syndrome. We have previously shown that adrenocorticotropic hormone and a selective agonist for the melanocortin 1 receptor (MC1R) exert beneficial actions in experimental membranous nephropathy with reduced proteinuria, reduced oxidative stress, and improved glomerular morphology and function. Our hypothesis is that MC1R activation in podocytes elicits beneficial effects by promoting stress fibers and maintaining podocyte viability. To test the hypothesis, we cultured podocytes and used highly specific agonists for MC1R. Podocytes were subjected to the nephrotic-inducing agent puromycin aminonucleoside, and downstream effects of MC1R activation on podocyte survival, antioxidant defense, and cytoskeleton dynamics were studied. To increase the response and enhance intracellular signals, podocytes were transduced to overexpress MC1R. We showed that puromycin promotes MC1R expression in podocytes and that activation of MC1R promotes an increase of catalase activity and reduces oxidative stress, which results in the dephosphorylation of p190RhoGAP and formation of stress fibers through RhoA. In addition, MC1R agonists protect against apoptosis. Together, these mechanisms protect the podocyte against puromycin. Our findings strongly support the hypothesis that selective MC1R-activating agonists protect podocytes and may therefore be useful to treat patients with nephrotic syndromes commonly considered as podocytopathies. PMID:26887829

  12. A Case of Podocytic Infolding Glomerulopathy with Focal Segmental Glomerulosclerosis

    Science.gov (United States)

    Iguchi, Akira; Sohma, Ayako; Yamazaki, Hajime; Ito, Tomoyuki; Saeki, Takako; Ito, Yumi; Imai, Naohumi; Osawa, Yutaka; Narita, Ichiei

    2013-01-01

    Podocytic infolding glomerulopathy (PIG) has been proposed as a new disease entity. A 14-year-old girl underwent renal biopsy at our institution because of a chance finding of proteinuria. Light microscopic findings revealed a minor glomerular abnormality, but under a higher magnification, after periodic acid methenamine silver staining, a bubbling appearance in the glomerular basement membrane (GBM) was observed. An electron microscopic examination revealed microspheres in the GBM, which were sparse but global. The patient was diagnosed as having PIG. After 3 years, her urinary protein had increased and a second biopsy was performed, showing focal segmental glomerulosclerosis in addition to a lesser degree of podocytic infolding than at the first biopsy. This is the first report of a case complicated by a different type of glomerulonephritis after being diagnosed as PIG. A few cases of PIG are complicated by focal segmental glomerulosclerosis, suggesting several mechanisms for the disorder. PMID:24027576

  13. Podocyte pathology and nephropathy - sphingolipids in glomerular diseases.

    Science.gov (United States)

    Merscher, Sandra; Fornoni, Alessia

    2014-01-01

    Sphingolipids are components of the lipid rafts in plasma membranes, which are important for proper function of podocytes, a key element of the glomerular filtration barrier. Research revealed an essential role of sphingolipids and sphingolipid metabolites in glomerular disorders of genetic and non-genetic origin. The discovery that glucocerebrosides accumulate in Gaucher disease in glomerular cells and are associated with clinical proteinuria initiated intensive research into the function of other sphingolipids in glomerular disorders. The accumulation of sphingolipids in other genetic diseases including Tay-Sachs, Sandhoff, Fabry, hereditary inclusion body myopathy 2, Niemann-Pick, and nephrotic syndrome of the Finnish type and its implications with respect to glomerular pathology will be discussed. Similarly, sphingolipid accumulation occurs in glomerular diseases of non-genetic origin including diabetic kidney disease (DKD), HIV-associated nephropathy, focal segmental glomerulosclerosis (FSGS), and lupus nephritis. Sphingomyelin metabolites, such as ceramide, sphingosine, and sphingosine-1-phosphate have also gained tremendous interest. We recently described that sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is expressed in podocytes where it modulates acid sphingomyelinase activity and acts as a master modulator of danger signaling. Decreased SMPDL3b expression in post-reperfusion kidney biopsies from transplant recipients with idiopathic FSGS correlates with the recurrence of proteinuria in patients and in experimental models of xenotransplantation. Increased SMPDL3b expression is associated with DKD. The consequences of differential SMPDL3b expression in podocytes in these diseases with respect to their pathogenesis will be discussed. Finally, the role of sphingolipids in the formation of lipid rafts in podocytes and their contribution to the maintenance of a functional slit diaphragm in the glomerulus will be discussed. PMID:25126087

  14. Proteinuria in preeclampsia from a podocyte injury perspective.

    Science.gov (United States)

    Henao, Daniel E; Saleem, Moin A

    2013-12-01

    Preeclampsia is a frequent cause of maternal and fetal morbidity and mortality worldwide. The underlying causes of this hypertensive complication have remained elusive. The placenta seems to be at the origin of the disease, as its removal appears to be the only effective treatment available. Many organs can potentially be affected. Nonetheless, kidney alterations are always present: proteinuria is one of the hallmarks for a preeclampsia diagnosis. VEGF is pivotal for maintaining glomerular filtration barrier function; hence, the elevated concentrations of placental-derived VEGF inhibitors, such as sFlt-1, may largely explain the renal alterations observed. Classically, glomerular endothelial injury was considered responsible for the renal impairment present in preeclampsia. Recent findings, however, have shown that podocytes are crucial in explaining the loss of filtration capacity of the preeclamptic kidney. The aims of this manuscript are to detail the main findings that associate podocyte injury with proteinuria in preeclampsia, and discuss the eventual applications of podocyte damage biomarkers in clinical practice. PMID:24214687

  15. Influence of dexamethasone on the expression and distribution of transient receptor potential cation channel 6 in glomerular podocytes

    Institute of Scientific and Technical Information of China (English)

    王辉阳

    2014-01-01

    Objective To observe the changes of foot processes,expression and distribution of transient receptor potential cation channel 6(TRPC6)in podocytes by puromycin aminonucleoside(PAN)and dexamethasone(DEX)intervention,then to investigate the function of TRPC6 in podocytes and its relation to proteinuria in kidney diseases.Methods Podocytes cultured in vitro were divided into three group:control group,PAN stimulation group and DEX intervention group.Mouse podocyte cell line

  16. Inhibition of p53 deSUMOylation Exacerbates Puromycin Aminonucleoside-Induced Apoptosis in Podocytes

    Directory of Open Access Journals (Sweden)

    Lingyu Wang

    2014-11-01

    Full Text Available Apoptosis is a major cause of reduced podocyte numbers, which leads to proteinuria and/or glomerulosclerosis. Emerging evidence has indicated that deSUMOylation, a dynamic post-translational modification that reverses SUMOylation, is involved in the apoptosis of Burkitt’s lymphoma cells and cardiomyocytes; however, the impact of deSUMOylation on podocyte apoptosis remains unexplored. The p53 protein plays a major role in the pathogenesis of podocyte apoptosis, and p53 can be SUMOylated. Therefore, in the present study, we evaluated the effect of p53 deSUMOylation, which is regulated by sentrin/SUMO-specific protease 1 (SENP1, on podocyte apoptosis. Our results showed that SENP1 deficiency significantly increases puromycin aminonucleoside (PAN-induced podocyte apoptosis. Moreover, SENP1 knockdown results in the accumulation of SUMOylated p53 protein and the increased expression of the p53 target pro-apoptotic genes, BAX, Noxa and PUMA, in podocytes during PAN stimulation. Thus, SENP1 may be essential for preventing podocyte apoptosis, at least partly through regulating the functions of p53 protein via deSUMOylation. The regulation of deSUMOylation may provide a novel strategy for the treatment of glomerular disorders that involve podocyte apoptosis.

  17. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    International Nuclear Information System (INIS)

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca2+ was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca2+]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway, which may

  18. Podocyte-specific loss of cdc42 leads to congenital nephropathy

    DEFF Research Database (Denmark)

    Scott, Rizaldy P; Hawley, Steve P; Ruston, Julie; Du, Jianmei; Brakebusch, Cord; Jones, Nina; Pawson, Tony

    2012-01-01

    Rho family GTPases are molecular switches best known for their pivotal role in dynamic regulation of the actin cytoskeleton. The prototypic members of this family are Cdc42, Rac1, and RhoA; these GTPases contribute to the breakdown of glomerular filtration and the resultant proteinuria, but their...... functions in normal podocyte physiology remain poorly understood. Here, mice lacking Cdc42 in podocytes developed congenital nephropathy and died as a result of renal failure within 2 weeks after birth. In contrast, mice lacking Rac1 or RhoA in podocytes were overtly normal and lived to adulthood. Kidneys...... from Cdc42-mutant mice exhibited protein-filled microcysts with hallmarks of collapsing glomerulopathy, as well as extensive effacement of podocyte foot processes with abnormal junctional complexes. Furthermore, we observed aberrant expression of several podocyte markers and cell polarity proteins in...

  19. APOL1 risk variants enhance podocyte necrosis through compromising lysosomal membrane permeability.

    Science.gov (United States)

    Lan, Xiqian; Jhaveri, Aakash; Cheng, Kang; Wen, Hongxiu; Saleem, Moin A; Mathieson, Peter W; Mikulak, Joanna; Aviram, Sharon; Malhotra, Ashwani; Skorecki, Karl; Singhal, Pravin C

    2014-08-01

    Development of higher rates of nondiabetic glomerulosclerosis (GS) in African Americans has been attributed to two coding sequence variants (G1 and G2) in the APOL1 gene. To date, the cellular function and the role of APOL1 variants (Vs) in GS are still unknown. In this study, we examined the effects of overexpressing wild-type (G0) and kidney disease risk variants (G1 and G2) of APOL1 in human podocytes using a lentivirus expression system. Interestingly, G0 inflicted podocyte injury only at a higher concentration; however, G1 and G2 promoted moderate podocyte injury at lower and higher concentrations. APOL1Vs expressing podocytes displayed diffuse distribution of both Lucifer yellow dye and cathepsin L as manifestations of enhanced lysosomal membrane permeability (LMP). Chloroquine attenuated the APOL1Vs-induced increase in podocyte injury, consistent with targeting lysosomes. The chloride channel blocker DIDS prevented APOL1Vs- induced injury, indicating a role for chloride influx in osmotic swelling of lysosomes. Direct exposure of noninfected podocytes with conditioned media from G1- and G2-expressing podocytes also induced injury, suggesting a contributory role of the secreted component of G1 and G2 as well. Adverse host factors (AHFs) such as hydrogen peroxide, hypoxia, TNF-α, and puromycin aminonucleoside augmented APOL1- and APOL1Vs-induced podocyte injury, while the effect of human immunodeficiency virus (HIV) on podocyte injury was overwhelming under conditions of APOLVs expression. We conclude that G0 and G1 and G2 APOL1 variants have the potential to induce podocyte injury in a manner which is further augmented by AHFs, with HIV infection being especially prominent. PMID:24899058

  20. Defining the molecular character of the developing and adult kidney podocyte.

    Directory of Open Access Journals (Sweden)

    Eric W Brunskill

    Full Text Available BACKGROUND: The podocyte is a remarkable cell type, which encases the capillaries of the kidney glomerulus. Although mesodermal in origin it sends out axonal like projections that wrap around the capillaries. These extend yet finer projections, the foot processes, which interdigitate, leaving between them the slit diaphragms, through which the glomerular filtrate must pass. The podocytes are a subject of keen interest because of their key roles in kidney development and disease. METHODOLOGY/PRINCIPAL FINDINGS: In this report we identified and characterized a novel transgenic mouse line, MafB-GFP, which specifically marked the kidney podocytes from a very early stage of development. These mice were then used to facilitate the fluorescent activated cell sorting based purification of podocytes from embryos at E13.5 and E15.5, as well as adults. Microarrays were then used to globally define the gene expression states of podocytes at these different developmental stages. A remarkable picture emerged, identifying the multiple sets of genes that establish the neuronal, muscle, and phagocytic properties of podocytes. The complete combinatorial code of transcription factors that create the podocyte was characterized, and the global lists of growth factors and receptors they express were defined. CONCLUSIONS/SIGNIFICANCE: The complete molecular character of the in vivo podocyte is established for the first time. The active molecular functions and biological processes further define their unique combination of features. The results provide a resource atlas of gene expression patterns of developing and adult podocytes that will help to guide further research of these incredible cells.

  1. Palmitate induces ER calcium depletion and apoptosis in mouse podocytes subsequent to mitochondrial oxidative stress

    OpenAIRE

    Xu, S; Nam, S M; Kim, J-H; Das, R.; Choi, S-K; T.T. Nguyen; Quan, X.; Choi, S. J.; Chung, C H; Lee, E Y; Lee, I-K; Wiederkehr, A; Wollheim, C. B.; Cha, S-K; Park, K-S.

    2015-01-01

    Pathologic alterations in podocytes lead to failure of an essential component of the glomerular filtration barrier and proteinuria in chronic kidney diseases. Elevated levels of saturated free fatty acid (FFA) are harmful to various tissues, implemented in the progression of diabetes and its complications such as proteinuria in diabetic nephropathy. Here, we investigated the molecular mechanism of palmitate cytotoxicity in cultured mouse podocytes. Incubation with palmitate dose-dependently i...

  2. Podocyte expression of membrane transporters involved in puromycin aminonucleoside-mediated injury.

    Directory of Open Access Journals (Sweden)

    Cristina Zennaro

    Full Text Available Several complex mechanisms contribute to the maintenance of the intricate ramified morphology of glomerular podocytes and to interactions with neighboring cells and the underlying basement membrane. Recently, components of small molecule transporter families have been found in the podocyte membrane, but expression and function of membrane transporters in podocytes is largely unexplored. To investigate this complex field of investigation, we used two molecules which are known substrates of membrane transporters, namely Penicillin G and Puromycin Aminonucleoside (PA. We observed that Penicillin G pre-administration prevented both in vitro and in vivo podocyte damage caused by PA, suggesting the engagement of the same membrane transporters by the two molecules. Indeed, we found that podocytes express a series of transporters which are known to be used by Penicillin G, such as members of the Organic Anion Transporter Polypeptides (OATP/Oatp family of influx transporters, and P-glycoprotein, a member of the MultiDrug Resistance (MDR efflux transporter family. Expression of OATP/Oatp transporters was modified by PA treatment. Similarly, in vitro PA treatment increased mRNA and protein expression of P-glycoprotein, as well as its activity, confirming the engagement of the molecule upon PA administration. In summary, we have characterized some of the small molecule transporters present at the podocyte membrane, focusing on those used by PA to enter and exit the cell. Further investigation will be needed to understand precisely the role of these transporter families in maintaining podocyte homeostasis and in the pathogenesis of podocyte injury.

  3. Nephropathy and Elevated BP in Mice with Podocyte-Specific NADPH Oxidase 5 Expression

    OpenAIRE

    Holterman, Chet E.; Thibodeau, Jean-François; Towaij, Chelsea; Gutsol, Alex; Montezano, Augusto C.; Robin J. Parks; Cooper, Mark E.; Touyz, Rhian M; Kennedy, Christopher R. J.

    2013-01-01

    NADPH oxidase (Nox) enzymes are a significant source of reactive oxygen species, which contribute to glomerular podocyte dysfunction. Although studies have implicated Nox1, -2, and -4 in several glomerulopathies, including diabetic nephropathy, little is known regarding the role of Nox5 in this context. We examined Nox5 expression and regulation in kidney biopsies from diabetic patients, cultured human podocytes, and a novel mouse model. Nox5 expression increased in human diabetic glomeruli c...

  4. Non-canonical NFκB activation promotes chemokine expression in podocytes

    Science.gov (United States)

    Valiño-Rivas, Lara; Gonzalez-Lafuente, Laura; Sanz, Ana B.; Ruiz-Ortega, Marta; Ortiz, Alberto; Sanchez-Niño, Maria D.

    2016-01-01

    TNF-like weak inducer of apoptosis (TWEAK) receptor Fn14 is expressed by podocytes and Fn14 deficiency protects from experimental proteinuric kidney disease. However, the downstream effectors of TWEAK/Fn14 in podocytes are poorly characterized. We have explored TWEAK activation of non-canonical NFκB signaling in cultured podocytes. In cultured podocytes, TWEAK increased the expression of the chemokines CCL21, CCL19 and RANTES in a time-dependent manner. The inhibitor of canonical NFκB activation parthenolide inhibited the CCL19 and the early RANTES responses, but not the CCL21 or late RANTES responses. In this regard, TWEAK induced non-canonical NFκB activation in podocytes, characterized by NFκB2/p100 processing to NFκB2/p52 and nuclear migration of RelB/p52. Silencing by a specific siRNA of NIK, the upstream kinase of the non-canonical NFκB pathway, prevented CCL21 upregulation but did not modulate CCL19 or RANTES expression in response to TWEAK, thus establishing CCL21 as a non-canonical NFκB target in podocytes. Increased kidney Fn14 and CCL21 expression was also observed in rat proteinuric kidney disease induced by puromycin, and was localized to podocytes. In conclusion, TWEAK activates the non-canonical NFκB pathway in podocytes, leading to upregulation of CCL21 expression. The non-canonical NFκB pathway should be explored as a potential therapeutic target in proteinuric kidney disease. PMID:27353019

  5. Alteration of podocyte phenotype in the urine of women with preeclampsia

    Science.gov (United States)

    Zhai, Tianyue; Furuta, Itsuko; Akaishi, Rina; Ishikawa, Satoshi; Morikawa, Mamoru; Yamada, Takahiro; Koyama, Takahiro; Minakami, Hisanori

    2016-01-01

    Podocyte injury has been suggested to induce phenotypic alteration of glomerular podocytes and accelerate the detachment of podocytes from the glomeruli resulting in podocyturia. However, it is not clear whether podocyte phenotypic alteration occurs in the urine of women with preeclampsia (PE). Seventy-seven and 116 pelleted urine samples from 38 and 18 women at various stages of normal and PE pregnancies, respectively underwent quantitative analysis of podocyte-specific or associated protein mRNA expression, including podocin, nephrin, and synaptopodin using RT-PCR. Significant proteinuria in pregnancy (SPIP) is defined as protein:creatinine ratio (P/Cr, mg/mg) ≥0.27 in the urine supernatant. All three urine-pellet mRNAs expression levels were significantly positively correlated with P/Cr levels, suggesting that podocyturia increased with proteinuria. The podocin:nephrin mRNA ratio (PNR) and synaptopodin:nephrin mRNA ratio (SNR) increased significantly with increasing P/Cr, while the podocin:synaptopodin mRNA ratio (PSR) did not change significantly according to P/Cr, resulting in significantly higher PNR and SNR, but not PSR levels, in urine from PE women with than without SPIP. The PNR, SNR, and PSR in urine from PE women before onset of SPIP were comparable to those from controls. Thus, nephrin mRNA expression was reduced in the podocytes recovered from PE women. PMID:27052160

  6. Pathogenesis of common glomerular diseases – role of the podocyte cytoskeleton

    Directory of Open Access Journals (Sweden)

    Kumagai T

    2012-10-01

    Full Text Available Takanori Kumagai, Flaviana Mouawad, Tomoko TakanoDepartment of Medicine, McGill University Health Centre, Montreal, Quebec, CanadaAbstract: Glomerulus is the filtration unit of the kidney where the first step of urine formation takes place. In the glomerulus, water and small molecules including waste products of the body are filtered into the urine, while large molecules essential for body function such as albumin are retained. When this barrier function of the kidney is impaired, protein leakage into the urine (proteinuria occurs. Proteinuria is not only a hallmark of many glomerular diseases but also a prognostic marker of kidney disease progression. Visceral glomerular epithelial cells (commonly called podocytes are known to have an important role in the maintenance of glomerular barrier function. In the last decade, remarkable progress has been made in podocyte biology, mainly led by the discoveries of important proteins that work together to maintain the intricate morphology and function of podocytes. Most of these so-called podocyte proteins modulate the actin cytoskeleton either directly or indirectly. The aim of the current review is to discuss the pathogenesis of common glomerular diseases with a particular focus on the role of the actin cytoskeleton in podocytes. The diseases covered include minimal change disease, focal segmental glomerulosclerosis (idiopathic and hereditary, membranous nephropathy, hypertensive glomerulosclerosis, and diabetic nephropathy.Keywords: glomerular disease, podocyte, cytoskeleton, proteinuria

  7. Inhibition of p66ShcA Longevity Gene Rescues Podocytes from HIV-1-induced Oxidative Stress and Apoptosis*

    OpenAIRE

    Husain, Mohammad; Meggs, Leonard G.; Vashistha, Himanshu; Simoes, Sonia; Griffiths, Kevin O.; Kumar, Dileep; Mikulak, Joanna; Mathieson, Peter W.; Saleem, Moin A.; Del Valle, Luis; Pina-Oviedo, Sergio; Wang, Jin Ying; Seshan, Surya V.; Malhotra, Ashwani; Reiss, Krzysztof

    2009-01-01

    Glomerular visceral epithelial cells (podocytes) play a critical role in the pathogenesis of human immunodeficiency virus (HIV)-associated nephropathy. A key question concerns the mechanism(s) by which the HIV-1 genome alters the phenotype of the highly specialized, terminally differentiated podocytes. Here, using an in vitro system of conditionally immortalized differentiated human podocytes (CIDHPs), we document a pivotal role for the p66ShcA protein in HIV-1-induced reactive oxygen species...

  8. GLCCI1 is a novel component associated with the PI3K signaling pathway in podocyte foot processes.

    Science.gov (United States)

    Kim, Sang-Hoon; Kim, Hyun-Jung; Kim, Chan-Wha

    2016-01-01

    Podocyte foot processes are interdigitated to form the slit diaphragm and are crucial for the glomerular filtration barrier. Glucocorticoid-induced transcript 1 (GLCCI1) is transcriptionally regulated, but its signaling pathway in podocytes is unknown. The main objective of this study was to investigate the regulation of podocyte foot process proteins and to investigate the role of GLCCI1 in the phosphoinositide 3-kinase (PI3K) pathway using high glucose-induced podocytes and streptozotocin-induced diabetic rats. In podocytes and rat kidneys, GLCCI1 was found to be highly specific for the glomerulus and podocyte foot processes similar to other podocyte-specific proteins (nephrin, podocin, synatopodin and podocalyxin) based on reverse transcription-PCR, western blotting, immunofluorescence and immunoelectron microscopy analyses. In addition, the decrease in the GLCCI1 expression level under hyperglycemic conditions was restored by treatment with a PI3K inhibitor (wortmannin). Immunofluorescence analysis confirmed that GLCCI1 colocalized with nephrin and synaptopodin both in vivo and in vitro. Finally, immunoelectron microscopy data from streptozotocin-induced diabetic rats showed that GLCCI1 also localized in podocyte foot processes. Hence, GLCCI1 is a component of podocyte foot processes, and its expression appears to be regulated via the PI3K pathway. PMID:27174202

  9. MiR-30a Inhibits the Epithelial—Mesenchymal Transition of Podocytes through Downregulation of NFATc3

    OpenAIRE

    Rui Peng; Li Zhou; Yuru Zhou; Ya Zhao; Qianyin Li; Dongsheng Ni; Yanxia Hu; Yaoshui Long; Jianing Liu; Zhongshi Lyu; Zhaomin Mao; Yue Yuan; Liyuan Huang; Hui Zhao; Ge Li

    2015-01-01

    MicroRNAs (miRNAs) possess an important regulating effect among numerous renal diseases, while their functions in the process of epithelial-to-mesenchymal transition (EMT) after podocyte injury remain unclear. The purpose of our study is to identify the potential functions of miR-30a in EMT of podocytes and explore the underlying mechanisms of miR-30a in the impaired podocytes. The results revealed that downregulation of miR-30a in podocyte injury animal models and patients, highly induced th...

  10. CD36 Mediated Fatty Acid-Induced Podocyte Apoptosis via Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Wei Hua

    Full Text Available Hyperlipidemia-induced apoptosis mediated by fatty acid translocase CD36 is associated with increased uptake of ox-LDL or fatty acid in macrophages, hepatocytes and proximal tubular epithelial cells, leading to atherosclerosis, liver damage and fibrosis in obese patients, and diabetic nephropathy (DN, respectively. However, the specific role of CD36 in podocyte apoptosis in DN with hyperlipidemia remains poorly investigated.The expression of CD36 was measured in paraffin-embedded kidney tissue samples (Ctr = 18, DN = 20 by immunohistochemistry and immunofluorescence staining. We cultured conditionally immortalized mouse podocytes (MPC5 and treated cells with palmitic acid, and measured CD36 expression by real-time PCR, Western blot analysis and immunofluorescence; lipid uptake by Oil red O staining and BODIPY staining; apoptosis by flow cytometry assay, TUNEL assay and Western blot analysis; and ROS production by DCFH-DA fluorescence staining. All statistical analyses were performed using SPSS 21.0 statistical software.CD36 expression was increased in kidney tissue from DN patients with hyperlipidemia. Palmitic acid upregulated CD36 expression and promoted its translocation from cytoplasm to plasma membrane in podocytes. Furthermore, palmitic acid increased lipid uptake, ROS production and apoptosis in podocytes, Sulfo-N-succinimidyloleate (SSO, the specific inhibitor of the fatty acid binding site on CD36, decreased palmitic acid-induced fatty acid accumulation, ROS production, and apoptosis in podocytes. Antioxidant 4-hydroxy-2,2,6,6- tetramethylpiperidine -1-oxyl (tempol inhibited the overproduction of ROS and apoptosis in podocytes induced by palmitic acid.CD36 mediated fatty acid-induced podocyte apoptosis via oxidative stress might participate in the process of DN.

  11. Astragaloside IV, a novel antioxidant, prevents glucose-induced podocyte apoptosis in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Dingkun Gui

    Full Text Available Glucose-induced reactive oxygen species (ROS production initiates podocyte apoptosis, which represents a novel early mechanism leading to diabetic nephropathy (DN. Here, we tested the hypothesis that Astragaloside IV(AS-IV exerts antioxidant and antiapoptotic effects on podocytes under diabetic conditions. Apoptosis, albuminuria, ROS generation, caspase-3 activity and cleavage, as well as Bax and Bcl-2 mRNA and protein expression were measured in vitro and in vivo. Cultured podocytes were exposed to high glucose (HG with 50, 100 and 200 µg/ml of AS-IV for 24 h. AS-IV significantly attenuated HG-induced podocyte apoptosis and ROS production. This antiapoptotic effect was associated with restoration of Bax and Bcl-2 expression, as well as inhibition of caspase-3 activation and overexpression. In streptozotocin (STZ-induced diabetic rats, severe hyperglycemia and albuminuria were developed. Increased apoptosis, Bax expression, caspase-3 activity and cleavage while decreased Bcl-2 expression were detected in diabetic rats. However, pretreatment with AS-IV (2.5, 5, 10 mg·kg(-1·d(-1 for 14 weeks ameliorated podocyte apoptosis, caspase-3 activation, renal histopathology, podocyte foot process effacement, albuminuria and oxidative stress. Expression of Bax and Bcl-2 mRNA and protein in kidney cortex was partially restored by AS-IV pretreatment. These findings suggested AS-IV, a novel antioxidant, to prevent Glucose-Induced podocyte apoptosis partly through restoring the balance of Bax and Bcl-2 expression and inhibiting caspase-3 activation.

  12. Beta1 integrin expression by podocytes is required to maintain glomerular structural integrity.

    Science.gov (United States)

    Pozzi, Ambra; Jarad, George; Moeckel, Gilbert W; Coffa, Sergio; Zhang, Xi; Gewin, Leslie; Eremina, Vera; Hudson, Billy G; Borza, Dorin-Bogdan; Harris, Raymond C; Holzman, Lawrence B; Phillips, Carrie L; Fassler, Reinhard; Quaggin, Susan E; Miner, Jeffrey H; Zent, Roy

    2008-04-15

    Integrins are transmembrane heteromeric receptors that mediate interactions between cells and extracellular matrix (ECM). beta1, the most abundantly expressed integrin subunit, binds at least 12 alpha subunits. beta1 containing integrins are highly expressed in the glomerulus of the kidney; however their role in glomerular morphogenesis and maintenance of glomerular filtration barrier integrity is poorly understood. To study these questions we selectively deleted beta1 integrin in the podocyte by crossing beta1(flox/flox) mice with podocyte specific podocin-cre mice (pod-Cre), which express cre at the time of glomerular capillary formation. We demonstrate that podocyte abnormalities are visualized during glomerulogenesis of the pod-Cre;beta1(flox/flox) mice and proteinuria is present at birth, despite a grossly normal glomerular basement membrane. Following the advent of glomerular filtration there is progressive podocyte loss and the mice develop capillary loop and mesangium degeneration with little evidence of glomerulosclerosis. By 3 weeks of age the mice develop severe end stage renal failure characterized by both tubulointerstitial and glomerular pathology. Thus, expression of beta1 containing integrins by the podocyte is critical for maintaining the structural integrity of the glomerulus. PMID:18328474

  13. Role of altered insulin signaling pathways in the pathogenesis of podocyte malfunction and microalbuminuria

    Science.gov (United States)

    Jauregui, Alexandra; Mintz, Daniel H; Mundel, Peter; Fornoni, Alessia

    2010-01-01

    Purpose of review In diabetic nephropathy (DN), insulin resistance and hyperinsulinemia correlate with the development of albuminuria. The possibility that altered insulin signaling in glomerular cells and particularly podocytes contributes to the development of DN will be discussed. Recent findings While normal podocytes uptake glucose in response to insulin, diabetic podocytes become insulin resistant in experimental DN prior to the development of significant albuminuria. Both clinical and experimental data suggest that insulin sensitizers may be renoprotective independently of their systemic effects on the metabolic control of diabetes. Summary We will review the clinical and experimental evidence that altered insulin signaling correlates with the development of DN in both type 1 and type 2 diabetes, and that insulin sensitizers may be superior to other hypoglycemic agents in the prevention of DN. We will then review potential mechanisms by which altered podocyte insulin signaling may contribute to the development of DN. Understanding the role of podocyte in glucose metabolism is important because it may lead to the discovery of novel pathogenetic mechanisms of DN, it may affect current strategies for prevention and treatment of DN, and it may allow for the identification of novel therapeutic targets. PMID:19724224

  14. Proteomic analysis of podocyte exosome-enriched fraction from normal human urine.

    Science.gov (United States)

    Prunotto, Marco; Farina, Annarita; Lane, Lydie; Pernin, Agnès; Schifferli, Jürg; Hochstrasser, Denis F; Lescuyer, Pierre; Moll, Solange

    2013-04-26

    Urine results from a coordinated activity of glomerular and tubular compartments of the kidney. As a footprint of these cellular functional processes, urinary exosomes, and 40-80 nm membrane vesicles released after fusion with the plasma membrane into the extracellular environment by renal epithelial cells, are a source for identification of proteins and investigation of their role in the kidney. The aim of the present study was the identification of podocyte exosome proteins based on urine immunoabsorption using podocyte-specific CR1-immunocoated beads followed by proteomic analysis using LC MS/MS techniques. This methodology allowed the identification of 1195 proteins. By using a bioinformatic approach, 27 brain-expressed proteins were identified, in which 14 out of them were newly demonstrated to be expressed in the kidney at a mRNA level, and, one of them, the COMT protein, was demonstrated to be expressed in podocytes at a protein level. These results, attesting the reliability of the methodology to identify podocyte proteins, need now to be completed by further experiments to analyze more precisely their biological function(s) in the podocytes. PMID:23376485

  15. Small Molecule Membrane Transporters in the Mammalian Podocyte: A Pathogenic and Therapeutic Target

    Directory of Open Access Journals (Sweden)

    Cristina Zennaro

    2014-11-01

    Full Text Available The intriguingly complex glomerular podocyte has been a recent object of intense study. Researchers have sought to understand its role in the pathogenesis of common proteinuric diseases such as minimal change disease and focal segmental glomerular sclerosis. In particular, considerable effort has been directed towards the anatomic and functional barrier to macromolecular filtration provided by the secondary foot processes, but little attention has been paid to the potential of podocytes to handle plasma proteins beyond the specialization of the slit diaphragm. Renal membrane transporters in the proximal tubule have been extensively studied for decades, particularly in relation to drug metabolism and elimination. Recently, uptake and efflux transporters for small organic molecules have also been found in the glomerular podocyte, and we and others have found that these transporters can engage not only common pharmaceuticals but also injurious endogenous and exogenous agents. We have also found that the activity of podocyte transporters can be manipulated to inhibit pathogen uptake and efflux. It is conceivable that podocyte transporters may play a role in disease pathogenesis and may be a target for future drug development.

  16. Arhgap24 inactivates Rac1 in mouse podocytes, and a mutant form is associated with familial focal segmental glomerulosclerosis.

    LENUS (Irish Health Repository)

    Akilesh, Shreeram

    2011-10-01

    The specialized epithelial cell of the kidney, the podocyte, has a complex actin-based cytoskeleton. Dynamic regulation of this cytoskeleton is required for efficient barrier function of the kidney. Podocytes are a useful cell type to study the control of the actin cytoskeleton in vivo, because disruption of components of the cytoskeleton results in podocyte damage, cell loss, and a prototypic injury response called focal segmental glomerulosclerosis (FSGS). Searching for actin regulatory proteins that are expressed in podocytes, we identified a RhoA-activated Rac1 GTPase-activating protein (Rac1-GAP), Arhgap24, that was upregulated in podocytes as they differentiated, both in vitro and in vivo. Increased levels of active Rac1 and Cdc42 were measured in Arhgap24 knockdown experiments, which influenced podocyte cell shape and membrane dynamics. Consistent with a role for Arhgap24 in normal podocyte functioning in vivo, sequencing of the ARHGAP24 gene in patients with FSGS identified a mutation that impaired its Rac1-GAP activity and was associated with disease in a family with FSGS. Thus, Arhgap24 contributes to the careful balancing of RhoA and Rac1 signaling in podocytes, the disruption of which may lead to kidney disease.

  17. MiRNA expression profile and miRNA-mRNA integrated analysis (MMIA) during podocyte differentiation.

    Science.gov (United States)

    Li, Zhigui; Wang, Lifeng; Xu, Jing; Yang, Zhuo

    2015-06-01

    The podocyte is a prominent cell type, which encases the capillaries of glomerulus. Podocyte-selective deletion of Dicer or Drosha was reported to induce proteinuria and glomerulosclerosis, suggesting the essential role of microRNA (miRNA) in podocytes for renal function. However, no comprehensive miRNA expression or miRNA-mRNA integrated analysis (MMIA) can be found during podocyte differentiation. Herein, miRNA and mRNA microarrays are presented, which were carried out in differentiated and undifferentiated mouse podocyte cell lines (MPC5). A total of 50 abnormal miRNAs (26 down-regulated and 24 up-regulated) were identified in differentiated and undifferentiated podocytes. Using MMIA, 80 of the 743 mRNAs (>twofold change) were predicted for potential crosstalk with 30 miRNAs of the 50 abnormal miRNAs. In addition, the gene ontology of mRNAs and the pathway analysis of miRNAs revealed a new potential-regulated network during podocyte differentiation. The expressions of three remarkably changed miRNAs (miR-34c, miR-200a and miR-467e) and four mRNAs (Runx1t1, Atp2a2, Glrp1, and Mmp15), were randomly chosen for further validation by the quantitative real-time polymerase chain reaction, and their expression trends were consistent with the microarray data. Reference searching was also conducted to confirm our data and to find potential new molecules and miRNA-target pairs involved in the podocyte differentiation. The dual luciferase reporter assay for miR-200a/GLRX and let-7b/ARL4D confirmed the prediction of MMIA. The results of this study provide a detailed integration of mRNA and miRNA during podocyte differentiation. The molecular integration mode will open up new perspectives for a better understanding of the mechanism during podocyte differentiation. PMID:25433550

  18. Visualization of podocyte substructure with structured illumination microscopy (SIM): a new approach to nephrotic disease.

    Science.gov (United States)

    Pullman, James M; Nylk, Jonathan; Campbell, Elaine C; Gunn-Moore, Frank J; Prystowsky, Michael B; Dholakia, Kishan

    2016-02-01

    A detailed microscopic analysis of renal podocyte substructure is essential to understand and diagnose nephrotic kidney disease. Currently only time consuming electron microscopy (EM) can resolve this substructure. We used structured illumination microscopy (SIM) to examine frozen sections of renal biopsies stained with an immunofluorescence marker for podocin, a protein localized to the perimeter of the podocyte foot processes and compared them with EM in both normal and nephrotic disease biopsies. SIM images of normal glomeruli revealed curvilinear patterns of podocin densely covering capillary walls similar to podocyte foot processes seen by EM. Podocin staining of all nephrotic disease biopsies were significantly different than normal, corresponding to and better visualizing effaced foot processes seen by EM. The findings support the first potential use of SIM in the diagnosis of nephrotic disease. PMID:26977341

  19. Effect of Cordyceps sinensis and Tripterygium wilfordii polyglycosidium on podocytes in rats with diabetic nephropathy.

    Science.gov (United States)

    Hao, Li; Pan, Meng-Shu; Zheng, Yun; Wang, Rui-Feng

    2014-06-01

    The aim of the present study was to investigate the effects of Cordyceps sinensis (CS) and Tripterygium wilfordii polyglycosidium (TWP) on podocytes in rats with diabetic nephropathy (DN). DN rat models were established and divided randomly into normal control (group A), DN (group B), CS (group C), TWP (group D) and CS and TWP groups (group E). After 12 weeks, levels of 24-h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), white blood cells, blood glucose (GLU), aspartate aminotransferase, alanine aminotransferase and kidney weight (KW)/body weight (BW) were determined. Renal pathological changes were evaluated using hematoxylin and eosin staining, whereas the structural changes in the podocytes were observed under a transmission electron microscope. The expression levels of nephrin and podocin were evaluated using immunofluorescence staining. Compared with group A, the SCR and BUN levels in group B were higher (P<0.05) and the GLU, KW/BW and the 24-h urine protein were markedly higher (P<0.01). Moreover, incidences of glomerular disorders, chronic tubulointerstitial damage and glomerular podocyte lesions in groups B, C, D and E were observed, compared with group A. The high cortical expression of nephrin and podocin protein decreased. Compared with group B, the KW/BW and 24-h urinary protein level in groups C, D and E were lower (P<0.01). The glomeruli, tubules and podocytes exhibited pathomorphological improvements and the nephrin and podocin protein expression levels were higher in the nephridial tissue. A decrease in KW/BW and the 24-h urinary protein level, as well as improvements in glomerular disorder, chronic tubulointerstitial damage and glomerular podocyte lesions, were observed in groups C, D and E. Therefore, the results demonstrated that CS and TWP exhibited a protective effect on the podocytes of rats with DN. Moreover, CS combined with TWP increased this protective effect. PMID:24926327

  20. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    International Nuclear Information System (INIS)

    Highlights: ► H2O2 activates the insulin signaling pathway and glucose uptake in podocytes. ► H2O2 induces time-dependent changes in AMPK phosphorylation. ► H2O2 enhances insulin signaling pathways via AMPK activation. ► H2O2 stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H2O2) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H2O2-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H2O2 (100 μM) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min (Δ 183%, P 2O2>. Furthermore, H2O2 inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; Δ −32%, P 2O2 on IR phosphorylation by about 40% (from 2.07 ± 0.28 to 1.28 ± 0.12, P 2O2 increased glucose uptake in podocytes (from 0.88 ± 0.04 to 1.29 ± 0.12 nmol/min/mg protein, P 2O2 activated the insulin signaling pathway and glucose uptake via AMPK in cultured rat podocytes. This signaling may play a potential role in the prevention of insulin resistance under conditions associated with oxidative stress.

  1. MicroRNA-30 family members regulate calcium/calcineurin signaling in podocytes

    Science.gov (United States)

    Wu, Junnan; Zheng, Chunxia; Wang, Xiao; Yun, Shifeng; Zhao, Yue; Liu, Lin; Lu, Yuqiu; Ye, Yuting; Zhu, Xiaodong; Zhang, Changming; Shi, Shaolin; Liu, Zhihong

    2015-01-01

    Calcium/calcineurin signaling is critical for normal cellular physiology. Abnormalities in this pathway cause many diseases, including podocytopathy; therefore, understanding the mechanisms that underlie the regulation of calcium/calcineurin signaling is essential. Here, we showed that critical components of calcium/calcineurin signaling, including TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3, are the targets of the microRNA-30 family (miR-30s). We found that these 5 genes are highly expressed as mRNA, but the level of the proteins is low in normal podocytes. Conversely, protein levels were markedly elevated in podocytes from rats treated with puromycin aminonucleoside (PAN) and from patients with focal segmental glomerulosclerosis (FSGS). In both FSGS patients and PAN-treated rats, miR-30s were downregulated in podocytes. In cultured podocytes, PAN or a miR-30 sponge increased TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3 expression; calcium influx; intracellular Ca2+ concentration; and calcineurin activity. Moreover, NFATC3 nuclear translocation, synaptopodin degradation, integrin β3 (ITGB3) activation, and actin fiber loss, which are downstream of calcium/calcineurin signaling, were induced by miR-30 reduction but blocked by the calcineurin inhibitor FK506. Podocyte-specific expression of the miR-30 sponge in mice increased calcium/calcineurin pathway component protein expression and calcineurin activity. The mice developed podocyte foot process effacement and proteinuria, which were prevented by FK506. miR-30s also regulated calcium/calcineurin signaling in cardiomyocytes. Together, our results identify miR-30s as essential regulators of calcium/calcineurin signaling. PMID:26436650

  2. 3,4-DGE is cytotoxic and decreases HSP27/HSPB1 in podocytes.

    Science.gov (United States)

    Sanchez-Niño, Maria Dolores; Poveda, Jonay; Sanz, Ana Belen; Carrasco, Susana; Ruiz-Ortega, Marta; Selgas, Rafael; Egido, Jesus; Ortiz, Alberto

    2014-03-01

    Hyperglycemia is the key driver of diabetic complications and increased concentrations of glucose degradation products. The study of peritoneal dialysis solution biocompatibility has highlighted the adverse biological effects of glucose degradation products. Recently, 3,4-dideoxyglucosone-3-ene (3,4-DGE) was identified as the most toxic glucose degradation product in peritoneal dialysis fluids. In addition, 3,4-DGE is present in high-fructose corn syrup, and its precursor 3-deoxyglucosone is increased in diabetes. The role of 3,4-DGE in glomerular injury had not been addressed. We studied the effects of 3,4-DGE on cultured human podocytes and in vivo in mice. 3,4-DGE induced apoptosis in podocytes in a dose- and time-dependent manner. 3,4-DGE promoted the release of cytochrome c from mitochondria and activation of caspase-3. While high glucose concentrations increased the levels of the podocyte intracellular antiapoptotic protein HSP27/HSPB1, 3,4-DGE decreased the expression of podocyte HSP27/HSPB1. Apoptosis induced by 3,4-DGE was caspase-dependent and could be prevented by the broad-spectrum caspase inhibitor zVAD-fmk. Antagonism of Bax by a Ku-70-derived peptide also prevented apoptosis. Intravenous administration of 3,4-DGE to healthy mice resulted in a decreased expression of HSP27/HSPB1 and caspase-3 activation in whole kidney and in podocytes in vivo. In conclusion, 3,4-DGE induces apoptotic cell death in cultured human podocytes, suggesting a potential role in glomerular injury resulting from metabolic disorders. PMID:24337777

  3. Acute ethanol induces apoptosis by stimulating TRPC6 via elevation of superoxide in oxygenated podocytes

    OpenAIRE

    Lu, Xiao-Yu; Liu, Bing-Chen; Wang, Li-Hua; Yang, Li-li; Bao, Qing; Zhai, Yu-Jia; Alli, Abdel A.; Thai, Tiffany L.; Eaton, Douglas C.; WANG Wei-zhi; Ma, He-Ping

    2015-01-01

    Our recent studies indicate that hydrogen peroxide (H2O2) only at high concentrations can cause oxidative stress in renal epithelial cells and induce apoptosis of podocytes. Consistently, the present study shows that H2O2, even at 1 mM, failed to induce intracellular oxidative stress and apoptosis of the podocytes due to efficient activity of catalase, an enzyme which degrades H2O2 to produce water and oxygen (O2). However, H2O2 acted as a source of O2 to allow acute ethanol to induce superox...

  4. Insulin directly stimulates VEGF-A production in the glomerular podocyte

    OpenAIRE

    Hale, L. J.; Hurcombe, J.; Lay, A.; Santamaría, B.; Valverde, A M; Saleem, M A; Mathieson, P. W.; Welsh, G. I.; Coward, R. J.

    2013-01-01

    Podocytes are critically important for maintaining the integrity of the glomerular filtration barrier and preventing albuminuria. Recently, it has become clear that to achieve this, they need to be insulin sensitive and produce an optimal amount of VEGF-A. In other tissues, insulin has been shown to regulate VEGF-A release, but this has not been previously examined in the podocyte. Using in vitro and in vivo approaches, in the present study, we now show that insulin regulates VEGF-A in the po...

  5. High glucose increases Cdk5 activity in podocytes via transforming growth factor-β1 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yue [Department of Diagnostics, Hebei Medical University, Shijiazhuang 050017 (China); Li, Hongbo; Hao, Jun [Department of Pathology, Hebei Medical University, Shijiazhuang 050017 (China); Zhou, Yi [Department of Neurology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000 (China); Liu, Wei, E-mail: lwei929@126.com [Department of Pathology, Hebei Medical University, Shijiazhuang 050017 (China)

    2014-08-15

    Podocytes are highly specialized and terminally differentiated glomerular cells that play a vital role in the development and progression of diabetic nephropathy (DN). Cyclin-dependent kinase 5 (Cdk5), who is an atypical but essential member of the Cdk family of proline-directed serine/threonine kinases, has been shown as a key regulator of podocyte differentiation, proliferation and morphology. Our previous studies demonstrated that the expression of Cdk5 was significantly increased in podocytes of diabetic rats, and was closely related with podocyte injury of DN. However, the mechanisms of how expression and activity of Cdk5 are regulated under the high glucose environment have not yet been fully elucidated. In this study, we showed that high glucose up-regulated the expression of Cdk5 and its co-activator p35 with a concomitant increase in Cdk5 kinase activity in conditionally immortalized mouse podocytes in vitro. When exposed to 30 mM glucose, transforming growth factor-β1 (TGF-β1) was activated. Most importantly, we found that SB431542, the Tgfbr1 inhibitor, significantly decreased the expression of Cdk5 and p35 and Cdk5 kinase activity in high glucose-treated podocytes. Moreover, high glucose increased the expression of early growth response-1 (Egr-1) via TGF-β1-ERK1/2 pathway in podocytes and inhibition of Egr-1 by siRNA decreased p35 expression and Cdk5 kinase activity. Furthermore, inhibition of Cdk5 kinase activity effectively alleviated podocyte apoptosis induced by high glucose or TGF-β1. Thus, the TGF-β1-ERK1/2-Egr-1 signaling pathway may regulate the p35 expression and Cdk5 kinase activity in high glucose-treated podocytes, which contributes to podocyte injury of DN. - Highlights: • HG up-regulated the expression of Cdk5 and p35, and Cdk5 activity in podocytes. • HG activated TGF-β1 pathway and SB431542 inhibited Cdk5 expression and activity. • HG increased the expression of Egr-1 via TGF-β1-ERK1/2 pathway. • Inhibition of Egr-1

  6. Podocyte-Specific VEGF-A Gain of Function Induces Nodular Glomerulosclerosis in eNOS Null Mice

    Science.gov (United States)

    Veron, Delma; Aggarwal, Pardeep K.; Velazquez, Heino; Kashgarian, Michael; Moeckel, Gilbert

    2014-01-01

    VEGF-A and nitric oxide are essential for glomerular filtration barrier homeostasis and are dysregulated in diabetic nephropathy. Here, we examined the effect of excess podocyte VEGF-A on the renal phenotype of endothelial nitric oxide synthase (eNOS) knockout mice. Podocyte-specific VEGF164 gain of function in eNOS−/− mice resulted in nodular glomerulosclerosis, mesangiolysis, microaneurysms, and arteriolar hyalinosis associated with massive proteinuria and renal failure in the absence of diabetic milieu or hypertension. In contrast, podocyte-specific VEGF164 gain of function in wild-type mice resulted in less pronounced albuminuria and increased creatinine clearance. Transmission electron microscopy revealed glomerular basement membrane thickening and podocyte effacement in eNOS−/− mice with podocyte-specific VEGF164 gain of function. Furthermore, glomerular nodules overexpressed collagen IV and laminin extensively. Biotin-switch and proximity ligation assays demonstrated that podocyte-specific VEGF164 gain of function decreased glomerular S-nitrosylation of laminin in eNOS−/− mice. In addition, treatment with VEGF-A decreased S-nitrosylated laminin in cultured podocytes. Collectively, these data indicate that excess glomerular VEGF-A and eNOS deficiency is necessary and sufficient to induce Kimmelstiel-Wilson–like nodular glomerulosclerosis in mice through a process that involves deposition of laminin and collagen IV and de-nitrosylation of laminin. PMID:24578128

  7. ADAM10 is expressed in human podocytes and found in urinary vesicles of patients with glomerular kidney diseases

    Directory of Open Access Journals (Sweden)

    Weide Thomas

    2010-01-01

    Full Text Available Abstract Background The importance of the Notch signaling in the development of glomerular diseases has been recently described. Therefore we analyzed in podocytes the expression and activity of ADAM10, one important component of the Notch signaling complex. Methods By Western blot, immunofluorescence and immunohistochemistry analysis we characterized the expression of ADAM10 in human podocytes, human urine and human renal tissue. Results We present evidence, that differentiated human podocytes possessed increased amounts of mature ADAM10 and released elevated levels of L1 adhesion molecule, one well known substrate of ADAM10. By using specific siRNA and metalloproteinase inhibitors we demonstrate that ADAM10 is involved in the cleavage of L1 in human podocytes. Injury of podocytes enhanced the ADAM10 mediated cleavage of L1. In addition, we detected ADAM10 in urinary podocytes from patients with kidney diseases and in tissue sections of normal human kidney. Finally, we found elevated levels of ADAM10 in urinary vesicles of patients with glomerular kidney diseases. Conclusions The activity of ADAM10 in human podocytes may play an important role in the development of glomerular kidney diseases.

  8. Nuclear translocation of IQGAP1 protein upon exposure to puromycin aminonucleoside in cultured human podocytes: ERK pathway involvement.

    Science.gov (United States)

    Rigothier, Claire; Saleem, Moin Ahson; Bourget, Chantal; Mathieson, Peter William; Combe, Christian; Welsh, Gavin Iain

    2016-10-01

    IQGAP1, a protein that links the actin cytoskeleton to slit diaphragm proteins, is involved in podocyte motility and permeability. Its regulation in glomerular disease is not known. We have exposed human podocytes to puromycin aminonucleoside (PAN), an inducer of nephrotic syndrome in rats, and studied the effects on IQGAP1 biology and function. In human podocytes exposed to PAN, a nuclear translocation of IQGAP1 was observed by immunocytolocalization and confirmed by Western blot after selective nuclear/cytoplasmic extraction. In contrast to IQGAP1, IQGAP2 expression remained cytoplasmic. IQGAP1 nuclear translocation was associated with a significant decrease in its interaction with nephrin and podocalyxin. Activation of the ERK pathway was observed in PAN treated podocytes with a preponderant nuclear localization of the phosphorylated form of ERK (P-ERK). The interaction between IQGAP1 and P-ERK increased upon podocyte exposure to PAN. Inhibitors of ERK pathway activation blocked IQGAP1 nuclear translocation (pinteraction protein assays demonstrated an interaction of IQGAP1 with chromatin and with Histone H3, which increased in response to PAN. In summary, PAN induces the ERK dependent translocation of IQGAP1 into the nuclei in human podocytes which leads to the interaction of IQGAP1 with chromatin and Histone H3, and decreased interactions between IQGAP1 and slit-diaphragm proteins. Therefore, IQGAP1 may have a role in podocyte gene regulation in glomerular disease. PMID:27377965

  9. MiR-30a Inhibits the Epithelial—Mesenchymal Transition of Podocytes through Downregulation of NFATc3

    Directory of Open Access Journals (Sweden)

    Rui Peng

    2015-10-01

    Full Text Available MicroRNAs (miRNAs possess an important regulating effect among numerous renal diseases, while their functions in the process of epithelial-to-mesenchymal transition (EMT after podocyte injury remain unclear. The purpose of our study is to identify the potential functions of miR-30a in EMT of podocytes and explore the underlying mechanisms of miR-30a in the impaired podocytes. The results revealed that downregulation of miR-30a in podocyte injury animal models and patients, highly induced the mesenchymal markers of EMT including Collagen I, Fibronectin and Snail. Furthermore, overexpression of miR-30a enhances epithelial markers (E-cadherin but diminished mesenchymal markers (Collagen I, Fibronectin and Snail in podocytes. In addition, we established miR-30a target NFATc3, an important transcription factor of Non-canonical Wnt signaling pathway. More importantly, our findings demonstrated that the augmentation of miR-30a level in podocytes inhibits the nuclear translocation of NFATc3 to protect cytoskeleton disorder or rearrangement. In summary, we uncovered the protective function of miR30a targeting NFATc3 in the regulation of podocyte injury response to EMT.

  10. Tacrolimus restores podocyte injury and stabilizes the expression of Cabin1 in 5/6 nephrectomized rats.

    Science.gov (United States)

    Wen, Yueqiang; Liu, Lingling; Zhou, Peilan; Li, Huiyuan; Wang, Zebin; Zhang, Yajie; Liang, Jianbo

    2016-05-01

    Podocyte injury is a vital factor, which induces massive proteinuria. Studies have shown that tacrolimus (TAC) protected podocyte via stabilizing cytoskeleton. Our latest study indicates that calcineurin binding protein 1 (Cabin1) undergoes nuclear translocation during podocytes injury. Whether TAC targets on Cabin1 during podocyte injury is still not clear. This study establishes non-immunological proteinuric model. To observe the effect of the treatment of TAC on Cabin1 expression in 5/6 nephrectomized rats. Sprague-Dawley rats were injected with TAC (0.2 mg/kg/day) for 4-8 weeks after 5/6 nephrectomy. Then, rats were sacrificed in the eighth week after operation, renal tissues were processed for morphological studies under light and electrical microscope. Cabin1 expression and distribution were detected by western blot and indirect immunofluorescence staining. In 5/6 nephrectomized rats, urinary protein excretion reached 90.2 ± 30.1 mg/24 h, glomerular sclerosis index and tubulointerstitial fibrosis score were significantly increased, and widespread of podocyte foot processes fusion was found. Moreover, Cabin1 protein expression was markedly increased, and its distribution became much more obviously in podocytes nuclei. In TAC treated rats, urinary protein excretion significantly decreased (44.9 ± 22.5 mg/24 h), glomerular sclerosis and tubulointerstitial fibrosis were alleviated, and podocyte foot processes fusion was inhibited. Furthermore, TAC alleviated the increased protein expression and abnormal distribution of Cabin1. In conclusion, TAC restores podocyte injury and stabilizes the expression of Cabin1. Cabin1 may become a new target to demonstrate the mechanism of TAC in podocyte injury. PMID:26905810

  11. Genes and podocytes – new insights and perspectives on mechanisms of podocytopathy

    Directory of Open Access Journals (Sweden)

    Agnieszka eBierzynska

    2015-01-01

    Full Text Available After decades of primarily morphological study, positional cloning of the NPHS1 gene was the landmark event that established aberrant podocyte genetics as a pivotal cause of malfunction of the glomerular filter. This ended any uncertainty whether genetic mutation plays a significant role in hereditary nephrotic syndromes and confirmed podocytes as critical players in regulating glomerular protein filtration. Although subsequent sequencing of candidate genes chosen on the basis of podocyte biology had less success, unbiased analysis of genetically informative kindreds and syndromic disease has led to further gene discovery. However, the 45 genes currently associated with human nephrotic syndrome explain no more than 20-30% of hereditary and only 10-20% of sporadic cases. It is becoming increasingly clear both from genetic analysis and phenotypic data - including occasional response to immunosuppressive agents and post-transplant disease recurrence in Mendelian disease - that monogenic inheritance of abnormalities in podocyte-specific genes disrupting filter function are only part of the story. Recent advances in genetic screening technology combined with increasingly robust bioinformatics are set to allow identification and characterisation of novel disease causing variants and more importantly, disease modifying genes. Emerging data also supports a significant but incompletely characterised immunoregulatory component.

  12. Palmitate induces ER calcium depletion and apoptosis in mouse podocytes subsequent to mitochondrial oxidative stress.

    Science.gov (United States)

    Xu, S; Nam, S M; Kim, J-H; Das, R; Choi, S-K; Nguyen, T T; Quan, X; Choi, S J; Chung, C H; Lee, E Y; Lee, I-K; Wiederkehr, A; Wollheim, C B; Cha, S-K; Park, K-S

    2015-01-01

    Pathologic alterations in podocytes lead to failure of an essential component of the glomerular filtration barrier and proteinuria in chronic kidney diseases. Elevated levels of saturated free fatty acid (FFA) are harmful to various tissues, implemented in the progression of diabetes and its complications such as proteinuria in diabetic nephropathy. Here, we investigated the molecular mechanism of palmitate cytotoxicity in cultured mouse podocytes. Incubation with palmitate dose-dependently increased cytosolic and mitochondrial reactive oxygen species, depolarized the mitochondrial membrane potential, impaired ATP synthesis and elicited apoptotic cell death. Palmitate not only evoked mitochondrial fragmentation but also caused marked dilation of the endoplasmic reticulum (ER). Consistently, palmitate upregulated ER stress proteins, oligomerized stromal interaction molecule 1 (STIM1) in the subplasmalemmal ER membrane, abolished the cyclopiazonic acid-induced cytosolic Ca(2+) increase due to depletion of luminal ER Ca(2+). Palmitate-induced ER Ca(2+) depletion and cytotoxicity were blocked by a selective inhibitor of the fatty-acid transporter FAT/CD36. Loss of the ER Ca(2+) pool induced by palmitate was reverted by the phospholipase C (PLC) inhibitor edelfosine. Palmitate-dependent activation of PLC was further demonstrated by following cytosolic translocation of the pleckstrin homology domain of PLC in palmitate-treated podocytes. An inhibitor of diacylglycerol (DAG) kinase, which elevates cytosolic DAG, strongly promoted ER Ca(2+) depletion by low-dose palmitate. GF109203X, a PKC inhibitor, partially prevented palmitate-induced ER Ca(2+) loss. Remarkably, the mitochondrial antioxidant mitoTEMPO inhibited palmitate-induced PLC activation, ER Ca(2+) depletion and cytotoxicity. Palmitate elicited cytoskeletal changes in podocytes and increased albumin permeability, which was also blocked by mitoTEMPO. These data suggest that oxidative stress caused by saturated FFA

  13. MicroRNA-218 promotes high glucose-induced apoptosis in podocytes by targeting heme oxygenase-1.

    Science.gov (United States)

    Yang, Haibo; Wang, Qingjun; Li, Sutong

    2016-03-18

    Emerging evidence has demonstrated that microRNAs (miRNAs) play a mediatory role in the pathogenesis of diabetic nephropathy. In this study, we found that miR-218 was upregulated in high glucose (HG) treated podocytes, which are essential components of the glomerular filtration barrier and a major prognostic determinant in diabetic nephropathy. Additionally, up-regulation of miR-218 was accompanied by an increased rate of podocyte death and down-regulation in the level of nephrin, a key marker of podocytes. However, inhibition of miR-218 exerted the opposite effect. In addition, the dual-luciferase reporter assay showed that miR-218 directly targeted the 3'-untranslated region of heme oxygenase-1 (HO-1), and further study confirmed an increase of HO-1 in HG-treated podocytes transfected with anti-miR-218. Knockdown of HO-1 blocked the anti-apoptotic effect of anti-miR-218. Furthermore, inhibition of miR-218 was associated with decreased expression of the known pro-apoptotic molecule p38-mitogen-activated protein kinase (p38-MAPK) activation. Following preconditioning with SB203580, an inhibitor of p38-MAPK, the stimulatory effect of HG on podocyte apoptosis was strikingly ameliorated. These findings suggested that miR-218 accelerated HG-induced podocyte apoptosis through directly down-regulating HO-1 and facilitating p38-MAPK activation. PMID:26876575

  14. Intravital imaging reveals angiotensin II–induced transcytosis of albumin by podocytes

    OpenAIRE

    Schießl, Ina Maria; Hammer, Anna; Kattler, Veronika; Gess, Bernhard; Theilig, Franziska; Witzgall, Ralph; Castrop, Hayo

    2016-01-01

    Albuminuria is a hallmark of kidney disease of various etiologies and usually caused by deterioration of glomerular filtration barrier integrity. We recently showed that angiotensin II (Ang II) acutely increases albumin filtration in the healthy kidney. Here, we used intravital microscopy to assess the effects of Ang II on podocyte function in rats. Acute infusion of 30, 60, or 80 ng/kg per minute Ang II enhanced the endocytosis of albumin by activation of the type 1 Ang II receptor and ...

  15. Effect of Cordyceps sinensis and Tripterygium wilfordii polyglycosidium on podocytes in rats with diabetic nephropathy

    OpenAIRE

    Hao, Li; PAN, MENG-SHU; Zheng, Yun; Rui-feng WANG

    2014-01-01

    The aim of the present study was to investigate the effects of Cordyceps sinensis (CS) and Tripterygium wilfordii polyglycosidium (TWP) on podocytes in rats with diabetic nephropathy (DN). DN rat models were established and divided randomly into normal control (group A), DN (group B), CS (group C), TWP (group D) and CS and TWP groups (group E). After 12 weeks, levels of 24-h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), white blood cells, blood glucose (GLU), aspartate a...

  16. Renal Podocyte Injury in a Rat Model of Type 2 Diabetes Is Prevented by Metformin

    OpenAIRE

    Junghyun Kim; Eunjin Shon; Chan-Sik Kim; Jin Sook Kim

    2012-01-01

    Hyperglycemia promotes oxidative stress and hence generation of reactive oxygen species (ROS), which is known to play a crucial role in the pathogenesis of diabetic nephropathy. Metformin, an oral hypoglycemic drug, possesses antioxidant effects. The aim of this paper is to investigate the protective effects of metformin on the injury of renal podocytes in spontaneously diabetic Torii (SDT) rats, a new model for nonobese type 2 diabetes. Metformin (350 mg/kg/day) was given to SDT rats for 17 ...

  17. Reactive oxygen species are involved in insulin-dependent regulation of autophagy in primary rat podocytes.

    Science.gov (United States)

    Audzeyenka, Irena; Rogacka, Dorota; Piwkowska, Agnieszka; Rychlowski, Michal; Bierla, Joanna Beata; Czarnowska, Elżbieta; Angielski, Stefan; Jankowski, Maciej

    2016-06-01

    Autophagy is an intracellular defense mechanism responsible for the turnover of damaged or non-functional cellular constituents. This process provides cells with energy and essential compounds under unfavorable environmental conditions-such as oxidative stress and hyperglycemia, which are both observed in diabetes. The most common diabetes complication is diabetic nephropathy (DN), which can lead to renal failure. This condition often includes impaired podocyte function. Here we investigated autophagic activity in rat podocytes cultured with a high insulin concentration (300nM). Autophagy was activated after 60min of insulin stimulation. Moreover, this effect was abolished following pharmacological (apocynin) or genetic (siRNA) inhibition of NAD(P)H oxidase activity, indicating that insulin-dependent autophagy stimulation involved reactive oxygen species (ROS). We also observed a continuous and time-dependent increase of podocyte albumin permeability in response to insulin, and this process was slightly improved by autophagy inhibition following short-term insulin exposure. Our results suggest that insulin may be a factor affecting the development of diabetic nephropathy. PMID:27026581

  18. Decreased miR-26a expression correlates with the progression of podocyte injury in autoimmune glomerulonephritis.

    Directory of Open Access Journals (Sweden)

    Osamu Ichii

    Full Text Available MicroRNAs contribute to the pathogenesis of certain diseases and may serve as biomarkers. We analyzed glomerular microRNA expression in B6.MRLc1, which serve as a mouse model of autoimmune glomerulonephritis. We found that miR-26a was the most abundantly expressed microRNA in the glomerulus of normal C57BL/6 and that its glomerular expression in B6.MRLc1 was significantly lower than that in C57BL/6. In mouse kidneys, podocytes mainly expressed miR-26a, and glomerular miR-26a expression in B6.MRLc1 mice correlated negatively with the urinary albumin levels and podocyte-specific gene expression. Puromycin-induced injury of immortalized mouse podocytes decreased miR-26a expression, perturbed the actin cytoskeleton, and increased the release of exosomes containing miR-26a. Although miR-26a expression increased with differentiation of immortalized mouse podocytes, silencing miR-26a decreased the expression of genes associated with the podocyte differentiation and formation of the cytoskeleton. In particular, the levels of vimentin and actin significantly decreased. In patients with lupus nephritis and IgA nephropathy, glomerular miR-26a levels were significantly lower than those of healthy controls. In B6.MRLc1 and patients with lupus nephritis, miR-26a levels in urinary exosomes were significantly higher compared with those for the respective healthy control. These data indicate that miR-26a regulates podocyte differentiation and cytoskeletal integrity, and its altered levels in glomerulus and urine may serve as a marker of injured podocytes in autoimmune glomerulonephritis.

  19. Podocyte-specific overexpression of wild type or mutant trpc6 in mice is sufficient to cause glomerular disease.

    Directory of Open Access Journals (Sweden)

    Paola Krall

    Full Text Available Mutations in the TRPC6 calcium channel (Transient receptor potential channel 6 gene have been associated with familiar forms of Focal and Segmental Glomerulosclerosis (FSGS affecting children and adults. In addition, acquired glomerular diseases are associated with increased expression levels of TRPC6. However, the exact role of TRPC6 in the pathogenesis of FSGS remains to be elucidated. In this work we describe the generation and phenotypic characterization of three different transgenic mouse lines with podocyte-specific overexpression of the wild type or any of two mutant forms of Trpc6 (P111Q and E896K previously related to FSGS. Consistent with the human phenotype a non-nephrotic range of albuminuria was detectable in almost all transgenic lines. The histological analysis demonstrated that the transgenic mice developed a kidney disease similar to human FSGS. Differences of 2-3 folds in the presence of glomerular lesions were found between the non transgenic and transgenic mice expressing Trpc6 in its wild type or mutant forms specifically in podocytes. Electron microscopy of glomerulus from transgenic mice showed extensive podocyte foot process effacement. We conclude that overexpression of Trpc6 (wild type or mutated in podocytes is sufficient to cause a kidney disease consistent with FSGS. Our results contribute to reinforce the central role of podocytes in the etiology of FSGS. These mice constitute an important new model in which to study future therapies and outcomes of this complex disease.

  20. Plekhh2, a novel podocyte protein downregulated in human focal segmental glomerulosclerosis, is involved in matrix adhesion and actin dynamics.

    Science.gov (United States)

    Perisic, Ljubica; Lal, Mark; Hulkko, Jenny; Hultenby, Kjell; Önfelt, Björn; Sun, Ying; Dunér, Fredrik; Patrakka, Jaakko; Betsholtz, Christer; Uhlen, Mathias; Brismar, Hjalmar; Tryggvason, Karl; Wernerson, Annika; Pikkarainen, Timo

    2012-11-01

    Pleckstrin homology domain-containing, family H (with MyTH4 domain), member 2 (Plekhh2) is a 1491-residue intracellular protein highly enriched in renal glomerular podocytes for which no function has been ascribed. Analysis of renal biopsies from patients with focal segmental glomerulosclerosis revealed a significant reduction in total podocyte Plekhh2 expression compared to controls. Sequence analysis indicated a putative α-helical coiled-coil segment as the only recognizable domain within the N-terminal half of the polypeptide, while the C-terminal half contains two PH, a MyTH4, and a FERM domain. We identified a phosphatidylinositol-3-phosphate consensus-binding site in the PH1 domain required for Plekhh2 localization to peripheral regions of cell lamellipodia. The N-terminal half of Plekkh2 is not necessary for lamellipodial targeting but mediates self-association. Yeast two-hybrid screening showed that Plekhh2 directly interacts through its FERM domain with the focal adhesion protein Hic-5 and actin. Plekhh2 and Hic-5 coprecipitated and colocalized at the soles of podocyte foot processes in situ and Hic-5 partially relocated from focal adhesions to lamellipodia in Plekhh2-expressing podocytes. In addition, Plekhh2 stabilizes the cortical actin cytoskeleton by attenuating actin depolymerization. Our findings suggest a structural and functional role for Plekhh2 in the podocyte foot processes. PMID:22832517

  1. Next generation sequencing and functional analysis of patient urine renal progenitor-derived podocytes to unravel the diagnosis underlying refractory lupus nephritis.

    Science.gov (United States)

    Romagnani, Paola; Giglio, Sabrina; Angelotti, Maria Lucia; Provenzano, Aldesia; Becherucci, Francesca; Mazzinghi, Benedetta; Müller, Susanna; Amann, Kerstin; Weidenbusch, Marc; Romoli, Simone; Lazzeri, Elena; Anders, Hans-Joachim

    2016-09-01

    Often the cause of refractory lupus nephritis (RLN) remains unclear. We performed next-generation sequencing for podocyte genes in an RLN patient and identified compound heterozygosity for APOL1 risk alleles G1 and G2 and a novel homozygous c.[1049C>T]+[1049C>T] NPHS1 gene variant of unknown significance. To test for causality renal progenitor cells isolated from urine of this patient were differentiated into podocytes in vitro. Podocytes revealed aberrant nephrin trafficking, cytoskeletal structure and lysosomal leakage, and increased detachment as compared with podocytes isolated from controls. Thus, lupus podocytopathy can be confirmed as a cause of RLN by functional genetics on patient-derived podocytes. PMID:27325253

  2. CLIC5A, a component of the ezrin-podocalyxin complex in glomeruli, is a determinant of podocyte integrity.

    Science.gov (United States)

    Wegner, Binytha; Al-Momany, Abass; Kulak, Stephen C; Kozlowski, Kathy; Obeidat, Marya; Jahroudi, Nadia; Paes, John; Berryman, Mark; Ballermann, Barbara J

    2010-06-01

    The chloride intracellular channel 5A (CLIC5A) protein, one of two isoforms produced by the CLIC5 gene, was isolated originally as part of a cytoskeletal protein complex containing ezrin from placental microvilli. Whether CLIC5A functions as a bona fide ion channel is controversial. We reported previously that a CLIC5 transcript is enriched approximately 800-fold in human renal glomeruli relative to most other tissues. Therefore, this study sought to explore CLIC5 expression and function in glomeruli. RT-PCR and Western blots show that CLIC5A is the predominant CLIC5 isoform expressed in glomeruli. Confocal immunofluorescence and immunogold electron microscopy reveal high levels of CLIC5A protein in glomerular endothelial cells and podocytes. In podocytes, CLIC5A localizes to the apical plasma membrane of foot processes, similar to the known distribution of podocalyxin and ezrin. Ezrin and podocalyxin colocalize with CLIC5A in glomeruli, and podocalyxin coimmunoprecipitates with CLIC5A from glomerular lysates. In glomeruli of jitterbug (jbg/jbg) mice, which lack the CLIC5A protein, ezrin and phospho-ERM levels in podocytes are markedly lower than in wild-type mice. Transmission electron microscopy reveals patchy broadening and effacement of podocyte foot processes as well as vacuolization of glomerular endothelial cells. These ultrastructural changes are associated with microalbuminuria at baseline and increased susceptibility to adriamycin-induced glomerular injury compared with wild-type mice. Together, the data suggest that CLIC5A is required for the development and/or maintenance of the proper glomerular endothelial cell and podocyte architecture. We postulate that the interaction between podocalyxin and subjacent filamentous actin, which requires ezrin, is compromised in podocytes of CLIC5A-deficient mice, leading to dysfunction under unfavorable genetic or environmental conditions. PMID:20335315

  3. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    Energy Technology Data Exchange (ETDEWEB)

    Piwkowska, Agnieszka, E-mail: apiwkowska@cmdik.pan.pl [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Rogacka, Dorota; Angielski, Stefan [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Jankowski, Maciej [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Medical University of Gdansk, Department of Therapy Monitoring and Pharmacogenetics (Poland)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer H{sub 2}O{sub 2} activates the insulin signaling pathway and glucose uptake in podocytes. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} induces time-dependent changes in AMPK phosphorylation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} enhances insulin signaling pathways via AMPK activation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H{sub 2}O{sub 2}) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H{sub 2}O{sub 2}-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H{sub 2}O{sub 2} (100 {mu}M) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min ({Delta} 183%, P < 0.05), 3 min ({Delta} 414%, P < 0.05), and 10 min ({Delta} 35%, P < 0.05), respectively. Immunostaining cells with an Akt-specific antibody showed increased intensity at the plasma membrane after treatment with H{sub 2}O{sub 2}>. Furthermore, H{sub 2}O{sub 2} inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; {Delta} -32%, P < 0.05) and stimulated phosphorylation of the AMP-dependent kinase alpha subunit (AMPK{alpha}; 78% at 3 min and 244% at 10 min). The stimulation of AMPK was abolished with an AMPK inhibitor, Compound C (100 {mu}M, 2 h). Moreover, Compound C significantly reduced the effect of H{sub 2}O{sub 2} on IR phosphorylation by about 40% (from 2.07 {+-} 0.28 to 1.28 {+-} 0.12, P < 0.05). In addition, H{sub 2}O{sub 2} increased glucose uptake in podocytes

  4. sPLA2 IB induces human podocyte apoptosis via the M-type phospholipase A2 receptor

    OpenAIRE

    Yangbin Pan; Jianxin Wan; Yipeng Liu,; Qian Yang; Wei Liang; Singhal, Pravin C; Saleem, Moin A.; Guohua Ding

    2014-01-01

    The M-type phospholipase A2 receptor (PLA2R) is expressed in podocytes in human glomeruli. Group IB secretory phospholipase A2 (sPLA2 IB), which is one of the ligands of the PLA2R, is more highly expressed in chronic renal failure patients than in controls. However, the roles of the PLA2R and sPLA2 IB in the pathogenesis of glomerular diseases are unknown. In the present study, we found that more podocyte apoptosis occurs in the kidneys of patients with higher PLA2R and serum sPLA2 IB levels....

  5. Synergistic effect of mesangial cell-induced CXCL1 and TGF-β1 in promoting podocyte loss in IgA nephropathy.

    Directory of Open Access Journals (Sweden)

    Li Zhu

    Full Text Available Podocyte loss has been reported to relate to disease severity and progression in IgA nephropathy (IgAN. However, the underlying mechanism for its role in IgAN remain unclear. Recent evidence has shown that IgA1 complexes from patients with IgAN could activate mesangial cells to induce soluble mediator excretion, and further injure podocytes through mesangial-podocytic cross-talk. In the present study, we explored the underlying mechanism of mesangial cell-induced podocyte loss in IgAN. We found that IgA1 complexes from IgAN patients significantly up-regulated the expression of CXCL1 and TGF-β1 in mesangial cells compared with healthy controls. Significantly higher urinary levels of CXCL1 and TGF-β1 were also observed in patients with IgAN compared to healthy controls. Moreover, IgAN patients with higher urinary CXCL1 and TGF-β1 presented with severe clinical and pathological manifestations, including higher 24-hour urine protein excretion, lower eGFR and higher cresentic glomeruli proportion. Further in vitro experiments showed that increased podocyte death and reduced podocyte adhesion were induced by mesangial cell conditional medium from IgAN (IgAN-HMCM, as well as rhCXCL1 together with rhTGF-β1. In addition, the over-expression of CXCR2, the receptor for CXCL1, by podocytes was induced by IgAN-HMCM and rhTGF-β1, but not by rhCXCL1. Furthermore, the effect of increased podocyte death and reduced podocyte adhesion induced by IgAN-HMCM and rhCXCL1 and rhTGF-β1 was rescued partially by a blocking antibody against CXCR2. Moreover, we observed the expression of CXCR2 in urine exfoliated podocytes in IgAN patients. Our present study implied that IgA1 complexes from IgAN patients could up-regulate the secretion of CXCL1 and TGF-β1 in mesangial cells. Additionally, the synergistic effect of CXCL1 and TGF-β1 further induced podocyte death and adhesion dysfunction in podocytes via CXCR2. This might be a potential mechanism for podocyte loss

  6. Human podocytes adhere to the KRGDS motif of the alpha3alpha4alpha5 collagen IV network.

    Science.gov (United States)

    Borza, Corina M; Borza, Dorin-Bogdan; Pedchenko, Vadim; Saleem, Moin A; Mathieson, Peter W; Sado, Yoshikazu; Hudson, Heather M; Pozzi, Ambra; Saus, Juan; Abrahamson, Dale R; Zent, Roy; Hudson, Billy G

    2008-04-01

    Podocyte adhesion to the glomerular basement membrane is required for proper function of the glomerular filtration barrier. However, the mechanism whereby podocytes adhere to collagen IV networks, a major component of the glomerular basement membrane, is poorly understood. The predominant collagen IV network is composed of triple helical protomers containing the alpha3alpha4alpha5 chains. The protomers connect via the trimeric noncollagenous (NC1) domains to form hexamers at the interface. Because the NC1 domains of this network can potentially support integrin-dependent cell adhesion, it was determined whether individual NC1 monomers or alpha3alpha4alpha5 hexamers support podocyte adhesion. It was found that, although human podocytes did not adhere to NC1 domains proper, they did adhere via integrin alphavbeta3 to a KRGDS motif located adjacent to alpha3NC1 domains. Because the KRGDS motif is a site of phosphorylation, its interactions with integrin alphavbeta3 may play a critical role in cell signaling in physiologic and pathologic states. PMID:18235087

  7. Mice with mutant Inf2 show impaired podocyte and slit diaphragm integrity in response to protamine-induced kidney injury.

    Science.gov (United States)

    Subramanian, Balajikarthick; Sun, Hua; Yan, Paul; Charoonratana, Victoria T; Higgs, Henry N; Wang, Fang; Lai, Ka-Man V; Valenzuela, David M; Brown, Elizabeth J; Schlöndorff, Johannes S; Pollak, Martin R

    2016-08-01

    Mutations in the INF2 (inverted formin 2) gene, encoding a diaphanous formin family protein that regulates actin cytoskeleton dynamics, cause human focal segmental glomerulosclerosis (FSGS). INF2 interacts directly with certain other mammalian diaphanous formin proteins (mDia) that function as RhoA effector molecules. FSGS-causing INF2 mutations impair these interactions and disrupt the ability of INF2 to regulate Rho/Dia-mediated actin dynamics in vitro. However, the precise mechanisms by which INF2 regulates and INF2 mutations impair glomerular structure and function remain unknown. Here, we characterize an Inf2 R218Q point-mutant (knockin) mouse to help answer these questions. Knockin mice have no significant renal pathology or proteinuria at baseline despite diminished INF2 protein levels. INF2 mutant podocytes do show impaired reversal of protamine sulfate-induced foot process effacement by heparin sulfate perfusion. This is associated with persistent podocyte cytoplasmic aggregation, nephrin phosphorylation, and nephrin and podocin mislocalization, as well as impaired recovery of mDia membrane localization. These changes were partially mimicked in podocyte outgrowth cultures, in which podocytes from knockin mice show altered cellular protrusions compared to those from wild-type mice. Thus, in mice, normal INF2 function is not required for glomerular development but normal INF2 is required for regulation of the actin-based behaviors necessary for response to and/or recovery from injury. PMID:27350175

  8. Advance of Podocyte Function in Glomerular%肾小球足细胞功能认识的进展

    Institute of Scientific and Technical Information of China (English)

    邹琦

    2011-01-01

    足细胞是肾小球高度分化的细胞类型,是肾小球滤过屏障的重要组成部分.假定足细胞的足突能抵消肾小球基底膜的弹力作用,而血管激素可能调节足突的收缩状态,从而调节肾小球的超滤系数Kf.足细胞损伤可导致蛋白尿的发生,而许多伴有足细胞损伤的肾小球疾病,可能进展为慢性肾衰竭.通过了解调节足细胞的生理特性及其细胞的损伤反应机制可进一步了解蛋白尿及肾小球疾病的发病机制.过去由于足细胞独特的解剖学位置以及足细胞难以通过细胞培养区分,很难发现足细胞的功能.然而,近年来由于生理学、分子生物学及细胞培养技术的进步,使人们更多地了解足细胞在维持肾小球功能中发挥的作用.%The podocyte is the most differentiated cells in the glomerulum, which forms a crucial component of the glomerular filtration barrier.It has been assumed that podocyte foot processes counteract the elastic force of the glomerular basement membrane and that vasoactive hormones may regulate the contractile state of their foot processes and thereby modulate the ultrafiltration coefficient Kf.podocyte damage leads to proteinuria, and podocyte injury occurs in many glomerular diseases,which may progress to chronic renal failure.The understanding of the regulation of physiological properties of the podocyte and the mechanisms of its cellular response to injury may thus provide a clue to the understanding of the pathogenesis of proteinuria and glomerular diseases.In the past it was difficult to study cellular functions in this cell type, because of its unique anatomic location and the difficulty in characterizing podocytes in cell culture.However, recent advances in physiological, molecular biological, and cell culture techniques have increased the knowledge of the role of the podocyte in glomerular function.

  9. Pretreatment with the Total Flavone Glycosides of Flos Abelmoschus manihot and Hyperoside Prevents Glomerular Podocyte Apoptosis in Streptozotocin-Induced Diabetic Nephropathy

    OpenAIRE

    Lei ZHOU; An, Xiao-Fei; Teng, Shi-Chao; Liu, Jing-Shun; Shang, Wen-bin; Zhang, Ai-Hua; Yuan, Yang-Gang; Yu, Jiang-yi

    2012-01-01

    Diabetic nephropathy (DN) is an important diabetic complication, and podocyte apoptosis plays a critical role in the development of DN. In the present study, we examined the preventive effect of the total flavone glycosides of Flos Abelmoschus manihot (TFA) on urinary microalbumin and glomerular podocyte apoptosis in experimental DN rats. The preliminary oral administration of TFA (200 mg/kg/day) for 24 weeks significantly decreased the urinary microalbumin to creatinine ratio and 24-h urinar...

  10. The Protective Effects of Curcumin on Obesity-Related Glomerulopathy Are Associated with Inhibition of Wnt/β-Catenin Signaling Activation in Podocytes

    Directory of Open Access Journals (Sweden)

    Bao-li Liu

    2015-01-01

    Full Text Available The present study investigated the effects of curcumin, one of the most important active ingredients of turmeric, on podocyte injury in vitro and obesity-related glomerulopathy (ORG in vivo. Cellular experiments in vitro showed that curcumin significantly antagonized leptin-induced downregulation of the mRNA and protein expression of podocyte-associated molecules including nephrin, podocin, podoplanin, and podocalyxin. Animal experiments in vivo showed that curcumin significantly reduced the body weight, Lee’s index, abdominal fat index, urinary protein excretion, and average glomerular diameter and significantly upregulated the mRNA and protein expressions of the above podocyte-associated molecules in ORG mice. Furthermore, the experiments in vitro and in vivo both displayed that curcumin could downregulate the mRNA and protein expressions of Wnt1, Wnt2b, Wnt6, and β-catenin and upregulate the phosphorylation level of β-catenin protein in podocytes and renal tissue. In conclusion, curcumin is able to alleviate the harmful reaction of leptin on podocytes and reduce the severity of ORG. The above protective effects are associated with the inhibition of Wnt/β-catenin signaling activation in podocytes.

  11. Angiotensin II receptor blocker attenuates intrarenal renin-angiotensin-system and podocyte injury in rats with myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Zhu-zhi Wen

    Full Text Available The mechanisms and mediators underlying common renal impairment after myocardial infarction (MI are still poorly understood. The present study aimed to test the hypothesis that angiotensin II type 1 receptor blockers (ARBs provides renoprotective effects after MI by preventing augmented intrarenal renin-angiotensin-system (RAS-induced podocyte injury. Sprague-Dawley rats that underwent ligation of their coronary arteries were treated with losartan (20 mg/kg/d or vehicle for 3 or 9 weeks. Renal function, histology and molecular changes were assessed. The current study revealed that MI-induced glomerular podocyte injury was identified by increased immunostaining for desmin and p16(ink4a, decreased immunostaining for Wilms' tumor-1 and podocin mRNA expression, and an induced increase of blood cystatin C at both 3 and 9 weeks. These changes were associated with increased intrarenal angiotensin II levels and enhanced expressions of angiotensinogen mRNA and angiotensin II receptor mRNA and protein. These changes were also associated with decreased levels of insulin-like growth factor (IGF-1 and decreased expressions of IGF-1 receptor (IGF-1R protein and mRNA and phosphorylated(p-Akt protein at 9 weeks, as well as increased expressions of 8-hydroxy-2'-deoxyguanosine at both time points. Treatment with losartan significantly attenuated desmin- and p16(ink4a-positive podocytes, restored podocin mRNA expression, and decreased blood cystatin C levels. Losartan also prevented RAS activation and oxidative stress and restored the IGF-1/IGF-1R/Akt pathway. In conclusion, ARBs prevent the progression of renal impairment after MI via podocyte protection, partially by inhibiting the activation of the local RAS with subsequent enhanced oxidative stress and an inhibited IGF-1/IGF-1R/Akt pathway.

  12. Insulin-like growth factor-II is produced by, signals to and is an important survival factor for the mature podocyte in man and mouse.

    Science.gov (United States)

    Hale, L J; Welsh, G I; Perks, C M; Hurcombe, J A; Moore, S; Hers, I; Saleem, M A; Mathieson, P W; Murphy, A J; Jeansson, M; Holly, J M; Hardouin, S N; Coward, R J

    2013-05-01

    Podocytes are crucial for preventing the passage of albumin into the urine and, when lost, are associated with the development of albuminuria, renal failure and cardiovascular disease. Podocytes have limited capacity to regenerate, therefore pro-survival mechanisms are critically important. Insulin-like growth factor-II (IGF-II) is a potent survival and growth factor; however, its major function is thought to be in prenatal development, when circulating levels are high. IGF-II has only previously been reported to continue to be expressed in discrete regions of the brain into adulthood in rodents, with systemic levels being undetectable. Using conditionally immortalized human and ex vivo adult mouse cells of the glomerulus, we demonstrated the podocyte to be the major glomerular source and target of IGF-II; it signals to this cell via the IGF-I receptor via the PI3 kinase and MAPK pathways. Functionally, a reduction in IGF signalling causes podocyte cell death in vitro and glomerular disease in vivo in an aged IGF-II transgenic mouse that produces approximately 60% of IGF-II due to a lack of the P2 promoter of this gene. Collectively, this work reveals the fundamental importance of IGF-II in the mature podocyte for glomerular health across mammalian species. PMID:23299523

  13. The effect of albumin on podocytes: The role of the fatty acid moiety and the potential role of CD36 scavenger receptor

    Energy Technology Data Exchange (ETDEWEB)

    Pawluczyk, I.Z.A., E-mail: izap1@le.ac.uk [Department of Infection, Immunity and inflammation, University of Leicester, Leicester (United Kingdom); John Walls Renal Unit, Leicester General Hospital Leicester (United Kingdom); Pervez, A.; Ghaderi Najafabadi, M. [Department of Infection, Immunity and inflammation, University of Leicester, Leicester (United Kingdom); Saleem, M.A. [Academic and Children' s Renal Unit, University of Bristol, Southmead Hospital, Bristol (United Kingdom); Topham, P.S. [Department of Infection, Immunity and inflammation, University of Leicester, Leicester (United Kingdom); John Walls Renal Unit, Leicester General Hospital Leicester (United Kingdom)

    2014-08-15

    Evidence is emerging that podocytes are able to endocytose proteins such as albumin using kinetics consistent with a receptor-mediated process. To date the role of the fatty acid moiety on albumin uptake kinetics has not been delineated and the receptor responsible for uptake is yet to be identified. Albumin uptake studies were carried out on cultured human podocytes exposed to FITC-labelled human serum albumin either carrying fatty acids (HSA{sub +FA}) or depleted of them (HSA{sub −FA}). Receptor-mediated endocytosis of FITC-HSA{sub +FA} over 60 min was 5 times greater than that of FITC-HSA{sub −FA}. 24 h exposure of podocytes to albumin up-regulated nephrin expression and induced the activation of caspase-3. These effects were more pronounced in response to HSA{sub −FA.} Individually, anti-CD36 antibodies had no effect upon endocytosis of FITC-HSA. However, a cocktail of 2 antibodies reduced uptake by nearly 50%. Albumin endocytosis was enhanced in the presence of the CD36 specific inhibitor sulfo-N-succinimidyl oleate (SSO) while knock-down of CD36 using CD36siRNA had no effect on uptake. These data suggest that receptor-mediated endocytosis of albumin by podocytes is regulated by the fatty acid moiety, although, some of the detrimental effects are induced independently of it. CD36 does not play a direct role in the uptake of albumin. - Highlights: • The fatty acid moiety is essential for receptor mediated endocytosis of albumin. • Fatty acid depleted albumin is more pathogenic to podocytes. • CD36 is not directly involved in albumin uptake by podocytes.

  14. The effect of albumin on podocytes: The role of the fatty acid moiety and the potential role of CD36 scavenger receptor

    International Nuclear Information System (INIS)

    Evidence is emerging that podocytes are able to endocytose proteins such as albumin using kinetics consistent with a receptor-mediated process. To date the role of the fatty acid moiety on albumin uptake kinetics has not been delineated and the receptor responsible for uptake is yet to be identified. Albumin uptake studies were carried out on cultured human podocytes exposed to FITC-labelled human serum albumin either carrying fatty acids (HSA+FA) or depleted of them (HSA−FA). Receptor-mediated endocytosis of FITC-HSA+FA over 60 min was 5 times greater than that of FITC-HSA−FA. 24 h exposure of podocytes to albumin up-regulated nephrin expression and induced the activation of caspase-3. These effects were more pronounced in response to HSA−FA. Individually, anti-CD36 antibodies had no effect upon endocytosis of FITC-HSA. However, a cocktail of 2 antibodies reduced uptake by nearly 50%. Albumin endocytosis was enhanced in the presence of the CD36 specific inhibitor sulfo-N-succinimidyl oleate (SSO) while knock-down of CD36 using CD36siRNA had no effect on uptake. These data suggest that receptor-mediated endocytosis of albumin by podocytes is regulated by the fatty acid moiety, although, some of the detrimental effects are induced independently of it. CD36 does not play a direct role in the uptake of albumin. - Highlights: • The fatty acid moiety is essential for receptor mediated endocytosis of albumin. • Fatty acid depleted albumin is more pathogenic to podocytes. • CD36 is not directly involved in albumin uptake by podocytes

  15. Quarkonium suppression

    Indian Academy of Sciences (India)

    P Petreczky

    2003-04-01

    I discuss quarkonium suppression in equilibrated strongly interacting matter. After a brief review of basic features of quarkonium production I discuss the application of recent lattice data on the heavy quark potential to the problem of quarkonium dissociation as well as the problem of direct lattice determination of quarkonium properties in finite temperature lattice QCD.

  16. Regulation of Neph3 gene in podocytes - key roles of transcription factors NF-kappaB and Sp1

    LENUS (Irish Health Repository)

    Ristola, Mervi

    2009-08-24

    Abstract Background Neph3 (filtrin) is expressed in the glomerular podocytes where it localizes at the specialized cell adhesion structures of the foot processes called slit diaphragms which form the outermost layer of the glomerular filtration barrier. Neph3 protein shows homology and structural similarity to Neph1, Neph2 and nephrin, which all are crucial for maintaining the normal glomerular ultrafiltration function. The exact function of Neph3 in the kidney is not known but we have previously shown that the level of Neph3 mRNA is decreased in proteinuric diseases. This suggests that Neph3 may play a role in the pathogenesis of kidney damage, and emphasizes the need to analyze the regulatory mechanisms of Neph3 gene. In this study we investigated the transcriptional regulation of Neph3 gene by identifying transcription factors that control Neph3 expression. Results We cloned and characterized approximately 5 kb fragment upstream of the Neph3 gene. Neph3 proximal promoter near the transcription start site was found to be devoid of TATA and CAAT boxes, but to contain a highly GC-rich area. Using promoter reporter gene constructs, we localized the main activating regulatory region of Neph3 gene in its proximal promoter region from -105 to -57. Within this region, putative transcription factor binding sites for NF-κB and Sp1 were found by computational analysis. Mutational screening indicated that NF-κB and Sp1 response elements are essential for the basal transcriptional activity of the Neph3 promoter. Co-transfection studies further showed that NF-κB and Sp1 regulate Neph3 promoter activity. In addition, overexpression of NF-κB increased endogenous Neph3 gene expression. Chromatin immunoprecipitation assay using cultured human podocytes demonstrated that both NF-κB and Sp1 interact with the Neph3 promoter. Conclusion Our results show that NF-κB and Sp1 are key regulators of Neph3 expression at the basal level in podocytes, therefore providing new insight

  17. Nuclear suppression

    International Nuclear Information System (INIS)

    This article draws attention to a number of cases where it seems that scientists and technologists have been penalized in various ways for having views opposed to those of the nuclear industry. Attempts to encourage the general public to understand nuclear issues have also been discouraged, nuclear knowledge being kept as the preserve of the experts and policy makers, especially in the military applications of nuclear power. It may be that publications are suppressed or careers are destroyed. One example highlighted in the article is of Dhirendra Shama, a critic of India's nuclear policy, who was suddenly transferred from the Centre of Studies in Science Policy at his University to the School of Languages. Other examples are given from other countries - Australia, Britain, Canada, Federal Republic of Germany, India, Japan, New Zealand, Soviet Union, Sweden and the United States of America. The main 'crime' of those victimised is not in having critical views, but in alerting the general public to those critical view and ideas. (UK)

  18. Leptin deficiency down-regulates IL-23 production in glomerular podocytes resulting in an attenuated immune response in nephrotoxic serum nephritis.

    Science.gov (United States)

    Goto, Kei; Kaneko, Yoshikatsu; Sato, Yuya; Otsuka, Tadashi; Yamamoto, Suguru; Goto, Shin; Yamamoto, Keiko; Yamamoto, Tadashi; Kawachi, Hiroshi; Madaio, Michael P; Narita, Ichiei

    2016-04-01

    Leptin, one of the typical adipokines, is reported to promote Th17 cell responses and to enhance production of proinflammatory cytokines. To clarify the role of leptin in the regulation of the IL-23/IL-17 axis and the development of kidney disease, we used a murine model of nephrotoxic serum (NTS) nephritis (NTN). Sheep NTS was administered in wild-type C57BL/6J mice and food-restricted, leptin-deficient C57BL/6J-ob/ob(FR-ob/ob) mice after preimmunization with sheep IgG. The profile of mRNA expression relevant to T helper lymphocytes in the kidneys was analyzed by quantitative real-time PCR (qRT-PCR). Cultured murine glomerular podocytes and peritoneal exudate macrophages (PEMs) were used to investigate the direct effect of leptin on IL-23 or MCP-1 production by qRT-PCR. Kidney injury and macrophage infiltration were significantly attenuated in FR-ob/obmice 7 days after NTS injection. The Th17-dependent secondary immune response against deposited NTS in the glomeruli was totally impaired in FR-ob/obmice because of deteriorated IL-17 and proinflammatory cytokine production including IL-23 and MCP-1 in the kidney. IL-23 was produced in glomerular podocytes in NTN mice and cultured murine glomerular podocytes produced IL-23 under leptin stimulation. MCP-1 production in PEMs was also promoted by leptin. Induction of MCP-1 expression was observed in PEMs regardless of Ob-Rb, and the leptin signal was transduced without STAT3 phosphorylation in PEMs. Leptin deficiency impairs the secondary immune response against NTS and down-regulates IL-23 production and Th17 responses in the NTN kidney, which is accompanied by decreased MCP-1 production and macrophage infiltration in the NTN kidney. PMID:26567290

  19. Effects of low protein diet supplemented with ketoacids on local renin-angiotensin system enzyme activities and podocytes loss in patients with diabetic nephropathy

    Institute of Scientific and Technical Information of China (English)

    谷立杰

    2014-01-01

    Objective To explore the effects of low-protein diet supplemented with ketoacids on podocytes as well as local RAS in the kidney of patients with diabetic nephropathy.Methods A total of 61 patients with T2DN and CKD stages 3-4 were included.All the patients were randomly divided into two groups:low protein group(0.6g·kg BW-1·d-1and 30 kcal·kg BW-1·d-1,LPD)

  20. Dexamethasone suppression test

    Science.gov (United States)

    DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medication. Afterward, your blood is drawn ...

  1. Sodium fire suppression

    International Nuclear Information System (INIS)

    Ignition and combustion studies have provided valuable data and guidelines for sodium fire suppression research. The primary necessity is to isolate the oxidant from the fuel, rather than to attempt to cool the sodium below its ignition temperature. Work along these lines has led to the development of smothering tank systems and a dry extinguishing powder. Based on the results obtained, the implementation of these techniques is discussed with regard to sodium fire suppression in the Super-Phenix reactor. (author)

  2. Assessment of the degree of oxidative stress injury, renin-angiotensin system activity and podocyte loss after combined treatment of keto acid with low protein diet for patients with diabetic nephropathy

    Institute of Scientific and Technical Information of China (English)

    Yuan-Hua Xu; Mei Wang

    2016-01-01

    Objective:To analyze the degree of oxidative stress injury, RAS activity and podocyte loss after patients with diabetic nephropathy received keto acid combined with low protein diet. Methods:A total of 106 cases of patients with diabetic nephropathy who received hospital treatment in our hospital from September 2012 to July 2015 were selected as research subjects and randomly divided into observation group and control group according to different treatment, each group with 53 cases. Control group received low protein diet treatment alone, observation group received keto acid combined with low protein diet treatment, and then the degree of oxidative stress injury, RAS activity and podocyte loss of two groups were compared. Results:Serum MDA and AOPP levels of observation group after treatment were lower than those of control group, and levels of SOD and T-AOC were higher than those of control group;PRA, AngⅡand Aldosterone levels of observation group after treatment were lower than those of control group;mRNA expression levels of podocin and synaptopodin in urine sediment of observation group after treatment were lower than those of control group. Conclusion:Keto acid combined with low protein diet treatment for patients with diabetic nephropathy can reduce the degree of oxidative stress injury and RAS activity, decrease podocyte loss and optimize patients’ condition.

  3. 人尿源性干细胞条件培养基对高糖诱导足细胞凋亡的影响%Effects of Human Urine Derived Stem Cells on Human Podocytes Apoptosis Exposed to High Glucose

    Institute of Scientific and Technical Information of China (English)

    姜珍珍; 汪年松; 汪泱; 刘四红; 王筱霞; 范瑛

    2014-01-01

    目的:通过正常人尿液提取干细胞,探讨尿源干细胞(human urine - derived stem cells,hUSCs)的条件培养基(conditioned medium,CM)对高糖所致人肾脏足细胞损伤的影响。方法:从健康男性尿液提取 hUSCs,鉴定后进行体外培养,制备 hUSCs - CM;体外培养人肾脏足细胞株,按培养条件不同,分为正常葡萄糖对照组( NG 组)、高糖组(HG 组)、甘露醇高渗对照组(MA 组)及 HG + hUSCs - CM 不同剂量(1×,5×,10×)干预组,干预24 h 后收集细胞,以 RT - PCR 检测足细胞骨架蛋白 synaptopodin 的表达;以 Annexin V - FITC 和 PI 双染方法,应用流式细胞仪观察各组足细胞的早期凋亡率。结果:HG 组足细胞 synaptopodin mRNA 的表达较 NG 组降低(P <0.05),HG + hUSCs - CM(1×,5×,10×)组的足细胞 synaptopodin mRNA 的表达较 HG 组均增加(P <0.05);HG 组足细胞凋亡率较 NG 组增高(P <0.05),hUSCs - CM 干预组较 HG 组足细胞凋亡率均下降,并和 hUSCs - CM 具有剂量相关性(P <0.05)。结论:hUSCs - CM 对高糖诱导的人足细胞凋亡及损伤具有保护作用。%Objective:To extract stem cells through normal urine and to investigate the effects of conditioned medium(CM) from human urine derived stem cells(hUSCs)on podocyte lesion induced by high glucose. Methods:hUSCs were isolated from void-ed urine of healthy men. After identification and proliferation,hUSCs - CM was prepared. According to the different culture condi-tions,human podocytes were divided into normal glucose group,high permeability group,high glucose group(HG),and HG +hUSCs - CM(1 × ,5 × ,10 × )group. Real - time PCR was applied to detect the expression levels of synaptopodin,and human podocytes apoptosis in each group were examined by flow cytometry after cultured for 24 hours. Results:Compared with incubated in NG,the expression of synaptopodin mRNA in HG was found to

  4. Hidden Complications of Thought Suppression

    OpenAIRE

    Najmi, Sadia; Wegner, Daniel M.

    2009-01-01

    Although the suppression of thoughts may seem to be an effective solution, this strategy can lead to an exacerbation of the very thought that one is attempting to suppress. This ironic effect is the most obvious unwanted outcome of suppression and has now been investigated empirically for more than two decades. However, the fact that suppression is an effortful process implies that, even when suppression does not lead to an ironic rebound of the unwanted thought, it puts an insidious cognitiv...

  5. The predominant WT1 isoform (+KTS) encodes a DNA-binding protein targeting the planar cell polarity gene Scribble in renal podocytes.

    Science.gov (United States)

    Wells, Julie; Rivera, Miguel N; Kim, Woo Jae; Starbuck, Kristen; Haber, Daniel A

    2010-07-01

    WT1 encodes a tumor suppressor first identified by its inactivation in Wilms' Tumor. Although one WT1 splicing variant encodes a well-characterized zinc finger transcription factor, little is known about the function of the most prevalent WT1 isoform, whose DNA binding domain is disrupted by a three-amino acid (KTS) insertion. Using cells that conditionally express WT1(+KTS), we undertook a genome-wide chromatin immunoprecipitation and cloning analysis to identify candidate WT1(+KTS)-regulated promoters. We identified the planar cell polarity gene Scribble (SCRB) as the first WT1(+KTS) target gene in podocytes of the kidney. WT1 and SCRB expression patterns overlap precisely in developing renal glomeruli of mice, and WT1(+KTS) binds to a 33-nucleotide region within the Scribble promoter in mouse and human cell lines and kidneys. Together, our results support a role for the predominant WT1(+KTS) isoform in transcriptional regulation and suggest a link between the WT1-dependent tumor suppressor pathway and a key component of the planar cell polarity pathway. PMID:20571064

  6. The predominant WT1 isoform (+KTS) encodes a DNA binding protein targeting the planar cell polarity gene Scribble in renal podocytes

    Science.gov (United States)

    Wells, Julie; Rivera, Miguel N.; Kim, Woo Jae; Starbuck, Kristen; Haber, Daniel A.

    2010-01-01

    WT1 encodes a tumor suppressor, first identified by its inactivation in Wilms Tumor. While one WT1 splicing variant encodes a well-characterized zinc finger transcription factor, little is known about the function of the most prevalent WT1 isoform, whose DNA binding domain is disrupted by a three amino acid (KTS) insertion. Using cells which conditionally express WT1(+KTS), we undertook a genome-wide chromatin immunoprecipitation and cloning (ChIP-cloning) analysis to identify candidate WT1(+KTS) regulated promoters. We identified the planar cell polarity (PCP) gene Scribble (SCRB) as the first WT1(+KTS) target gene in podocytes of the kidney. WT1 and SCRB expression patterns overlap precisely in developing renal glomeruli of mice, and WT1(+KTS) binds to a 33 nucleotide region within the Scribble promoter in both mouse and human cell lines and kidneys. Together, our results support a role for the predominant WT1(+KTS) isoform in transcriptional regulation and suggest a link between the WT1-dependent tumor suppressor pathway and a key component of the planar cell polarity pathway. PMID:20571064

  7. Interactions between surround suppression and interocular suppression in human vision.

    Directory of Open Access Journals (Sweden)

    Yong-Chun Cai

    Full Text Available Several types of suppression phenomena have been observed in the visual system. For example, the ability to detect a target stimulus is often impaired when the target is embedded in a high-contrast surround. This contextual modulation, known as surround suppression, was formerly thought to occur only in the periphery. Another type of suppression phenomena is interocular suppression, in which the sensitivity to a monocular target is reduced by a superimposed mask in the opposite eye. Here, we explored how the two types of suppression operating across different spatial regions interact with one another when they simultaneously exert suppressive influences on a common target presented at the fovea. In our experiments, a circular target grating presented to the fovea of one eye was suppressed interocularly by a noise pattern of the same size in the other eye. The foveal stimuli were either shown alone or surrounded by a monocular annular grating. The orientation and eye-of-origin of the surround grating were varied. We found that the detection of the foveal target subjected to interocular suppression was severely impaired by the addition of the surround grating, indicating strong surround suppression in the fovea. In contrast, when the interocular suppression was released by superimposing a binocular fusion ring onto both the target and the dichoptic mask, the surround suppression effect was found to be dramatically decreased. In addition, the surround suppression was found to depend on the contrast of the dichoptic noise with the greatest surround suppression effect being obtained only when the noise contrast was at an intermediate level. These findings indicate that surround suppression and interocular suppression are not independent of each other, but there are strong interactions between them. Moreover, our results suggest that strong surround suppression may also occur at the fovea and not just the periphery.

  8. Suppression or expression

    OpenAIRE

    Patricia Lewis

    2005-01-01

    Based on an interview study of neonatal nurses, this article sets out to explore the management of emotions within a work context where their suppression is a professional requirement. Drawing on Bolton’s (2000a, 2000b) identification of different types of organizational emotionality, in particular prescriptive and philanthropic emotion management, the article seeks to demonstrate the complexities involved in the performance of emotional labour. It does this by first exploring the times whe...

  9. Tremor suppression in ECG

    Directory of Open Access Journals (Sweden)

    Mihov Georgy S

    2008-11-01

    Full Text Available Abstract Background Electrocardiogram recordings are very often contaminated by high-frequency noise usually power-line interference and EMG disturbances (tremor. Specific method for interference cancellation without affecting the proper ECG components, called subtraction procedure, was developed some two decades ago. Filtering out the tremor remains a priori partially successful since it has a relatively wide spectrum, which overlaps the useful ECG frequency band. Method The proposed method for tremor suppression implements the following three procedures. Contaminated ECG signals are subjected to moving averaging (comb filter with linear phase characteristic with first zero set at 50 Hz to suppress tremor and PL interference simultaneously. The reduced peaks of QRS complexes and other relatively high and steep ECG waves are then restored by an introduced by us procedure called linearly-angular, so that the useful high frequency components are preserved in the range specified by the embedded in the ECG instrument filter, usually up to 125 Hz. Finally, a Savitzky-Golay smoothing filter is applied for supplementary tremor suppression outside the QRS complexes. Results The results obtained show a low level of the residual EMG disturbances together with negligible distortion of the wave shapes regardless of rhythm and morphology changes.

  10. Menstrual suppression: current perspectives

    Directory of Open Access Journals (Sweden)

    Hillard PA

    2014-06-01

    Full Text Available Paula Adams Hillard Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA Abstract: Menstrual suppression to provide relief of menstrual-related symptoms or to manage medical conditions associated with menstrual morbidity or menstrual exacerbation has been used clinically since the development of steroid hormonal therapies. Options range from the extended or continuous use of combined hormonal oral contraceptives, to the use of combined hormonal patches and rings, progestins given in a variety of formulations from intramuscular injection to oral therapies to intrauterine devices, and other agents such as gonadotropin-releasing hormone (GnRH antagonists. The agents used for menstrual suppression have variable rates of success in inducing amenorrhea, but typically have increasing rates of amenorrhea over time. Therapy may be limited by side effects, most commonly irregular, unscheduled bleeding. These therapies can benefit women's quality of life, and by stabilizing the hormonal milieu, potentially improve the course of underlying medical conditions such as diabetes or a seizure disorder. This review addresses situations in which menstrual suppression may be of benefit, and lists options which have been successful in inducing medical amenorrhea. Keywords: menstrual molimena, amenorrhea, inducing amenorrhea, quality of life

  11. Vibrotactile suppression of tinnitus

    Science.gov (United States)

    Lenhardt, Martin L.

    2002-05-01

    At the Society's 142nd meeting, the efficacy of high frequency bone conducted stimulation in suppressing tinnitus was presented. The hypothesized mechanism was the reprogramming of frequency tuning of auditory neurons in the central nervous system, secondarily to peripheral hearing loss. This mechanism is unlikely in cases of tinnitus in the presence of normal audiometric sensitivity. There is the possibility that hearing loss above 10 kHz can play a role in tinnitus, an association not thoroughly explored. Somatomotor stimulation influencing the quality of tinnitus has been reported, as have interconnections of the auditory and somatosensory systems. There would appear to be an evolutionary advantage of linking the sensorimotor organization of the external ear and the auditory function of the brainstem in sound localization. Thus, stimulation of the pinna and post auricular area may be a means of suppressing tinnitus. To that end a thin aluminum ceramic bimorph was constructed to fit on the inner surface of the pinna. When driven by low (10 kHz) frequencies multiplied by MHz carriers, demodulation in the skin resulted in vibrotactile stimulation. Tactile stimulation was an adjunct to the high frequencies resulting in a multimodal suppressive effect in a small pilot study.

  12. Next generation fire suppressants

    Science.gov (United States)

    Brown, Jerry A.

    1995-01-01

    Spectrex, Inc., located in Cedar Grove, NJ is a manufacturer of fire detection and suppression equipment. Spectrex is one of the original pioneers in high speed fire detection and suppression systems for combat vehicles. Spectrex has installed fire suppressions systems in thousands of combat vehicles and ships throughout the world. Additionally, they manufacture flame explosion detectors, ship damage control systems, and optical gas and vapor detectors. The culmination of several years of research and development has recently produced an innovative electro-optical continuous monitoring systems called SharpEye 20/20I IR(sup 3) and SAFEYE that provide fast and reliable gas, vapor, aerosol, flame, and explosion detection. SharpEye 20/20I IR(sup 3) is a self-contained triple spectrum flame detector which scans for oscillating IR radiation (1 to 10 Hz) in the spectral bands ranging from 4.0 to 5.0 microns and uses programmed algorithms to check the ratio and correlation of data received by the three sensors to make the system highly immune to false alarms. It is extremely sensitive as it can detect a 1 x 1 square foot gasoline pan fire at 200 feet in less than 3 seconds. The sensitivity is user programmable, offering 4 ranges of detection. SAFEYE is comprised of a selected number of multispectral ban microprocessors controlled detectors which are in communication with one or more radiation sources that is projected along a 600 feet optical path. The signals from the selected narrow bands are processed and analyzed by highly sophisticated algorithms. It is ideal for high risk, remote, large areas such as petroleum and chemical manufacturing sites, waste dumps, aircraft cargo bays, and ship compartments. The SAFEYE will perform direct readings of the presence or rate of rise of concentrations of gases, vapors, or aerosols at the range of parts per million and provide alarms at various set points at different levels of concentrations.

  13. The pressure suppression system

    International Nuclear Information System (INIS)

    Nuclear plants with boiling water reactors have a safety containment with a pressure suppression system (PSS). Proceeding on significant self-developments, today the three PSS-lines of General Electric Co. (GE), Kraftwerk Union AG (KWU) and ASEA-ATOM are predominant, which are currently represented by the MARK III type, the KWU type 72 and the BWR 75 containment. In addition, there are special developments for the nuclear ship propulsion and for the pressurized water reactors in the Soviet Union. Key design values of the PSS allow a first valuation of its loads during a hypothetical loss-of-coolant accident. (orig.)

  14. Planck-suppressed operators

    International Nuclear Information System (INIS)

    We show that the recent Planck limits on primordial non-Gaussianity impose strong constraints on light hidden sector fields coupled to the inflaton via operators suppressed by a high mass scale Λ. We study a simple effective field theory in which a hidden sector field is coupled to a shift-symmetric inflaton via arbitrary operators up to dimension five. Self-interactions in the hidden sector lead to non-Gaussianity in the curvature perturbations. To be consistent with the Planck limit on local non-Gaussianity, the coupling to any hidden sector with light fields and natural cubic couplings must be suppressed by a very high scale Λ > 105H. Even if the hidden sector has Gaussian correlations, nonlinearities in the mixing with the inflaton still lead to non-Gaussian curvature perturbations. In this case, the non-Gaussianity is of the equilateral or orthogonal type, and the Planck data requires Λ > 102H

  15. 活性维生素D及其类似物对足细胞保护的作用机制%Mechanism of active vitamin D and its analogues on the protection of podocytes

    Institute of Scientific and Technical Information of China (English)

    江罗佳(综述); 房向东; 涂卫平(审校)

    2014-01-01

    近年来,活性维生素D独立于调节钙磷代谢外的抗炎、调节细胞凋亡、介导免疫及减少蛋白尿的肾保护作用,成为国内外研究的热点药物。以临床及动物为基础的多数实验数据均有力证明足细胞是其主要的作用靶点,文中就目前的国内外文献关于活性维生素D及其类似物对足细胞保护的作用机制作一综述,展望活性维生素D在未来的应用前景。%In recent years , active vitamin D is a hot research drugs because of its renal protective effect of independent regu -lation of anti-inflammatory effects outside calcium and phosphorus metabolism , regulation of apoptosis , mediated immunity and reduc-tion of proteinuria .Podocyte is the main target of active vitamin D based on the result of clinical and animal studies .In this article, we review the current literature on mechanism of active vitamin D and its analogues on the protection of podocytes about and give the clini -cal perspectives of activity vitamin D .

  16. Effect of astragaloside IV on diabetic nephropathy rat podocytes and its mechanism%黄芪甲苷对糖尿病肾病大鼠足细胞的影响及其机制研究

    Institute of Scientific and Technical Information of China (English)

    罗蕴龄; 陈宜方; 何东元; 陈建国

    2014-01-01

    Objective To investigate the protect effects of astragaloside IV(AS- IV) on diabetic nephropathy rat podocytes and explore its mechanism. Methods Healthy male Sprague- Dawley (SD) rats of 180~200g were randomly divided into normal control group(NC), diabetic nephropathy group(DN) and diabetic nephropathy with AS- IV treatment group(DN+AS- IV). DN was induced by intraperitoneal injection of streptozotocin. AS- IV treatment was started 2 weeks before STZ injection and lasted 14 weeks. 24 hour urine were col ected and 24 hour urinary protein were measured at the end of the 6th,12th week after STZ injec-tion. At the end of 6th and 12th week after STZ injection, rats were sacrificed and the blood samples were col ected for measuring biochemical parameters. The kidneys were harvested for histopathology, immunohistochemistry, electron microscopy and West-ern blot examinations, and the renal pathology, morphological changes of podocytes, podocyte density changes and expression ofα3β1 integrin protein were analyzed. Results In STZ- induced DN rats severe hyperglycemia and proteinuria were devel-oped. Mesangial expansion, increased podocyte loss and decreased integrin α3 and β1 expression were detected in DN rats. Treatment with AS- IV10mg/ (kg·d) for 14 weeks ameliorated proteinuria and podocyte foot process effacement, attenuated the loss of podocytes in glomerules and up- regulated the expression of integrinα3 andβ1 in podocytes. Conclusion AS- IV may protect podocyte and ameliorate diabetic nephropathy by restoring the expression ofα3β1 integrin in diabetic rats.%目的:探讨黄芪甲苷(AS- IV)对糖尿病肾病(DN)大鼠足细胞的保护作用及其机制,为DN早期防治开辟一条新途径。方法体重180~200g健康雄性SD大鼠45只按配伍法分为正常对照组(NC组)、DN组和AS- IV治疗组(DN+AS- IV组),链脲佐菌素腹腔注射建立大鼠早期DN模型。DN+AS- IV组大鼠在造模前2周予AS- IV 10mg/(kg·d)

  17. Profiles of Everyday Thought Suppression

    OpenAIRE

    Ie, Amanda Yen Lin

    2014-01-01

    The present research assessed whether levels of depression, anxiety and worry, obsessive-compulsive distress, and psychopathy were differentially related to distinct thought suppression profiles. As a means to achieving this goal, the Profiles of Everyday Thought Suppression (PETS) scale was constructed to measure the frequencies with which various target thoughts are suppressed. The PETS scale demonstrated good internal consistency and test-retest reliability, and scores were positively co...

  18. An Alternative to Thought Suppression?

    Science.gov (United States)

    Boice, Robert

    2012-01-01

    Comments on the original article, "Setting free the bears: Escape from thought suppression," by D. M. Wegner (see record 2011-25622-008). While Wegner supposed that we might have to learn to live with bad thoughts, the present author discusses the use of imagination and guided imagery as an alternative to forced thought suppression.

  19. Inducing amnesia through systemic suppression.

    Science.gov (United States)

    Hulbert, Justin C; Henson, Richard N; Anderson, Michael C

    2016-01-01

    Hippocampal damage profoundly disrupts the ability to store new memories of life events. Amnesic windows might also occur in healthy people due to disturbed hippocampal function arising during mental processes that systemically reduce hippocampal activity. Intentionally suppressing memory retrieval (retrieval stopping) reduces hippocampal activity via control mechanisms mediated by the lateral prefrontal cortex. Here we show that when people suppress retrieval given a reminder of an unwanted memory, they are considerably more likely to forget unrelated experiences from periods surrounding suppression. This amnesic shadow follows a dose-response function, becomes more pronounced after practice suppressing retrieval, exhibits characteristics indicating disturbed hippocampal function, and is predicted by reduced hippocampal activity. These findings indicate that stopping retrieval engages a suppression mechanism that broadly compromises hippocampal processes and that hippocampal stabilization processes can be interrupted strategically. Cognitively triggered amnesia constitutes an unrecognized forgetting process that may account for otherwise unexplained memory lapses following trauma. PMID:26977589

  20. 亚麻木酚素提取物对糖尿病大鼠肾脏足细胞的影响%Effect of flaxseed lignan extract on podocytes in diabetic nephropathy rats

    Institute of Scientific and Technical Information of China (English)

    徐海娥; 张慧; 王孙璟; 顾呈华; 李莉

    2013-01-01

    目的:观察亚麻木酚素提取物对糖尿病大鼠肾脏足细胞损伤的影响.方法:将未造模大鼠作为正常对照组;成模大鼠随机分为3组(模型组、实验组、药物对照组).实验12周末检测24h尿白蛋白排泄率、肾重系数等变化,透射电镜观察肾脏足细胞超微病理结构变化.结果:与糖尿病模型组比较,实验组降低肾重、24h尿白蛋白排泄率、Scr、BUN (P <0.05).实验组和药物对照组病理改变均较糖尿病模型组明显减轻,足突部分融合,系膜基质轻度增多,肾小球基底膜增厚减轻.结论:亚麻木酚素提取物可减轻糖尿病大鼠肾脏足细胞病理损伤,改善肾功能.%Objective: To explore the effect of Flaxseed Lignan Extract on the podocytes of rats with diabetes nephropathy. Methods; Fifty Wistar rats were randomly divided into normal control group, DN model group (model group) .Enalapril treatment group, Flaxseed Lignan Extract treatment group. After 12 weeks, 24 h urinary protein excretion rate, BUN, Scr and kidney weight/body weight were determined. The renal pathology and the changes of podocytes were observed under light microscope and transmission electron microscope. Results: After treatment of Flaxseed Lignan Extract and Enalapril, urinary protein quantity in 24 h, SCr, BUN were reduced ( respectively P < 0.05) compared with the DN model group. Flaxseed Lignan Extract and Enalapril can improve ultrastructure in kidney of diabetic rats, lessen the fusion of foot process, ameliorate the renal pathomorphology change. Conclusion: Flaxseed Lignan Extract can rescue the podocyte injury and provide protective effects on renal fuction of diabetic nephropathy rats.

  1. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

    In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

  2. Cryogenic Acoustic Suppression Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will explore and test the feasibility and effectiveness of using a cryogenic fluid (liquid nitrogen) to facilitate acoustic suppression in a...

  3. Thyroid suppression test with dextrothyroxine

    International Nuclear Information System (INIS)

    The classic thyroid suppression test with triiodothyronine (l-T3) has been shown to be efficient as an auxiliary method in the diagnosis of thyroid diseases, but should not be performed on elderly patients or on those with heart disease or a tendency to tachycardia. Since these subjects seem able to support a short period of dextro-thyronine (d-T4) feeding, we compared the effect of d-T4 and l-T3 on the 24 hours thyroid uptake in euthyroid and hyperthyroid subjects. After basal radio-iodine uptake determination, 99 patients without hyperthyroidism and 27 with Graves' disease were randomly divided in 2 groups; one received 100μg of l-T3 per day and the other 4 mg of d-T4 per day, both groups being treated for a period of 10 days. At the end of this suppression period the 24 hours radio-iodine uptake was measured again and the percentual suppression index (S.I.) calculated. Since the comparison of the two groups showed no difference between the suppressive effect of l-T3 and d-T4 in euthyroid subjects, while dextro-thyronine, as levo-triiodothyronine, did not suppress the 24 hours uptake of hyperthyroid patients, l-T3 or d-T4 can be used interchangeably to test thyroid suppressibility. In the euthyroid subjects the normal range for the post-suppression uptake was 0-17.1% and for the suppression index 54,7.100%

  4. Cardioprotective effect of an L/N-type calcium channel blocker in patients with hypertensive heart disease

    International Nuclear Information System (INIS)

    Left ventricular (LV) diastolic dysfunction is related to increased cardiac sympathetic activity. We investigated the effect of cilnidipine, an L/N-type calcium channel blocker, on LV diastolic function and cardiac sympathetic activity in patients with hypertensive heart disease (HHD) using radionuclide myocardial imaging. Thirty-two frame electrocardiography (ECG)-gated 99mTc-sestamibi (MIBI) myocardial single photon emission computed tomography (SPECT), and 123I-metaiodobenzylguanidine (MIBG) imaging were performed before and 6 months after drug administration in 32 outpatients with HHD. Sixteen of the patients were treated with cilnidipine and the other 16 were treated with nifedipine retard. The parameters for assessing LV diastolic function evaluated using ECG-gated 99mTc-MIBI SPECT were peak filling rate (PFR), first-third filling rate (1/3FR), and time to peak filling (TPF). Cardiac sympathetic activity was assessed as early and delayed heart to mediastinum (H/M) ratios and a washout rate (WR), using 123I-MIBG imaging. The PFR and 1/3FR significantly increased after 6 months of treatment with cilnidipine (p<0.05 for both), but did not with nifedipine retard. The H/M ratios significantly increased (p<0.05 for both) in conjunction with a decreased WR (p<0.05) in the cilnidipine group. Moreover, a significant positive correlation was seen between the rate of change in PFR and the rate of change in early and delayed H/M ratios in the cilnidipine group (p<0.05 for both). The same results were obtained for the relationship between the rate of change in 1/3FR and the rate of change in H/M ratios (p<0.05 for both). However, no such relationship was seen in the nifedipine group. These data indicate that cilnidipine seems to suppress cardiac sympathetic overactivity via blockade of N-type calcium channels and improves LV diastolic function in patients with HHD. (author)

  5. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie; /Vrije U., Amsterdam

    2011-11-28

    This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle {gamma}, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle {gamma} can be performed using the decays of neutral B mesons. The B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay is sensitive to the angle {gamma} and, in comparison to the current decays that are being employed, could significantly enhance the

  6. Protective Effect of Candesartan on Podocyte Damage in Rats with Diabetic Nephropathy%坎地沙坦对糖尿病肾病大鼠足细胞保护作用的研究

    Institute of Scientific and Technical Information of China (English)

    李桂霞; 周静; 李秋月; 吕金雷; 李六生

    2011-01-01

    Objective To investigate the changes in podocyte ultrastructure and nephrin expression in rats with diabetic nephropathy(DN) ,and to observe the effect of candesartan on podocyte damage. Methods Thirty-six Sprague-Dawley rats were randomly divided into normal control group(group A),DN model group(group B),and candesartan treatment group (group C),with 12 rats in each group. DN was induced by intravenous injection of streptozotocin (30 mg · kg-1) and rats in group C were intragastricly given candesartan (5 mg · kg-1 · d-1) 1 week after induction of DN. Rats in group A and group B were given the same amount of normal saline. Blood glucose levels, body weight, 24-hour urinary protein excretion and endogenous creatinine clearance(Ccr) were measured at 4 and 7 weeks after treatment. Pathological changes in renal tissues were evaluated by HE staining and podocyte ultrastructure was observed using electron microscop. The expression of nephrin was detected by RT-PCR. Results Compared with group A, 24-hour urinary protein excretion and serum creatinine increased, Ccr decreased at 7 weeks, and nephrin expression reduced in group B(all P<0. 05). Compared with group B, 24-hour urinary protein excretion,serum creatinine,foot process width and glomerular basement membrane thickness decreased,and Ccr and nephrin expression increased in group C (all P<0.05). Conclusion DN patients have abnormal podocyte ultrastructure and nephrin expression. Candesartan can protect podocyte damage through up-regulating nephrin expression and improving podocyte ultrastructure.%目的 探讨糖尿病肾病(diabetic nephropathy,DN)大鼠足细胞超微结构及其相关分子nephrin表达的变化,以及坎地沙坦对其干预的影响,为DN的防治提供理论依据.方法 选择健康雄性SD大鼠36只,按随机数字表法分为A组(正常对照组)、B组(DN组)和C组(DN+坎地沙坦组),每组12只.B、C组尾静脉注射链脲佐菌素(30 mg·kg-1)制

  7. Soft substrates suppress droplet splashing

    CERN Document Server

    Howland, Christopher J; Style, Robert W; Castrejón-Pita, A A

    2015-01-01

    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. We show that substrate stiffness also impacts the splashing threshold by imaging ethanol drops impacting silicone gels of different stiffnesses. Splashing is significantly suppressed: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that splash suppression is likely to be due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Youngs modulus $\\lesssim O(10^5)$Pa suppress splashing, in agreement with simple scaling arguments. Thus materials like soft gels and elastomers can be used as simple coatings for effective splash prevention.

  8. Aging and repeated thought suppression success.

    Directory of Open Access Journals (Sweden)

    Ann E Lambert

    Full Text Available Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility.

  9. Aging and repeated thought suppression success.

    Science.gov (United States)

    Lambert, Ann E; Smyth, Frederick L; Beadel, Jessica R; Teachman, Bethany A

    2013-01-01

    Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility. PMID:23776442

  10. Teaching to suppress Polglish processes

    OpenAIRE

    Dziubalska-Kołaczyk, Katarzyna; Balas, Anna; Schwartz, Geoffrey; Rojczyk, Arkadiusz; Wrembel, Magdalena

    2015-01-01

    Advanced second language (henceforth L2) learners in a formal setting can suppress many first language (henceforth L1) processes in L2 pronunciation when provided with sufficient exposure to L2 and meta competence (see Sect. 4 for a definition of this term). This paper shows how imitation in L2 teaching can be enhanced on the basis of current phonetic research and how complex allophonic processes such as nasal vocalization and glottal stop insertion can be suppressed using “repair”—a method o...

  11. Aging and Repeated Thought Suppression Success

    OpenAIRE

    Ann E Lambert; Smyth, Frederick L.; Jessica R Beadel; Teachman, Bethany A.

    2013-01-01

    Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differe...

  12. High temperature suppression of dioxins.

    Science.gov (United States)

    Zhan, Ming-Xiu; Chen, Tong; Fu, Jian-Ying; Lin, Xiao-Qing; Lu, Sheng-Yong; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-03-01

    Combined Sulphur-Nitrogen inhibitors, such as sewage sludge decomposition gases (SDG), thiourea and amidosulphonic acid have been observed to suppress the de novo synthesis of dioxins effectively. In this study, the inhibition of PCDD/Fs formation from model fly ash was investigated at unusually high temperatures (650 °C and 850 °C), well above the usual range of de novo tests (250-400 °C). At 650 °C it was found that SDG evolving from dried sewage sludge could suppress the formation of 2,3,7,8-substituted PCDD/Fs with high efficiency (90%), both in weight units and in I-TEQ units. Additionally, at 850 °C, three kinds of sulphur-amine or sulphur-ammonium compounds were tested to inhibit dioxins formation during laboratory-scale tests, simulating municipal solid waste incineration. The suppression efficiencies of PCDD/Fs formed through homogeneous gas phase reactions were all above 85% when 3 wt. % of thiourea (98.7%), aminosulphonic acid (96.0%) or ammonium thiosulphate (87.3%) was added. Differences in the ratio of PCDFs/PCDDs, in weight average chlorination level and in the congener distribution of the 17 toxic PCDD/Fs indicated that the three inhibitors tested followed distinct suppression pathways, possibly in relation to their different functional groups of nitrogen. Furthermore, thiourea reduced the (weight) average chlorinated level. In addition, the thermal decomposition of TUA was studied by means of thermogravimetry-fourier transform infrared spectroscopy (TG-FTIR) and the presence of SO2, SO3, NH3 and nitriles (N≡C bonds) was shown in the decomposition gases; these gaseous inhibitors might be the primary dioxins suppressants. PMID:26716881

  13. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  14. Chk1 suppressed cell death

    Directory of Open Access Journals (Sweden)

    Meuth Mark

    2010-09-01

    Full Text Available Abstract The role of Chk1 in the cellular response to DNA replication stress is well established. However recent work indicates a novel role for Chk1 in the suppression of apoptosis following the disruption of DNA replication or DNA damage. This review will consider these findings in the context of known pathways of Chk1 signalling and potential applications of therapies that target Chk1.

  15. Visual Surround Suppression in Schizophrenia

    OpenAIRE

    Tibber, Marc S.; Elaine J Anderson; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the targ...

  16. Visual surround suppression in schizophrenia

    OpenAIRE

    Marc Samuel Tibber; Elaine J Anderson; Tracy eBobin; Elena eAntonova; Alice eSeabright; Bernice eWright; Patricia eCarlin; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the tar...

  17. Jet Suppression Measured in ATLAS

    CERN Document Server

    Citron, Zvi Hirsh; The ATLAS collaboration

    2015-01-01

    In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced, and jets propagating through this medium are known to suffer energy loss. This results in a lower yield of jets emerging from the medium than expected in the absence of medium effects, and thus modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. Parton showers initiated by quarks tend to have fewer fragments carrying a larger fraction of the total jet energy than those resulting from gluons. In this talk, the latest ATLAS results on single jet suppression will be presented. Measurements of the nuclear modification factor, RAA, for fully reconstructed jets are shown. The rapidity dependence of jet suppression is discussed, which is sensitive to the relative energy loss between quark and gluon jets. New measurements of single hadron suppression out to pT~150 GeV ...

  18. FLUTTER SUPPRESSION USING DISTRIBUTEDPIEZOELECTRIC ACTUATORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A piezoelectric actuator has the benefits of flexibility of its position, without time lag and wide bandpass characteristics. The early results of the wind tunnel flutter suppression test using the piezoeletric actuator were presented in Ref.[1]. A rigid rectangular wing model is constrained by a plunge spring and a pitch spring, and a pair of piezoelectric actuators is bonded on both sides of the plunge spring so as to carry out the active control. Refs.[2,3] reported two flutter suppression wind tunnel tests where the distributed piezoelectric actuators were used. In Ref.[2] low speed wind tunnel tests were conducted with aluminum and composite plate-like rectangular models fully covered by piezoelectric actuators. Flutter speed is increased by 11%. In Ref.[3] a composite plate-like swept back model with piezoceramic actuators bonded on the inboard surface was tested in a transonic wind tunnel and a 12% increment of flutter dynamic pressure was achieved.  In the present investigation, an aluminum plate-like rectangular model with inboard bonded piezoceramic actuators is adopted. Active flutter suppression control law has been designed. A series of analyses and ground tests and, finally, low-speed wind tunnel tests with the active control system opened and closed are conducted. Reasonable results have been obtained.

  19. Adaptive Filtering for Aeroservoelastic Response Suppression Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CSA Engineering proposes the design of an adaptive aeroelastic mode suppression for advanced fly-by-wire aircraft, which will partition the modal suppression...

  20. Continuous flash suppression reduces negative afterimages

    OpenAIRE

    Tsuchiya, Naotsugu; Koch, Christof

    2005-01-01

    Illusions that produce perceptual suppression despite constant retinal input are used to manipulate visual consciousness. Here we report on a powerful variant of existing techniques, continuous flash suppression. Distinct images flashed successively at approx10 Hz into one eye reliably suppress an image presented to the other eye. The duration of perceptual suppression is at least ten times greater than that produced by binocular rivalry. Using this tool we show that the strength of the negat...

  1. Burst Suppression: A Review and New Insights

    OpenAIRE

    Jonathan Dillon Kenny; M. Brandon Westover; ShiNung Ching; Brown, Emery N.; Ken Solt

    2014-01-01

    Burst suppression is a pattern of brain electrical activity characterized by alternating periods of high-amplitude bursts and electrical silence. Burst suppression can arise from several different pathological conditions, as well as from general anesthesia. Here we review current algorithms that are used to quantify burst suppression, its various etiologies, and possible underlying mechanisms. We then review clinical applications of anesthetic-induced burst suppression. Finally, we report the...

  2. 他克莫司通过上调自噬作用保护2型糖尿病大鼠足细胞%Tacrolimus protects podocytes by up-regulating autophagy in type 2 diabetic model rats

    Institute of Scientific and Technical Information of China (English)

    王彤; 马瑞霞; 武国华; 孙益婷

    2016-01-01

    Objective To assess the effects of tacrolimus (FKS06) on podocyte in type 2 diabetic model rats and to explore the potential mechanism.Methods The model rats were fed with high fat and high sugar food and combining with a low-dose of streptozotocin (STZ).They were then randomly divided into a diabetic mellitus group (DM group) and a FK506 group.A normal control group (NC group) was also set.The rats in FK506 group were given with 0.5 mg· kg-1· d-1 FK506 for 8 weeks.The biochemical parameters were measured.The changes of renal pathology and ultrastructure of podocyte were observed by the light and electron microscopy.The expression of nephrin and LC3-Ⅱ was determined by immunohistochemistry and Western blotting.Results (1) Compared with those in NC group,KW/BW,systolic blood pressure (SBP),fasting blood glucose (FBG),triglyceride (TG),total cholesterol (TC),urinary albumin excretion rate (UAE) and creatinine clearance rate (Ccr) in DM group were significantly increased (all P < 0.05).And the KW/BW,UAE and Ccr were decreased in FK506 group compared to those in DM group (all P < 0.05),while other parameters had no significant difference (all P > 0.05).(2) Compared with those in NC group,the glomerular volume,mesangial cell proliferation and accumulation of mesangial matrix were increased,and the foot process became disorder and fusion in DM group,while these changes were significantly reduced in FK506 group.(3) Compared with that in NC group,the expression of nephrin and LC3-Ⅱ was decreased in DM group (all P < 0.05),and both of parameters were higher in FK506 group than those in DM group (all P < 0.05).Conclusion FK506 may enhance podocyte autophagy in type 2 diabetic model rats and attenuate podocyte injury.%目的 探讨他克莫司(FK506)对2型糖尿病(T2DM)大鼠足细胞的保护作用及其可能机制.方法 高糖高脂喂养联合小剂量链佐星(STZ)构建T2DM大鼠模型,模型大鼠随机分为糖尿病组(DM组)和FK506

  3. Distracted by cues for suppressed memories.

    Science.gov (United States)

    Hertel, Paula T; Hayes, Jeffrey A

    2015-06-01

    We examined the potential cost of practicing suppression of negative thoughts on subsequent performance in an unrelated task. Cues for previously suppressed and unsuppressed (baseline) responses in a think/no-think procedure were displayed as irrelevant flankers for neutral words to be judged for emotional valence. These critical flankers were homographs with one negative meaning denoted by their paired response during learning. Responses to the targets were delayed when suppression cues (compared with baseline cues and new negative homographs) were used as flankers, but only following direct-suppression instructions and not when benign substitutes had been provided to aid suppression. On a final recall test, suppression-induced forgetting following direct suppression and the flanker task was positively correlated with the flanker effect. Experiment 2 replicated these findings. Finally, valence ratings of neutral targets were influenced by the valence of the flankers but not by the prior role of the negative flankers. PMID:25904596

  4. Suppression effects on musical and verbal memory.

    Science.gov (United States)

    Schendel, Zachary A; Palmer, Caroline

    2007-06-01

    Three experiments contrasted the effects of articulatory suppression on recognition memory for musical and verbal sequences. In Experiment 1, a standard/comparison task was employed, with digit or note sequences presented visually or auditorily while participants remained silent or produced intermittent verbal suppression (saying "the") or musical suppression (singing "la"). Both suppression types decreased performance by equivalent amounts, as compared with no suppression. Recognition accuracy was lower during suppression for visually presented digits than during that for auditorily presented digits (consistent with phonological loop predictions), whereas accuracy was equivalent for visually presented notes and auditory tones. When visual interference filled the retention interval in Experiment 2, performance with visually presented notes but not digits was impaired. Experiment 3 forced participants to translate visually presented music sequences by presenting comparison sequences auditorily. Suppression effects for visually presented music resembled those for digits only when the recognition task required sensory translation of cues. PMID:17848022

  5. Chaos suppression through asymmetric coupling

    Science.gov (United States)

    Bragard, J.; Vidal, G.; Mancini, H.; Mendoza, C.; Boccaletti, S.

    2007-12-01

    We study pairs of identical coupled chaotic oscillators. In particular, we have used Roessler (in the funnel and no funnel regimes), Lorenz, and four-dimensional chaotic Lotka-Volterra models. In all four of these cases, a pair of identical oscillators is asymmetrically coupled. The main result of the numerical simulations is that in all cases, specific values of coupling strength and asymmetry exist that render the two oscillators periodic and synchronized. The values of the coupling strength for which this phenomenon occurs is well below the previously known value for complete synchronization. We have found that this behavior exists for all the chaotic oscillators that we have used in the analysis. We postulate that this behavior is presumably generic to all chaotic oscillators. In order to complete the study, we have tested the robustness of this phenomenon of chaos suppression versus the addition of some Gaussian noise. We found that chaos suppression is robust for the addition of finite noise level. Finally, we propose some extension to this research.

  6. 缬沙坦对高糖诱导肾小球足细胞活化T细胞核因子2活化及细胞凋亡的影响%Effects of valsartan on high glucose-induced NFAT2 activation and apoptosis in podocytes

    Institute of Scientific and Technical Information of China (English)

    李锐钊; 章斌; 张丽; 史伟; 梁馨苓; 刘双信; 王文健

    2013-01-01

    AIM To investigate the effects of valsartan on nuclear factor 2 of activated T cells (NFAT2)activation and apoptosis induced by high glucose in podocytes.METHODS The podocytes were treated with various conditions,including different concentrations of glucose (10-40 mmol· L-1),different incubation time (0.5-48 h),valsartan,NFAT2 inhibitor (11 R-VIVI) and NFAT2 activator (ionomycin).The protein levels of NFAT2 in the nucleus of podocytes were detected by western blot and podocyte apoptosis was evaluated by flow cytometry.RESULTS NFAT2 was significantly activated in podocytes when treated with high glucose (20 mmol·L-1) for 2 hours.Ionomycin also increased the expression of NFAT2 in nucleus of podocyte (P > 0.05).NFAT2 nuclear accumulation was significantly inhibited in the podocytes pretreatment with valsartan (0.1 mmol·L-1) or 11R-VIVIT compared with high glucose treated alone groups (P < 0.01),without difference between valsartan and 11R-VIVIT groups (P > 0.05).Apoptosis rate was markedly increased in podocytes treated with high glucose ((21.47 ± 6.24) %) at 48 h compared with that treated with normal glucose ((12.27 ±1.31) %,P < 0.05).High glucose-induced apoptosis was also significantly abrogated by concomitant treatment with valsartan or 11R-VIVIT (P < 0.01),again no significant difference between valsartan and 11R-VIVIT groups (P > 0.05).CONCLUSION Valsartan inhibits podocyte high glucose-induce apoptosis via decreasing nuclear NFAT2 activation.%目的 探讨缬沙坦对高糖诱导肾小球足细胞活化T细胞核因子2 (NFAT2)活化及细胞凋亡的影响.方法 将分化成熟的足细胞分组给予不同糖浓度、不同干预时间、NFAT2抑制剂11R-VIVIT、NFAT2活化剂ionomycin等刺激,采用Western blot检测足细胞胞核中NFAT2的表达水平、流式细胞仪检测足细胞凋亡情况.结果 高糖能刺激足细胞NFAT2活化入核,20 mmol· L-1葡萄糖作用2h时NFAT2活化入核达到高峰;这与Ionomycin作

  7. Continuous flash suppression reduces negative afterimages.

    Science.gov (United States)

    Tsuchiya, Naotsugu; Koch, Christof

    2005-08-01

    Illusions that produce perceptual suppression despite constant retinal input are used to manipulate visual consciousness. Here we report on a powerful variant of existing techniques, continuous flash suppression. Distinct images flashed successively at approximately 10 Hz into one eye reliably suppress an image presented to the other eye. The duration of perceptual suppression is at least ten times greater than that produced by binocular rivalry. Using this tool we show that the strength of the negative afterimage of an adaptor was reduced by half when it was perceptually suppressed by input from the other eye. The more completely the adaptor was suppressed, the more strongly the afterimage intensity was reduced. Paradoxically, trial-to-trial visibility of the adaptor did not correlate with the degree of reduction. Our results imply that formation of afterimages involves neuronal structures that access input from both eyes but that do not correspond directly to the neuronal correlates of perceptual awareness. PMID:15995700

  8. Engineered decoherence: Characterization and suppression

    Science.gov (United States)

    Hegde, Swathi S.; Mahesh, T. S.

    2014-06-01

    Due to omnipresent environmental interferences, quantum coherences inevitably undergo irreversible transformations over certain time scales, thus leading to the loss of encoded information. This process, known as decoherence, has been a major obstacle in realizing efficient quantum information processors. Understanding the mechanism of decoherence is crucial in developing tools to inhibit it. Here we utilize a method proposed by Teklemariam et al. [Phys. Rev. A 67, 062316 (2003), 10.1103/PhysRevA.67.062316] to engineer artificial decoherence in the system qubits by randomly perturbing their surrounding ancilla qubits. Using a two-qubit nuclear magnetic resonance quantum register, we characterize the artificial decoherence by noise spectroscopy and quantum process tomography. Further, we study the efficacy of dynamical decoupling sequences in suppressing the artificial decoherence. Here we describe the experimental results and their comparisons with theoretical simulations.

  9. MEK5 suppresses osteoblastic differentiation

    International Nuclear Information System (INIS)

    Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and is activated by its upstream kinase, MAPK kinase 5 (MEK5), which is a member of the MEK family. Although the role of MEK5 has been investigated in several fields, little is known about its role in osteoblastic differentiation. In this study, we have demonstrated the role of MEK5 in osteoblastic differentiation in mouse preosteoblastic MC3T3-E1 cells and bone marrow stromal ST2 cells. We found that treatment with BIX02189, an inhibitor of MEK5, increased alkaline phosphatase (ALP) activity and the gene expression of ALP, osteocalcin (OCN) and osterix, as well as it enhanced the calcification of the extracellular matrix. Moreover, osteoblastic cell proliferation decreased at a concentration of greater than 0.5 μM. In addition, knockdown of MEK5 using siRNA induced an increase in ALP activity and in the gene expression of ALP, OCN, and osterix. In contrast, overexpression of wild-type MEK5 decreased ALP activity and attenuated osteoblastic differentiation markers including ALP, OCN and osterix, but promoted cell proliferation. In summary, our results indicated that MEK5 suppressed the osteoblastic differentiation, but promoted osteoblastic cell proliferation. These results implied that MEK5 may play a pivotal role in cell signaling to modulate the differentiation and proliferation of osteoblasts. Thus, inhibition of MEK5 signaling in osteoblasts may be of potential use in the treatment of osteoporosis. - Highlights: • MEK5 inhibitor BIX02189 suppresses proliferation of osteoblasts. • MEK5 knockdown and MEK5 inhibitor promote differentiation of osteoblasts. • MEK5 overexpression inhibits differentiation of osteoblasts

  10. MEK5 suppresses osteoblastic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaneshiro, Shoichi [Department of Orthopaedic Surgery, Japan Community Health Care Organization Osaka Hospital, 4-2-78 Fukushima, Fukushima Ward, Osaka City, Osaka 553-0003 (Japan); Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Otsuki, Dai; Yoshida, Kiyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Higuchi, Chikahisa, E-mail: c-higuchi@umin.ac.jp [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-07-31

    Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and is activated by its upstream kinase, MAPK kinase 5 (MEK5), which is a member of the MEK family. Although the role of MEK5 has been investigated in several fields, little is known about its role in osteoblastic differentiation. In this study, we have demonstrated the role of MEK5 in osteoblastic differentiation in mouse preosteoblastic MC3T3-E1 cells and bone marrow stromal ST2 cells. We found that treatment with BIX02189, an inhibitor of MEK5, increased alkaline phosphatase (ALP) activity and the gene expression of ALP, osteocalcin (OCN) and osterix, as well as it enhanced the calcification of the extracellular matrix. Moreover, osteoblastic cell proliferation decreased at a concentration of greater than 0.5 μM. In addition, knockdown of MEK5 using siRNA induced an increase in ALP activity and in the gene expression of ALP, OCN, and osterix. In contrast, overexpression of wild-type MEK5 decreased ALP activity and attenuated osteoblastic differentiation markers including ALP, OCN and osterix, but promoted cell proliferation. In summary, our results indicated that MEK5 suppressed the osteoblastic differentiation, but promoted osteoblastic cell proliferation. These results implied that MEK5 may play a pivotal role in cell signaling to modulate the differentiation and proliferation of osteoblasts. Thus, inhibition of MEK5 signaling in osteoblasts may be of potential use in the treatment of osteoporosis. - Highlights: • MEK5 inhibitor BIX02189 suppresses proliferation of osteoblasts. • MEK5 knockdown and MEK5 inhibitor promote differentiation of osteoblasts. • MEK5 overexpression inhibits differentiation of osteoblasts.

  11. Two Effects of Firepower: Attrition and Suppression

    OpenAIRE

    Hughes, Wayne P.

    1995-01-01

    A new basis for the quantitative study of ground combat is introduced that argues the inadequacy of attrition models and the need to incorporate the effects of suppression of the enemy with firepower. A quantitative approach to suppression of enemy fire is offered. Then an analysis shows that the effect of own fire in suppressing enemy fire will, in suitable, frequent circumstances, reverse the conclusions derived from the Lanchester square law, so that the sq...

  12. Psychopathology and Thought Suppression: A Quantitative Review

    OpenAIRE

    Magee, Joshua C; Harden, K. Paige; Teachman, Bethany A.

    2012-01-01

    Recent theories of psychopathology have suggested that thought suppression intensifies the persistence of intrusive thoughts, and proposed that difficulty with thought suppression may differ between groups with and without psychopathology. The current meta-analytic review evaluates empirical evidence for difficulty with thought suppression as a function of the presence and specific type of psychopathology. Based on theoretical proposals from the psychopathology literature, diagnosed and analo...

  13. Studies on pressure suppression pool dynamic loads

    International Nuclear Information System (INIS)

    Several newly identified pressure suppression pool hydrodynamic loads associated with a loss-of-coolant accident, or actuation of the safety/relief valves, are attracting attention because of their potential influence on integrity of the BWR pressure suppression containment. This report provides a survey of the research works and experiences on performance of the pressure suppression system during abnormal and normal reactor operating conditions. Specific areas for future studies are also indicated. (author)

  14. NOVEL BIPHASE CODE -INTEGRATED SIDELOBE SUPPRESSION CODE

    Institute of Scientific and Technical Information of China (English)

    Wang Feixue; Ou Gang; Zhuang Zhaowen

    2004-01-01

    A kind of novel binary phase code named sidelobe suppression code is proposed in this paper. It is defined to be the code whose corresponding optimal sidelobe suppression filter outputs the minimum sidelobes. It is shown that there do exist sidelobe suppression codes better than the conventional optimal codes-Barker codes. For example, the sidelobe suppression code of length 11 with filter of length 39 has better sidelobe level up to 17dB than that of Barker code with the same code length and filter length.

  15. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified......, here among 2-heptyl-3-hydroxy-4-quinolone (PQS). An unidentified green pseudomonas compound was also observed. Interestingly the P. aeruginosa mutant rpoN was unable to suppress A. fumigatus, but suppressed A. flavus, A. oryzae and A. niger. However several other P. aeruginosa mutants suppressed A...

  16. Deconstructing Interocular Suppression: Attention and Divisive Normalization.

    Science.gov (United States)

    Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J

    2015-10-01

    In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression. PMID:26517321

  17. The number of podocyte and slit diaphragm is decreased in experimental diabetic nephropathy O número de podócitos e fendas diafragmáticas estão alterados na nefropatia diabética

    Directory of Open Access Journals (Sweden)

    Mauro Masson Lerco

    2006-04-01

    Full Text Available PURPOSE: To determine the number of podocyte, slit diaphragms, slit diaphragm extensions and GBM thickness in diabetic nephropathy. METHODS: Sixty "Rattus Wistar"of both sexes weighing 200-300g were divided in two experimental groups: normal group 10 animals, and alloxan diabetic rats - 50 animals. Alloxan was administered in a single IV dose of 42mg/kg body weight. Body weight, water and food intake, diuresis, and blood and urine glucose were determined in both groups before alloxan injection and two weeks, six and twelve months after alloxan injection. Proteinuria was measured at 12 months in both groups. After 12 months animals were sacrificed, and the right kidney processed for electron microscopy. RESULTS: Clear clinical and laboratory signs of severe diabetes were seen, in all alloxan-diabetic rats at all follow-up times. Glomerular basement membrane (GBM thickening, podocyte number, and slit diaphragm number and extension were determined. GBM of all diabetic rats was significantly thicker (median=0.29µm; semi-interquartile range=0.065µm than in the normal rats (0.23µm; 0.035µm. Diabetic rat podocyte number (8; 1, slit diaphragm number (4; 1, and slit diaphragm extension (0.021µm; 0.00435µm were significantly lower than in normal rats (11; 1 and (7; 1.5, and (0.031µm; 0.0058µm. Diabetic rat proteinuria (0.060mg/24h; 0.037mg/24h was higher than in normal rats (0.00185mg/24h; 0.00055mg/24h. CONCLUSION: Experimental diabetes is associated with significant (pOBJETIVO: Determinar o número de podocitos e fendas diafragmáticas, a extensão das fendas diafragmáticas e a espessura da Membrana Basal Glomerular (MBG na nefropatia diabética. MÉTODOS: Sessenta "Rattus Wistar" de ambos os sexos, pesando entre 200-300g, foi dividido em dois grupos experimentais: grupo normal 10 animais, e grupo diabético induzido por aloxana - 50 animais. A Aloxana foi administrada em dose única endovenosa de 42mg/kg de peso. Medimos o peso, ingestão de

  18. Effect of Yishe Capsule on Podocytes in Renal Tissue of Rats with Diabetic Nephropathy%益肾胶囊对糖尿病肾病模型肾小球足细胞的影响

    Institute of Scientific and Technical Information of China (English)

    许洪燕; 方敬爱; 张晓东; 孙艳艳

    2009-01-01

    Objective:To observe the effect of yishe capsule on pathological changes of renal tissue and podocyte ultrastruc-ture. Method:Totally 60 wistar rats were divided into four groups: normol control group (controf group),DN model group(model group) ,yishe capsule treatment gronp,benazepril treatment group.The rat in group of yishe capsule were garage given 625 mg.kg-1.water was used. AU the mrs received daily gavage for 12 weeks, the urinary protein in 24 h and the level of serum creatinine,urea ni-trogen were measured. The renal pathology and the changes of podocyte ultrastructure were detected under light microscope and transmission electron microscope. Results: In 12 w,urinary protein quantity in 24 h,Scr and BUN of model group rats were higher distinctly than those of control group( respectively, P < 0.05). After treatment of benazepril and yishe capsule, urinary protein quanti-ty in 24 h,Scr,BUN were reduced( respectively P < 0.05). We observed basement membrane thicken,foot process with disorders,foot process fusion,increased mesangial matrix, widened mesangium in model group by light microscope and transmission eletron mi-croscope. Benazepril and yishe capsule can improve ultrastructure in kidney of diabetic rats, lessen the fusion of foot process, ameliorate the renal pathomorphology change. Conclusion: Yishe capsule had a effect on the podocyte of diabetic nephropathy rats by reducing urine protein and improving renal function, thus alleviated the renal damage in diabetic rats.%目的:观察益肾胶囊对糖尿病肾病(DN)大鼠肾组织病理改变及足细胞超微结构的影响.方法:将60只wis-tar大鼠随机分为4组:正常对照组(对照组)、DN模型组(模型组)、苯那普利组、益肾胶囊组.于注射链脲佐菌素(STZ)后3d起,苯那普利组每日每只灌胃苯那普利3.125 mg·kg-1·d-1,益肾胶囊组每日每只灌胃益肾胶囊625 mg·kg-1·d-1,对照组及模型组每日给予等量的蒸镏水.各组分别干预12周,观察24

  19. The effects of hydrochloride Benazepril on podocyte nephrin protein expression in diabetic rats%盐酸贝那普利对糖尿病大鼠肾脏足细胞及其蛋白nephrin表达的影响

    Institute of Scientific and Technical Information of China (English)

    孔敏; 任伟; 王艳; 陈玉米; 叶山东; 邢燕; 胡闻; 江洁龙

    2012-01-01

    目的 观察盐酸贝那普利对糖尿病大鼠足细胞及其nephrin蛋白表达的影响,初步探讨其对糖尿病大鼠肾脏保护作用及其可能的机制.方法 将健康雄性SD大鼠随机分为正常对照(NC组)和实验组.实验组通过一次性腹腔注射链脲佐菌素建立糖尿病大鼠模型,造模成功后,随机分为糖尿病对照组(DM组)和贝那普利干预组(DT组),DT组予以盐酸贝那普利10 mg·kg-1 ·d-1,混悬液灌胃.NC、DM组予以等量0.9%氯化钠注射溶液相应时间灌胃.每周监测各组大鼠尾外周血血糖.4周后,检测糖化血红蛋白( HbA1c)及尿液中nephrin蛋白、白蛋白(ALB)及视黄醇结合蛋白(RBP).处死大鼠留取肾脏标本,在电镜下观察肾脏组织形态学及足细胞超微结构的变化,采用免疫组织化学方法检测肾组织nephrin蛋白的表达水平.结果 造膜4周后,DM和DT组的HbA1c、肾脏肥大指数、尿nephrin/肌酐(Cr)、尿ALB/Cr、尿RBP/Cr与NC组相比,差异有统计学意义(P<0.05),DM和DT组与NC组nephrin表达水平差异有统计学意义(P<0.05),电镜下糖尿病大鼠组与NC组相比肾组织病变明显.与DM组比较,DT组除血糖和HbA1c水平外,其余各项指标二组之间均差异有统计学意义(P<0.05),肾组织病理改变亦明显减轻.结论 贝那普利通过上调nephrin表达水平改善修复受损足细胞,减少足细胞脱落,从而减少糖尿病大鼠蛋白尿,对糖尿病肾病发挥保护作用.%Objective To observe effects of hydrochloride benazepril on podocyte nephrin protein expression in diabetic rats and investigate its protective effects on the kidney of rats and its possible mechanism. Methods Spra-gue-Dawley (SD) rats were assigned to normal control and model group. The diabetes model was established by a single injection of streptozotoin (STZ) ,randomly divided into diabetic nephropathy (DM group) and benazepril intervention group (DT group). DT group received benazepril hydrochloride

  20. Evaluation of the pharmacokinetic and pharmacodynamic drug interactions between cilnidipine and valsartan, in healthy volunteers

    OpenAIRE

    Lee J; Lee H; Jang K; Lim KS; Shin D; Yu KS

    2014-01-01

    Jieon Lee,1,* Howard Lee,2,* Kyungho Jang,1 Kyoung Soo Lim,3 Dongseong Shin,1 Kyung-Sang Yu11Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Clinical Trials Center, Seoul National University Hospital, Seoul, Republic of Korea; 3Department of Clinical Pharmacology and Therapeutics, CHA University School of Medicine and CHA Bundang Medical Center, Seongnam, Republic of Korea *These authors contributed e...

  1. Emotional and non-emotional memories are suppressible under direct suppression instructions

    NARCIS (Netherlands)

    K. van Schie (Kevin); E.G. Geraerts (Elke); M.C. Anderson (Michael)

    2013-01-01

    textabstractResearch on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, across studies, participants adopt different approaches to memory control. Cognitive and neur

  2. Emotional and non-emotional memories are suppressible under direct suppression instructions

    OpenAIRE

    van Schie, Kevin; Geraerts, Elke; Anderson, Michael

    2013-01-01

    textabstractResearch on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, across studies, participants adopt different approaches to memory control. Cognitive and neurobiological research points to two mechanisms that achieve retrieval suppression: thought-substitution and direct suppression (Benoit & Anderson, 2012; Bergström, de Fockert, & Richardson-Klavehn, ...

  3. Suppression on Your Own Terms: Internally Generated Displays of Craving Suppression Predict Rebound Effects

    OpenAIRE

    Sayers, W. Michael; Sayette, Michael A.

    2013-01-01

    Research on emotion suppression has shown a rebound effect, in which expression of the targeted emotion increases following a suppression attempt. In prior investigations, participants have been explicitly instructed to suppress their responses, which has drawn the act of suppression into metaconsciousness. Yet emerging research emphasizes the importance of nonconscious approaches to emotion regulation. This study is the first in which a craving rebound effect was evaluated without simultaneo...

  4. Consequences of stereotype suppression and internal suppression motivation : A self-regulation approach

    NARCIS (Netherlands)

    Gordijn, EH; Hindriks, [No Value; Koomen, W; Dijksterhuis, A; Van Knippenberg, A; Hindriks, I; van Knipppenberg, A.

    2004-01-01

    The present research studied the effects of suppression of stereotypes on subsequent stereotyping. Moreover, the moderating influence of motivation to suppress stereotypes was examined. The first three experiments showed that suppression of stereotypes leads to the experience of engaging in self-con

  5. Heavy flavour suppression and flow

    CERN Document Server

    Das, Santosh K

    2011-01-01

    The drag and diffusion coefficients of charm and bottom quarks propagating through quark gluon plasma have been evaluated for conditions relevant to nuclear collisions at Large Hadron Collider and Relativistic Heavy Ion Collider. Both the radiative and collisional processes of energy loss are included in evaluating the {\\it effective} drag and diffusion coefficients. The Landau-Pomeronchuk-Migdal (LPM) and the dead cone effects on the radiative energy loss of heavy quarks have been included. With the effective transport coefficients the Fokker Plank (FP) equation has been solved for the evolution of heavy quarks in QGP. The solution of the FP equation has been used to evaluate the nuclear suppression factor, $R_{\\mathrm AA}$ and the elliptic flow, $v_2^{HF}$ for the non-photonic single electron spectra resulting from the semi-leptonic decays of hadrons containing charm and bottom quarks. It is observed that the experimental data from RHIC on $R_{\\mathrm AA}$ and $v_2^{HF} $ can be reproduced simultaneously wi...

  6. Impacts of suppressing guide on information spreading

    CERN Document Server

    Xu, Jinghong; Ma, Baojun; Wu, Ye

    2015-01-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  7. Hydrogen suppresses UO 2 corrosion

    Science.gov (United States)

    Carbol, Paul; Fors, Patrik; Gouder, Thomas; Spahiu, Kastriot

    2009-08-01

    Release of long-lived radionuclides such as plutonium and caesium from spent nuclear fuel in deep geological repositories will depend mainly on the dissolution rate of the UO 2 fuel matrix. This dissolution rate will, in turn, depend on the redox conditions at the fuel surface. Under oxidative conditions UO 2 will be oxidised to the 1000 times more soluble UO 2.67. This may occur in a repository as the reducing deep groundwater becomes locally oxidative at the fuel surface under the effect of α-radiolysis, the process by which α-particles emitted from the fuel split water molecules. On the other hand, the groundwater corrodes canister iron generating large amounts of hydrogen. The role of molecular hydrogen as reductant in a deep bedrock repository is questioned. Here we show evidence of a surface-catalysed reaction, taking place in the H 2-UO 2-H 2O system where molecular hydrogen is able to reduce oxidants originating from α-radiolysis. In our experiment the UO 2 surface remained stoichiometric proving that the expected oxidation of UO 2.00 to UO 2.67 due to radiolytic oxidants was absent. As a consequence, the dissolution of UO 2 stopped when equilibrium was reached between the solid phase and U 4+ species in the aqueous phase. The steady-state concentration of uranium in solution was determined to be 9 × 10 -12 M, about 30 times lower than previously reported for reducing conditions. Our findings show that fuel dissolution is suppressed by H 2. Consequently, radiotoxic nuclides in spent nuclear fuel will remain immobilised in the UO 2 matrix. A mechanism for the surface-catalysed reaction between molecular hydrogen and radiolytic oxidants is proposed.

  8. Psychopathology and thought suppression: a quantitative review.

    Science.gov (United States)

    Magee, Joshua C; Harden, K Paige; Teachman, Bethany A

    2012-04-01

    Recent theories of psychopathology have suggested that thought suppression intensifies the persistence of intrusive thoughts, and proposed that difficulty with thought suppression may differ between groups with and without psychopathology. The current meta-analytic review evaluates empirical evidence for difficulty with thought suppression as a function of the presence and specific type of psychopathology. Based on theoretical proposals from the psychopathology literature, diagnosed and analogue samples were expected to show greater recurrence of intrusive thoughts during thought suppression attempts than non-clinical samples. However, results showed no overall differences in the recurrence of thoughts due to thought suppression between groups with and without psychopathology. There was, nevertheless, variation in the recurrence of thoughts across different forms of psychopathology, including relatively less recurrence during thought suppression for samples with symptoms of Obsessive-Compulsive Disorder, compared to non-clinical samples. However, these differences were typically small and provided only mixed support for existing theories. Implications for cognitive theories of intrusive thoughts are discussed, including proposed mechanisms underlying thought suppression. PMID:22388007

  9. Strangeness suppression in the unquenched quark model

    CERN Document Server

    Bijker, Roelof; Santopinto, Elena

    2016-01-01

    In this contribution, we discuss the strangeness suppression in the proton in the framework of the unquenched quark model. The theoretical results are in good agreement with the values extracted from CERN and JLab experiments.

  10. Strangeness suppression in the unquenched quark model

    Science.gov (United States)

    Bijker, Roelof; García-Tecocoatzi, Hugo; Santopinto, Elena

    2016-07-01

    In this contribution, we discuss the strangeness suppression in the proton in the framework of the unquenched quark model. The theoretical results are in good agreement with the values extracted from CERN and JLab experiments.

  11. The social consequences of expressive suppression

    OpenAIRE

    Butler, Emily A.; Egloff, Boris; Wilhelm, Frank H.; Smith, Nancy C.; Erickson, Elizabeth A.; Gross, James J.

    2003-01-01

    At times, people keep their emotions from showing during social interactions. The authors' analysis suggests that such expressive suppression should disrupt communication and increase stress levels. To test this hypothesis, the authors conducted 2 studies in which unacquainted pairs of women discussed an upsetting topic. In Study 1, one member of each pair was randomly assigned to (a) suppress her emotional behavior, (b) respond naturally, or (c) cognitively reappraise in a way that reduced e...

  12. Noise suppression in surface microseismic data

    Science.gov (United States)

    Forghani-Arani, Farnoush; Batzle, Mike; Behura, Jyoti; Willis, Mark; Haines, Seth S.; Davidson, Michael

    2012-01-01

    We introduce a passive noise suppression technique, based on the τ − p transform. In the τ − p domain, one can separate microseismic events from surface noise based on distinct characteristics that are not visible in the time-offset domain. By applying the inverse τ − p transform to the separated microseismic event, we suppress the surface noise in the data. Our technique significantly improves the signal-to-noise ratios of the microseismic events and is superior to existing techniques for passive noise suppression in the sense that it preserves the waveform. We introduce a passive noise suppression technique, based on the τ − p transform. In the τ − p domain, one can separate microseismic events from surface noise based on distinct characteristics that are not visible in the time-offset domain. By applying the inverse τ − p transform to the separated microseismic event, we suppress the surface noise in the data. Our technique significantly improves the signal-to-noise ratios of the microseismic events and is superior to existing techniques for passive noise suppression in the sense that it preserves the waveform.

  13. Effects of eplerenone, amlodipine and telmisartan on podocyte injury in aldosterone-infused rats%不同降压药对醛固酮输注大鼠足细胞损伤的影响

    Institute of Scientific and Technical Information of China (English)

    粱伟; 陈铖; 丁国华; 石明; 石晶; 任志龙; 胡凤琪; 杨红霞

    2008-01-01

    Objective To investigate whether aldosterone infusion induces glomerular or podocyte injury in rats and to evaluate the effects of eplerenoen (EPL), andodipine (CCB) and telmisartan (ARB) on aldosterone- induced injury. Methods Thirty male Sprague-Dawley rats were divided into 5 groups: control, subcutaneous infusion of aldosterone (1.5 μg/h, ALD group) and aldosterone infusion plus eplerenone (100 mg·kg-1·d-1, EPL group), amlodipine(10 nag·kg-1·d-1 CCB group), telmisartan (3 mg·kg-1·d-1, ARB group), respectively. Systolic blood pressure(SBP) and urinary albumin excretion ratio(UAER) were measured at day 0, 7, 14, 21, 28. Blood samples were harvested to detect plasma angiotensin Ⅱ, plasma aldosterone, serum sodium, serum potassium and serum creatinine at day 28. Glomerular damge was quantified by morphological glomerular injury score (GIS). Immunohistochemistry and RT-PCR were performed to evaluate podocyte lesion, and apoptosis ratio of pedocyte (ARP) in a glomerular cross section was analyzed by TUNEL. Results ALD infusion progressively increased SBP and UAER compared with CTL (P<0.01). SBP was significantly reduced in EPL, CCB or ARB-treated animals, meanwhile, UAER was decreased in EPL and ARB group, but not in CCB group. The ALD-infused rats exibited hypernatremia and hypopotassaemia, which were blocked by EPL adminstration but not by CCB or ARB treatment. ARB group had a significant increase in plasma angiotensin Ⅱ compared with ALD, CCB and EPL groups(P<0.01). The ALD-infused animals developed hyperaldosteronemia compared with CTL, but with no difference of plasma aldosterone among ALD, EPL, CCB and ARB-treated rats. Treatment with EPL prevented an increase of GIS and ARP compared with CCB and ARB (P<0.05, P<0.01). Protein and mRNA expression of nephfin was up-regulated in ALD group (P< 0.01), but was significantly prevented by EPL treatment(P<0.01), whereas CCB and ARB therapy had no such effect. Conclusion ALD infusion significantly

  14. Effect of all trans-retinoic acid on the expression of synaptopodin in human podocytes induced by high glucose%全反式维甲酸对高糖培养的人肾小球足细胞synaptopodin蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    邵珊; 白波; 李荣山; 于为民; 黄轶嵘

    2012-01-01

    Objective To investigate the effect of all trans-retinoic acid on the expression of synaptopodin in human podocytes induced by high glucose.Methods Conditionally immortalized human podocytes were exposed to nomal glucose group (NG) and high glucose group (HG).The expression of synaptopodin in podocytes was detected by Western blot.Results The expression of synaptopodin decreased significantly in time-dependent manner after 3,6 and 9 days of high glucose (HG) stimulation [ ( 1.15 ± 0.04) %,(0.78 ± 0.04) %,(0.41 ± 0.05 ) % vs ( 1.49 ± 0.07) %,P < 0.05 ].Compared to HG group,5 μmol/L and 15 μmol/L all-trans retinoic acid (ATRA) increased synaptopodin expressionat 9th day dramaticaly [ (0.41 ± 0.05 ) %,(0.86 ± 0.04) %,(0.90 ± 0.07 ) % vs ( 1.47 ± 0.08) %,P < 0.05 ].Conclusions High concentration of glucose decreases the expression of synaptopodin in podocyte.All trans retinoic acid(ATRA)may exert protective role on diabetic nephropathy by increasing synaptopodin expression which is downregulated by HG.%目的 探讨高糖培养的人肾小球足细胞synaptopodin蛋白表达的变化以及全反式维甲酸对其表达的干预效应.方法 以体外培养的条件性永生人肾小球足细胞为研究对象,平均分为正常糖(NG)组、高糖(HG)组、HG+5tmol/L全反式维甲酸干预组、HG+ 15 μmol/L全反式维甲酸干预组.蛋白质印迹法检测HG组足细胞培养0、3、6、9d时和其他各组足细胞培养9 dsynaptopodin蛋白的表达.结果 HG组足细胞培养3、6、9d时synaptopodin蛋白表达灰度值与培养0d时比较明显降低[(1.15±0.04)%、(0.78±0.04)%、(0.41±0.05)%比(1.49±0.07)%,P<0.05].培养9d后,与NG组比较,HG组、HG+5μmol/L维甲酸干预组、HG+ 15 μmol/L维甲酸干预组足细胞synaptopodin蛋白表达灰度值均明显下降[(0.41±0.05)%、(0.86±0.04)%、(0.90±0.07)%比(1.47 ±0.08)%,均P<0.05].结论 高糖可以使体外培养的足细胞synaptopodin蛋白

  15. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  16. Star formation suppression in compact group galaxies

    DEFF Research Database (Denmark)

    Alatalo, K.; Appleton, P. N.; Lisenfeld, U.;

    2015-01-01

    We present CO(1-0) maps of 12 warm H-2-selected Hickson Compact Groups (HCGs), covering 14 individually imaged warm H2 bright galaxies, with the Combined Array for Research in Millimeter Astronomy. We found a variety of molecular gas distributions within the HCGs, including regularly rotating disks......, bars, rings, tidal tails, and possibly nuclear outflows, though the molecular gas morphologies are more consistent with spirals and earlytype galaxies than mergers and interacting systems. Our CO-imaged HCG galaxies, when plotted on the Kennicutt-Schmidt relation, shows star formation (SF) suppression......-to-dust ratios of these galaxies to determine if an incorrect LCO-M(H2) conversion caused the apparent suppression and find that HCGs have normal gas-to-dust ratios. It is likely that the cause of the apparent suppression in these objects is associated with shocks injecting turbulence into the molecular gas...

  17. Suppression of fertility in adult cats

    DEFF Research Database (Denmark)

    Goericke-Pesch, Sandra Kathrin; Wehrend, A.; Georgiev, P.

    2014-01-01

    Contents: Cats are animals with highly efficient reproduction, clearly pointing to a need for suppression of fertility. Although surgical contraception is highly effective, it is not always the method of choice. This is predominantly because it is cost-intensive, time-consuming and irreversible......, with the latter being of major importance for cat breeders. This article reviews the use of progestins, scleroting agents, immunocontraception, melatonin, GnRH antagonists and finally, GnRH agonists, in adult male and female cats in detail, according to the present state of the art. By now, various...... scientific and clinical options are available for the suppression of fertility in adult cats and the decision as to which should be chosen - independent of the legal registration of any state - depends on different facts: (i) feral or privately owned animal? (ii) temporary or permanent suppression of...

  18. Large-scale identification and analysis of suppressive drug interactions.

    Science.gov (United States)

    Cokol, Murat; Weinstein, Zohar B; Yilancioglu, Kaan; Tasan, Murat; Doak, Allison; Cansever, Dilay; Mutlu, Beste; Li, Siyang; Rodriguez-Esteban, Raul; Akhmedov, Murodzhon; Guvenek, Aysegul; Cokol, Melike; Cetiner, Selim; Giaever, Guri; Iossifov, Ivan; Nislow, Corey; Shoichet, Brian; Roth, Frederick P

    2014-04-24

    One drug may suppress the effects of another. Although knowledge of drug suppression is vital to avoid efficacy-reducing drug interactions or discover countermeasures for chemical toxins, drug-drug suppression relationships have not been systematically mapped. Here, we analyze the growth response of Saccharomyces cerevisiae to anti-fungal compound ("drug") pairs. Among 440 ordered drug pairs, we identified 94 suppressive drug interactions. Using only pairs not selected on the basis of their suppression behavior, we provide an estimate of the prevalence of suppressive interactions between anti-fungal compounds as 17%. Analysis of the drug suppression network suggested that Bromopyruvate is a frequently suppressive drug and Staurosporine is a frequently suppressed drug. We investigated potential explanations for suppressive drug interactions, including chemogenomic analysis, coaggregation, and pH effects, allowing us to explain the interaction tendencies of Bromopyruvate. PMID:24704506

  19. FLUTTER SUPPRESSION USING DISTRIBUTED PIEZOELECTRIC ACTUATORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Flutter suppression using distributed piezoelectric actuators has been analyzed and tested. In constructing the finite element equation, effects of piezoelectric matrices are investigated. LQG method is used in designing the control law. In reducing the order of the control law, both balance realization and LK methods are used. For the rational approximation of the unsteady aerodynamic forces LS method is improved. In determining the piezoelectric constants d31 a new dynamic response method is developed. Laser vibrameter is used to pick up the model response and in ground resonance test the model is excited by piezoelectric actuators. Reasonable agreement of the wind tunnel flutter suppression test with calculated results is obtained.

  20. Suppression pool swell analysis using CFD code

    International Nuclear Information System (INIS)

    A two-dimensional axi-symmetric model of suppression pool of Containment Studies Facility (CSF) along with single vent pipe was modeled to estimate the jet and hydrodynamic loads due to flow of steam air mixture during simulated loss of coolant accident (LOCA). The analysis was carried out using CFD ACE+ software with Volume of Fluid (VOF) approach. The flow velocity variation through vent pipe was estimated using in-house containment thermal hydraulic code CONTRAN, was given as input at inlet boundary condition. The transient calculations were performed for 20 seconds and suppression pool level variation, pressure loads over the floor, walls and vent pipes etc were evaluated. (author)

  1. Suppressed epidemics in multi-relational networks

    OpenAIRE

    Xu, Elvis H. W.; Wang, Wei; Xu, C.; Tang, Ming; Do, Younghae; Hui, P. M.

    2014-01-01

    A two-state epidemic model in networks with links mimicking two kinds of relationships between connected nodes is introduced. Links of weights w1 and w0 occur with probabilities p and 1-p, respectively. The fraction of infected nodes rho(p) shows a non-monotonic behavior, with rho drops with p for small p and increases for large p. For small to moderate w1/w0 ratios, rho(p) exhibits a minimum that signifies an optimal suppression. For large w1/w0 ratios, the suppression leads to an absorbing ...

  2. Task motivation influences alpha suppression following errors.

    Science.gov (United States)

    Compton, Rebecca J; Bissey, Bryn; Worby-Selim, Sharoda

    2014-07-01

    The goal of the present research is to examine the influence of motivation on a novel error-related neural marker, error-related alpha suppression (ERAS). Participants completed an attentionally demanding flanker task under conditions that emphasized either speed or accuracy or under conditions that manipulated the monetary value of errors. Conditions in which errors had greater motivational value produced greater ERAS, that is, greater alpha suppression following errors compared to correct trials. A second study found that a manipulation of task difficulty did not affect ERAS. Together, the results confirm that ERAS is both a robust phenomenon and one that is sensitive to motivational factors. PMID:24673621

  3. Propofol and sevoflurane induce distinct burst suppression patterns in rats

    OpenAIRE

    Kenny, Jonathan D.; Westover, M. Brandon; Ching, ShiNung; Brown, Emery N.; Solt, Ken

    2014-01-01

    Burst suppression is an EEG pattern characterized by alternating periods of high-amplitude activity (bursts) and relatively low amplitude activity (suppressions). Burst suppression can arise from several different pathological conditions, as well as from general anesthesia. Here we review current algorithms that are used to quantify burst suppression, its various etiologies, and possible underlying mechanisms. We then review clinical applications of anesthetic-induced burst suppression. Final...

  4. Quantum origin of suppression for vacuum fluctuations

    Science.gov (United States)

    Balitsky, Ja. V.; Kiselev, V. V.

    2016-03-01

    By example of a model with a spatially global scalar field, we show that the energy density of zero-point modes is exponentially suppressed by an average number of field quanta in a finite volume with respect to the energy density in the stationary state of minimal energy. We describe cosmological implications of mechanism.

  5. Quantum origin of vacuum energy suppression

    CERN Document Server

    Balitsky, Ja V

    2014-01-01

    By example of a model with a spatially global scalar field, we show that the energy density of zero-point modes is exponentially suppressed by an average number of field quanta in a finite volume with respect to the energy density in the stationary state of minimal energy. We describe cosmological implications of mechanism.

  6. Radio Science Measurements with Suppressed Carrier

    Science.gov (United States)

    Asmar, Sami; Divsalar, Dariush; Oudrhiri, Kamal

    2013-01-01

    Radio Science started when it became apparent with early Solar missions that occultations by planetary atmospheres would affect the quality of radio communications. Since then the atmospheric properties and other aspects of planetary science, solar science, and fundamental physics were studied by scientists. Radio Science data was always extracted from a received pure residual carrier (without data modulation). For some missions, it is very desirable to obtain Radio Science data from a suppressed carrier modulation. In this paper we propose a method to extract Radio Science data when a coded suppressed carrier modulation is used in deep space communications. Type of modulation can be BPSK, QPSK, OQPSK, MPSK or even GMSK. However we concentrate mostly on BPSK modulation. The proposed method for suppressed carrier simply tries to wipe out data that acts as an interference for Radio Science measurements. In order to measure the estimation errors in amplitude and phase of the Radio Science data we use Cramer-Rao bound (CRB). The CRB for the suppressed carrier modulation with non-ideal data wiping is then compared with residual carrier modulation under the same noise condition. The method of derivation of CRB for non-ideal data wiping is an innovative method that presented here. Some numerical results are provided for coded system.

  7. Government Doublethink: Protection or Suppression in Information.

    Science.gov (United States)

    Drake, Miriam A.

    2003-01-01

    Discusses regulations and actions related to government withholding, suppressing, and altering information since September 11, 2001. Topics include conflicting goals of an informed citizenry versus national security, science and technology progress versus protection of sensitive information, and public health versus ideology; political pressure;…

  8. Emotions shape memory suppression in trait anxiety

    Directory of Open Access Journals (Sweden)

    Tessa eMarzi

    2014-01-01

    Full Text Available The question that motivated this study was to investigate the relation between trait anxiety, emotions and memory control. To this aim, memory suppression was explored in high and low trait anxiety individuals with the Think/No-think paradigm. After learning associations between neutral words and emotional scenes (negative, positive and neutral, participants were shown a word and were requested either to think about the associated scene or to block it out from mind. Finally, in a test phase, participants were again shown each word and asked to recall the paired scene. The results show that memory control is influenced by high trait anxiety and emotions. Low trait anxiety individuals showed a memory suppression effect, whereas there was a lack of memory suppression in high trait anxious individuals, especially for emotionally negative scenes. Thus, we suggest that individuals with anxiety may have difficulty exerting cognitive control over memories with a negative valence. These findings provide evidence that memory suppression can be impaired by anxiety thus highlighting the crucial relation between cognitive control, emotions and individual differences in regulating emotions.

  9. Thought Suppression in Patients With Bipolar Disorder

    Science.gov (United States)

    Miklowitz, David J.; Alatiq, Yousra; Geddes, John R.; Goodwin, Guy M.; Williams, J. Mark G.

    2010-01-01

    Suppression of negative thoughts has been observed under experimental conditions among patients with major depressive disorder (MDD) but has never been examined among patients with bipolar disorder (BD). Patients with BD (n = 36), patients with MDD (n = 20), and healthy controls (n = 20) completed a task that required unscrambling 6-word strings into 5-word sentences, leaving out 1 word. The extra word allowed the sentences to be completed in a negative, neutral, or “hyperpositive” (manic/goal-oriented) way. Participants completed the sentences under conditions of cognitive load (rehearsing a 6-digit number), reward (a bell tone), load and reward, or neither load nor reward. We hypothesized that patients with BD would engage in more active suppression of negative and hyperpositive thoughts than would controls, as revealed by their unscrambling more word strings into negative or hyperpositive sentences. Under conditions of load or reward and in the absence of either load or reward, patients with BD unscrambled more negative sentences than did controls. Under conditions of reward, patients with BD unscrambled more negative sentences than did patients with MDD. Patients with BD also reported more use of negative thought suppression than did controls. These group differences in negative biases were no longer significant when current mood states were controlled. Finally, the groups did not differ in the proportion of hyperpositive sentence completions in any condition. Thought suppression may provide a critical locus for psychological interventions in BD. PMID:20455608

  10. Noise suppression by time exposure oscilloscope photography.

    Science.gov (United States)

    Huchital, G. S.; Young, M.

    1972-01-01

    We describe a simple and inexpensive means of enhancing repetitive signals obscured by noise with roughly equal amplitude. The signal and noise are displayed on an oscilloscope, and we perform a time average over many traces by time exposure photography. If the oscilloscope triggering is synchronous with the signal, the result is a significant suppression of the offending noise.

  11. Normal dexamethasone-suppression adrenal scintiscan

    International Nuclear Information System (INIS)

    To establish the parameters of adrenal imaging under dexamethasone suppression (DS), 18 normotensive, normal male volunteers underwent dexamethasone-suppression adrenal scintiscanning. Five control groups were established and given dexamethasone, either 8 mg for 2 days or 4 mg for 7 days before 6β-[1311]iodomethyl-norcholesterol (NP-59) administration. NP-59 was given in doses of 2, 1, or 0.5 mCi. Early visualization (3-5 days) of the adrenals was noted in the groups on the 8 mg DS regimen with either 1 or 2 mCi of NP-59. Late visualization (5-7 days) was noted in the groups that received 4 mg DS and either 2, 1, or 0.5 mCi of MP-59, respectively. The normal adrenal will demonstrate uptake of NP-59 under DS, and the duration of DS before imaging is the critical factor as to when discernible adrenal visualization will occur. The documentation of the normal suppression interval on these DS regimens provides a basis for the correct diagnostic interpretation of adrenal hyperfunction as seen on the dexamethasone-suppression NP-59 adrenal scan

  12. The tendency to suppress, inhibiting thoughts, and dream rebound.

    Science.gov (United States)

    Taylor, Fiona; Bryant, Richard A

    2007-01-01

    Ironic control theory proposes that suppressing thoughts leads to increased occurrence of the suppressed thought because monitoring for the unwanted thought leads to intrusions. This study investigated the influence of suppressing unwanted thoughts on dream content. One hundred participants who had high or low levels of tendency to suppress unwanted thoughts nominated an intrusive thought, and half of the participants were instructed to suppress that thought for 5 min prior to sleeping. Participants completed a dream diary upon waking, which was subsequently rated by independent raters for dream content. In terms of the 79 participants who reported dreaming, more high suppressors who were instructed to suppress dreamt about the intrusive thought than high suppressors in the control condition. There was no difference between low suppressors in the suppression and control conditions. These results suggest that dream content can be influenced by attempted suppression prior to sleep, and this is particularly apparent in people with a tendency to suppress unwanted thoughts. PMID:16516140

  13. Benchmark enclosure fire suppression experiments - phase 1 test report.

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  14. Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression

    OpenAIRE

    Chemali, Jessica; Ching, ShiNung; Purdon, Patrick L; Solt, Ken; Brown, Emery N.

    2013-01-01

    Objective. Burst suppression is an electroencephalogram pattern in which bursts of electrical activity alternate with an isoelectric state. This pattern is commonly seen in states of severely reduced brain activity such as profound general anesthesia, anoxic brain injuries, hypothermia and certain developmental disorders. Devising accurate, reliable ways to quantify burst suppression is an important clinical and research problem. Although thresholding and segmentation algorithms readily ident...

  15. Breaking Continuous Flash Suppression: A New Measure of Unconscious Processing during Interocular Suppression?

    OpenAIRE

    Stein, Timo; Hebart, Martin N; Sterzer, Philipp

    2011-01-01

    Until recently, it has been thought that under interocular suppression high-level visual processing is strongly inhibited if not abolished. With the development of continuous flash suppression (CFS), a variant of binocular rivalry, this notion has now been challenged by a number of reports showing that even high-level aspects of visual stimuli, such as familiarity, affect the time stimuli need to overcome CFS and emerge into awareness. In this “breaking continuous flash suppression” (b-CFS) p...

  16. Breaking continuous flash suppression: A new measure of unconscious processing during interocular suppression?

    OpenAIRE

    Timo eStein; Hebart, Martin N; Philipp eSterzer

    2011-01-01

    Until recently, it has been thought that under interocular suppression high-level visual processing is strongly inhibited if not abolished. With the development of continuous flash suppression (CFS), a variant of binocular rivalry, this notion has now been challenged by a number of reports showing that even high-level aspects of visual stimuli, such as familiarity, affect the time stimuli need to overcome CFS and emerge into awareness. In this breaking CFS (b-CFS) paradigm, differential uncon...

  17. Overcoming fixation with repeated memory suppression.

    Science.gov (United States)

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information. PMID:24575886

  18. Speckle Suppression Method for SAR Image

    Directory of Open Access Journals (Sweden)

    Jiming Guo

    2013-04-01

    Full Text Available In this study, a new speckle reduction method was proposed in terms of by Bidimensional Empirical Mode Decomposition (BEMD. In this method, the SAR image containing speckle noise was decomposed into a number of elementary components by using BEMD and then the extremal points are done the boundary equivalent extension after screening and the residual continue to be done the boundary equivalent extension until screening is completed, finally, the image was reconstructed, which reduced the speckle noise. Experimental results show that this method has good effect on suppressing speckle noise, compared to the average filter, median filter and gaussian filter and has advantages of sufficiently retaining edge and detail information while suppressing speckle noise.

  19. Suppression pool swell analysis. Special report. [BWR

    Energy Technology Data Exchange (ETDEWEB)

    Chambre, P.L.

    1978-01-01

    The dynamic response of a Mark I pressure suppression system during the early air discharge phase of a postulated loss-of-coolant accident (LOCA) is studied mathematically. The mathematical analysis of the surface swell caused by the initial discharge, located a finite depth below the free surface, is described in detail with the surface elevation shape as a function of time being one of the results. The initial approach considers the case of an infinite pool with the approach progressing to vertical boundary walls and finally to the semicircular pool cross section of the Mark I pressure suppression system. This analysis is valid for the time interval before the free surface impacts any structure.

  20. Suppression pool swell analysis. Special report

    International Nuclear Information System (INIS)

    The dynamic response of a Mark I pressure suppression system during the early air discharge phase of a postulated loss-of-coolant accident (LOCA) is studied mathematically. The mathematical analysis of the surface swell caused by the initial discharge, located a finite depth below the free surface, is described in detail with the surface elevation shape as a function of time being one of the results. The initial approach considers the case of an infinite pool with the approach progressing to vertical boundary walls and finally to the semicircular pool cross section of the Mark I pressure suppression system. This analysis is valid for the time interval before the free surface impacts any structure

  1. Glare suppression by coherence gated negation

    CERN Document Server

    Zhou, Edward Haojiang; Brake, Joshua; Ruan, Haowen; Yang, Changhuei

    2016-01-01

    Imaging of a weak target hidden behind a scattering medium can be significantly confounded by glare. We report a method, termed coherence gated negation (CGN), that uses destructive optical interference to suppress glare and allow improved imaging of a weak target. As a demonstration, we show that by permuting through a set range of amplitude and phase values for a reference beam interfering with the optical field from the glare and target reflection, we can suppress glare by an order of magnitude, even when the optical wavefront is highly disordered. This strategy significantly departs from conventional coherence gating methods in that CGN actively 'gates out' the unwanted optical contributions while conventional methods 'gate in' the target optical signal. We further show that the CGN method can outperform conventional coherence gating image quality in certain scenarios by more effectively rejecting unwanted optical contributions.

  2. Immersion diuresis without expected suppression of vasopressin

    Science.gov (United States)

    Keil, L. C.; Silver, J. E.; Wong, N.; Spaul, W. A.; Greenleaf, J. E.; Kravik, S. E.

    1984-01-01

    There is a shift of blood from the lower parts of the body to the thoracic circulation during bed rest, water immersion, and presumably during weightlessness. On earth, this central fluid shift is associated with a profound diuresis. However, the mechanism involved is not yet well understood. The present investigation is concerned with measurements regarding the plasma vasopressin, fluid, electrolyte, and plasma renin activity (PRA) responses in subjects with normal preimmersion plasma vasopressin (PVP) concentration. In the conducted experiments, PRA was suppressed significantly at 30 min of immersion and had declined by 74 percent by the end of the experiment. On the basis of previously obtained results, it appears that sodium excretion during immersion may be independent of aldosterone action. Experimental results indicate that PVP is not suppressed by water immersion in normally hydrated subjects and that other factors may be responsible for the diuresis.

  3. Quarkonium suppression: Gluonic dissociation vs. colour screening

    Indian Academy of Sciences (India)

    Binoy Krishna Patra; Dinesh Kumar Srivastava

    2003-05-01

    We evaluate the suppression of / production in an equilibrating quark gluon plasma for two competing mechanisms: Debye screening of colour interaction and dissociation due to energetic gluons. Results are obtained for S + S and Au + Au collisions at RHIC and LHC energies. At RHIC energies the gluonic dissociation of the charmonium is found to be equally important for both the systems while the screening of the interaction plays a significant role only for the larger systems. At LHC energies the Debye mechanism is found to dominate both the systems. While considering the suppression of directly produced $\\Upsilon$ at LHC energies, we find that only the gluonic dissociation mechanism comes into play for the initial conditions taken from the self screened parton cascade model in these studies.

  4. Managing for soil health can suppress pests

    Directory of Open Access Journals (Sweden)

    Amanda Hodson

    2016-08-01

    Full Text Available A “healthy” soil can be thought of as one that functions well, both agronomically and ecologically, and one in which soil biodiversity and crop management work in synergy to suppress pests and diseases. UC researchers have pioneered many ways of managing soil biology for pest management, including strategies such as soil solarization, steam treatment and anaerobic soil disinfestation, as well as improvements on traditional methods, such as reducing tillage, amending soil with organic materials, and cover cropping. As managing for soil health becomes more of an explicit focus due to restrictions on the use of soil fumigants, integrated soil health tests will be needed that are validated for use in California. Other research needs include breeding crops for disease resistance and pest suppressive microbial communities as well as knowledge of how beneficial organisms influence plant health.

  5. Correcting intermittent central suppression improves binocular marksmanship.

    Science.gov (United States)

    Hussey, Eric S

    2007-04-01

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

  6. Compton suppression through rise-time analysis.

    Science.gov (United States)

    Selvi, S; Celiktas, C

    2007-11-01

    We studied Compton suppression for 60Co and 137Cs radioisotopes using a signal selection criterion based on contrasting the fall time of the signals composing the photo peak with those composing the Compton continuum. The fall time criterion is employed by using the pulse shape analysis observing the change in the fall times of the gamma-ray pulses. This change is determined by measuring the changes in the rise times related to the fall time of the scintillator and the timing signals related to the fall time of the input signals. We showed that Compton continuum suppression is achieved best via the precise timing adjustment of an analog rise-time analyzer connected to a NaI(Tl) scintillation spectrometer. PMID:17703943

  7. Mechanisms underlying UV-induced immune suppression

    International Nuclear Information System (INIS)

    Skin cancer is the most prevalent form of human neoplasia. Estimates suggest that in excess of one million new cases of skin cancer will be diagnosed this year alone in the United States (www.cancer.org/statistics). Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from skin cancer. The cost of treating non-melanoma skin cancer is estimated to be in excess of US$ 650 million a year [J.G. Chen, A.B. Fleischer, E.D. Smith, C. Kancler, N.D. Goldman, P.M. Williford, S.R. Feldman, Cost of non-melanoma skin cancer treatment in the United States, Dermatol. Surg. 27 (2001) 1035-1038], and when melanoma is included, the estimated cost of treating skin cancer in the United States is estimated to rise to US$ 2.9 billion annually (www.cancer.org/statistics). Because the morbidity and mortality associated with skin cancer is a major public health problem, it is important to understand the mechanisms underlying skin cancer development. The primary cause of skin cancer is the ultraviolet (UV) radiation found in sunlight. In addition to its carcinogenic potential, UV radiation is also immune suppressive. In fact, data from studies with both experimental animals and biopsy proven skin cancer patients suggest that there is an association between the immune suppressive effects of UV radiation and its carcinogenic potential. The focus of this manuscript will be to review the mechanisms underlying the induction of immune suppression following UV exposure. Particular attention will be directed to the role of soluble mediators in activating immune suppression

  8. Myc suppression of Nfkb2 accelerates lymphomagenesis

    International Nuclear Information System (INIS)

    Deregulated c-Myc expression is a hallmark of several human cancers where it promotes proliferation and an aggressive tumour phenotype. Myc overexpression is associated with reduced activity of Rel/NF-κB, transcription factors that control the immune response, cell survival, and transformation, and that are frequently altered in cancer. The Rel/NF-κB family member NFKB2 is altered by chromosomal translocations or deletions in lymphoid malignancies and deletion of the C-terminal ankyrin domain of NF-κB2 augments lymphocyte proliferation. Precancerous Eμ-Myc-transgenic B cells, Eμ-Myc lymphomas and human Burkitt lymphoma samples were assessed for Nfkb2 expression. The contribution of Nfkb2 to Myc-driven apoptosis, proliferation, and lymphomagenesis was tested genetically in vivo. Here we report that the Myc oncoprotein suppresses Nfkb2 expression in vitro in primary mouse fibroblasts and B cells, and in vivo in the Eμ-Myc transgenic mouse model of human Burkitt lymphoma (BL). NFKB2 suppression by Myc was also confirmed in primary human BL. Promoter-reporter assays indicate that Myc-mediated suppression of Nfkb2 occurs at the level of transcription. The contribution of Nfkb2 to Myc-driven lymphomagenesis was tested in vivo, where Nfkb2 loss was shown to accelerate lymphoma development in Eμ-Myc transgenic mice, by impairing Myc's apoptotic response. Nfkb2 is suppressed by c-Myc and harnesses Myc-driven lymphomagenesis. These data thus link Myc-driven lymphomagenesis to the non-canonical NF-κB pathway

  9. PUMA Suppresses Intestinal Tumorigenesis in Mice

    OpenAIRE

    Qiu, Wei; Carson-Walter, Eleanor B.; Kuan, Shih Fan; Zhang, Lin; Yu, Jian

    2009-01-01

    Defective apoptosis contributes to tumorigenesis, although the critical molecular targets remain to be fully characterized. PUMA, a BH3-only protein essential for p53-dependent apoptosis, has been shown to suppress lymphomagenesis. In this study, we investigated the role of PUMA in intestinal tumorigenesis using two animal models. In the azoxymethane (AOM)/dextran sulfate sodium salt model, PUMA deficiency increased the multiplicity and size of colon tumors but reduced the frequency of β-cate...

  10. Mechanisms underlying UV-induced immune suppression

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, Stephen E. [Department of Immunology, University of Texas, MD Anderson Cancer Center, South Campus Research Building 1, 7455 Fannin St., P.O. Box 301402, Houston, TX 77030-1903 (United States)]. E-mail: sullrich@mdanderson.org

    2005-04-01

    Skin cancer is the most prevalent form of human neoplasia. Estimates suggest that in excess of one million new cases of skin cancer will be diagnosed this year alone in the United States (www.cancer.org/statistics). Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from skin cancer. The cost of treating non-melanoma skin cancer is estimated to be in excess of US$ 650 million a year [J.G. Chen, A.B. Fleischer, E.D. Smith, C. Kancler, N.D. Goldman, P.M. Williford, S.R. Feldman, Cost of non-melanoma skin cancer treatment in the United States, Dermatol. Surg. 27 (2001) 1035-1038], and when melanoma is included, the estimated cost of treating skin cancer in the United States is estimated to rise to US$ 2.9 billion annually (www.cancer.org/statistics). Because the morbidity and mortality associated with skin cancer is a major public health problem, it is important to understand the mechanisms underlying skin cancer development. The primary cause of skin cancer is the ultraviolet (UV) radiation found in sunlight. In addition to its carcinogenic potential, UV radiation is also immune suppressive. In fact, data from studies with both experimental animals and biopsy proven skin cancer patients suggest that there is an association between the immune suppressive effects of UV radiation and its carcinogenic potential. The focus of this manuscript will be to review the mechanisms underlying the induction of immune suppression following UV exposure. Particular attention will be directed to the role of soluble mediators in activating immune suppression.

  11. Parental alarm calls suppress nestling vocalization.

    OpenAIRE

    Platzen, Dirk; Magrath, Robert D.

    2004-01-01

    Evolutionary models suggest that the cost of a signal can ensure its honesty. Empirical studies of nestling begging imply that predator attraction can impose such a cost. However, parents might reduce or abolish this cost by warning young of the presence of danger. We tested, in a controlled field playback experiment, whether alarm calls cause 5-, 8- and 11-day-old nestlings of the white-browed scrubwren, Sericornis frontalis, to suppress vocalization. In this species, nestlings vocalize when...

  12. Subspace modelling for structured noise suppression

    CERN Document Server

    Xu, Zhiqiang; Plastino, A

    2009-01-01

    The problem of structured noise suppression is addressed by i)modelling the subspaces hosting the components of the signal conveying the information and ii)applying a non-extensive nonlinear technique for effecting the right separation. Although the approach is applicable to all situations satisfying the hypothesis of the proposed framework, this work is motivated by a particular scenario, namely, the cancellation of low frequency noise in broadband seismic signals.

  13. Culture shapes electrocortical responses during emotion suppression

    OpenAIRE

    Murata, Asuka; Moser, Jason S.; Kitayama, Shinobu

    2012-01-01

    Previous work has shown that emotional control is highly valued in Asian culture. However, little is known about how this cultural value might influence emotional processing. Here, we hypothesized that Asians are ‘culturally trained’ to down-regulate emotional processing when required to suppress emotional expressions. Such down-regulation, however, is unlikely for European Americans because their culture values emotional expression (vs control) more. To test these predictions, we adopted the...

  14. Emotions shape memory suppression in trait anxiety

    OpenAIRE

    Marzi, Tessa; Regina, Antonio; Righi, Stefania

    2014-01-01

    The question that motivated this study was to investigate the relation between trait anxiety, emotions and memory control. To this aim, memory suppression was explored in high and low trait anxiety individuals with the Think/No-think paradigm. After learning associations between neutral words and emotional scenes (negative, positive, and neutral), participants were shown a word and were requested either to think about the associated scene or to block it out from mind. Finally, in a test phase...

  15. Emotions shape memory suppression in trait anxiety

    OpenAIRE

    Tessa eMarzi; Antonio eRegina; Stefania eRighi

    2014-01-01

    The question that motivated this study was to investigate the relation between trait anxiety, emotions and memory control. To this aim, memory suppression was explored in high and low trait anxiety individuals with the Think/No-think paradigm. After learning associations between neutral words and emotional scenes (negative, positive and neutral), participants were shown a word and were requested either to think about the associated scene or to block it out from mind. Finally, in a test phase,...

  16. An Equivalent Noise Investigation of Saccadic Suppression

    OpenAIRE

    Tamara L Watson; Krekelberg, Bart

    2011-01-01

    Visual stimuli presented just before or during an eye movement are more difficult to detect than those same visual stimuli presented during fixation. This laboratory phenomenon – behavioral saccadic suppression – is thought to underlie the everyday experience of not perceiving the motion created by our own eye movements – saccadic omission. At the neural level, many cortical and subcortical areas respond differently to perisaccadic visual stimuli than to stimuli presented during fixation. Tho...

  17. Thought Suppression in Patients With Bipolar Disorder

    OpenAIRE

    Miklowitz, David J.; Alatiq, Yousra; Geddes, John R.; Goodwin, Guy M.; Williams, J. Mark G.

    2010-01-01

    Suppression of negative thoughts has been observed under experimental conditions among patients with major depressive disorder (MDD) but has never been examined among patients with bipolar disorder (BD). Patients with BD (n = 36), patients with MDD (n = 20), and healthy controls (n = 20) completed a task that required unscrambling 6-word strings into 5-word sentences, leaving out 1 word. The extra word allowed the sentences to be completed in a negative, neutral, or “hyperpositive” (manic/goa...

  18. A Convnet for Non-maximum Suppression

    OpenAIRE

    Hosang, J.; Benenson, R.; Schiele, B.

    2015-01-01

    Non-maximum suppression (NMS) is used in virtually all state-of-the-art object detection pipelines. While essential object detection ingredients such as features, classifiers, and proposal methods have been extensively researched surprisingly little work has aimed to systematically address NMS. The de-facto standard for NMS is based on greedy clustering with a fixed distance threshold, which forces to trade-off recall versus precision. We propose a convnet designed to perform NMS of a given s...

  19. Temporary Suppression of Tinnitus by Modulated Sounds

    OpenAIRE

    Reavis, Kelly M.; Rothholtz, Vanessa S.; Tang, Qing; Carroll, Jeff A.; Djalilian, Hamid; Zeng, Fan-Gang

    2012-01-01

    Despite high prevalence of tinnitus and its impact on quality life, there is no cure for tinnitus at present. Here, we report an effective means to temporarily suppress tinnitus by amplitude- and frequency-modulated tones. We systematically explored the interaction between subjective tinnitus and 17 external sounds in 20 chronic tinnitus sufferers. The external sounds included traditionally used unmodulated stimuli such as pure tones and white noise and dynamically modulated stimuli known to ...

  20. Dexmedetomidine induced catecholamine suppression in pheochromocytoma

    OpenAIRE

    Singh, Sanjeev; Singh, Arti

    2014-01-01

    Pheochromocytoma is a neuroendocrine tumour of chromaffin cells, though rare but a known cause of paroxysmal hypertension with a triad of headache, diaphoresis and palpitation. The biochemical diagnosis of pheochromocytoma is based on estimation of plasma nor-adrenaline, adrenaline and their metabolites in plasma or urine. Clonidine suppression test is performed to differentiate the raised catecholamine level due to pheochromocytoma or other than heochromocytoma especially in cases where plas...

  1. Temporal Analysis of Image-Rivalry Suppression

    OpenAIRE

    Rishi Bhardwaj; Robert P. O'shea

    2012-01-01

    During binocular rivalry, perception alternates between two different images presented one to each eye. At any moment, one image is visible, dominant, while the other is invisible, suppressed. Alternations in perception during rivalry could involve competition between eyes, eye-rivalry, or between images, image-rivalry, or both. We measured response criteria, sensitivities, and thresholds to brief contrast increments to one of the rival stimuli in conventional rivalry displays and in a displa...

  2. Currently available cough suppressants for chronic cough.

    Science.gov (United States)

    Chung, Kian Fan

    2008-01-01

    Chronic cough is a common symptom but only a fraction of patients seek medical attention. Addressing the causes of chronic cough may lead to control of cough; however, this approach is not always successful since there is a certain degree of failure even when the cause(s) of cough are adequately treated; in idiopathic cough, there is no cause to treat. Persistent cough may be associated with deterioration of quality of life, and treatment with cough suppressants is indicated. Currently available cough suppressants include the centrally acting opioids such as morphine, codeine, and dextromethorphan. Peripherally acting antitussives include moguisteine and levodropropizine. Early studies report success in reducing cough in patients with chronic bronchitis or COPD; however, a carefully conducted study showed no effect of codeine on cough of COPD. Success with these cough suppressants can be achieved at high doses that are associated with side effects. Slow-release morphine has been reported to be useful in controlling intractable cough with good tolerance to constipation and drowsiness. There have been case reports of the success of centrally acting drugs such as amitryptiline, paroxetine, gabapentin, and carbamezepine in chronic cough. New opioids such as nociceptin or antagonists of TRPV1 may turn out to be more effective. Efficacy of cough suppressants must be tested in double-blind randomised trials using validated measures of cough in patients with chronic cough not responding to specific treatments. Patients with chronic cough are in desperate need of effective antitussives that can be used either on demand or on a long-term basis. PMID:17909897

  3. MR image noise suppression using wavelet filtering

    Czech Academy of Sciences Publication Activity Database

    Bartušek, Karel; Gescheidtová, E.; Smékal, Z.

    Budapest : Asszisztencia Szervező Kft, 2008, TSP081216309954: 1-3. ISBN 978-963-06-5487-6. [Telecommunications and Signal Processing /31./ - TSP 2008. Parádfürdö (HU), 03.09.2008-04.09.2008] R&D Projects: GA ČR(CZ) GA102/07/0389 Institutional research plan: CEZ:AV0Z20650511 Keywords : MRI * spin density suppression * temporomandibular joint * wavelet tansform Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  4. Coating Thermoelectric Devices To Suppress Sublimation

    Science.gov (United States)

    Sakamoto, Jeffrey; Caillat, Thierry; Fleurial, Jean-Pierre; Snyder, G. Jeffrey

    2007-01-01

    A technique for suppressing sublimation of key elements from skutterudite compounds in advanced thermoelectric devices has been demonstrated. The essence of the technique is to cover what would otherwise be the exposed skutterudite surface of such a device with a thin, continuous film of a chemically and physically compatible metal. Although similar to other sublimation-suppression techniques, this technique has been specifically tailored for application to skutterudite antimonides. The primary cause of deterioration of most thermoelectric materials is thermal decomposition or sublimation - one or more elements sublime from the hot side of a thermoelectric couple, changing the stoichiometry of the device. Examples of elements that sublime from their respective thermoelectric materials are Ge from SiGe, Te from Pb/Te, and now Sb from skutterudite antimonides. The skutterudite antimonides of primary interest are CoSb3 [electron-donor (n) type] and CeFe(3-x)Co(x)Sb12 [electron-acceptor (p) type]. When these compounds are subjected to typical operating conditions [temperature of 700 C and pressure niobium, which was selected for its chemical stability. In the experiment, the wrapped specimen was heated to a temperature of 700 C in a vacuum of residual pressure niobium foil prevented sublimation of antimony at 700 C. This was a considerable improvement, considering that uncoated CoSb3 had been found to decompose to form the lowest antimonide at the surface at only 600 C. Evidently, because the mean free path of Sb at the given temperature and pressure was of the order of tens of centimeters, any barrier closer than tens of centimeters (as was the niobium foil) would have suppressed transport of Sb vapor, thereby suppressing sublimation of Sb

  5. Comoving suppression mechanism and cosmological constant problem

    OpenAIRE

    Shen, Jian Qi

    2004-01-01

    In this paper, we assume that the observer is fixed in a comoving frame of reference with $g_{00}=\\frac{\\lambda}{\\Lambda}$, where $\\lambda$ and $\\Lambda$ denote the comoving parameter and the cosmological constant, respectively. By using the {\\it comoving suppression mechanism} and {\\it Mach's principle} (the latter of which is used to determine the comoving parameter $\\lambda$), we calculate the vacuum energy density of quantum fluctuation field in the above-mentioned comoving frame of refer...

  6. Suppression of infanticide in mother rats

    OpenAIRE

    Peters, L. C.; Kristal, M. B.

    1983-01-01

    In order to test the hypothesis that infanticidal tendencies are suppressed when rats become mothers, very young newborn pups, either naturally born or cesarean-delivered, were presented to virgin females and to newly delivered mothers. Provided that the pups were lively, uncleaned of fetal fluids or membranes, and presented without placentas, nearly all virgins killed and nearly all mothers did not. Newborns were also presented to Day 22 pregnant rats and to rats whose pregnancies had recent...

  7. Suppression of Ostwald Ripening by Chemical Reactions

    Science.gov (United States)

    Zwicker, David; Hyman, Anthony A.; Jülicher, Frank

    2015-03-01

    Emulsions consisting of droplets immersed in a fluid are typically unstable and coarsen over time. One important coarsening process is Ostwald ripening, which is driven by the surface tension of the droplets. Ostwald ripening must thus be suppressed to stabilize emulsions, e.g. to control the properties of pharmaceuticals, food, or cosmetics. Suppression of Ostwald ripening is also important in biological cells, which contain stable liquid-like compartments, e.g. germ granules, Cajal-bodies, and centrosomes. Such systems are often driven away from equilibrium by chemical reactions and can thus be called active emulsions. Here, we show that non-equilibrium chemical reactions can suppress Ostwald Ripening, leading to stable, monodisperse emulsions. We derive analytical approximations of the typical droplet size, droplet count, and time scale of the dynamics from a coarse-grained description of the droplet dynamics. We also compare these results to numerical simulations of the continuous concentration fields. Generally, we thus show how chemical reactions can be used to stabilize emulsions and to control their properties in technology and nature.

  8. Atomic Clocks with Suppressed Blackbody Radiation Shift

    International Nuclear Information System (INIS)

    We develop a concept of atomic clocks where the blackbody radiation shift and its fluctuations can be suppressed by 1-3 orders of magnitude independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies ν1 and ν2) which are exposed to the same thermal environment, there exists a 'synthetic' frequency νsyn ∝ (ν1-ε12ν2) largely immune to the blackbody radiation shift. For example, in the case of 171Yb+ it is possible to create a synthetic-frequency-based clock in which the fractional blackbody radiation shift can be suppressed to the level of 10-18 in a broad interval near room temperature (300±15 K). We also propose a realization of our method with the use of an optical frequency comb generator stabilized to both frequencies ν1 and ν2, where the frequency νsyn is generated as one of the components of the comb spectrum.

  9. Neural Networks for Mindfulness and Emotion Suppression.

    Directory of Open Access Journals (Sweden)

    Hiroki Murakami

    Full Text Available Mindfulness, an attentive non-judgmental focus on "here and now" experiences, has been incorporated into various cognitive behavioral therapy approaches and beneficial effects have been demonstrated. Recently, mindfulness has also been identified as a potentially effective emotion regulation strategy. On the other hand, emotion suppression, which refers to trying to avoid or escape from experiencing and being aware of one's own emotions, has been identified as a potentially maladaptive strategy. Previous studies suggest that both strategies can decrease affective responses to emotional stimuli. They would, however, be expected to provide regulation through different top-down modulation systems. The present study was aimed at elucidating the different neural systems underlying emotion regulation via mindfulness and emotion suppression approaches. Twenty-one healthy participants used the two types of strategy in response to emotional visual stimuli while functional magnetic resonance imaging was conducted. Both strategies attenuated amygdala responses to emotional triggers, but the pathways to regulation differed across the two. A mindful approach appears to regulate amygdala functioning via functional connectivity from the medial prefrontal cortex, while suppression uses connectivity with other regions, including the dorsolateral prefrontal cortex. Thus, the two types of emotion regulation recruit different top-down modulation processes localized at prefrontal areas. These different pathways are discussed.

  10. Jet suppression at LHC: theory vs. experiment

    International Nuclear Information System (INIS)

    Suppression of light and heavy flavor observables is one of the most important probes in studying the properties of QCD matter created at RHIC and LHC experiments. We will here summarize the most up-to-date light and heavy flavor suppression predictions for 2.76 TeV central Pb+Pb collisions at LHC. The predictions are based on our recent improvements in the energy loss calculations that take into account: i) theoretical formalism which includes finite size dynamical QCD medium with finite magnetic mass effects and running coupling, and ii) numerical procedure which includes path-length and multi-gluon fluctuations. Our theoretical predictions, obtained with no free parameters used in model testing, show a very good agreement with the experimental results for all available particle species. Our results show that the developed theoretical formalism is able to robustly explain suppression data at LHC, which strongly suggests that pQCD in Quark-Gluon Plasma can provide a reasonable description of the underlying jet physics in ultra relativistic heavy ion collisions

  11. 低密度脂蛋白受体表达失调在炎性反应介导的糖尿病肾病足细胞损伤中的作用%Disruption of low-density lipoprotein receptor pathway induced by inflammation contributes to podocyte injury in diabetic nephropathy

    Institute of Scientific and Technical Information of China (English)

    张洋; 马坤岭; 刘晶; 吴娱; 胡泽波; 吕林莉; 刘必成

    2014-01-01

    目的 观察微炎性反应状态下低密度脂蛋白受体(low density lipoprotein receptor,LDLr)途径在糖尿病肾病(DN)足细胞损伤中的作用.方法 选取8周龄雄性db/db小鼠及对照组db/m小鼠,分别按随机数字表法分为db/db、db/db+酪蛋白组和db/m、db/m+酪蛋白组,每组均为8只.参照本实验室已建立的方法制备糖尿病肾病微炎性反应模型,每周收集24 h尿液、检测24 h尿蛋白量,8周后处死,收集血清标本,留取肾组织,检测血清脂质谱的变化.透射电镜观察足细胞超微结构变化,激光共聚焦显微镜及Western印迹观察足细胞特异性标志蛋白WT-1、nephrin及间充质细胞表型标志物α平滑肌肌动蛋白(α-SMA)的表达情况.油红O染色和胞内游离胆固醇定量测定法观察肾小球中脂质积聚情况,免疫组化及Western印迹观察LDLr、固醇调节元件结合蛋白2(sterol regulatory element binding protein-2,SREBP-2)及其裂解激活蛋白(SREBP cleavage-activating protein,SCAP)在肾脏的表达情况,并且通过激光共聚焦显微镜观察WT-1与LDLr在肾脏的共表达情况.分析LDLr与nephrin、α-SMA表达的相关性.结果 与db/db组相比,db/db+酪蛋白组小鼠的蛋白尿、足细胞结构损害及足细胞的丢失明显加重,足细胞α-SMA的蛋白表达量显著增加,肾小球内脂质积聚明显增多,肾脏LDLr、SREBP-2和SCAP的蛋白表达量也明显增加(均P<0.05),并且LDLr的表达与nephrin的表达呈负相关(r=-0.855,P< 0.01),与α-SMA的表达呈正相关(r=0.768,P<0.01).激光共聚焦荧光显微镜证实,小鼠肾脏的LDLr与足细胞特异性标志物WT-1存在共表达.结论 炎性反应能够促进糖尿病小鼠足细胞损伤及表型改变,部分机制可能与炎性反应诱导肾脏足细胞LDLr表达上调,增加细胞内胆固醇摄入,导致足细胞内脂质堆积有关.%Objective To investigate the effects of low density lipoprotein receptor (LDLr) pathway on podocyte

  12. Effects of triperygium wilfordii polyglucoside on kidney structure and nephrin expression in podocytes in rats with diabetic nephropathy%雷公藤多苷对糖尿病肾病大鼠肾组织结构及足细胞nephrin蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    赵芊; 郑妙艳; 李玉荣; 常宝成; 陈莉明

    2012-01-01

    Objective To explore the effects of triperygium wilfordii polyglucoside (TWP) on proteinuria,podocytes damages,nephrin expression in rats with diabetic nephropathy.Methods Diabetic nephropathy was established in rats using high lipids diet combined with streptozotocin (STZ).Diabetic rats were randomized into diabetic nephropathy model,low dosage of TWP( 6 mg · kg- 1 · d-1) and high dosage of TWP( 12 mg · kg-1 · d-1 )group.Normal rats were used as control and 12 rats for each group.After intervention for 12 weeks,24 h urinary protein excretion rate (UAER),serum creatinine and plasma urea nitrogen were accessed.The pathological changes of kidney were evaluated by Haematoxylin and eosin( HE),Periodic acid schiff(PAS),Masson staining.Ultrastructural alteration was examined by transmission electron microscope.The expressions of nephrin were evaluated by immunohistochemical staining.Results Compared with normal rats [ ( 3.28 ± 0.26 ) mg/24 h ],macroalbuminuia increased in diabetic rats [ ( 27.60 ± 0.24 ) mg/24 h],whereas the level of urine protein significantly decreased in 6 and 12 mg · kg-1 · d-1 TWP treatment for 12 weeks[ ( 12.63 ±0.21 ) and( 10.50 ± 0.15 ) mg/24 h ].There was no significant statistical difference between high and low dose of TWP group( P <0.05 ).In renal pathologic examination of diabetic nephropathy model group,the glomerular were sclerosis,with thicker basement membranes,deformed renal tubules,vacuolar degenerated epithelial cells and sclerosed interstitial were observed.The foot processes of podocyte were widen and fused,and the number of podocyte was also decreased.However,the kidney and podocyte lesions were improved significantly both in high and low dose of TWP groups.The expressions of nephrin by immunohistochemistry were also increased in both TWP treatment groups,with more statistical improvement in high dose group.Conclusions TWP may exert its protective effect on podocytes function in diabetic nephropathy through increasing

  13. Large-Scale Identification and Analysis of Suppressive Drug Interactions

    OpenAIRE

    Cokol, Murat; Weinstein, Zohar B.; Yilancioglu, Kaan; Tasan, Murat; Doak, Allison; Cansever, Dilay; Mutlu, Beste; Li, Siyang; Rodriguez-Esteban, Raul; Akhmedov, Murodzhon; Guvenek, Aysegul; Cokol, Melike; Cetiner, Selim; Giaever, Guri; Iossifov, Ivan

    2014-01-01

    One drug may suppress the effects of another. Although knowledge of drug suppression is vital to avoid efficacy-reducing drug interactions or discover countermeasures for chemical toxins, drug-drug suppression relationships have not been systematically mapped. Here, we analyze the growth response of Saccharomyces cerevisiae to anti-fungal compound (“drug”) pairs. Among 440 ordered drug pairs, we identified 94 suppressive drug interactions. Using only pairs not selected on the basis of their s...

  14. Large-scale identification and analysis of suppressive drug interactions

    OpenAIRE

    Çokol, Murat; Cokol, Murat; Weinstein, Zohar Bat-El; Yılancıoğlu, Kaan; Yilancioglu, Kaan; Tasan, Murat; Doak, Allison; Cansever, Dilay; Mutlu, Beste; Li, Siyang; Rodriguez-Esteban, Raul; Akhmedov, Murodzhon; Güvenek, Ayşegül; Guvenek, Aysegul; Çokol, Melike

    2014-01-01

    One drug may suppress the effects of another. Although knowledge of drug suppression is vital to avoid efficacy-reducing drug interactions or discover countermeasures for chemical toxins, drug-drug suppression relationships have not been systematically mapped. Here, we analyze the growth response of Saccharomyces cerevisiae to anti-fungal compound ("drug") pairs. Among 440 ordered drub pairs, we identified 94 suppressive drug interactions. Using only pairs not selected on the basis of their s...

  15. Incubation and suppression processes in creative problem solving

    OpenAIRE

    Gilhooly, KJ; Georgiou, GJ; Sirota, M; Paphiti-Galeano, A

    2015-01-01

    The present study investigated the role of thought suppression in incubation, using a delayed incubation paradigm. A total of 301 participants were tested over five conditions, viz., continuous work control, incubation with a mental rotations interpolated task, focussed suppression, unfocussed suppression and a conscious expression condition. Checks were made for intermittent work during the incubation condition. The target task was alternative uses for a brick. In the incubation and suppress...

  16. Orientation-tuned surround suppression in mouse visual cortex

    OpenAIRE

    Self, Matthew W.; Lorteije, Jeannette A. M.; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N.; Heimel, J.A.; Roelfsema, Pieter R.

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those containing orientation contrast. This effect is thought to be important for scene segmentation, but the underlying neural mechanisms are poorly understood. We asked whether it is possible to study these ...

  17. The role of suppression in figurative language comprehension✩

    OpenAIRE

    Gemsbacher, Morton Ann; Robertson, Rachel R.W.

    1999-01-01

    In this paper, we describe the crucial role that suppression plays in many aspects of language comprehension. We define suppression as a general, cognitive mechanism, the purpose of which is to attenuate the interference caused by the activation of extraneous, unnecessary, or inappropriate information. We illustrate the crucial role that suppression plays in general comprehension by reviewing numerous experiments. These experiments demonstrate that suppression attenuates interference during l...

  18. System and method for suppressing sublimation using opacified aerogel

    Science.gov (United States)

    Sakamoto, Jeff S. (Inventor); Snyder, G. Jeffrey (Inventor); Calliat, Thierry (Inventor); Fleurial, Jean-Pierre (Inventor); Jones, Steven M. (Inventor); Palk, Jong-Ah (Inventor)

    2008-01-01

    The present invention relates to a castable, aerogel-based, ultra-low thermal conductivity opacified insulation to suppress sublimation. More specifically, the present invention relates to an aerogel opacified with various opacifying or reflecting constituents to suppress sublimation and provide thermal insulation in thermoelectric modules. The opacifying constituent can be graded within the aerogel for increased sublimation suppression, and the density of the aerogel can similarly be graded to achieve optimal thermal insulation and sublimation suppression.

  19. Noise Suppression of a single Frequency Fiber Laser

    Institute of Scientific and Technical Information of China (English)

    LIU Kui; CUI Shu-Zhen; ZHANG Hai-Long; ZHANG Jun-Xiang; GAO Jiang-Rui

    2011-01-01

    We present an experimental demonstration of fiber laser noise suppression by the mode cleaner.The intensity noise of a single frequency fiber laser is suppressed near the shot noise limit after a sideband frequency of 3 MHz.Two series mode cleaners are used to improve the noise suppression.The noise reduction is over 27 dB at 3 MHz.

  20. Effects of suppression and appraisals on thought frequency and distress.

    Science.gov (United States)

    Corcoran, Kathleen M; Woody, Sheila R

    2009-12-01

    Cognitive theories of obsessions highlight appraisals of personal significance and thought suppression in the development and maintenance of intrusive thoughts. The current study examined the role of personal significance within the context of a thought suppression paradigm. The primary aim was to examine whether suppression would have differential effects for target thoughts appraised as personally meaningful versus relatively unimportant. A blasphemous thought served as the target thought, and highly religious and nonreligious participants were recruited. Participants completed a two-interval thought suppression task; during interval 1 they were randomly assigned to suppress or not suppress the target thought and during interval 2, all participants were given "do not suppress" instructions. Suppression resulted in sustained frequency of thoughts in contrast to the decline in thought frequency observed for non-suppression. Differential effects of suppression were found across the two groups. Moreover, suppression was associated with increased negative mood and anxiety. Results suggest that suppression of personally meaningful thoughts is a counterproductive strategy. PMID:19765684

  1. Why expressive suppression does not pay? Cognitive costs of negative emotion suppression: The mediating role of subjective tense-arousal

    Directory of Open Access Journals (Sweden)

    Szczygieł Dorota

    2015-09-01

    Full Text Available The aim of this paper was to contribute to a broader understanding of the cognitive consequences of expressive suppression. Specifically, we examined whether the deteriorating effect of expressive suppression on cognitive functioning is caused by tense arousal enhanced by suppression. Two experiments were performed in order to test this prediction. In both studies we tested the effect of expressive suppression on working memory, as measured with a backwards digit-span task (Study 1, N = 43 and anagram problem-solving task (Study 2, N = 60. In addition, in Study 2 we tested whether expressive suppression degrades memory of the events that emerged during the period of expressive suppression. Both studies were conducted in a similar design: Participants watched a film clip which evoked negative emotions (i.e. disgust in Study 1 and a combination of sadness and anxiety in Study 2 under the instruction to suppress those negative emotions or (in the control condition to simply watch the film. The results of these experiments lead to three conclusions. First, the results reveal that expressive suppression degrades memory of the events that emerged during the period of expressive suppression and leads to poorer performance on working memory tasks, as measured with a backwards digit-span task and anagram problem-solving task. Second, the results indicate that expressive suppression leads to a significant increase in subjective tense arousal. Third, the results support our prediction that expressive suppression decreases cognitive performance through its effects on subjective tense arousal. The results of the Study 1 show that tense arousal activated during expressive suppression of disgust fully mediates the negative effect of suppression on working memory as measured with a backwards digit-span task. The results of Study 2 reveal that subjective tense arousal elicited while suppressing sadness and anxiety mediates both the effect of suppression on

  2. Why expressive suppression does not pay? Cognitive costs of negative emotion suppression: The mediating role of subjective tense-arousal

    OpenAIRE

    Szczygieł Dorota; Maruszewski Tomasz

    2015-01-01

    The aim of this paper was to contribute to a broader understanding of the cognitive consequences of expressive suppression. Specifically, we examined whether the deteriorating effect of expressive suppression on cognitive functioning is caused by tense arousal enhanced by suppression. Two experiments were performed in order to test this prediction. In both studies we tested the effect of expressive suppression on working memory, as measured with a backwards digit-span task (Study 1, N = 43) a...

  3. Effect of gypenoside on the podocyte injury and its mechanism in rats with diabetic nephropathy%绞股蓝总皂苷对糖尿病肾病大鼠足细胞损伤的影响及机制

    Institute of Scientific and Technical Information of China (English)

    黄平; 王雁秋

    2012-01-01

    目的:研究绞股蓝总皂苷对糖尿病肾病(DN)大鼠肾脏足细胞相关分子( nephrin)、血管通透因子(VEGF)mRNA表达的影响,探讨其降低尿蛋白、保护肾脏的机制.方法:采用单侧肾切除加链脲佐菌素( STZ)注射法改良复制DN模型,实验分为正常组、模型组、治疗组(绞股蓝总皂苷高、中、低剂量组)和缬沙坦组.干预4周后电镜观察肾小球超微结构改变,RT-PCR检测nephrin、VEGF mRNA表达.结果:各治疗组病理变化较模型组均有不同程度改善:足突增宽或部分融合,基底膜增厚减轻,同时nephrin mRNA表达水平较模型组明显上调(P<0.01),VEGF表达明显抑制(P<0.01),其中高剂量组和缬沙坦组效果类似,明显优于低剂量组(P<0.01).结论:绞股蓝总皂苷可能通过上调足细胞相关分子nephrin表达,抑制分泌VEGF过表达,减轻足细胞超微结构改变,从而保护足细胞,降低尿蛋白,延缓肾小球硬化.%Objective: To investigate the effect of gypenoside on the expressions of nephrin, vascular endothelial growth factor (VEGF) in rats with diabetic nephropathy (DN) and explore its mechanism of the reduction of proteinuria and renal protection. Methods: DN model was established by uninephrectomized and induced with streptozotocin (STZ), then randomly divided into model group and treatment groups (groups of high, medium, low dose of gypenoside, and valsartan group), with normal rats as the control group. All the rats received daily gavage for 4 weeks, and then the ultramicrostructure changes of the glomerulus were observed with transmission electron microscope. The expressions of Nephrin, VEGF mRNA in the podocytes were detected by real-time quantitative PCR. Results: Comparing to the model group, the pathological changes of every treatment groups were improved in different degree: the extension and fusion of foot processes and the thickness of glomerular basement membrane were all ameliorated. Simultaneously, the

  4. Metasurfaces for suppressing reflection over broadband

    CERN Document Server

    Patra, Anuradha; Nagarajan, Arvind; Achanta, Venu Gopal

    2015-01-01

    Surfaces patterned with arrays of quasi-periodic air holes having conical depth profile have been studied for their effectiveness in suppressing air-substrate reflection in the wavelength range of 450-1350 nm (limited by our measurement). The role of quasi-periodic air-hole pattern, depth of holes and launch angle on the observed antireflection behavior are investigated. The average optical transmittance of the patterned quartz substrate at near normal incidence is more than 97% and reflectance is less than 2%. Patterned quartz surfaces with 450 nm thin graded rarefaction region maintain the antireflective property up to 30{\\deg} (limited by our measurements) angle of incidence.

  5. Overvoltage Suppression for UHV Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    LI Yongli; LIU Taihua; LI Zhongqing; JING Lei; LONG Ying; FAN Jianzhong

    2008-01-01

    The overvoltage phenomena of ultra high voltage (UHV) transmission lines are analyzed and verified by EMTDC/PSCAD simulation. Referring to the theoretical analyses and operating experiences of extra high voltage (EHV) transmission lines in China and UHV transmission lines in Russia and Japan, the methods to suppress the internal overvoltage in UHV transmission lines by protection and control strategies are discussed. Through the cooperation among the recloser, shunt reactor, tripping and closing resistance, and metal oxide varistor (MOV), the overvoltage can be restrained within an acceptable level.

  6. Curvature suppresses the Rayleigh-Taylor instability

    CERN Document Server

    Trinh, Philippe H; Hammoud, Naima; Howell, Peter D; Chapman, S Jonathan; Stone, Howard A

    2014-01-01

    The dynamics of a thin liquid film on the underside of a curved cylindrical substrate is studied. The evolution of the liquid layer is investigated as the film thickness and the radius of curvature of the substrate are varied. A dimensionless parameter (a modified Bond number) that incorporates both geometric parameters, gravity, and surface tension is identified, and allows the observations to be classified according to three different flow regimes: stable films, films with transient growth of perturbations followed by decay, and unstable films. Experiments and theory confirm that, below a critical value of the Bond number, curvature of the substrate suppresses the Rayleigh-Taylor instability.

  7. Improved attractants for enhancing tsetse fly suppression

    International Nuclear Information System (INIS)

    At the initiation of this co-ordinated research project (CRP), the available visually attractant devices and odours for entomological monitoring and for suppression of tsetse fly populations were not equally effective against all economically important tsetse fly species. For species like G. austeni, G. brevipalpis, G. swynnertoni and some species of the PALPALIS-group of tsetse flies no sufficiently effective combinations of visual or odour attractants were available for efficient suppression and standardized monitoring as part of an operational integrated intervention campaign against the tsetse and trypanosomosis (T and T) problem. The Co-ordinated Research Project on Improved Attractants for Enhancing the Efficiency of Tsetse Fly Suppression Operations and Barrier Systems used in Tsetse Control/Eradication Campaigns involved (a) the identification, synthesis and provision of candidate kairomones, their analogues and of dispensers; (b) laboratory screening of synthesised candidate kairomones through electrophysiological studies and wind tunnel experiments; (c) field tests of candidate kairomones alone or as part of odour blends, in combination with available and or new trap designs; and (d) analysis of hydrocarbons that influence tsetse sexual behaviour. The CRP accomplished several main objectives, namely: - The screening of new structurally related compounds, including specific stereoisomers, of known tsetse attractants resulted in the identification of several new candidate odour attractants with promising potential. - An efficient two-step synthetic method was developed for the pilot plant scale production of 3-n-propyphenol, synergistic tsetse kairomone component. - Electrophysiological experiments complemented with wind tunnel studies provided an efficient basis for the laboratory screening of candidate attractants prior to the initiation of laborious field tests. - New traps were identified and modifications of existing traps were tested for some species

  8. Strangeness Suppression in Proton-Proton Collisions

    OpenAIRE

    Drescher, Hans-Joachim; Aichelin, Joerg; Werner, Klaus

    2001-01-01

    We analyse strangeness production in proton-proton (pp) collisions at SPS and RHIC energies, using the recently advanced NeXus approach. After having verified that the model reproduces well the existing data, we interpret the results: strangeness is suppressed in proton-proton collisions at SPS energy as compared to electron-positron (e+e-) annihilation due to the limited masses of the strings produced in the reaction, whereas high energy pp and e+e- collisions agree quantitatively . Thus str...

  9. Suppression of Dephasing of Optically Trapped Atoms

    CERN Document Server

    Andersen, M F; Grünzweig, T; Davidson, N

    2003-01-01

    Ultra-cold atoms trapped in an optical dipole trap and prepared in a coherent superposition of their hyperfine ground states, decohere as they interact with their environment. We demonstrate than the loss in coherence in an "echo" experiment, which is caused by mechanisms such as Rayleigh scattering, can be suppressed by the use of a new pulse sequence. We also show that the coherence time is then limited by mixing to other vibrational levels in the trap and by the finite lifetime of the internal quantum states of the atoms.

  10. The Relation of Weight Suppression and BMI to Bulimic Symptoms

    Science.gov (United States)

    Butryn, Meghan L.; Juarascio, Adrienne; Lowe, Michael R.

    2016-01-01

    Objective High levels of weight suppression have been associated with greater binge eating and weight gain as well as poorer treatment outcome in bulimia nervosa. This study examined the relationship between weight suppression and bulimia nervosa symptoms and explored how weight suppression might interact with body mass index (BMI) in accounting for level of symptomatology at presentation for treatment. Method Participants were 64 women with threshold or sub-threshold bulimia nervosa. A clinical interview assessed binge eating and purging. Results Weight suppression and the interaction between BMI and weight suppression predicted frequency of binge eating such that participants with low BMI and high weight suppression engaged in the most binge eating. High levels of weight suppression also predicted more frequent purging. Discussion Additional research is warranted to examine mediators of these relationships. PMID:21997424

  11. Suppression of Ostwald ripening in active emulsions

    Science.gov (United States)

    Zwicker, David; Hyman, Anthony A.; Jülicher, Frank

    2015-07-01

    Emulsions consisting of droplets immersed in a fluid are typically unstable since they coarsen over time. One important coarsening process is Ostwald ripening, which is driven by the surface tension of the droplets. Stability of emulsions is relevant not only in complex fluids but also in biological cells, which contain liquidlike compartments, e.g., germ granules, Cajal bodies, and centrosomes. Such cellular systems are driven away from equilibrium, e.g., by chemical reactions, and thus can be called active emulsions. In this paper, we study such active emulsions by developing a coarse-grained description of the droplet dynamics, which we analyze for two different chemical reaction schemes. We first consider the simple case of first-order reactions, which leads to stable, monodisperse emulsions in which Ostwald ripening is suppressed within a range of chemical reaction rates. We then consider autocatalytic droplets, which catalyze the production of their own droplet material. Spontaneous nucleation of autocatalytic droplets is strongly suppressed and their emulsions are typically unstable. We show that autocatalytic droplets can be nucleated reliably and their emulsions stabilized by the help of chemically active cores, which catalyze the production of droplet material. In summary, different reaction schemes and catalytic cores can be used to stabilize emulsions and to control their properties.

  12. Suppression of Coronavirus Replication by Cyclophilin Inhibitors

    Directory of Open Access Journals (Sweden)

    Takashi Sasaki

    2013-05-01

    Full Text Available Coronaviruses infect a variety of mammalian and avian species and cause serious diseases in humans, cats, mice, and birds in the form of severe acute respiratory syndrome (SARS, feline infectious peritonitis (FIP, mouse hepatitis, and avian infectious bronchitis, respectively. No effective vaccine or treatment has been developed for SARS-coronavirus or FIP virus, both of which cause lethal diseases. It has been reported that a cyclophilin inhibitor, cyclosporin A (CsA, could inhibit the replication of coronaviruses. CsA is a well-known immunosuppressive drug that binds to cellular cyclophilins to inhibit calcineurin, a calcium-calmodulin-activated serine/threonine-specific phosphatase. The inhibition of calcineurin blocks the translocation of nuclear factor of activated T cells from the cytosol into the nucleus, thus preventing the transcription of genes encoding cytokines such as interleukin-2. Cyclophilins are peptidyl-prolyl isomerases with physiological functions that have been described for many years to include chaperone and foldase activities. Also, many viruses require cyclophilins for replication; these include human immunodeficiency virus, vesicular stomatitis virus, and hepatitis C virus. However, the molecular mechanisms leading to the suppression of viral replication differ for different viruses. This review describes the suppressive effects of CsA on coronavirus replication.

  13. On the quantum loop suppressed electroweak processes

    CERN Document Server

    Palle, Davor

    2012-01-01

    The quantum loop suppressed electroweak processes appear to be very sensitive probes for the symmetry-breaking mechanisms. Since the Standard Model does not involve massive neutrinos, baryon or lepton number violations and the cold dark matter particle, there are great expectations in search for physics beyond the Standard Model. The LHC experiments reported no new physics, except for the probable appearance of the 125 GeV heavy resonance. If this resonance turns out to be a Higgs boson, we shall be faced with the paradox that the Standard Model, as a theoretically and experimentally incomplete and defective theory, is confirmed. If, on the other hand, this resonance is a pseudoscalar meson - a mixture of a pseudoscalar glueball and toponium, as suggested by P. Cea, one has to study alternative symmetry-breaking mechanisms. This paper is devoted to the evaluations of the gauge invariant electroweak functions that are relevant for the suppressed electroweak processes within the SM or the UV finite theory in wh...

  14. Suppression of fertility in adult dogs.

    Science.gov (United States)

    Maenhoudt, C; Santos, N R; Fontbonne, A

    2014-06-01

    Unfortunately, the overpopulation of dogs is still a problem in the majority of countries and even though surgical methods of sterilization, the most traditional and commonly used technique, have been intensively performed, the impact on the dog population is negligible. The neutering of companion animals as ovariohysterectomy (spaying) or orchidectomy (castration) has its limitations because of the cost, the need of a surgical environment and the risk of surgical and/or anaesthetical complications (ACCD 2009). In fact, surgical castration has been banished in some northern European countries and has limited acceptance in other countries. In a survey performed in Sao Paulo, Brazil, 56.5% of the owners of adopted shelter dogs were against the surgical procedure for different reasons (Soto et al. 2005). Currently, the options for contraception, defined as suppression of fertility are based on hormonal treatment. The treatments can be divided into analogues of gonadotropin releasing hormone (GnRH), progestins and androgens. Other possibilities of contraception are via the immunological system with vaccinations against GnRH, the luteinizing hormone (LH) receptor and the zona pellucida proteins. Finally, there is also the intra-epididymal or intratesticular injection of sclerosing substances in dogs. Mechanical devices to disrupt fertility are not used anymore due to the side effects. Suppression of fertility in adult dogs will be reviewed in order of use and possible impact on the dog population. PMID:24947862

  15. An analysis of pressure suppression pool swell

    International Nuclear Information System (INIS)

    An analysis of the pressure suppression pool swell phenomenon has been carried out for a Pressurized Heavy Water Reactor (PHWR) of Indian design. In the event of a Loss-of-Coolant Accident (LOCA), the upper chamber of the containment, i.e., Drywell, would experience higher pressure because of mass and energy release from the reactor coolant system into the drywell. To alleviate the problem of drywell overpressurization, there is a large volume of water or suppression pool at the bottom of the containment where steam from the drywell could flow and condense. The present analysis models the transient air-steam mixture flow from drywell through the vent shafts, distribution headers and downcomers into the pool. After the initial vent-clearing stage, bubble growth at the exit of individual downcomers is modeled. Finally, the coalesced bubble growth and rise are modeled for groups of downcomers. For all these stages, the pool-swell and wetwell air-space pressure are also calculated. A four-equation model consisting of conservation of mixture mass, momentum, energy and noncondensible (air) mass has been used

  16. Electroproduction of Baryon Resonances and Strangeness Suppression

    CERN Document Server

    Santopinto, E; Tecocoatzi, H Garcia

    2016-01-01

    We describe the electroproduction ratios of baryon-meson states from nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: Lambda K , Sigma K, p pion, and n pion. These predictions are in agreement with the new Jlab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial test of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we computed the so called strangeness suppression factor, lambda s, that is the suppression of strange quark-antiquarks compared to nonstrange pairs, and we found that our finding with this simple extension of the qua...

  17. Inhibition of SIRT2 suppresses hepatic fibrosis.

    Science.gov (United States)

    Arteaga, Maribel; Shang, Na; Ding, Xianzhong; Yong, Sherri; Cotler, Scott J; Denning, Mitchell F; Shimamura, Takashi; Breslin, Peter; Lüscher, Bernhard; Qiu, Wei

    2016-06-01

    Liver fibrosis can progress to cirrhosis and result in serious complications of liver disease. The pathogenesis of liver fibrosis involves the activation of hepatic stellate cells (HSCs), the underlying mechanisms of which are not fully known. Emerging evidence suggests that the classic histone deacetylases play a role in liver fibrosis, but the role of another subfamily of histone deacetylases, the sirtuins, in the development of hepatic fibrosis remains unknown. In this study, we found that blocking the activity of sirtuin 2 (SIRT2) by using inhibitors or shRNAs significantly suppressed fibrogenic gene expression in HSCs. We further demonstrated that inhibition of SIRT2 results in the degradation of c-MYC, which is important for HSC activation. In addition, we discovered that inhibition of SIRT2 suppresses the phosphorylation of ERK, which is critical for the stabilization of c-MYC. Moreover, we found that Sirt2 deficiency attenuates the hepatic fibrosis induced by carbon tetrachloride (CCl4) and thioacetamide (TAA). Furthermore, we showed that SIRT2, p-ERK, and c-MYC proteins are all overexpressed in human hepatic fibrotic tissues. These data suggest a critical role for the SIRT2/ERK/c-MYC axis in promoting hepatic fibrogenesis. Inhibition of the SIRT2/ERK/c-MYC axis represents a novel strategy to prevent and to potentially treat liver fibrosis and cirrhosis. PMID:27125275

  18. Suppressing drift chamber diffusion without magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Martoff, C.J. E-mail: cmartoff@nimbus.temple.edu; Snowden-Ifft, D.P.; Ohnuki, T.; Spooner, N.; Lehner, M

    2000-02-01

    The spatial resolution in drift chamber detectors for ionizing radiation is limited by diffusion of the primary electrons. A strong magnetic field along the drift direction is often applied (Fancher et al., Nucl. Instr. and Meth. A 161 (1979) 383) because it suppresses the transverse diffusion, improving the resolution but at considerable increase in cost and complexity. Here we show that transverse track diffusion can be strongly suppressed without any magnetic field. This is achieved by using a gas additive which reversibly captures primary ionization electrons, forming negative ions. The ions drift with thermal energies even at very high drift fields and low pressures (E/P=28.5 V/cm torr), and the diffusion decreases with increasing drift field. Upon arrival at the avalanche region of the chamber the negative ions are efficiently stripped and ordinary avalanche gain is obtained. Using this technique, r.m.s. transverse diffusion less than 200 {mu}m has been achieved over a 15 cm drift path at 40 torr with zero magnetic field. The method can provide high spatial resolution in detectors with long drift distances and zero magnetic field. Negative ion drift chambers would be particularly useful at low pressures and in situations such as space-based or underground experiments where detector size scaleability is important and cost, space, or power constraints preclude the use of a magnetic field.

  19. Suppression of glioma progression by Egln3.

    Directory of Open Access Journals (Sweden)

    Vicki A Sciorra

    Full Text Available Grade IV astrocytoma or glioblastoma has a poor clinical outcome that can be linked to hypoxia, invasiveness and active vascular remodeling. It has recently been suggested that hypoxia-inducible factors, Hifs, increase glioma growth and aggressiveness [1], [2], [3]. Here, we tested the hypothesis that Egl 9 homolog 3 (Egln3, a prolyl-hydroxylase that promotes Hif degradation, suppresses tumor progression of human and rodent glioma models. Through intracranial tumorigenesis and in vitro assays, we demonstrate for the first time that Egln3 was sufficient to decrease the kinetics of tumor progression and increase survival. We also find that Klf5, a transcription factor important to vascular remodeling, was regulated by hypoxia in glioma. An analysis of the tumor vasculature revealed that elevated Egln3 normalized glioma capillary architecture, consistent with a role for Egln3 in eliciting decreases in the production of Hif-regulated, angiogenic factors. We also find that the hydroxylase-deficient mutant, Egln3(H196A partially maintained tumor suppressive activity. These results highlight a bifurcation of Egln3 signaling and suggest that Egln3 has a non-hydroxylase-dependent function in glioma. We conclude that Egln3 is a critical determinant of glioma formation and tumor vascular functionality.

  20. Wireless Inductive Power Device Suppresses Blade Vibrations

    Science.gov (United States)

    Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

    2011-01-01

    Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

  1. Detection and description of soils with specific nematode suppressiveness.

    Science.gov (United States)

    Westphal, Andreas

    2005-03-01

    Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation with a target nematode, have been employed to identify nematode-suppressive soils. Biocidal treatments, soil transfer tests, and baiting approaches together with observations of the plant-parasitic nematode in the root zone of susceptible host plants have improved the understanding of nematode-suppressive soils. Techniques to demonstrate specific soil suppressiveness against plant-parasitic nematodes are compared in this review. The overlap of studies on soil suppressiveness with recent advances in soil health and quality is briefly discussed. The emphasis is on methods (or criteria) used to detect and identify soils that maintain specific soil suppressiveness to plant-parasitic nematodes. While biocidal treatments can detect general and specific soil suppressiveness, soil transfer studies, by definition, apply only to specific soil suppressiveness. Finally, potential strategies to exploit suppressive soils are presented. PMID:19262851

  2. Reduction of podocytes number in late diabetic alloxan nephropathy: prevention by glycemic control Redução do número de podócitos na fase tardia da nefropatia diabética aloxânica: prevenção pelo controle glicêmico

    Directory of Open Access Journals (Sweden)

    Célia Sperandéo Macedo

    2007-10-01

    Full Text Available PURPOSE: To determine podocyte number and GBM thickness in diabetic rats either under glycemic control or without glycemic control at 6 and 12 months after diabetes induction. METHODS: 100 wistar rats weighing 200-300g were divided into 6 groups: Normal group (N6 and N12- 25 rats; Diabetic group (D6 and D12- 25 rats, diabetic treated group ( DT 6 and DT 12- 25 rats on insulin 1,8- 3,0 IU/Kg associated with acarbose (50mg to 100g of food daily mixed in chow. Alloxan was injected intravenously in a dose of 42 mg/Kg of weight. Body weight, waterintake, 24-h diuresis, glycemia and glucosuria were determined before induction, 7 and 14 days after induction and monthly thereafter. Treatment started at day 14. Three groups were sacrificed at 6 months (N6,D6, DT6 and 3 groups at 12 months (N12, D12, DT12 with the renal tissue being prepared for electron microscopy. RESULTS: Glycemia in DT6¨and in DT12 was significantly different from that in D6 and D12 rats and similar to that in N6 and N12 animals. The number of podocytes in DT6 was not different from that in N6 and D6 (median = 11; the number of podocytes in DT12 (median = 11 differed from that in D12 (median = 8, but not from that in N12 (median = 11. GBM thickness in D6 (0.18 micrometers was lower than in D12 (0.29 micrometers; while in DT6 (0.16 micrometers it was lower than in D6 (0.18 micrometers. In DT12 (0.26 micrometers, it was lower than in D12 (0.29 micrometers. CONCLUSION: The control of hyperglycemia prevented GBM thickening in early and late (12 mo alloxan diabetic nephropathy and podocyte number reduction.OBJETIVO: Avaliar o número de podócitos e espessamento da membrana basal glomerular (MBG em ratos diabéticos com e sem controle glicêmico com 6 e 12 meses da indução. MÉTODOS: 100 ratos Wistar com 200-300g compuseram 6 grupos: Normal (N6, N12 - 25 animais Diabético (D6,D12 - 25 animais e diabético tratado com insulina 1,8 a 3,0 U/Kg e acarbose misturada a ração (50g para cada

  3. Thought suppression failures in combat PTSD: a cognitive load hypothesis.

    Science.gov (United States)

    Aikins, Deane E; Johnson, Douglas C; Borelli, Jessica L; Klemanski, David H; Morrissey, Paul M; Benham, Todd L; Southwick, Steven M; Tolin, David F

    2009-09-01

    The present study investigated the relation between thought suppression of emotionally neutral content [i.e., Wegner's (1994) "white bear"], incidental traumatic thought intrusion, and skin conductance responses in combat-related Posttraumatic Stress Disorder (PTSD). Participants included service members who either: a) had PTSD following an Operation Iraqi Freedom deployment; b) were free of psychiatric diagnosis following deployment (Combat Equivalent), or c) were pre-deployed and without psychiatric diagnosis (Pre-Deployed). PTSD Service Members reported the greatest intrusion of combat thoughts during the suppression task and demonstrated a post-suppression rebound effect with a neutral thought. Non-specific skin conductance responses indicated that the suppression task was related to similar levels of increased sympathetic activity for both the PTSD and Pre-Deployed groups, whereas the Combat Equivalent group showed no increased activation during thought suppression. Intrusive traumatic thoughts combined with failures in neutral thought suppression may be a consequence of increased cognitive load in PTSD. PMID:19586619

  4. Maintenance of microflora suppression in irradiated monkeys

    International Nuclear Information System (INIS)

    After at least two weeks of decontamination, rhesus monkeys were submitted to a total body irradiation of 8.5 Gy, followed by a bone marrow graft. In the following weeks, a number of colonizations were found. Twenty-seven colonizations were known to be present on the day of irradiation. Sixteen colonizations were due to microorganisms suppressed before irradiation. Thirty-two colonizations were considered as exogenous. Only a few colonizations in the irradiated animals could not be controlled. Irradiation caused severe diarrhoea in decontaminated animals, leading to a life-threatening loss of water and electrolytes. When this loss was corrected, the monkeys survived for prolonged periods following irradiation. The amount of food consumed, which contained antibiotics, had no effect on the faecal concentration. The addition of solid food particles, however, resulted in a much lower faecal concentration. No significant antibiotic serum levels were found. (orig.)

  5. Infinite volume suppression versus quantum fluctuations

    CERN Document Server

    Kartavtsev, Alexander

    2014-01-01

    It is routinely argued that tunneling of the Higgs field along the minimum of the Mexican hat potential is suppressed by the infinite space volume. In the path integral formalism this conclusion is drawn from the analysis of paths on which the field is homogeneous in the whole infinite space. Here we demonstrate that this approach fails to reproduce vacuum properties of even the simplest systems like free real scalar field. On the other hand, adding also the contributions of inhomogeneous field configurations we obtain for the free field the established results. This casts some doubt on the conclusions drawn for the Higgs field using the `homogeneous paths' approach and might call for a careful reanalysis of the mechanism of spontaneous symmetry breaking in quantum field theory.

  6. Suppression of decoherence by bath ordering

    Institute of Scientific and Technical Information of China (English)

    Jing Jun; Ma Hong-Ru

    2007-01-01

    The dynamics of two coupled spins-1/2 coupled to a spin-bath is studied as an extended model of the TessieriWilkie Hamiltonian. The pair of spins served as an open subsystem is prepared in one of the Bell states and the bath consisting of some spins-1/2 is in a thermal equilibrium state from the very beginning. It is found that with increasing coupling strength of the bath spins, the bath forms a resonant antiferromagnetic order. The polarization correlation between the two spins of the subsystem and the concurrence of it are recovered to some extent in the isolated subsystem. This suppression of the subsystem decoherence may be used to control the quantum devices in practical applications.

  7. Are Patents used to Suppress Useful Technology?

    DEFF Research Database (Denmark)

    Howells, John

    2006-01-01

    of innovation, other than in the trivial sense of excluding third parties from the right to develop the technology covered by the patent? There are many references to this possibility in the management, economic and legal literatures, but two highly-cited papers stand out for grounding their claims of corporate...... suppression of innovation in the historical record (Dunford 1987; Merges and Nelson 1990). This paper shows that there are many errors of interpretation, both in the historical papers and in Dunford and Merges and Nelson's writing. Most important are confusions about the nature of technological competition...... of the historical narrative evidence and of the relatively recent Tetrapak case brought before the European courts than the rhetoric of competition policy and economic monopoly that continues to dominate analysis of such patent cases....

  8. Ion suppression from blood collection devices

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo; Sejr Gothelf, Aase

    The aim of the study was to examine the variation in ion suppression in ultra high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS-MS) methods when using different blood collection devices. Three different methods measuring 18 antidepressants and antipsychotics in total were...... studied. The blood collection devices were all designed to activate clot formation. They were made of glass with or without silicone coating or plastic containing silicate particles, thrombin or polystyrene particles coated with kaolin. The blood collection devises Venoject and Venosafe were supplied from...... Terumo, S-monovette from Sarstedt, Vacuette from Greiner Bio-One and three BD Vacutainer serum tubes from BD. These seven different blood collection devices were used to withdraw blood from five healthy drug free donors (n=35) in random order. The samples were centrifuged and serum from each sample...

  9. Suppression of Instability in Rotatory Hydromagnetic Convection

    Indian Academy of Sciences (India)

    Joginder S Dhiman

    2000-08-01

    Recently discovered hydrodynamic instability [1], in a simple Bénard configuration in the parameter regime 02 > 1 under the action of a nonadverse temperature gradient, is shown to be suppressed by the simultaneous action of a uniform rotation and a uniform magnetic field both acting parallel to gravity for oscillatory perturbations whenever $(\\mathscr{Q}_1/^2+\\mathscr{J}/^4) > 1$ and the effective Rayleigh number $\\mathcal{R}$(1-02) is dominated by either 274(1 + 1/1)/4 or 274/2 according as 1 ≥ 1 or 1 ≤ 1 respectively. Here 0 is the temperature of the lower boundary while 2 is the coefficient of specific heat at constant volume due to temperature variation and 1, $\\mathcal{R}, \\mathscr{Q}$ and $\\mathscr{T}$ respectively denote the magnetic Prandtl number, the Rayleigh number, the Chandrasekhar number and the Taylor number.

  10. Obtuse triangle suppression in anisotropic meshes

    KAUST Repository

    Sun, Feng

    2011-12-01

    Anisotropic triangle meshes are used for efficient approximation of surfaces and flow data in finite element analysis, and in these applications it is desirable to have as few obtuse triangles as possible to reduce the discretization error. We present a variational approach to suppressing obtuse triangles in anisotropic meshes. Specifically, we introduce a hexagonal Minkowski metric, which is sensitive to triangle orientation, to give a new formulation of the centroidal Voronoi tessellation (CVT) method. Furthermore, we prove several relevant properties of the CVT method with the newly introduced metric. Experiments show that our algorithm produces anisotropic meshes with much fewer obtuse triangles than using existing methods while maintaining mesh anisotropy. © 2011 Elsevier B.V. All rights reserved.

  11. Noise analysis and column FPN suppression technology

    Directory of Open Access Journals (Sweden)

    Xiao-Fen Jia

    2013-01-01

    Full Text Available Noise is an important indicator that affects the image quality. Among the different processing strategies implemented in image sensors, the effect on the noise is complicated. The two types of noise that influences the imaging quality of the digital camera are analyzed firstly. The optical signal and reset signal of the typical correlated double sampling (CDS are read out through two column amplifiers (CA, respectively. The performance of the two column amplifiers are not exactly the same, resulting in itself will bring the column FPN. To suppress the column FPN effectively, a single amplifier CDS scheme is proposed, which have only one CA, the power consumption and area of the proposed CDS circuit is reduced by half.

  12. Suppressing photochemical reactions with quantized light fields

    CERN Document Server

    Galego, Javier; Feist, Johannes

    2016-01-01

    Photoisomerization, i.e., a change of molecular structure after absorption of a photon, is one of the most fundamental photochemical processes. It can perform desirable functionality, e.g., as the primary photochemical event in human vision, where it stores electronic energy in the molecular structure, or for possible applications in solar energy storage and as memories, switches, and actuators; but it can also have detrimental effects, for example as an important damage pathway under solar irradiation of DNA, or as a limiting factor for the efficiency of organic solar cells. While photoisomerization can be avoided by shielding the system from light, this is of course not a viable pathway for approaches that rely on the interaction with external light (such as solar cells or solar energy storage). Here, we show that strong coupling of organic molecules to a confined light mode can be used to strongly suppress photoisomerization, and thus convert molecules that normally show fast photodegradation into photosta...

  13. Gel fire suppressants for controlling underground heating

    Institute of Scientific and Technical Information of China (English)

    HU Sheng-gen; XUE Sheng

    2011-01-01

    One of the major safety issues in coal mining is heatings and the resultant spontaneous combustion in underground coal mines.CSIRO researchers have developed a number of polymer gels suitable for controlling heatings in coal mines.These gels were developed to meet strict selection criteria including easy preparation,no or low toxicity,controllable gelation time,adaptable to mine water chemistry,adjustable viscosity,relatively long gel life,thermally and chemically stable and low cost.The HPAM-Aluminum Citrate gel system was identified to be the most favourable gel system for fire suppression in underground coal mines.These gels can be applied to the areas undergoing coal heating or gas leakage at a controllable gelation time and impermeable gel barriers can be formed in the areas to block ingress of air.

  14. In-Beam Background Suppression Shield

    CERN Document Server

    Santoro, V; DiJulio, D D; Ansell, S; Bentley, P M

    2015-01-01

    The long (3ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument capabilities will be limited by it's Signal to Noise (S/N) ratio. The instruments with a direct view of the moderator, which do not use a bender to help mitigate the fast neutron background, are the most challenging. For these beam lines we propose the innovative shielding of placing blocks of material directly into the guide system, which allow a minimum attenuation of the cold and thermal fluxes relative to the background suppression. This shielding configuration has been worked into a beam line model using Geant4. We study particularly the advantages of single crystal sapphire and silicon blocks .

  15. Latest results on $J/$ anomalous suppression

    Indian Academy of Sciences (India)

    Sérgio Ramos; NA50 Collaboration; B Allessandro; C Alexa; R Arnaldi; M Atayan; C Baglin; A Baldit; M Bedjidian; S Beolè; V Boldea; P Bordalo; S R Borenstein; G Borges; A Bussière; L Capelli; C Castanier; J Castor; B Chaurand; B Cheynis; E Chiavassa; C Cicalo; T Claudino; M P Comets; S Constantinescu; P Cortese; J Cruz; A DeFalco; N DeMarco; G Dellacasa; A Devaux; S Dita; O Drapier; B Espagnon; J Fargeix; P Force; M Gallio; Y K Gavrilov; C Gerschel; P Giubellino; M B Golubeva; M Gonin; A A Grigorian; S Grigorian; J Y Grossiord; F F Guber; A Guichard; H Gulkanyan; R Hakobyan; R Haroutunian; M Idzik; D Jouan; T L Karavitcheva; L Kluberg; A B Kurepin; Y Le Bornée; C Lourenço; P Macciotta; M Mac Cormick; A Marzari-Chiesa; M Masera; A Masoni; M Monteno; A Musso; P Petiau; A Piccotti; J R Pizzi; W L Prado da Silva; F Prino; G Puddu; C Quintans; L Ramello; S Ramos; P Rato Mendes; L Riccati; A Romana; H Santos; P Saturnini; E Scalas; E Scomparin; S Serci; R Shahoyan; F Sigaudo; M Sitta; P Sonderegger; X Tarrago; N S Topilskaya; G L Usai; E Vercellin; L Villatte; N Willis; T Wu

    2004-03-01

    The NA50 experiment deals with Pb–Pb collisions at 158 GeV/nucleon at the CERN SPS accelerator. The $J/$ production is studied through the muon decay channel, using the Drell–Yan dimuons as a reference. New results based on recent analyses, from data taken with improved experimental conditions and using different centrality estimators, are presented and compared to an update of those already obtained from previous data samples. The stepwise pattern of the anomalous $J/$ suppression as a function of centrality, already present in these previous results, is confirmed. This observation could be a fingerprint of the theoretically predicted melting of charmonia resonances in a deconfined quark–gluon plasma.

  16. Passive runaway electron suppression in tokamak disruptions

    International Nuclear Information System (INIS)

    Runaway electrons created in disruptions pose a serious problem for tokamaks with large current. It would be desirable to have a runaway electron suppression method which is passive, i.e., a method that does not rely on an uncertain disruption prediction system. One option is to let the large electric field inherent in the disruption drive helical currents in the wall. This would create ergodic regions in the plasma and increase the runaway losses. Whether these regions appear at a suitable time and place to affect the formation of the runaway beam depends on disruption parameters, such as electron temperature and density. We find that it is difficult to ergodize the central plasma before a beam of runaway current has formed. However, the ergodic outer region will make the Ohmic current profile contract, which can lead to instabilities that yield large runaway electron losses

  17. Suppression of indigo bush with pod pests

    Directory of Open Access Journals (Sweden)

    Gagić-Serdar Renata

    2013-01-01

    Full Text Available The recorded seed predators of Amorpha fruticosa L., indigo bush weevils and pteromalid wasps, were the subject of laboratory and field research studies in the period from 2006 to 2011. Sample analyses were carried out on more than 30 localities in Serbia with the aim of measuring the summarized pre-dispersal and post dispersal predation preferences. The percentages of the total pre-dispersal (max≈33% and post-dispersal re-infested material (over 95%, make these insects serious candidates for host-plant suppression. Their bionomics were monitored through continuous collection, dessection and observation of infested seeds, in correlation with environmental parameters, especially water-level fluctuations in endangered forests. [Projekat Ministarstva nauke Republike Srbije, br. TP-31070: The development of technological methods in forestry in order to attain optimal forest cover

  18. SUPPRESSION OF STAR FORMATION IN NGC 1266

    International Nuclear Information System (INIS)

    NGC 1266 is a nearby lenticular galaxy that harbors a massive outflow of molecular gas powered by the mechanical energy of an active galactic nucleus (AGN). It has been speculated that such outflows hinder star formation (SF) in their host galaxies, providing a form of feedback to the process of galaxy formation. Previous studies, however, indicated that only jets from extremely rare, high-power quasars or radio galaxies could impart significant feedback on their hosts. Here we present detailed observations of the gas and dust continuum of NGC 1266 at millimeter wavelengths. Our observations show that molecular gas is being driven out of the nuclear region at M-dot out≈110 M⊙ yr–1, of which the vast majority cannot escape the nucleus. Only 2 M ☉ yr–1 is actually capable of escaping the galaxy. Most of the molecular gas that remains is very inefficient at forming stars. The far-infrared emission is dominated by an ultra-compact (≲ 50 pc) source that could either be powered by an AGN or by an ultra-compact starburst. The ratio of the SF surface density (ΣSFR) to the gas surface density (ΣH2) indicates that SF is suppressed by a factor of ≈50 compared to normal star-forming galaxies if all gas is forming stars, and ≈150 for the outskirt (98%) dense molecular gas if the central region is powered by an ultra-compact starburst. The AGN-driven bulk outflow could account for this extreme suppression by hindering the fragmentation and gravitational collapse necessary to form stars through a process of turbulent injection. This result suggests that even relatively common, low-power AGNs are able to alter the evolution of their host galaxies as their black holes grow onto the M-σ relation

  19. SUPPRESSION OF STAR FORMATION IN NGC 1266

    Energy Technology Data Exchange (ETDEWEB)

    Alatalo, Katherine; Lanz, Lauranne; Bitsakis, Theodoros; Appleton, Philip N.; Ogle, Patrick M. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Lacy, Mark; Lonsdale, Carol J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Nyland, Kristina; Meier, David S. [Physics Department, New Mexico Tech, Socorro, NM 87801 (United States); Cales, Sabrina L. [Department of Astronomy, Faculty of Physical and Mathematical Sciences, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Chang, Philip [Department of Physics, University of Wisconsin—Milwaukee, Milwaukee, WI 53201 (United States); Davis, Timothy A.; De Zeeuw, P. T. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Martín, Sergio, E-mail: kalatalo@ipac.caltech.edu [Institut de Radioastronomie Millimétrique, 300 Rue de la Piscine, Domaine Universitaire, F-38406 Saint Martin d' Hères (France)

    2015-01-01

    NGC 1266 is a nearby lenticular galaxy that harbors a massive outflow of molecular gas powered by the mechanical energy of an active galactic nucleus (AGN). It has been speculated that such outflows hinder star formation (SF) in their host galaxies, providing a form of feedback to the process of galaxy formation. Previous studies, however, indicated that only jets from extremely rare, high-power quasars or radio galaxies could impart significant feedback on their hosts. Here we present detailed observations of the gas and dust continuum of NGC 1266 at millimeter wavelengths. Our observations show that molecular gas is being driven out of the nuclear region at M-dot {sub out}≈110 M{sub ⊙} yr{sup –1}, of which the vast majority cannot escape the nucleus. Only 2 M {sub ☉} yr{sup –1} is actually capable of escaping the galaxy. Most of the molecular gas that remains is very inefficient at forming stars. The far-infrared emission is dominated by an ultra-compact (≲ 50 pc) source that could either be powered by an AGN or by an ultra-compact starburst. The ratio of the SF surface density (Σ{sub SFR}) to the gas surface density (Σ{sub H{sub 2}}) indicates that SF is suppressed by a factor of ≈50 compared to normal star-forming galaxies if all gas is forming stars, and ≈150 for the outskirt (98%) dense molecular gas if the central region is powered by an ultra-compact starburst. The AGN-driven bulk outflow could account for this extreme suppression by hindering the fragmentation and gravitational collapse necessary to form stars through a process of turbulent injection. This result suggests that even relatively common, low-power AGNs are able to alter the evolution of their host galaxies as their black holes grow onto the M-σ relation.

  20. Are Claims of Global Warming Being Suppressed?

    Science.gov (United States)

    Crowley, Thomas J.

    2006-02-01

    Over the last few years, I have heard many rumors that climate science relevant to the global warming discussion is being suppressed by the Bush Administration. One cannot do much about third-hand information. However, on 29 January, the New York Times published a front page article on NASA efforts to suppress statements about global warming by James Hansen, director of the NASA Goddard Institute for Space Studies. A claim by one government scientist, though, no matter how distinguished, still requires examples from other scientists before a general conclusion can be drawn about the overall scope of the problem. But if the charges are more widespread, then some government scientists might be reluctant to make such claims, because they might feel that their positions were jeopardized. Therefore, an alternate way may be needed to determine the scope of the issue, while still safeguarding government workers from possible retaliation. -On 30 January, Rep. Sherwood Boehlert (R-N.Y.), chairman of the U.S. House of Representatives Committee on Science, wrote a letter to NASA Administrator Michael Griffin addressing many of the concerns Crowley has raised. Boehlert wrote,``It ought to go without saying that government scientists must be free to describe their scientific conclusions and the implications of those conclusions to their fellow scientists, policymakers and the general public.'' He continued,``Good science cannot long persist in an atmosphere of intimidation. Political figures ought to be reviewing their public statements to make sure they are consistent with the best available science; scientists should not be reviewing their statements to make sure they are consistent with the current political orthodoxy.'' I commend Rep. Boehlert for his quick and clear statement of the importance of unfettered communication of science. -FRED SPILHAUS, Editor

  1. Suppression of the critical current of a balanced SQUID

    OpenAIRE

    Kemppinen, Antti; Manninen, Antti J.; Möttönen, Mikko; Vartiainen, Juha J.; Peltonen, Joonas T.; Pekola, Jukka P.

    2007-01-01

    We present an experimental study of the magnetic flux dependence of the critical current of a balanced SQUID with three Josephson junctions in parallel. Unlike for ordinary dc SQUIDs, the suppression of the critical current does not depend on the exact parameters of the Josephson junctions. The suppression is essentially limited only by the inductances of the SQUID loops. We demonstrate a critical current suppression ratio of higher than 300 in a balanced SQUID with a maximum critical current...

  2. Organic and Inorganic Nitrogen Amendments to Soil as Nematode Suppressants

    OpenAIRE

    Rodríguez-Kábana, R.

    1986-01-01

    Inorganic fertilizers containing ammoniacal nitrogen or formulations releasing this form of N in the soil are most effective for suppressing nematode populations. Anhydrous ammonia has been shown to reduce soil populations of Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Heterodera glycines. The rates required to obtain significant suppression of nematode populations are generally in excess of 150 kg N/ha. Urea also suppresses several nematode species, including Meloidogyne spp., ...

  3. Sediment suppresses herbivory across a coral reef depth gradient

    OpenAIRE

    Goatley, Christopher H. R.; Bellwood, David R.

    2012-01-01

    Sediments are a ubiquitous feature of all coral reefs, yet our understanding of how they affect complex ecological processes on coral reefs is limited. Sediment in algal turfs has been shown to suppress herbivory by coral reef fishes on high-sediment, low-herbivory reef flats. Here, we investigate the role of sediment in suppressing herbivory across a depth gradient (reef base, crest and flat) by observing fish feeding following benthic sediment reductions. We found that sediment suppresses h...

  4. Suppression of Insulin Production and Secretion by a Decretin Hormone

    OpenAIRE

    Alfa, Ronald W.; Park, Sangbin; Skelly, Kathleen-Rose; Poffenberger, Gregory; Jain, Nimit; Gu, Xueying; Kockel, Lutz; Jing WANG; Liu, Yinghua; Powers, Alvin C.; Kim, Seung K.

    2015-01-01

    Decretins, hormones induced by fasting that suppress insulin production and secretion, have been postulated from classical human metabolic studies. From genetic screens, we identified Drosophila Limostatin (Lst), a peptide hormone that suppresses insulin secretion. Lst is induced by nutrient restriction in gut-associated endocrine cells. limostatin deficiency led to hyperinsulinemia, hypoglycemia and excess adiposity. A conserved 15-residue polypeptide encoded by limostatin suppressed secreti...

  5. Cardiovascular Costs of Emotion Suppression Cross Ethnic Lines1

    OpenAIRE

    Nicole A Roberts; Levenson, Robert W.; Gross, James J.

    2008-01-01

    Previous research has shown that inhibiting emotion-expressive behavior (emotion suppression) leads to increased sympathetic activation of the cardiovascular system (Gross & Levenson, 1993). Ethnic differences have been reported in how frequently suppression is used as an emotion regulation strategy (Gross & John, 2003); however, it remains unknown whether there are ethnic differences in the physiological consequences of suppression. To test this, 168 participants from four ethnic groups (Afr...

  6. Multiplex allele-specific target amplification based on PCR suppression

    OpenAIRE

    Broude, Natalia E.; Zhang, Lingang; Woodward, Karen; Englert, David; Cantor, Charles R.

    2001-01-01

    We have developed a strategy for multiplex PCR based on PCR suppression. PCR suppression allows DNA target amplification with only one sequence-specific primer per target and a second primer that is common for all targets. Therefore, an n-plex PCR would require only n + 1 primers. We have demonstrated uniform, efficient amplification of targeted sequences in 14-plex PCR. The high specificity of suppression PCR also provides multiplexed amplification with allele specifi...

  7. Inhibitory Stabilization of the Cortical Network Underlies Visual Surround Suppression

    OpenAIRE

    Ozeki, Hirofumi; Finn, Ian M.; Schaffer, Evan S.; Miller, Kenneth D.; Ferster, David

    2009-01-01

    In what regime does the cortical circuit operate? Our intracellular studies of surround suppression in cat primary visual cortex (V1) provide strong evidence on this question. Although suppression has been thought to arise from an increase in lateral inhibition, we find that the inhibition that cells receive is reduced, not increased, by a surround stimulus. Instead, suppression is mediated by a withdrawal of excitation. Thalamic recordings and previous work show that these effects cannot be ...

  8. Genetic identification of a neural circuit that suppresses appetite

    OpenAIRE

    Carter, Matthew E.; Soden, Marta E.; Zweifel, Larry S.; Palmiter, Richard D.

    2013-01-01

    Appetite suppression occurs following a meal and also during conditions when it is unfavorable to eat, such as during illness or exposure to toxins. A brain region hypothesized to play a role in appetite suppression is the parabrachial nucleus (PBN) 1-3 , a heterogeneous population of neurons surrounding the superior cerebellar peduncle in the brainstem. The PBN is thought to mediate the suppression of appetite induced by the anorectic hormones amylin and cholecystokinin, as well as lithium c...

  9. RFI Suppression in Ultrawideband SAR Using an Adaptive Line Enhancer

    OpenAIRE

    Vu, Viet Thuy; Sjögren, Thomas; Pettersson, Mats; Håkansson, Lars; Gustavsson, Anders; Ulander, Lars

    2010-01-01

    In this letter, we propose an approach to suppress radio-frequency interference (RFI) in ultrawideband (UWB) low-frequency synthetic aperture radar (SAR). According to the proposal, RFI is suppressed by using an adaptive line enhancer controlled by the normalized least mean square algorithm. The approach is tested successfully on real UWB low-frequency SAR data. In order to keep the computational burden down, possible ways to integrate the RFI suppression approach into SAR imaging algorithms ...

  10. Identifying indicators of soil suppressiveness to fungal diseases

    OpenAIRE

    Siegel, Katarzyna; Aime, Sébastien; Chapelle, Emilie; Edel Hermann, Veronique; Raaijmakers, Jos M; Lemanceau, Philippe; Steinberg, Christian

    2013-01-01

    Soils suppressive to soil-borne diseases are defined by a low disease incidence in spite of the presence of a virulent pathogen and a susceptible plant. In many cases, the inhibition of the disease development relies on the activity of the resident soil microbiome. To identify taxonomic microbial indicators linked to the suppressiveness phenotype of soils, culture independent-based methods have been employed to analyse and compare microbial dynamics in two different soils suppressive to eithe...

  11. Detection and Description of Soils with Specific Nematode Suppressiveness

    OpenAIRE

    Westphal, Andreas

    2005-01-01

    Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation with a target nematode, have been employed to identify nematode-suppressive soils. Biocidal treatme...

  12. A spray-suppression model for turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

    2000-02-14

    A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

  13. An Examination of a Potential Moderator of the Relationship Between Thought Suppression and Preoccupation with Previously Suppressed Thoughts

    OpenAIRE

    Fikretoglu, Deniz

    2003-01-01

    Findings from numerous laboratory studies on thought suppression suggest that engaging in deliberate thought suppression may lead to the ironic effects of becoming preoccupied by the very same thoughts one wishes to avoid. Based on the results of these laboratory studies, a sophisticated model of thought suppression (i.e., Ironic Process Theory) has been developed. It has been argued that Ironic Process Theory can inform our understanding of the processes involved in the development and maint...

  14. Suppression of uninvolved immunoglobulins defined by heavy/light chain pair suppression is a risk factor for progression of MGUS

    OpenAIRE

    Katzmann, JA; Clark, R.; Kyle, RA; Larson, DR; Therneau, TM; Melton, LJ; Benson, JT; Colby, CL; Dispenzieri, A; Landgren, O; Kumar, S; Bradwell, AR; Cerhan, JR; Rajkumar, SV

    2012-01-01

    We hypothesized that the suppression of uninvolved immunoglobulin in monoclonal gammopathy of undetermined significance (MGUS) as detected by suppression of the isotype-specific heavy and light chain (HLC-pair suppression) increases the risk of progression to malignancy. This approach required quantitation of individual heavy/light chains (for example, IgGλ in IgGκ MGUS patients). Of 1384 MGUS patients from Southeastern Minnesota seen at the Mayo Clinic from 1960 to 1994, baseline serum sampl...

  15. Breaking continuous flash suppression: A new measure of unconscious processing during interocular suppression?

    Directory of Open Access Journals (Sweden)

    Timo eStein

    2011-12-01

    Full Text Available Until recently, it has been thought that under interocular suppression high-level visual processing is strongly inhibited if not abolished. With the development of continuous flash suppression (CFS, a variant of binocular rivalry, this notion has now been challenged by a number of reports showing that even high-level aspects of visual stimuli, such as familiarity, affect the time stimuli need to overcome CFS and emerge into awareness. In this breaking CFS (b-CFS paradigm, differential unconscious processing during suppression is inferred when (a speeded detection responses to initially invisible stimuli differ, and (b no comparable differences are found in non-rivalrous control conditions supposed to measure general threshold differences between stimuli. To critically evaluate these assumptions was the aim of the present study. In six experiments we compared the time upright and inverted faces needed to be detected. We found that not only under CFS, but also in control conditions upright faces were detected faster and more accurately than inverted faces, although the effect was larger during CFS. However, reaction time (RT distributions indicated critical differences between the CFS and the control condition. When RT distributions were matched, similar effect sizes were obtained in both conditions. Moreover, subjective ratings revealed that CFS and control conditions are not perceptually comparable. These findings cast doubt on the usefulness of non-rivalrous control conditions to rule out mere detection threshold differences as a cause of shorter detection latencies during CFS. In conclusion, we acknowledge that the b-CFS paradigm can be fruitfully applied as a highly sensitive device to probe differences between stimuli in their potency to gain access to awareness. However, our current findings suggest that such differences can not unequivocally be attributed to differential unconscious processing under interocular suppression.

  16. To suppress, or not to suppress? That is repression: controlling intrusive thoughts in addictive behaviour.

    Science.gov (United States)

    Moss, Antony C; Erskine, James A K; Albery, Ian P; Allen, James Richard; Georgiou, George J

    2015-05-01

    Research to understand how individuals cope with intrusive negative or threatening thoughts suggests a variety of different cognitive strategies aimed at thought control. In this review, two of these strategies--thought suppression and repressive coping--are discussed in the context of addictive behaviour. Thought suppression involves conscious, volitional attempts to expel a thought from awareness, whereas repressive coping, which involves the avoidance of thoughts without the corresponding conscious intention, appears to be a far more automated process. Whilst there has been an emerging body of research exploring the role of thought suppression in addictive behaviour, there remains a dearth of research which has considered the role of repressive coping in the development of, and recovery from, addiction. Based on a review of the literature, and a discussion of the supposed mechanisms which underpin these strategies for exercising mental control, a conceptual model is proposed which posits a potential common mechanism. This model makes a number of predictions which require exploration in future research to fully understand the cognitive strategies utilised by individuals to control intrusive thoughts related to their addictive behaviour. PMID:25648574

  17. TRANSFORM DOMAIN SMART ANTENNAS ALGORITHM FOR MAI SUPPRESSION

    Institute of Scientific and Technical Information of China (English)

    Li Ke; Shi Xinhua; Zhang Eryang

    2004-01-01

    Multiple Access Interference(MAI) is the major factor that degrades the performance of a CDMA system. In this paper, a novel transform domain algorithm combined with parameter estimation for MAI suppression is proposed. Compared with the method that combines an adaptive array antenna with parameter estimation for interference suppression, it converges faster with the same Bit Error Rate(BER) performance.

  18. Thought Suppression and Meaning in Life: A Longitudinal Investigation

    Science.gov (United States)

    Krause, Neal

    2007-01-01

    The purpose of this study is to see if older adults who experience problems with thought suppression tend to encounter greater difficulty deriving a sense of meaning in life. Data from a longitudinal nationwide survey of older people (N = 988) indicate that greater difficulty with thought suppression is associated with a decline in meaning over…

  19. One-tone suppression in the frog auditory nerve

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    frequencies ranged from 700 to 1200 Hz. Spontaneous activities for the fibers showing one-tone suppression ranged from 3 to 75 spikes/s. Spontaneous activities above 40 spikes/s and the phenomenon of one-tone suppression itself has not been reported previously for frogs. The population of fibers showing one...

  20. PHYSIOLOGICAL TRAITS OF WEED GROWTH-SUPPRESSIVE RHIZOBACTERIA

    Science.gov (United States)

    Deleterious rhizobacteria (DRB) may contribute to weed suppression in soils under specific management or as applied biocontrol agents. To understand the mechanisms for growth suppression of weeds, we examined rhizobacteria from several important weeds in seven agroecosystems for a wide array of phys...

  1. Suppressing buzz-saw noise in jet engines

    Science.gov (United States)

    Maestrello, L.

    1980-01-01

    Buzz-saw noise, most annoying noise component generated by turbofan engines, can be suppresses by installing porous surface on duct wall directly above engine fan-blade tip. Porous surface and its housing would reduce shock-wave reflection from wall and thus suppress noise.

  2. Social hierarchy and depression: the role of emotion suppression.

    Science.gov (United States)

    Langner, Carrie A; Epel, Elissa S; Matthews, Karen A; Moskowitz, Judith T; Adler, Nancy E

    2012-01-01

    Position in the social hierarchy is a major determinant of health outcomes. We examined the associations between aspects of social hierarchy and depressive symptoms with a specific focus on one potential psychological mechanism: emotion suppression. Suppressing negative emotion has mental health costs, but individuals with low social power and low social status may use these strategies to avoid conflict. Study 1 assessed perceived social power, tendency to suppress negative emotion, and depressive symptoms in a community sample of women. Low social power was related to greater depressive symptoms, and this relationship was partially mediated by emotion suppression. Study 2 examined education as a proxy for social hierarchy position, anger suppression, and depressive symptoms in a national, longitudinal cohort study (The coronary artery risk development in young adults [CARDIA] study; Cutter et al., 1991). Much as in study 1, low education levels were correlated with greater depressive symptoms, and this relationship was partially mediated by anger suppression. Further, suppression mediated the relationship between low education and subsequent depression up to 15 years later. These findings support the theory that social hierarchy affects mental health in part through a process of emotion suppression. PMID:22808688

  3. Eye Contact Facilitates Awareness of Faces during Interocular Suppression

    Science.gov (United States)

    Stein, Timo; Senju, Atsushi; Peelen, Marius V.; Sterzer, Philipp

    2011-01-01

    Eye contact captures attention and receives prioritized visual processing. Here we asked whether eye contact might be processed outside conscious awareness. Faces with direct and averted gaze were rendered invisible using interocular suppression. In two experiments we found that faces with direct gaze overcame such suppression more rapidly than…

  4. Enhanced precision pointing jitter suppression system

    Science.gov (United States)

    Gilmore, Jerold P.; Luniewicz, Michael F.; Sargent, Darryl

    2002-06-01

    Space based defense systems, such as a Space Based Laser (SBL), and space based surveillance systems share a common objective: extremely high resolution Line of Sight (LOS) target imaging. In order to achieve the mission objectives, their beam control subsystem must provide precise LOS pointing and tracking capabilities with suppression of LOS jitter. Draper Laboratory has developed concepts and instrumentation that address these needs based upon a stabilized inertial platform mechanization that holds a collimated light source, called the Inertial Pseudo Star Reference Unit (IPSRU). This paper describes the original IPSRU design and a design concept for a new High Performance version of the IPSRU system (HP-IPSRU) that meet the jitter stabilization needs of the SBL. The IPSRU provides an inertially stabilized optical probe beam that provides a precise pointing and tracking reference with nanoradian jitter performance. The IPSRU serves as a master reference for stabilizing imaging and weapon system pointing and tracking. This paper describes the IPSRU system, its measured error allocation and integrated performance. It presents the error budget required to achieving the 5 nrad rms jitter stabilization performance projected to be necessary for an operational Space Based Laser system. A conceptual design for the HP-IPSRU is presented.

  5. Can predictive coding explain repetition suppression?

    Science.gov (United States)

    Grotheer, Mareike; Kovács, Gyula

    2016-07-01

    While in earlier work various local or bottom-up neural mechanisms were proposed to give rise to repetition suppression (RS), current theories suggest that top-down processes play a role in determining the repetition related reduction of the neural responses. In the current review we summarise those results, which support the role of these top-down processes, concentrating on the Bayesian models of predictive coding (PC). Such models assume that RS is related to the statistical probabilities of prior stimulus occurrences and to the future predictability of these stimuli. Here we review the current results that support or argue against this explanation. We point out that the heterogeneity of experimental manipulations that are thought to reflect predictive processes are likely to measure different processing steps, making their direct comparison difficult. In addition we emphasize the importance of identifying these sub-processes and clarifying their role in explaining RS. Finally, we propose a two-stage model for explaining the relationships of repetition and expectation phenomena in the human cortex. PMID:26861559

  6. 't Hooft suppression and holographic entropy

    Science.gov (United States)

    Kelly, William R.; Kuns, Kevin; Marolf, Donald

    2015-10-01

    Recent works have related the bulk first law of black hole mechanics to the first law of entanglement in a dual CFT. These are first order relations, and receive corrections for finite changes. In particular, the latter is naively expected to be accurate only for small changes in the quantum state. But when Newton's constant is small relative to the AdS scale, the former holds to good approximation even for classical perturbations that contain many quanta. This suggests that — for appropriate states — corrections to the first law of entanglement are suppressed by powers of N in CFTs whose correlators satisfy 't Hooft large- N power counting. We take first steps toward verifying that this is so by studying the large- N structure of the entropy of spatial regions for a class of CFT states motivate dby those created from the vacuum by acting with real-time single-trace sources. We show that 1 /N counting matches bulk predictions, though we require the effect of the source on the modular hamiltonian to be non-singular. The magnitude of our sources is ɛ N with ɛ fixed-but-small as N → ∞. Our results also provide a perturbative derivation — without relying on the replica trick — of the subleading Faulkner-Lewkowycz-Maldacena correction to the Ryu-Takayagi and Hubeny-Rangamani-Takayanagi conjectures at all orders in 1 /N.

  7. 't Hooft suppression and holographic entropy

    CERN Document Server

    Kelly, William R; Marolf, Donald

    2015-01-01

    Recent works have related the bulk first law of black hole mechanics to the first law of entanglement in a dual CFT. These are first order relations, and receive corrections for finite changes. In particular, the latter is naively expected to be accurate only for small changes in the quantum state. But when Newton's constant is small relative to the AdS scale, the former holds to good approximation even for classical perturbations that contain many quanta. This suggests that -- for appropriate states -- corrections to the first law of entanglement are suppressed by powers of $N$ in CFTs whose correlators satisfy 't Hooft large-$N$ power counting. We take first steps toward verifying that this is so by studying the large-$N$ structure of the entropy of spatial regions for a class of CFT states motivated by those created from the vacuum by acting with real-time single-trace sources. We show that $1/N$ counting matches bulk predictions, though we require the effect of the source on the modular hamiltonian to be ...

  8. Heavy quarkonium suppression in a fireball

    Energy Technology Data Exchange (ETDEWEB)

    Escobedo, Miguel Ángel [Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany Institut de Physique Théorique, CEA Saclay, F-91191 Gif-sur-Yvette (France)

    2016-01-22

    The dissociation of heavy quarkonium seen in heavy-ion collisions is a phenomena that allows to extract information of the produced thermal medium. This was believed to be due to the screening of the static potential but recently perturbative computations and some lattice studies have pointed out the possibility of having an imaginary part of the potential that would also contribute to dissociation. In recent years a program to study heavy quarkonium with the use of non-relativistic effective field theories (EFTs) has been started, this allows to make the computations in a more systematic way by defining a more suitable power counting and making it more difficult to miss necessary resummations. However until now these studies have been done assuming thermal equilibrium. In this work we will discuss what happens in the EFT formalism when heavy quarkonium is in a medium that is not in thermal equilibrium and what is the expected suppression when a medium with a time dependent effective temperature that follows Bjorken evolution is considered. This will be done adapting previous results from different temperature regimes.

  9. Myeloma cells suppress osteoblasts through sclerostin secretion

    International Nuclear Information System (INIS)

    Wingless-type (Wnt) signaling through the secretion of Wnt inhibitors Dickkopf1, soluble frizzled-related protein-2 and -3 has a key role in the decreased osteoblast (OB) activity associated with multiple myeloma (MM) bone disease. We provide evidence that another Wnt antagonist, sclerostin, an osteocyte-expressed negative regulator of bone formation, is expressed by myeloma cells, that is, human myeloma cell lines (HMCLs) and plasma cells (CD138+ cells) obtained from the bone marrow (BM) of a large number of MM patients with bone disease. We demonstrated that BM stromal cells (BMSCs), differentiated into OBs and co-cultured with HMCLs showed, compared with BMSCs alone, reduced expression of major osteoblastic-specific proteins, decreased mineralized nodule formation and attenuated the expression of members of the activator protein 1 transcription factor family (Fra-1, Fra-2 and Jun-D). Moreover, in the same co-culture system, the addition of neutralizing anti-sclerostin antibodies restored OB functions by inducing nuclear accumulation of β-catenin. We further demonstrated that the upregulation of receptor activator of nuclear factor κ-B ligand and the downregulation of osteoprotegerin in OBs were also sclerostin mediated. Our data indicated that sclerostin secretion by myeloma cells contribute to the suppression of bone formation in the osteolytic bone disease associated to MM

  10. Rotator cuff injury: fat suppression MR image

    International Nuclear Information System (INIS)

    We performed the study prospectively to evaluate the advantage of fat suppression MR in the diagnosis of rotator cuff injury. Ten symptomatic patients were studied with both conventional T2WI and FST2WI using chemical shift technique. Each image was analyzed for the assessment of injuries, conspicuity of the lesion, the presence of effusion in subacromical bursae and joint space, and presence of humeral head injury. Arthroscopy was done in 4 patients following MRI. We could made presumptive diagnoses on FSMR as identical as on conventional MR in six cases(1 normal, 2 tendinitis, 2 partial thickness tear, 1 full thickness tear), two of them were confirmed by arthroscopic procedures. Two cases of partial thickness tear proved by arthroscopy were detected on FST2WI, whereas they were considered tendinitis on conventional T2WI. There were another 2 cases who showed tendinitis on FSMR, but normal on conventional T2WI. They, however, were not confirmed by either arthroscopy or surgical procedure. We found the FSMR were superior to conventional T2WI in the conspicuity of lesions and detection of joint effusion and abnormalities on the humeral head. We think FSMR of the shoulder could have significant diagnostic advantages over the conventional spin-echo MR imaging

  11. Rotator cuff injury: fat suppression MR image

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong Yoon; Suh, Jin Suck; Park, Chang Yun; Lee, Yeon Hee [Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Yong Soo [Inje University College of Medicine, Busan (Korea, Republic of)

    1994-04-15

    We performed the study prospectively to evaluate the advantage of fat suppression MR in the diagnosis of rotator cuff injury. Ten symptomatic patients were studied with both conventional T2WI and FST2WI using chemical shift technique. Each image was analyzed for the assessment of injuries, conspicuity of the lesion, the presence of effusion in subacromical bursae and joint space, and presence of humeral head injury. Arthroscopy was done in 4 patients following MRI. We could made presumptive diagnoses on FSMR as identical as on conventional MR in six cases(1 normal, 2 tendinitis, 2 partial thickness tear, 1 full thickness tear), two of them were confirmed by arthroscopic procedures. Two cases of partial thickness tear proved by arthroscopy were detected on FST2WI, whereas they were considered tendinitis on conventional T2WI. There were another 2 cases who showed tendinitis on FSMR, but normal on conventional T2WI. They, however, were not confirmed by either arthroscopy or surgical procedure. We found the FSMR were superior to conventional T2WI in the conspicuity of lesions and detection of joint effusion and abnormalities on the humeral head. We think FSMR of the shoulder could have significant diagnostic advantages over the conventional spin-echo MR imaging.

  12. Considering alternative calculations of weight suppression.

    Science.gov (United States)

    Schaumberg, Katherine; Anderson, Lisa M; Reilly, Erin E; Gorrell, Sasha; Anderson, Drew A; Earleywine, Mitch

    2016-01-01

    Weight suppression (WS)--the difference between an individual's highest adult weight and current weight-relates to eating pathology and weight gain; however, there are several methodological issues associated with its calculation. The current study presents four alternative methods of calculating WS and tests whether these methods differentially relate to maladaptive outcomes. Alternative methods of calculation included: (1) change in BMI units; (2) BMI category change; (3) percent change in weight; and (4) two different uses of regression residuals. A sample of undergraduate students (N=631) completed self-report measures of eating pathology, current and past weight, and teasing. Measures included the Eating Disorder Examination-Questionnaire and the Perceptions of Teasing Scale. Results indicated that components of WS, current weight and highest weight, were strongly related in the present sample. The traditional method of calculating WS was related to eating pathology, binge eating and teasing for both males and females. However, WS indices orthogonal to the highest weight did not correlate with eating pathology and teasing in both males and females; for females, WS indices orthogonal to current weight were also unrelated to eating pathology. Findings suggest that the link between WS and eating pathology is mitigated after accounting for an individual's highest weight. Future research should continue to assess the reliability and clinical utility of this construct and consider using alternative WS calculations. PMID:26643591

  13. Heavy quarkonium suppression in a fireball

    Science.gov (United States)

    Escobedo, Miguel Ángel

    2016-01-01

    The dissociation of heavy quarkonium seen in heavy-ion collisions is a phenomena that allows to extract information of the produced thermal medium. This was believed to be due to the screening of the static potential but recently perturbative computations and some lattice studies have pointed out the possibility of having an imaginary part of the potential that would also contribute to dissociation. In recent years a program to study heavy quarkonium with the use of non-relativistic effective field theories (EFTs) has been started, this allows to make the computations in a more systematic way by defining a more suitable power counting and making it more difficult to miss necessary resummations. However until now these studies have been done assuming thermal equilibrium. In this work we will discuss what happens in the EFT formalism when heavy quarkonium is in a medium that is not in thermal equilibrium and what is the expected suppression when a medium with a time dependent effective temperature that follows Bjorken evolution is considered. This will be done adapting previous results from different temperature regimes.

  14. A dual purpose Compton suppression spectrometer

    CERN Document Server

    Parus, J; Raab, W; Donohue, D

    2003-01-01

    A gamma-ray spectrometer with a passive and an active shield is described. It consists of a HPGe coaxial detector of 42% efficiency and 4 NaI(Tl) detectors. The energy output pulses of the Ge detector are delivered into the 3 spectrometry chains giving the normal, anti- and coincidence spectra. From the spectra of a number of sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co sources a Compton suppression factor, SF and a Compton reduction factor, RF, as the parameters characterizing the system performance, were calculated as a function of energy and source activity and compared with those given in literature. The natural background is reduced about 8 times in the anticoincidence mode of operation, compared to the normal spectrum which results in decreasing the detection limits for non-coincident gamma-rays up to a factor of 3. In the presence of other gamma-ray activities, in the range from 5 to 11 kBq, non- and coincident, the detection limits can be decreased for some nuclides by a factor of 3 to 5.7.

  15. Relationships between thought suppression and symptoms of borderline personality disorder.

    Science.gov (United States)

    Sauer, Shannon E; Baer, Ruth A

    2009-02-01

    The current study examined relationships among childhood emotional vulnerability, an invalidating childhood environment, thought suppression, and symptoms of borderline personality disorder (BPD). Emotional vulnerability and an invalidating childhood environment are described by Linehan (1993) as important biosocial precursors to the development of BPD. Using a student sample selected to have a wide range of BPD symptoms, we examined whether thought suppression mediates the relationship between these biosocial precursors and symptoms of BPD. Results supported the hypothesis that thought suppression fully mediates the relationship between invalidating environment and BPD symptoms. Mixed support was found for the hypothesis that thought suppression mediates the relationship between emotional vulnerability and BPD symptoms. We also examined whether fear of emotions mediates the relationship between the biosocial precursors and thought suppression. Results supported this hypothesis, and also suggested that fear of emotion contributes independently to mediating the relationship between biosocial precursors and BPD symptoms. PMID:19267661

  16. Effects of paradoxical suppression on contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) with contrast medium is increasingly being used in examination of the abdomen, pelvis, and lower limbs. However, angiography at opposed phase causes paradoxical suppression (PS) due to the higher fat content of these areas. We evaluated the effect of PS on the ability to visualize blood vessels. The items evaluated included the effect of contrast medium concentration and TE (echo time) on PS as well as a comparison of fat suppression with the subtraction technique by referring to a mock blood vessel and pictures obtained by subjecting volunteers to MRA with contrast medium. Shorter TE and higher concentrations of contrast medium both reduced PS. The ability to visualize blood vessels was reduced by the subtraction technique, as compared with fat suppression. In clinical studies, fat suppression is essential. Hence, when MRA with contrast medium is performed with an apparatus or at a site where fat suppression is not feasible, PS must be taken into account to establish parameters. (author)

  17. Repetition suppression and its contextual determinants in predictive coding.

    Science.gov (United States)

    Auksztulewicz, Ryszard; Friston, Karl

    2016-07-01

    This paper presents a review of theoretical and empirical work on repetition suppression in the context of predictive coding. Predictive coding is a neurobiologically plausible scheme explaining how biological systems might perform perceptual inference and learning. From this perspective, repetition suppression is a manifestation of minimising prediction error through adaptive changes in predictions about the content and precision of sensory inputs. Simulations of artificial neural hierarchies provide a principled way of understanding how repetition suppression - at different time scales - can be explained in terms of inference and learning implemented under predictive coding. This formulation of repetition suppression is supported by results of numerous empirical studies of repetition suppression and its contextual determinants. PMID:26861557

  18. Temporal suppression and augmentation of click-evoked otoacoustic emissions

    DEFF Research Database (Denmark)

    Verhulst, Sarah; Harte, James; Dau, Torsten

    2008-01-01

    This study investigates and models temporal suppression of click-evoked otoacoustic emissions (CEOAEs). This suppression-effect is created when a suppressor-click is presented close in time to a test-click. The analysis was carried out for short time-frames of short- and long-latency CEOAEs. The...... latter is defined as a CEOAE with duration greater than 20 ms, typically observed for test subjects with spontaneous otoacoustic emissions (SOAEs). Previous studies have tended to exclude these test subjects but they are incorporated here. The results from six exemplary subjects demonstrate that temporal...... temporal suppression and augmentation of CEOAEs. Recently, a feedback automatic gain control (AGC) system has been used to model CEOAE suppression. However, this system cannot account for augmentation and therefore another, dynamic nonlinear model was developed. Suppression and augmentation were modeled...

  19. Deciphering the rhizosphere microbiome for disease-suppressive bacteria.

    Science.gov (United States)

    Mendes, Rodrigo; Kruijt, Marco; de Bruijn, Irene; Dekkers, Ester; van der Voort, Menno; Schneider, Johannes H M; Piceno, Yvette M; DeSantis, Todd Z; Andersen, Gary L; Bakker, Peter A H M; Raaijmakers, Jos M

    2011-05-27

    Disease-suppressive soils are exceptional ecosystems in which crop plants suffer less from specific soil-borne pathogens than expected owing to the activities of other soil microorganisms. For most disease-suppressive soils, the microbes and mechanisms involved in pathogen control are unknown. By coupling PhyloChip-based metagenomics of the rhizosphere microbiome with culture-dependent functional analyses, we identified key bacterial taxa and genes involved in suppression of a fungal root pathogen. More than 33,000 bacterial and archaeal species were detected, with Proteobacteria, Firmicutes, and Actinobacteria consistently associated with disease suppression. Members of the γ-Proteobacteria were shown to have disease-suppressive activity governed by nonribosomal peptide synthetases. Our data indicate that upon attack by a fungal root pathogen, plants can exploit microbial consortia from soil for protection against infections. PMID:21551032

  20. Delta modulation. [overshoot suppression algorithm for video data transmission

    Science.gov (United States)

    Schilling, D. L.

    1973-01-01

    The overshoot suppression algorithm has been more extensively studied. Computer generated test-pictures show a radical improvement due to the overshoot suppression algorithm. Considering the delta modulator link as a nonlinear digital filter, a formula that relates the minimum rise time that can be handled for given filter parameters and voltage swings has been developed. The settling time has been calculated for the case of overshoot suppression as well as when no suppression is employed. The results indicate a significant decrease in settling time when overshoot suppression is used. An algorithm for correcting channel errors has been developed. It is shown that pulse stuffing PCM words in the DM bit stream results in a significant reduction in error length.

  1. Large Scale Power Suppression in a Multifield Landscape

    CERN Document Server

    Blanco-Pillado, Jose J; Frazer, Jonathan; Sousa, Kepa

    2015-01-01

    Power suppression of the cosmic microwave background on the largest observable scales could provide valuable clues about the particle physics underlying inflation. Here we consider the prospect of power suppression in the context of the multifield landscape. Based on the assumption that our observable universe emerges from a tunnelling event and that the relevant features originate purely from inflationary dynamics, we find that the power spectrum not only contains information on single-field dynamics, but also places strong con- straints on all scalar fields present in the theory. We find that the simplest single-field models giving rise to power suppression do not generalise to multifield models in a straightforward way, as the resulting superhorizon evolution of the curvature perturbation tends to erase any power suppression present at horizon crossing. On the other hand, multifield effects do present a means of generating power suppression which to our knowledge has so far not been considered. We propose ...

  2. A Compton-suppression spectrometer for γ-γ coincidence measurements: Large solid angle and excellent suppression

    NARCIS (Netherlands)

    Aarts, H.J.M.; Poel, C.J. van der; Scherpenzeel, D.E.C.; Arciszewski, H.F.R.; Engelbertink, G.A.P.

    1980-01-01

    For γ-γ coincidence measurements a Compton-suppression spectrometer with a large solid angle of 120 msr and excellent suppression has been designed. The dimensions of the NaI anticoincidence shield have been optimized by means of Monte Carlo calculations. The NaI shield has a length of 35 cm and a d

  3. Genetic Control of Mosquitoes: population suppression strategies

    Directory of Open Access Journals (Sweden)

    André Barretto Bruno Wilke

    2012-10-01

    Full Text Available Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

  4. Suitable level of suppression in Pinus sylvestris

    Energy Technology Data Exchange (ETDEWEB)

    Hagner, Mats

    1999-10-01

    It is `well known` among Swedish foresters that pine trees need light and cannot grow suppressed. It is also `well known` that old trees that have grown slowly are unable to react with good growth. However, these facts can be questioned in the light of new research as it has been found that thinning reaction is not correlated with age. It is also well known that the commercial value of a pine is closely related to the growth at young age. If the first 20 annual rings close to pith are wide (>3 mm) the log cannot be accepted as first class. This is related to number and size of branches on the young tree and to the features of the juvenile wood. This is to say that a pine must not grow fast when it is small and if this has happened it cannot be cured by artificial debranching or by growing the tree slowly at higher age. Accordingly, young pines should be grown under bigger trees that in their young age were grown under big trees, and so on. Today, when clear cutting is the dominating forest management system, the only way to obtain high quality pine trees is to start the rotation age with stands of very high density. This is of course a very expensive way as dense planting, followed by intensive thinning requires a lot of input. However, if pine is a pioneer species and cannot be grown in multistoried stands, then the economic solution is not present. This was the reason why the annual increment of three pines was measured. They were selected because their different growth pattern showed that old `well known facts` should be revised Working papers 139. 3 refs, 7 figs, 1 tab

  5. The use of repetition suppression paradigms in developmental cognitive neuroscience.

    Science.gov (United States)

    Nordt, Marisa; Hoehl, Stefanie; Weigelt, Sarah

    2016-07-01

    Repetition suppression paradigms allow a more detailed look at brain functioning than classical paradigms and have been applied vigorously in adult cognitive neuroscience. These paradigms are well suited for studies in the field of developmental cognitive neuroscience as they can be applied without collecting a behavioral response and across all age groups. Furthermore, repetition suppression paradigms can be employed in various neuroscience techniques, such as functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG) and magnetoencephalography (MEG). In the present article we review studies using repetition suppression paradigms in developmental cognitive neuroscience covering the age range from infancy to adolescence. Our first goal is to point out characteristics of developmental repetition suppression effects. In doing so, we discuss the relationship of the direction of repetition effects (suppression vs enhancement) with developmental factors, and address the question how the direction of repetition effects might be related to looking-time effects in behavioral infant paradigms, the most prominently used behavioral measure in infant research. To highlight the potential of repetition suppression paradigms, our second goal is to provide an overview on the insights recently obtained by applying repetition paradigms in neurodevelopmental studies, including research on children with autism spectrum disorders (ASDs). We conclude that repetition suppression paradigms are valuable tools for investigating neurodevelopmental processes, while at the same time we highlight the necessity for further studies that disentangle methodological and developmental factors. PMID:27161033

  6. Suppression of insulin production and secretion by a decretin hormone.

    Science.gov (United States)

    Alfa, Ronald W; Park, Sangbin; Skelly, Kathleen-Rose; Poffenberger, Gregory; Jain, Nimit; Gu, Xueying; Kockel, Lutz; Wang, Jing; Liu, Yinghua; Powers, Alvin C; Kim, Seung K

    2015-02-01

    Decretins, hormones induced by fasting that suppress insulin production and secretion, have been postulated from classical human metabolic studies. From genetic screens, we identified Drosophila Limostatin (Lst), a peptide hormone that suppresses insulin secretion. Lst is induced by nutrient restriction in gut-associated endocrine cells. limostatin deficiency led to hyperinsulinemia, hypoglycemia, and excess adiposity. A conserved 15-residue polypeptide encoded by limostatin suppressed secretion by insulin-producing cells. Targeted knockdown of CG9918, a Drosophila ortholog of Neuromedin U receptors (NMURs), in insulin-producing cells phenocopied limostatin deficiency and attenuated insulin suppression by purified Lst, suggesting CG9918 encodes an Lst receptor. NMUR1 is expressed in islet β cells, and purified NMU suppresses insulin secretion from human islets. A human mutant NMU variant that co-segregates with familial early-onset obesity and hyperinsulinemia fails to suppress insulin secretion. We propose Lst as an index member of an ancient hormone class called decretins, which suppress insulin output. PMID:25651184

  7. The experimental study of the effects of forkhead transcription factor O1 on the podocyte injury in diabetic rats%叉头状转录因子O1对糖尿病大鼠足细胞影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    张媛媛; 王庆祝; 秦贵军; 周英旎; 马晓君

    2014-01-01

    目的 探讨叉头状转录因子O1(Fox01)对糖尿病大鼠足细胞的影响.方法 链脲佐菌素(STZ)诱导构建糖尿病大鼠模型90只,并采用简单随机抽样法分为糖尿病(DM)+空慢病毒载体(LV-pSC-GFP)感染组(LV-NC组,n=30),DM+大鼠结构性活性FoxO1慢病毒载体(LV-CA-FoxO1)感染组(LV-CA组,n=30),DM组(n=30),另设对照组(NG组,n=30)注射相应体积的柠檬酸钠-柠檬酸缓冲液.于慢病毒感染后的2、4、8周末,测大鼠尿白蛋白、体重、血糖、血肌酐、尿素氮,光镜和透射电镜观察肾小球及其足细胞结构变化,实时定量聚合酶链反应(RT-PCR)和Western blotting法检测大鼠肾皮质中FoxO1、足盂蛋白(PCX)、nephrin mRNA和蛋白的表达.多组间比较采用单因素方差分析.结果 与LV-NC、DM组相比,LV-CA组大鼠肾脏中FoxO1 mRNA、蛋白表达水平明显升高(F8W值分别为10 919.75、3 867.34,均P<0.05),尿白蛋白、血肌酐、尿素氮明显降低(2周除外)(F8W值分别为132.72、187.68、503.69,均P<0.05),肾脏中PCX、nephrin mRNA和蛋白水平明显升高(mRNA F8w值分别为778.94、478.10;蛋白F8W值分别为393.64、255.79,均P<0.05),肾脏病理学变化也明显改善,可见肾小球体积减小,系膜细胞及基底膜增生程度降低,足突融合也有一定程度改善.结论 通过靶向注射慢病毒载体来上调FoxO1的表达可改善DM大鼠足细胞的损伤.%Objective To study the effects of forkhead transcription factor O1 (FoxO1) on the podocyte injury in diabetic rats.Methods 90 Streptozotocin-induced diabetic rats were divided into three groups:diabetic rats (DM,n=30),rats transfected with blank lentiviral vectors (DM plus LV-pSC-GFP group,designated LV-NC,n=30) and rats which were transfected with lentiviral vectors carrying constitutively active FoxO1 (DM plus LV-CA-FoxO1 group,designated LV-CA,n=30).The rats which received an injection of diluent buffer served as normal control (NG,n=30).At 2,4,and 8 weeks after

  8. Circadian rhythm of TSH secretion during TSH-suppression therapy

    OpenAIRE

    M A Sviridonova; A V Ilyin; V V Fadeyev

    2011-01-01

    Тo investigate circadian rhythm of TSH secretion during TSH-suppression therapy. 17 patients taking TSH-suppression therapy, at the age of 18–60 years have been included. Measurements of serum TSH were performed at8.00–9.00h and 14.00–16.00 during the day. The median of TSH concentrations in the morning was 0,016mU/l, at the daytime – 0.015mU/l. The amplitude of TSH circadian variability reached 200% (Me – 19%). At boundary TSH value stability of TSH-suppression can be broken. As specifying a...

  9. Tetracycline-Regulated Suppression of Amber Codons in Mammalian Cells

    OpenAIRE

    Park, Ho-Jin; RajBhandary, Uttam L.

    1998-01-01

    As an approach to inducible suppression of nonsense mutations in mammalian cells, we described recently an amber suppression system in mammalian cells dependent on coexpression of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) along with the E. coli glutamine-inserting amber suppressor tRNA. Here, we report on tetracycline-regulated expression of the E. coli GlnRS gene and, thereby, tetracycline-regulated suppression of amber codons in mammalian HeLa and COS-1 cells. The E. coli GlnRS co...

  10. The Etiology and Outcome Analysis of Neonatal Burst Suppression EEG

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lian; ZHOU Yanxia; XU Sanqing

    2007-01-01

    The neonatal burst suppression is a severe EEG pattern and always demonstrates serious damage of nerve system. But the outcome of these patients depends on the different etiology. A total of 256 cases of video EEG recordings were analyzed in order to summarize the etiology and outcome of burst suppression. The results showed that some patients in all 17 cases of burst suppression showed EEG improvement. The etiology was the dominant factor in long term outcome. It was sug-gested that effective video EEG monitoring is helpful for etiologic study and prognosis evaluation.

  11. Auditory two-tone suppression from a subcritical Hopf cochlea

    Science.gov (United States)

    Stoop, R.; Steeb, W.-H.; Gallas, J. C.; Kern, A.

    2005-06-01

    Cochlear two-tone suppression is the dominant contrast-sharpening phenomenon of hearing and provides a decisive test for the correct implementation of hearing nonlinearities in models of the cochlea. Although critically tuned Hopf amplifiers were shown recently to be fruitful models of intricate phenomena in the physiology of the human ear, we find that only a model based on subcritical Hopf amplifiers is capable of reproducing physiologically measured two-tone suppression data adequately. In addition, we provide a detailed explanation of the two-tone suppression phenomenon, including its quantitative characterization.

  12. Regularized Adaptive Notch Filters for Acoustic Howling Suppression

    DEFF Research Database (Denmark)

    Gil-Cacho, Pepe; van Waterschoot, Toon; Moonen, Marc;

    2009-01-01

    In this paper, a method for the suppression of acoustic howling is developed, based on adaptive notch filters (ANF) with regularization (RANF). The method features three RANFs working in parallel to achieve frequency tracking, howling detection and suppression. The ANF-based approach to howling...... components in the source signal are not affected. The RANFs proposed in this paper are implemented in direct form and are updated using a gradient descent type algorithm. Results show that, under certain conditions, the level of suppression and sound quality is similar to what is obtained with frame...

  13. Suppression of Platelet Aggregation by Bordetella pertussis Adenylate Cyclase Toxin

    OpenAIRE

    Iwaki, Masaaki; Kamachi, Kazunari; Heveker, Nikolaus; Konda, Toshifumi

    1999-01-01

    The effect of Bordetella pertussis adenylate cyclase toxin (ACT) on platelet aggregation was investigated. This cell-invasive adenylate cyclase completely suppressed ADP (10 μM)-induced aggregation of rabbit platelets at 3 μg/ml and strongly suppressed thrombin (0.2 U/ml)-induced aggregation at 10 μg/ml. The suppression was accompanied by marked increase in platelet intracellular cyclic AMP (cAMP) content and was diminished by the anti-ACT monoclonal antibody B7E11. A catalytically inactive p...

  14. Suppressing voltage transients in high voltage power supplies

    International Nuclear Information System (INIS)

    A high voltage power supply for an X-ray tubes includes voltage adjusting means, a high voltage transformer, switch means connected to make and interrupt the primary current of the transformer, and over-voltage suppression means to suppress the voltage transient produced when the current is switched on. In order to reduce the power losses in the suppression means, an impedance is connected in the transformer primary circuit on operation of the switch means and is subsequently short-circuited by a switch controlled by a timer after a period which is automatically adjusted to the duration of the transient overvoltage. (U.K.)

  15. A simple configuration setup for compton suppression spectroscopy

    CERN Document Server

    Hai, N X; Dien, N N; Tan, V H; Hoa, N D

    2013-01-01

    The fast timing, standard timing and easy timing are popular timing configurations of compton suppression spectroscopy. Such spectroscopes always use a module of coincidence or time-to-amplitude converter (TAC). A compton suppression spectroscopy with semi-timing configuration is presented in this paper. The semi-timing configuration is relatively simple and easy system setup, especially this spectroscopy does not need to use module of coincidence or TAC. The performance of spectroscopy was tested and summarized. The count rate background, full peak efficiency and the ratios of area/background of peaks in suppressed and unsuppressed modes were comparative.

  16. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    OpenAIRE

    LIU, FENGHAI; Xueyan, Zheng; Pedersen, Rune Johan Skullerud; Jeppesen, Palle

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.

  17. Vehicle wheels vibration suppression by dynamic vibration absorber

    Directory of Open Access Journals (Sweden)

    Zinovij STOTSKO

    2007-01-01

    Full Text Available The article deals with the methods of calculation and optimization ofdynamic processes in vibroexcitated constructions with dynamic absorbers. The improved constructions of such absorbers for vehicle wheels vibration suppression are discussed.

  18. Nuclear Suppression of Dileptons at Large xF

    CERN Document Server

    Cepila, J

    2009-01-01

    We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, it is tempting to interpret this as a manifestation of coherence or of a Color Glass Condensate. We demonstrate, however, that this suppression mechanism is governed by the energy conservation restrictions in multiple parton rescatterings in nuclear matter. To eliminate nuclear shadowing effects coming from the coherence, we calculate nuclear suppression in the light-cone dipole approach at large dilepton masses and at energy accessible at FNAL. Our calculations are in a good agreement with data from the E772 experiment. Using the same mechanism we predict also nuclear suppression at forward rapidities in the RHIC energy range.

  19. Sidelobe Suppression with Null Steering by Independent Weight Control

    Directory of Open Access Journals (Sweden)

    Zafar-Ullah Khan

    2015-01-01

    Full Text Available A uniform linear array of n antenna elements can steer up to n-1 nulls. In situations where less than n-1 nulls are required to be steered, the existing algorithms have no criterion to utilize the remaining weights for sidelobe suppression. This work combines sidelobe suppression capability with null steering by independent weight control. For this purpose, the array factor is transformed as the product of two polynomials. One of the polynomials is used for null steering by independent weight control, while the second one is for sidelobe suppression whose coefficients or weights are determined by using convex optimization. Finally, a new structure is proposed to incorporate the product of two polynomials such that sidelobe suppression weights are decoupled from those of null steering weights. Simulation results validate the effectiveness of the proposed scheme.

  20. Genomic Basis of Plant Pathogen Suppression by Biocontrol Pseudomonas Species

    Science.gov (United States)

    Various plant commensal bacterial species, which naturally colonize the plant rhizosphere, are able to suppress fungal, bacterial, viral and even insect plant pathogens. These biocontrol activities are elicited primarily through the production of secreted exoenzymes and secondary metabolites that ma...

  1. Quadratic Dynamical Decoupling with Non-Uniform Error Suppression

    CERN Document Server

    Quiroz, G

    2011-01-01

    We analyze numerically the performance of the near-optimal quadratic dynamical decoupling (QDD) single-qubit decoherence errors suppression method [J. West et al., Phys. Rev. Lett. 104, 130501 (2010)]. The QDD sequence is formed by nesting two optimal Uhrig dynamical decoupling sequences for two orthogonal axes, comprising N1 and N2 pulses, respectively. Varying these numbers, we study the decoherence suppression properties of QDD directly by isolating the errors associated with each system basis operator present in the system-bath interaction Hamiltonian. Each individual error scales with the lowest order of the Dyson series, therefore immediately yielding the order of decoherence suppression. We show that the error suppression properties of QDD are dependent upon the parities of N1 and N2, and near-optimal performance is achieved for general single-qubit interactions when N1=N2.

  2. Method of suppressing burnable gas connection in nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To reduce the burnable gas concentration and improve the safety by suppressing the amount of evolved gaseous hydrogen and oxygen with no requirement for complicate and large-scaled devices. Method: Suppression burnable gas concentration in nuclear reactor has usually been conducted by an indirect method of recombining gaseous hydrogen and oxygen evolved, not by suppressing the amount of evolved gaseous hydrogen and gaseous oxygen as burnable gases. Accordingly, there has been a problem, in view of the safety, such as passage of gaseous hydrogen and gaseous oxygen once in the reactor containers, etc. and there has been also a trend that the reactor system of the device is complicated in the structure and increased in the size. In view of the above, material combining iodine ions are charged into coolants to reduce iodine ion concentration therein and suppress the generation of burnable gases due to radiolysis of the coolants in this method. (T.M.)

  3. Suppression of bunch transverse instabilities by the chamber asymmetry

    International Nuclear Information System (INIS)

    Axial asymmetry of a vacuum chamber gives rise to wake forces producing betatron tune shifts for tail particles. In the result, the bunch transverse instabilities could be suppressed or even eliminated

  4. Central nervous system stimulants and drugs that suppress appetite

    DEFF Research Database (Denmark)

    Aagaard, Lise

    2014-01-01

    of the January 2012 to June 2013 publications on central nervous system stimulants and drugs that suppress appetite covers amphetamines (including metamfetamine, paramethoxyamfetamine and paramethoxymetamfetamine), fenfluramine and benfluorex, atomoxetine, methylphenidate, modafinil and armodafinil...

  5. Suppression of magnetic islands by rf-driven currents

    International Nuclear Information System (INIS)

    The quasilinear theory for the saturation of nonlinear tearing modes is modified to include rf driven currents. It is shown that the presence of lower hybrid driven currents can strongly suppress the growth of magnetic islands

  6. Monoclonal regulatory T cells provide insights into T cell suppression.

    Science.gov (United States)

    Gubser, Céline; Schmaler, Mathias; Rossi, Simona W; Palmer, Ed

    2016-01-01

    Regulatory T cells (Tregs) have a crucial role in maintaining lymphocyte homeostasis. However an understanding of how Tregs function at a cellular and molecular level has not yet been fully elucidated. Here, we make use of a T cell receptor (TCR) transgenic, Rag(-/-) mouse expressing a Forkhead-Box-Protein P3 (Foxp3) transgene. This mouse provides a source of monoclonal CD4(+) Foxp3(+) T cells with a defined specificity. Here we show that monoclonal B3K506 Tregs are functional in vitro and in vivo and clearly require cognate antigen to be suppressive. We further show that the strength of Treg stimulation determines the strength of Treg mediated suppression. Finally we analysed various suppressive mechanisms used by monoclonal Tregs and found that Treg-Tconv proximity is a parameter, which correlates with enhanced suppression. PMID:27210828

  7. Optical frequency tripling with improved suppression and sideband selection.

    Science.gov (United States)

    Thakur, Manoj P; Medeiros, Maria C R; Laurêncio, Paula; Mitchell, John E

    2011-12-12

    A novel optical dispersion tolerant millimetre-wave radio-over-fibre system using optical frequency tripling technique with enhanced and selectable sideband suppression is demonstrated. The implementation utilises cascaded optical modulators to achieve either an optical single sideband (OSSB) or double sideband-suppressed carrier (DSB-SC) signal with high sideband suppression. Our analysis and simulation results indicate that the achievable suppression ratio of this configuration is only limited by other system factors such as optical noise and drifting of the operational conditions. The OSSB transmission system performance is assessed experimentally by the transport of 4 WiMax channels modulating a 10 GHz optical upconverted RF carrier as well as for optical frequency doubling and tripling. The 10 GHz and tripled carrier at 30 GHz are dispersion tolerant resulting both in an average relative constellation error (RCE) of -28.7 dB after 40 km of fibre. PMID:22274056

  8. Antigen-specific suppression of inflammatory arthritis using liposomes.

    Science.gov (United States)

    Capini, Christelle; Jaturanpinyo, Montree; Chang, Hsin-I; Mutalik, Srinivas; McNally, Alice; Street, Shayna; Steptoe, Raymond; O'Sullivan, Brendan; Davies, Nigel; Thomas, Ranjeny

    2009-03-15

    Existing therapies for rheumatoid arthritis and other autoimmune diseases are not Ag specific, which increases the likelihood of systemic toxicity. We show that egg phosphatidylcholine liposomes loaded with Ag (OVA or methylated BSA) and a lipophilic NF-kappaB inhibitor (curcumin, quercetin, or Bay11-7082) suppress preexisting immune responses in an Ag-specific manner. We injected loaded liposomes into mice primed with Ag or into mice suffering from Ag-induced inflammatory arthritis. The liposomes targeted APCs in situ, suppressing the cells' responsiveness to NF-kappaB and inducing Ag-specific FoxP3(+) regulatory T cells. This regulatory mechanism suppressed effector T cell responses and the clinical signs of full-blown Ag-induced arthritis. Thus, liposomes encapsulate Ags and NF-kappaB inhibitors stably and efficiently and could be readily adapted to deliver Ags and inhibitors for Ag-specific suppression of other autoimmune and allergic diseases. PMID:19265134

  9. Tumor suppression in Xiphophorus by an accidentally acquired promoter

    OpenAIRE

    Adam, Dieter; Dimitrijevic, Nicola; Schartl, Manfred

    2011-01-01

    Melanoma formation in the teleost Xiphophorus is caused by a dominant genetic locus, Tu. This locus includes the Xmrk oncogene, which encodes a receptor tyrosine kinase. Tumor induction is. suppressed in wild-type fish by a tumor suppressor locus, R. Molecular genetic analyses revealed that the Tu locus emerged by nonhomologaus recombination of the Xmrk proto-oncogene with a previously uncharacterized sequence, D. This event generated an additional copy of Xmrkwith a new promoter. Suppression...

  10. Application of phase coherent transform to cloud clutter suppression

    Energy Technology Data Exchange (ETDEWEB)

    Ng, L.C. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    This paper describes a tracking algorithm using frame-to-frame correlation with frequency domain clutter suppression. Clutter suppression was mechanized via a `Phase Coherent Transform` (PCT) approach. This approach was applied to explore the feasibility of tracking a post-boost rocket from a low earth orbit satellite with real cloud background data. Simulation results show that the PCT/correlation tracking algorithm can perform satisfactorily at signal-to-clutter ratio (SCR) as low as 5 or 7 dB.

  11. Voluntary driven elbow orthosis with speed controlled tremor suppression

    Directory of Open Access Journals (Sweden)

    Gil eHerrnstadt

    2016-03-01

    Full Text Available Robotic technology is gradually becoming commonplace in the medical sector and in the service of patients. Medical conditions that have benefited from significant technological development include stroke, for which rehabilitation with robotic devices is administered, and surgery assisted by robots. Robotic devices have also been proposed for assistance of movement disorders. Pathological tremor, among the most common movement disorders, is such one example. In practice, the dissemination and availability of tremor suppression robotic systems has been limited. Devices in the marketplace tend to either be non-ambulatory or to target specific functions such as eating and drinking.We have developed a one degree-of-freedom (DOF elbow orthosis that could be worn by an individual with tremor. A speed controlled voluntary driven suppression approach is implemented with the orthosis. Typically tremor suppression methods estimate the tremor component of the signal and produce a canceling counterpart signal. The suggested approach, instead estimates the voluntary component of the motion. A controller then actuates the orthosis based on the voluntary signal while simultaneously rejecting the tremorous motion.In this work, we tested the suppressive orthosis using a 1 DOF robotic system that simulates the human arm. The suggested suppression approach does not require a model of the human arm. Moreover, the human input along with the orthosis forearm gravitational forces, of nonlinear nature, are considered as part of the disturbance to the suppression system. Therefore, the suppression system can be modeled linearly. Nevertheless, the orthosis forearm gravitational forces can be compensated by the suppression system.The electromechanical design of the orthosis is presented, and data from an Essential Tremor patient is used as the human input. Velocity tracking results demonstrate an RMS error of 0.31 rad/s, and a power spectral density shows a reduction of

  12. A Designated Harmonic Suppression Technology for Sampled SPWM

    Institute of Scientific and Technical Information of China (English)

    YANG Ping

    2005-01-01

    Sampled SPWM is an excellent VVVF method of motor speed control, meanwhile the harmonic components of the output wave impairs its applications in practice. A designated harmonic suppression technology is presented for sampled SPWM, which is an improved algorithm for the harmonic suppression in high voltage and high frequency spectrum. As the technology is applied in whole speed adjusting range, the voltage can be conveniently controlled and high frequency harmonic of SP WM is also improved.

  13. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    DEFF Research Database (Denmark)

    Liu, Fenghai; Xueyan, Zheng; Pedersen, Rune Johan Skullerud;

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.......Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA....

  14. Active Flutter Suppression Combining the Receptance Method and Flutter Margin

    OpenAIRE

    Wu, Zhigang; Cooper, Jonathan

    2016-01-01

    Active flutter suppression is used to prevent flutter throughout the flight envelope by supplying active control forces in response to vehicle motions. In recent years, studies have been conducted on active flutter suppression using the receptance method. The advantage of the receptance method is that the feedback control gains are purely based upon measured receptances, without any need to evaluate or know the mass, damping, and stiffness matrices of the system. However, determination of the...

  15. Expressive suppression and neural responsiveness to nonverbal affective cues.

    Science.gov (United States)

    Petrican, Raluca; Rosenbaum, R Shayna; Grady, Cheryl

    2015-10-01

    Optimal social functioning occasionally requires concealment of one's emotions in order to meet one's immediate goals and environmental demands. However, because emotions serve an important communicative function, their habitual suppression disrupts the flow of social exchanges and, thus, incurs significant interpersonal costs. Evidence is accruing that the disruption in social interactions, linked to habitual expressive suppression use, stems not only from intrapersonal, but also from interpersonal causes, since the suppressors' restricted affective displays reportedly inhibit their interlocutors' emotionally expressive behaviors. However, expressive suppression use is not known to lead to clinically significant social impairments. One explanation may be that over the lifespan, individuals who habitually suppress their emotions come to compensate for their interlocutors' restrained expressive behaviors by developing an increased sensitivity to nonverbal affective cues. To probe this issue, the present study used functional magnetic resonance imaging (fMRI) to scan healthy older women while they viewed silent videos of a male social target displaying nonverbal emotional behavior, together with a brief verbal description of the accompanying context, and then judged the target's affect. As predicted, perceivers who reported greater habitual use of expressive suppression showed increased neural processing of nonverbal affective cues. This effect appeared to be coordinated in a top-down manner via cognitive control. Greater neural processing of nonverbal cues among perceivers who habitually suppress their emotions was linked to increased ventral striatum activity, suggestive of increased reward value/personal relevance ascribed to emotionally expressive nonverbal behaviors. These findings thus provide neural evidence broadly consistent with the hypothesized link between habitual use of expressive suppression and compensatory development of increased responsiveness to

  16. Akustisch evozierte Potentiale mittlerer Latenz unter Burst Suppression EEG

    OpenAIRE

    Jochum, Sybille

    2007-01-01

    Akustisch evozierte Potentiale mittlerer Latenz (MLAEPs) und Elektroenzephalogramm (EEG) finden bei der Untersuchung der hypnotischen Komponente von Narkose seit langem Verwendung In dieser Studie wurde untersucht, inwiefern sehr tiefe Narkose mit dem Korrelat Burst Suppression im EEG mit Hilfe von MLAEPs erfasst werden kann. Hierfür wurde zunächst die Frage geklärt, ob MLAEPs unter Burst Suppression, hervorgerufen durch eine Propofol Monoanästhesie, vorhanden sind. Nachdem MLAEPs unter B...

  17. Determining Absorption, Emissivity Reduction, and Local Suppression Coefficients inside Sunspots

    OpenAIRE

    Ilonidis, Stathis; Zhao, Junwei

    2010-01-01

    The power of solar acoustic waves is reduced inside sunspots mainly due to absorption, emissivity reduction, and local suppression. The coefficients of these power-reduction mechanisms can be determined by comparing time-distance cross-covariances obtained from sunspots and from the quiet Sun. By analyzing 47 active regions observed by SOHO/MDI without using signal filters, we have determined the coefficients of surface absorption, deep absorption, emissivity reduction, and local suppression....

  18. Burst suppression electroencephalogram with mushroom poisoning, Amanita pantherina

    OpenAIRE

    Yuka Ogawa; Hiromasa Sato; Motoyoshi Yamamoto; Hiroyuki Tada; Takao Hashimoto

    2015-01-01

    We report on a patient with Amanita pantherina poisoning who showed a burst suppression pattern on electroencephalography during a comatose state. The patient recovered without sequelae a week after ingestion. Burst suppression pattern is defined as alternating bursts and periods of electrical silence, and it is associated with comatose states of various causes. The major toxins contained in A. pantherina are ibotenic acid, an excitatory amino acid at the glutamate receptors, and muscimol, an...

  19. Steam jet direct condensation in a water suppression pool

    OpenAIRE

    Aramayo Hernández, Clara Inés

    2013-01-01

    Direct contact condensation (DCC) of a steam jet discharged into a subcooled water pool is an efficient way to condensate a large quantities of water at high pressure and temperature without introducing any complex device. This phenomenon is used in many nuclear engineering fields, such as pressure suppression pool in Boiling Water Reactors (BWRs), condensing pool in Pressurized Water Reactors (PWRs) and suppression tank in International Thermonuclear Experimental Reactor (ITER...

  20. Predictors for partial suppression of spermatogenesis of hormonal male contraception

    Institute of Scientific and Technical Information of China (English)

    Jing-Wen Li; Yi-Qun Gu

    2008-01-01

    Aim: To analyze factors influencing the efficacy of hormonal suppression of spermatogenesis for male contraception. Methods: A nested case-control study was conducted, involving 43 subjects, who did not achieve azoospermia or severe oligozoospermia when given monthly injections of 500 mg testosterone undecanoate (TU), defined as partial suppressors compared with 855 subjects who had suppressed spermatogenesis (complete suppressors). Sperm density, serum testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations at the baseline and the suppression phase were compared between partial and complete suppressors. Polymorphisms of androgen receptor (AR) and three single nucleotide variants and their haplotypes of FSH receptor (FSHR) genes determined by polymerase chain reaction (PCR) and DNA sequencing technique were compared between 29 partial and 34 complete suppressors. Results: Baseline serum LH level was higher and serum LH as well as FSH level during the suppression phase was less suppressed in partial suppressors. Additionally, in a logistic regression analysis larger testis volume, higher serum FSH concentrations alone, or interaction of serum LH, FSH, testosterone and sperm concentrations were associated with degree of suppression. The distribution of polymorphisms of AR or FSH receptor genes did not differ between partial and complete suppressors. In cases with incomplete FSH suppression (FSH > 0.2 IU/L), the chances of reaching azoospermia were 1.5 times higher in the subjects with more than 22 CAG triplet repeats. Conclusion: Partial suppression of spermatogenesis induced by 500 mg TU monthly injections is weakly influenced by hormonal and clinical features but not polymorphism in AR and FSHR genes.

  1. Emotional suppression in chronic fatigue syndrome (CFS): Experimental study

    OpenAIRE

    Rimes, Katharine Amber.; Ashcroft, Joanna Caroline; Bryan, Lauren; Chalder, Trudie

    2016-01-01

    Objective: Emotional processing differences in chronic fatigue syndrome (CFS) have been reported but have rarely been investigated experimentally. This study used self-report, observer ratings, and electrodermal responses to test hypotheses about emotion suppression and autonomic reactivity.Methods: Eighty adults with CFS and 80 healthy controls (HC) watched a distressing film clip. Half of each group were instructed to suppress their emotions and half were told to express their feelings as t...

  2. Thought Suppression and Self-Injurious Thoughts and Behaviors

    OpenAIRE

    Najmi, Sadia; Wegner, Daniel M.; Nock, Matthew K.

    2006-01-01

    This study proposes and tests a theoretical model suggesting that the propensity to suppress unwanted thoughts is associated with an increased presence and frequency of self-injurious thoughts and behaviors (SITB). In the model, propensity to suppress unwanted thoughts is hypothesized to be a cognitive mediator of the relationship between emotional reactivity and SITB, and is expected to be related to the extent to which SITB is initiated to escape from aversive emotions. Results of this cros...

  3. Social responses to expressive suppression: The role of personality judgments.

    Science.gov (United States)

    Tackman, Allison M; Srivastava, Sanjay

    2016-04-01

    Why do people who suppress their emotion-expressive behavior have difficulty forming close, supportive relationships? Previous studies have found that suppression disrupts the dynamics of social interactions and existing relationships. We evaluated a complementary hypothesis: that suppression functions as a behavioral cue leading others to form negative personality impressions of suppressors, even at zero-acquaintance. In 2 studies, participants reported personality judgments and other impressions of targets who either suppressed or expressed their emotion-expressive behavior in response to amusing or sad film clips. In findings replicated across studies, targets who suppressed either amusement or sadness were judged as less extraverted, less agreeable, and more interpersonally avoidant and anxious than targets who expressed emotions, and participants were less interested in affiliating with suppressors compared with expressers. Effects were amplified when targets suppressed amusement (compared with sadness) and when participants knew the emotional context (compared with when they did not) and, thus, could form expectations about what emotions targets should be showing. Extraversion and agreeableness judgments mediated the effect of suppression on participants' disinterest in affiliating. In Study 2, which extended Study 1 in several ways, effects were pronounced for the enthusiasm aspect of extraversion and the compassion aspect of agreeableness. We also found evidence that judgments of suppressors do not simply fall between neutral and fully expressing targets; rather, judgments of suppressors are qualitatively different. We discuss implications for understanding the social consequences of emotion regulation-in particular, how beyond disrupting relationships, suppression may prevent some relationships from even forming in the first place. PMID:26280841

  4. EMOTION SUPPRESSION AND ITS IMPACT ON POSITIVE EMOTION EXPERIENCE.

    OpenAIRE

    Pacini, Adele

    2011-01-01

    Abstract This thesis aimed to examine the impact of emotion suppression of negative material on subsequent reactivity to positive material with a group of MDD participants and healthy controls. A mixed design laboratory based experiment was used, where in the first condition participants firstly “just viewed” a sad film clip, and in the second condition they suppressed their emotions to a different sad film clip. Before and after each of the film clips, positive self referen...

  5. Two Components of Nocturnal Locomotor Suppression by Light

    OpenAIRE

    Morin, Lawrence P; Lituma, Pablo J.; Studholme, Keith M.

    2010-01-01

    In nocturnal rodents, millisecond light (“flash”) stimuli can induce both a large circadian rhythm phase shift and an associated state change from highly active to quiescence followed by behavioral sleep. Suppression of locomotion (“negative masking”) is an easily measured correlate of the state change. The present mouse studies used both flashes and longer light stimuli (“pulses”) to distinguish initiation from maintenance effects of light on locomotor suppression and to determine whether th...

  6. Overnight Dexamethasone Suppression Test in the Diagnosis of Cushing's Disease

    OpenAIRE

    Fatemeh Esfahanian; Rozana Kazemi

    2010-01-01

    Realizing the cause of Cushing's Syndrome (CS) is one of the most challenging processes in clinical endocrinology. The long high dose dexamethasone suppression test (standard test) is costly and need an extended inpatient stay. In this study we want to show the clinical utility of the overnight 8 mg dexamethasone suppression test (DST) for differential diagnosis of CS in a referral center. Retrospectively from 2002-2005 we selected the patients of endocrinology ward in Imam hospital who were ...

  7. The Mesoscopic Modeling of Burst Suppression during Anesthesia

    OpenAIRE

    Liley, David T. J.; Walsh, Matthew

    2013-01-01

    The burst-suppression pattern is well recognized as a distinct feature of the mammalian electroencephalogram (EEG) waveform. Consisting of alternating periods of high amplitude oscillatory and isoelectric activity, it can be induced in health by deep anesthesia as well as being evoked by a range of pathophysiological processes that include coma and anoxia. While the electroencephalographic phenomenon and clinical implications of burst suppression have been studied extensively, the physiologic...

  8. Disease suppressive soilless culture systems; characterisation of its microflora

    OpenAIRE

    Postma, J; Willemsen-de Klein, M.J.E.I.M.; Rattink, H.; Os, van, H.

    2001-01-01

    The trend in glasshouse horticulture has always been to start culture systems as aseptic as possible. However, several root diseases still cause problems under these conditions. The present paper shows the importance of the microflora to suppress Pythium aphanidermatum, a fungal root pathogen which is a serious threat in cucumber. Introduced single antagonists as well as the indigenous microflora suppressed pythium root and crown rot. Pseudomonas fluorescens, Streptomyces griseoviridis, Pythi...

  9. Counterproductive Effect of Saccadic Suppression during Attention Shifts

    OpenAIRE

    Zenon, Alexandre; Corneil, Brian D.; Alamia, Andrea; Filali-Sadouk, Nabil; Olivier, Etienne

    2014-01-01

    During saccadic eye movements, the processing of visual information is transiently interrupted by a mechanism known as "saccadic suppression" [1] that is thought to ensure perceptual stability [2]. If, as proposed in the premotor theory of attention [3], covert shifts of attention rely on sub-threshold recruitment of oculomotor circuits, then saccadic suppression should also occur during covert shifts. In order to test this prediction, we designed two experiments in which participants had to ...

  10. Mode of ATM-dependent suppression of chromosome translocation

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, Motohiro, E-mail: motoyama@nagasaki-u.ac.jp [Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Suzuki, Keiji; Oka, Yasuyoshi; Suzuki, Masatoshi; Kondo, Hisayoshi; Yamashita, Shunichi [Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan)

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer We addressed how ATM suppresses frequency of chromosome translocation. Black-Right-Pointing-Pointer We found ATM/p53-dependent G1 checkpoint suppresses translocation frequency. Black-Right-Pointing-Pointer We found ATM and DNA-PKcs function in a common pathway to suppress translocation. -- Abstract: It is well documented that deficiency in ataxia telangiectasia mutated (ATM) protein leads to elevated frequency of chromosome translocation, however, it remains poorly understood how ATM suppresses translocation frequency. In the present study, we addressed the mechanism of ATM-dependent suppression of translocation frequency. To know frequency of translocation events in a whole genome at once, we performed centromere/telomere FISH and scored dicentric chromosomes, because dicentric and translocation occur with equal frequency and by identical mechanism. By centromere/telomere FISH analysis, we confirmed that chemical inhibition or RNAi-mediated knockdown of ATM causes 2 to 2.5-fold increase in dicentric frequency at first mitosis after 2 Gy of gamma-irradiation in G0/G1. The FISH analysis revealed that ATM/p53-dependent G1 checkpoint suppresses dicentric frequency, since RNAi-mediated knockdown of p53 elevated dicentric frequency by 1.5-fold. We found ATM also suppresses dicentric occurrence independently of its checkpoint role, as ATM inhibitor showed additional effect on dicentric frequency in the context of p53 depletion and Chk1/2 inactivation. Epistasis analysis using chemical inhibitors revealed that ATM kinase functions in the same pathway that requires kinase activity of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to suppress dicentric frequency. From the results in the present study, we conclude that ATM minimizes translocation frequency through its commitment to G1 checkpoint and DNA double-strand break repair pathway that requires kinase activity of DNA-PKcs.

  11. Signal Enhancement and Suppression During Visual-Spatial Selective Attention

    OpenAIRE

    Couperus, J. W.; Mangun, G.R.

    2010-01-01

    Selective attention involves the relative enhancement of relevant versus irrelevant stimuli. However, whether this relative enhancement involves primarily enhancement of attended stimuli, or suppression of irrelevant stimuli, remains controversial. Moreover, if both enhancement and suppression are involved, whether they result from a single mechanism or separate mechanisms during attentional control or selection is not known. In two experiments using a spatial cuing paradigm with task-relevan...

  12. The proposed role of suppression in simultaneous interpretation

    OpenAIRE

    Gernsbacher, Morton Ann; Shlesinger, Miriam

    1997-01-01

    In this paper we suggest that the cognitive mechanism of suppression attenuates interference in many language comprehension phenomena, and is particularly crucial when comprehension must share processing capacity with other cognitive tasks, as is manifestly the case in simultaneous interpreting. During lexical access, the mechanism of suppression attenuates the interference caused by the activation of other lexical information, such as the inappropriate meanings of homonyms. During anaphoric ...

  13. Pile-up reduction by detector-induced beam suppression

    International Nuclear Information System (INIS)

    The technique of detector-induced beam suppression using a beam deflector and a high power pulse generator has been explored. The γ spectra of the 98Mo(α,xn) reactions are presented with and without beam suppression and it is seen that with the pile-up reduction system working, there is a considerable increase in the count rate in the 98Rn 653 keV peak, with almost the same background. (C.F.)

  14. Emotional suppression when processing trauma: Consequences for mood and memory.

    OpenAIRE

    Dunn, B.

    2004-01-01

    The thought suppression literature (Wegner et al. 1987; Wegner and Erber, 1992) illustrates that there are secondary costs of suppressing the cognitive content of conscious experience. A 'thought rebound' effect has been demonstrated in both healthy populations and psychopathology (Purdon, 1999), whereby the harder a thought is pushed out of mind the more likely it is to subsequently return. It is increasingly realised that people try to control affect as well as cognitions (Gross, 1998; 2001...

  15. A Model of Binocular Rivalry and Cross-orientation Suppression

    OpenAIRE

    Said, Christopher P.; Heeger, David J.

    2013-01-01

    Binocular rivalry and cross-orientation suppression are well-studied forms of competition in visual cortex, but models of these two types of competition are in tension with one another. Binocular rivalry occurs during the presentation of dichoptic grating stimuli, where two orthogonal gratings presented separately to the two eyes evoke strong alternations in perceptual dominance. Cross-orientation suppression occurs during the presentation of plaid stimuli, where the responses to a component ...

  16. Suppression of extraneous thermal noise in cavity optomechanics

    OpenAIRE

    Zhao, Yi; Wilson, Dalziel J.; Ni, Kang-Kuen; Kimble, H. Jeff

    2012-01-01

    Extraneous thermal motion can limit displacement sensitivity and radiation pressure effects, such as optical cooling, in a cavity-optomechanical system. Here we present an active noise suppression scheme and its experimental implementation. The main challenge is to selectively sense and suppress extraneous thermal noise without affecting motion of the oscillator. Our solution is to monitor two modes of the optical cavity, each with different sensitivity to the oscillator's motion but similar ...

  17. Lateral suppression of mesopic rod and cone flicker detection

    OpenAIRE

    Cao, Dingcai; Lu, Yolanda H.

    2012-01-01

    This study investigated the mechanisms of flicker detection suppression by measuring mesopic rod and cone critical flicker frequencies (CFFs) at different center and surround illuminance levels. Stimuli were generated with a four-primary photostimulator that provided independent control of rod and cone excitations. The results showed that dim surrounds ≤0.2 Td suppressed cone-mediated CFFs at ≥20 Td but not rod-mediated CFFs. These results can be understood in terms of peak amplitudes of phot...

  18. Memory Suppression is an Active Process that Improves Over Childhood

    OpenAIRE

    Paz-Alonso, Pedro M.; Ghetti, Simona; Bryan J Matlen; Anderson, Michael C.; Bunge, Silvia A.

    2009-01-01

    We all have memories that we prefer not to think about. The ability to suppress retrieval of unwanted memories has been documented in behavioral and neuroimaging research using the Think/No-Think (TNT) paradigm with adults. Attempts to stop memory retrieval are associated with increased activation of lateral prefrontal cortex (PFC) and concomitant reduced activation in medial temporal lobe (MTL) structures. However, the extent to which children have the ability to actively suppress their memo...

  19. Appetite suppressants and valvular heart disease - a systematic review

    OpenAIRE

    2002-01-01

    Background Although appetite suppressants have been implicated in the development of valvular heart disease, the exact level of risk is still uncertain. Initial studies suggested that as many as 1 in 3 exposed patients were affected, but subsequent research has yielded substantially different figures. Our objective was to systematically assess the risk of valvular heart disease with appetite suppressants. Methods We accepted studies involving obese patients treated with any of the following a...

  20. Cognitive Load Undermines Thought Suppression in Acute Stress Disorder.

    Science.gov (United States)

    Nixon, Reginald D V; Rackebrandt, Julie

    2016-05-01

    Thought suppression studies demonstrate that attempts to suppress can be undermined by cognitive load. We report the first instance in which this has been tested experimentally in a sample of recently traumatized individuals. Individuals with and without acute stress disorder (ASD) were recruited following recent trauma and randomized to load or no load conditions (N=56). They monitored intrusive memories during baseline, suppression, and think anything phases. The impact of suppression and load on self-reported intrusions, attention bias (dot-probe), and memory priming (word-stem task) was assessed. The ASD load group were less able to suppress memories (d=0.32, CI95 [-0.15, 0.83], p=.088) than the ASD no load group (d=0.63, CI95 [0.08, 1.24], panything phase, the ASD load group reported more intrusions than the ASD no load or non-ASD groups (with and without load). No consistent findings were observed in relation to attentional bias. ASD load individuals exhibited stronger priming responses for motor vehicle accident and assault words than all other groups (ds between 0.35-0.73). Working memory did not moderate any outcomes of interest. The findings indicate that cognitive load interferes with suppression and may enhance access to trauma memories and associated material. The study extends previous research by demonstrating these effects for the first time in a clinical sample of recent survivors of trauma. PMID:27157032

  1. Suppression of aggressive rorschach responses among violent offenders and nonoffenders.

    Science.gov (United States)

    Benjestorf, Sue TaVoularis; Viglione, Donald J; Lamb, Judy D; Giromini, Luciano

    2013-10-01

    This Rorschach study explored the suppression of aggression content when violent offenders and nonoffenders are asked to present themselves as not posing a threat of dangerousness in a court role-playing context. Aggressive content and complexity in this suppressive role-play context was compared to a neutral control condition. A total of 41 participants, approximately half violent offenders and half nonoffenders took the Rorschach under both conditions. Results indicate that both groups suppressed aggression content on the Rorschach without altering response complexity. This large effect size for testing condition may partly explain the inconsistencies across previous studies. It is possible that violent offenders have typically been tested in highly suppressive conditions whereas nonoffender or normative groups may have been tested in relatively low suppression conditions. If so, aggression score differences may be a reflection of the testing condition, not group differences. Both instructional sets produced similar levels of complexity, so that individuals do not simplify responses when they screen out aggressive attributions. Violent offenders did not differ from nonviolent offenders in terms of aggression content, but did produce more simplistic records. In addition, this study also undertook a semantic, textual analysis and found that individuals in the suppressive condition tended to eliminate many response elaborations, particularly those with negative of threatening connotations. PMID:23711990

  2. Memory suppression is an active process that improves over childhood

    Directory of Open Access Journals (Sweden)

    Pedro M Paz-Alonso

    2009-09-01

    Full Text Available We all have memories that we prefer not to think about. The ability to suppress retrieval of unwanted memories has been documented in behavioral and neuroimaging research using the Think/No-Think (TNT paradigm with adults. Attempts to stop memory retrieval are associated with increased activation of lateral prefrontal cortex (PFC and concomitant reduced activation in medial temporal lobe (MTL structures. However, the extent to which children have the ability to actively suppress their memories is unknown. This study investigated memory suppression in middle childhood using the TNT paradigm. Forty children aged 8 to 12 and 30 young adults were instructed either to remember (Think or suppress (No-Think the memory of the second word of previously studied word-pairs, when presented with the first member as a reminder. They then performed two different cued recall tasks, testing their memory for the second word in each pair after the Think/No-Think phase using the same first studied word within the pair as a cue (intra-list cue and also an independent cue (extra-list cue. Children exhibited age-related improvements in memory suppression from age 8 to 12 in both memory tests, against a backdrop of overall improvements in declarative memory over this age range. These findings suggest that memory suppression is an active process that develops during late childhood, likely due to an age-related refinement in the ability to engage PFC to down-regulate activity in areas involved in episodic retrieval.

  3. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  4. Neurotropin suppresses inflammatory cytokine expression and cell death through suppression of NF-κB and JNK in hepatocytes.

    Directory of Open Access Journals (Sweden)

    Bi Zhang

    Full Text Available Inflammatory response and cell death in hepatocytes are hallmarks of chronic liver disease, and, therefore, can be effective therapeutic targets. Neurotropin® (NTP is a drug widely used in Japan and China to treat chronic pain. Although NTP has been demonstrated to suppress chronic pain through the descending pain inhibitory system, the action mechanism of NTP remains elusive. We hypothesize that NTP functions to suppress inflammatory pathways, thereby attenuating disease progression. In the present study, we investigated whether NTP suppresses inflammatory signaling and cell death pathways induced by interleukin-1β (IL-1β and tumor necrosis factor-α (TNFα in hepatocytes. NTP suppressed nuclear factor-κB (NF-κB activation induced by IL-1β and TNFα assessed by using hepatocytes isolated from NF-κB-green fluorescent protein (GFP reporter mice and an NF-κB-luciferase reporter system. The expression of NF-κB target genes, Il6, Nos2, Cxcl1, ccl5 and Cxcl2 induced by IL-1β and TNFα was suppressed after NTP treatment. We also found that NTP suppressed the JNK phosphorylation induced by IL-1β and TNFα. Because JNK activation contributes to hepatocyte death, we determined that NTP treatment suppressed hepatocyte death induced by IL-1β and TNFα in combination with actinomycin D. Taken together, our data demonstrate that NTP attenuates IL-1β and TNFα-mediated inflammatory cytokine expression and cell death in hepatocytes through the suppression of NF-κB and JNK. The results from the present study suggest that NTP may become a preventive or therapeutic strategy for alcoholic and non-alcoholic fatty liver disease in which NF-κB and JNK are thought to take part.

  5. A simplified model of decontamination by BWR steam suppression pools

    Energy Technology Data Exchange (ETDEWEB)

    Powers, D.A.

    1997-05-01

    Phenomena that can decontaminate aerosol-laden gases sparging through steam suppression pools of boiling water reactors during reactor accidents are described. Uncertainties in aerosol properties, aerosol behavior within gas bubbles, and bubble behavior in plumes affect predictions of decontamination by steam suppression pools. Uncertainties in the boundary and initial conditions that are dictated by the progression of severe reactor accidents and that will affect predictions of decontamination by steam suppression pools are discussed. Ten parameters that characterize boundary and initial condition uncertainties, nine parameters that characterize aerosol property and behavior uncertainties, and eleven parameters that characterize uncertainties in the behavior of bubbles in steam suppression pools are identified. Ranges for the values of these parameters and subjective probability distributions for parametric values within the ranges are defined. These uncertain parameters are used in Monte Carlo uncertainty analyses to develop uncertainty distributions for the decontamination that can be achieved by steam suppression pools and the size distribution of aerosols that do emerge from such pools. A simplified model of decontamination by steam suppression pools is developed by correlating features of the uncertainty distributions for total decontamination factor, DF(total), mean size of emerging aerosol particles, d{sub p}, and the standard deviation of the emerging aerosol size distribution, {sigma}, with pool depth, H. Correlations of the median values of the uncertainty distributions are suggested as the best estimate of decontamination by suppression pools. Correlations of the 10 percentile and 90 percentile values of the uncertainty distributions characterize the uncertainty in the best estimates. 295 refs., 121 figs., 113 tabs.

  6. A simplified model of decontamination by BWR steam suppression pools

    International Nuclear Information System (INIS)

    Phenomena that can decontaminate aerosol-laden gases sparging through steam suppression pools of boiling water reactors during reactor accidents are described. Uncertainties in aerosol properties, aerosol behavior within gas bubbles, and bubble behavior in plumes affect predictions of decontamination by steam suppression pools. Uncertainties in the boundary and initial conditions that are dictated by the progression of severe reactor accidents and that will affect predictions of decontamination by steam suppression pools are discussed. Ten parameters that characterize boundary and initial condition uncertainties, nine parameters that characterize aerosol property and behavior uncertainties, and eleven parameters that characterize uncertainties in the behavior of bubbles in steam suppression pools are identified. Ranges for the values of these parameters and subjective probability distributions for parametric values within the ranges are defined. These uncertain parameters are used in Monte Carlo uncertainty analyses to develop uncertainty distributions for the decontamination that can be achieved by steam suppression pools and the size distribution of aerosols that do emerge from such pools. A simplified model of decontamination by steam suppression pools is developed by correlating features of the uncertainty distributions for total decontamination factor, DF(total), mean size of emerging aerosol particles, dp, and the standard deviation of the emerging aerosol size distribution, σ, with pool depth, H. Correlations of the median values of the uncertainty distributions are suggested as the best estimate of decontamination by suppression pools. Correlations of the 10 percentile and 90 percentile values of the uncertainty distributions characterize the uncertainty in the best estimates. 295 refs., 121 figs., 113 tabs

  7. Arsenite suppression of BMP signaling in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Marjorie A.; Qin, Qin [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States); Hu, Qin; Zhao, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Rice, Robert H., E-mail: rhrice@ucdavis.edu [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States)

    2013-06-15

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte

  8. Basic study of T1-weighted images with fat suppression

    International Nuclear Information System (INIS)

    Magnetic resonance methods for scanning using Gd-DTPA have been improved. Enhanced MR angiography and dynamic MRI, which enable detection of movement in the body shortly after rapid intravenous injection of Gd-DTPA, are often performed using fat-suppression methods. In this study, the spoiled gradient echo sequence, which is mainly used in these examinations, was analyzed, and the significant differences in signal intensity and fat-suppression effects on a hand-made phantom using Gd-DTPA solutions and olive oil were evaluated. The optimal flip angle in each pulse sequence under basic scanning conditions was first determined. As a result, there was correlation between the concentration and signal intensity of Gd-DTPA, and the angle of the stronger fat-suppression effect was found. Also, the relationship between repetition time (TR) and echo time (TE) was almost understood. The fat-suppression effects differed depending on pulse sequence, and were greatest one in T1 fast field echo (FFE)-ProSet1331 and T1 fast field echo planar imaging (FFEEPI)-ProSet1331. However, attention must be paid to the use of ProSet due to the extension of TE. It was concluded that we determined the optimal sequence for MR angiography and dynamic MRI in the 1.0T MRI equipment, In MR angiography, T1 turbo field echo-spectral presaturation inversion recovery (TFE-SPIR) should be selected because of the largest fat-suppression effects in some scanning regions. (author)

  9. Juggling reveals a decisional component to tactile suppression.

    Science.gov (United States)

    Juravle, Georgiana; Spence, Charles

    2011-08-01

    Goal-directed movements are characterized by sensory suppression, that is, by decreased sensitivity to tactile stimuli. In the present study, we investigated tactile suppression during movement using a complex motor task: basic 3-ball juggling. It was hypothesized that a decrease in tactile sensitivity would be observed, together with a shift in participants' response bias while juggling. In a first experiment, participants had to detect a short gap in an otherwise continuous vibratory stimulus, which was delivered to their wrist under conditions of rest or else while juggling. In a second experiment, participants detected a short time gap in a continuous auditory signal, under the same conditions. In a final control experiment performed at rest, participants detected a short time gap in an auditory or tactile signal. In an additional condition, the detection of a gap in tactile stimulation was required under conditions of intramodal tactile interference. Participants were significantly less sensitive to detect a gap in tactile stimulation whilst juggling. Most importantly, these results were paired with a significant shift toward participants adopting a more conservative criterion when responding to the presence of the gap (i.e. they were more likely to say that a gap was not present). Taken together, these results demonstrate movement-related tactile sensory suppression and point to a decisional component in tactile suppression, thus suggesting that tactile suppression could already be triggered in the brain ahead of the motor command. PMID:21717097

  10. Shikonin Suppresses Skin Carcinogenesis via Inhibiting Cell Proliferation.

    Science.gov (United States)

    Li, Wenjuan; Zhang, Chunjing; Ren, Amy; Li, Teena; Jin, Rong; Li, Guohong; Gu, Xin; Shi, Runhua; Zhao, Yunfeng

    2015-01-01

    The M2 isoform of pyruvate kinase M2 (PKM2) has been shown to be up-regulated in human skin cancers. To test whether PKM2 may be a target for chemoprevention, shikonin, a natural product from the root of Lithospermum erythrorhizon and a specific inhibitor of PKM2, was used in a chemically-induced mouse skin carcinogenesis study. The results revealed that shikonin treatment suppressed skin tumor formation. Morphological examinations and immunohistochemical staining of the skin epidermal tissues suggested that shikonin inhibited cell proliferation without inducing apoptosis. Although shikonin alone suppressed PKM2 activity, it did not suppress tumor promoter-induced PKM2 activation in the skin epidermal tissues at the end of the skin carcinogenesis study. To reveal the potential chemopreventive mechanism of shikonin, an antibody microarray analysis was performed, and the results showed that the transcription factor ATF2 and its downstream target Cdk4 were up-regulated by chemical carcinogen treatment; whereas these up-regulations were suppressed by shikonin. In a promotable skin cell model, the nuclear levels of ATF2 were increased during tumor promotion, whereas this increase was inhibited by shikonin. Furthermore, knockdown of ATF2 decreased the expression levels of Cdk4 and Fra-1 (a key subunit of the activator protein 1. In summary, these results suggest that shikonin, rather than inhibiting PKM2 in vivo, suppresses the ATF2 pathway in skin carcinogenesis. PMID:25961580

  11. Investigation of tritium activity ingress to pressure suppression pool

    International Nuclear Information System (INIS)

    Kakrapar Atomic Power Station is a standardised design Indian PHWR consisting of twin units of 220 MWe each. Pressure suppression pool situated at the basement of reactor building holds about 2200 m3 of DM water. It acts as a media separating the high enthalpy areas from low enthalpy areas and remain passive during normal operation. During LOCA it reduces the pressure in RB atmosphere by condensing the steam passing through it. In both units of KAPS tritium activity is observed in suppression pool, most predominantly in KAPS-1. Activity build up in suppression pool can act as potential source of tritium activity in RB atmosphere leading to increased internal exposure of occupational workers. Also during de-watering of suppression pool, this water adds to the amount of liquid waste generated from the station which eventually results in exposure of the public to tritium. This paper discusses the activity build up trend in KAPS-1 suppression pool, its sources, works done to prevent the activity ingress and suggestions for design improvement. (author)

  12. Attenuation of antigenic immunogenicity by kynurenine, a novel suppressive adjuvant.

    Science.gov (United States)

    Duan, Zhiqing; Duan, Yunqing; Lei, Huangui; Hu, Ningzhu; Shi, Jiandong; Shen, Dong; Wang, Xi; Hu, Yunzhang

    2014-01-01

    A novel therapeutic strategy is required for autoimmune diseases characterized by the production of autoantibody, because current clinical strategies have limitations. Vaccination against autoimmune diseases is a feasible strategy because vaccines induce immune response memory and the antigen specificity. However, no suitable adjuvant is available to direct the immune response toward tolerance or suppression. In the current study, we evaluated whether kynurenine (Kyn) could serve as a novel suppressive adjuvant to decrease the humoral immune responses against hepatitis A virus (HAV) in the ICR mouse model in vivo and lipopolysaccharide (LPS) in B cells in vitro. The underlying mechanisms of Kyn-mediated suppression of LPS-induced IgM responses were explored. The results showed that Kyn significantly decreased HAV immunogenicity when co-administered with HAV, and that Kyn (100 μM/1000 μM) impaired IgM generation compared with that induced by LPS alone. We also demonstrated that microRNA30b (miR30b) played a critical role in the process of Kyn-mediated suppression of IgM responses induced by LPS, and that Bach2, a transcriptional repressor of B cell terminal differentiation, was a novel target of miR30b. These findings suggest that Kyn can serve as a novel and effective suppressive adjuvant for vaccines. PMID:24583631

  13. Interaction between noise suppression and inhomogeneity correction in MRI

    Science.gov (United States)

    Montillo, Albert; Udupa, Jayaram K.; Axel, Leon; Metaxas, Dimitri N.

    2003-05-01

    While cardiovascular disease is the leading cause of death in most developed countries, SPAMM-MRI can reduce morbidity by facilitating patient diagnosis. An image analysis method with a high degree of automation is essential for clinical adoption of SPAMM-MRI. The degree of this automation is dependent on the amount of thermal noise and surface coil-induced intensity inhomogeneity that can be removed from the images. An ideal noise suppression algorithm removes thermal noise yet retains or enhances the strength of the edges of salient structures. In this paper, we quantitatively compare and rank several noise suppression algorithms in images from both normal and diseased subjects using measures of the residual noise and edge strength and the statistical significance levels and confidence intervals of these measures. We also investigate the interrelationship between inhomogeneity correction and noise suppression algorithms and compare the effect of the ordering of these algorithms. The variance of thermal noise does not tend to change with position, however, inhomogeneity correction increases noise variance in deep thoracic regions. We quantify the degree to which an inhomogeneity estimate can improve noise suppression and how well noise suppression can facilitate the identification of homogeneous tissue regions and thereby, assist in inhomogeneity correction.

  14. Suppression of galactic outflows by cosmological infall and circumgalactic medium

    Science.gov (United States)

    Singh, Priyanka; Rana, Sandeep; Bagla, Jasjeet S.; Nath, Biman B.

    2016-06-01

    We investigate the relative importance of two galactic outflow suppression mechanisms: (a) cosmological infall of the intergalactic gas on to the galaxy, and (b) the existence of a hot circumgalactic medium (CGM). Considering only radial motion, the infall reduces the speed of outflowing gas and even halts the outflow, depending on the mass and redshift of the galaxy. For star-forming galaxies, there exists an upper mass limit beyond which outflows are suppressed by the gravitational field of the galaxy. We find that infall can reduce this upper mass limit approximately by a factor of 2 (independent of the redshift). Massive galaxies (≳1012 M⊙) host large reservoir of hot, diffuse CGM around the central part of the galaxy. The CGM acts as a barrier between the infalling and outflowing gas and provides an additional source of outflow suppression. We find that at low redshifts (z ≲ 3.5), the CGM is more effective than the infall in suppressing the outflows. Together, these two processes give a mass range in which galaxies are unable to have effective outflows. We also discuss the impact of outflow suppression on the enrichment history of the galaxy and its environment.

  15. Desensitization of delayed-type hypersensitivity in mice: suppressive environment

    Directory of Open Access Journals (Sweden)

    Takashi Katsura

    1993-01-01

    Full Text Available The systemic injection of high doses of antigen into a preimmunized animal results in transient unresponsiveness of cell-mediated immune responses. This phenomenon is known as desensitization. Serum interleukin 2 (IL-2 activity was found transiently in desensitized mice at 3 h after the antigen challenge. These mice could not reveal antigen nonspecific delayed-type hypersensitivity (DTH 1 d after the challenge. Specific suppression of DTH was observed at later stages. Sera from 3 h desensitized mice showed suppressive effects on DTH in preo immunized mice. Administration of recombinant IL-2 into preimmunized mice led to the failure of development of DTH to antigens. These observations suggest that IL-2 plays an important role in the suppressive environment.

  16. Practical dexamethasone suppression test to evaluate hirsute women

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.H. (Thomas Jefferson Univ., Philadelphia, PA (USA). Dept. of Obstetrics and Gynaecology)

    1982-02-01

    Fifty-five hirsute women were subjected to a 2-week dexamethasone (DXM) suppression test. The pre- and post-DXM plasma dehydroepiandrosteronesulfate (DS) and testosterone (T) were measured by radioimmunoassay to define the source of androgen excess in hirsute women. Four patients (7%) failed to have adequate adrenal suppression due to failure in medication. Among the 51 patients with adequate adrenal suppression, the source of androgen excess was clearly defined in 48 patients (94%). Seventeen patients (33%) showed ovarian source, 13 patients (26%) had adrenal source, while 18 patients (35%) revealed a mixed adrenal and ovarian source. Normal baseline DS and T levels were noted in 22% of hirsute women and more than half (55%) of them had ovarian androgen excess. Even in 17 patients with normal DS and elevated T, 6 patients (36%) suggested adrenal androgen excess. The source of androgen excess in hirsute women seems evenly distributed among the ovarian, the adrenal, and the mixed group.

  17. A practical dexamethasone suppression test to evaluate hirsute women

    International Nuclear Information System (INIS)

    Fifty-five hirsute women were subjected to a 2-week dexamethasone (DXM) suppression test. The pre- and post-DXM plasma dehydroepiandrosteronesulfate (DS) and testosterone (T) were measured by radioimmunoassay to define the source of androgen excess in hirsute women. Four patients (7%) failed to have adequate adrenal suppression due to failure in medication. Among the 51 patients with adequate adrenal suppression, the source of androgen excess was clearly defined in 48 patients (94%). Seventeen patients (33%) showed ovarian source, 13 patients (26%) had adrenal source, while 18 patients (35%) revealed a mixed adrenal and ovarian source. Normal baseline DS and T levels were noted in 22% of hirsute women and more than half (55%) of them had ovarian androgen excess. Even in 17 patients with normal DS and elevated T, 6 patients (36%) suggested adrenal androgen excess. The source of androgen excess in hirsute women seems evenly distributed among the ovarian, the adrenal, and the mixed group. (author)

  18. Investigation of chemical suppressants for inactivation of sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  19. Active and passive vibration suppression for space structures

    Science.gov (United States)

    Hyland, David C.

    1991-01-01

    The relative benefits of passive and active vibration suppression for large space structures (LSS) are discussed. The intent is to sketch the true ranges of applicability of these approaches using previously published technical results. It was found that the distinction between active and passive vibration suppression approaches is not as sharp as might be thought at first. The relative simplicity, reliability, and cost effectiveness touted for passive measures are vitiated by 'hidden costs' bound up with detailed engineering implementation issues and inherent performance limitations. At the same time, reliability and robustness issues are often cited against active control. It is argued that a continuum of vibration suppression measures offering mutually supporting capabilities is needed. The challenge is to properly orchestrate a spectrum of methods to reap the synergistic benefits of combined advanced materials, passive damping, and active control.

  20. Nonsuppressible Oral Dexamethasone Suppression Tests but Not Cushing Syndrome.

    Science.gov (United States)

    Nair, Abilash; Dhingra, Atul; Gopi, Anjana; Jyotsna, Viveka P

    2016-01-01

    In spite of the presence of definitive diagnostic criteria to diagnose Cushing syndrome diagnosis may become challenging. We report a young female with mild clinical features of Cushing syndrome, who had nonsuppressible oral dexamethasone suppression tests; also she had a suspicious pituitary lesion. She underwent pituitary surgery and a pituitary microadenoma (non-ACTH staining) was removed. Now she had come to us with similar complaints to those before. Again she had nonsuppressible oral dexamethasone suppression tests. As the diurnal variation of serum and salivary cortisol was maintained and urinary free cortisol was normal, further evaluation with IV dexamethasone suppression test was performed which clearly ruled out Cushing syndrome. The patient was not on any medicines known to alter dexamethasone metabolism. Fat malabsorption was also ruled out using appropriate tests. The reason for this discrepancy is thought to be altered (increased) metabolism of dexamethasone in this patient as it is widely variable in the general population. PMID:27092281

  1. The Role of Gluon Depletion in J/$\\psi$ Suppression

    CERN Document Server

    Hwa, R C; Pisútová, N

    1997-01-01

    The depletion of gluons as the parton flux traverses a nucleus in a heavy-ion collision can influence the production rate of heavy-quark states. Thus the suppression of $J/\\psi$ can be due to gluon depletion in the initial state in addition to nuclear and hadronic absorption in the final state. A formalism is developed to describe the depletion effect. It is shown that, without constraints from other experimental facts beside the $J/\\psi$ suppression data in $pA$ and $AB$ collisions, it is not possible to determine the relative importance of depletion vs absorption. Possible relevance to the enhanced suppression seen in the $Pb - Pb$ data is mentioned but not studied.

  2. A new solvent suppression method via radiation damping effect

    Institute of Scientific and Technical Information of China (English)

    Cui Xiao-Hong; Peng Ling; Zhang Zhen-Min; Cai Shu-Hui; Chen Zhong

    2011-01-01

    Radiation damping effects induced by the dominated solvent in a solution sample can be applied to suppress the solvent signal.The precession pathway and rate back to equilibrium state between solute and solvent spins are different under radiation damping.In this paper,a series of pulse sequences using radiation damping were designed for the solvent suppression in nuclear magnetic resonance (NMR) spectroscopy.Compared to the WATERGATE method,the solute signals adjacent to the solvent would not be influenced by using the radiation damping method.The one-dimensional (1D) 1H NMR,two-dimensional (2D) gCOSY,and J-resolved experimental results show the practicability of solvent suppression via radiation damping effects in 1D and 2D NMR spectroscopy.

  3. Suppression induction in vivo by a T helper clone?

    DEFF Research Database (Denmark)

    Crispe, I N; Owens, T

    1985-01-01

    We have previously described a helper T cell clone which augments in vivo cytotoxic T cell responses when injected at 10(4) cells per mouse, but not at 10(5) per mouse (Crispe, I. N. et al., Immunology 1984. 52:55). To test whether this dose-response relationship was due to the induction of...... suppression, naive syngeneic mice were injected with 10(5) cloned T helper cells, and their spleen cells were subsequently assayed for suppressive activity in adoptive transfer experiments. Lymphocytes from such mice indeed suppressed an antigen-specific cytotoxic response, but only in the presence of the...... same T helper cell clone freshly added at the time of adoptive transfer. On this basis we argue that the distinction between T helper cell activity and T suppressor-inducer activity corresponds to differences in cell numbers, rather than to two separate cell lineages....

  4. Suppression of Dielectronic Recombination Due to Finite Density Effects

    CERN Document Server

    Nikolić, D; Korista, K T; Ferland, G J; Badnell, N R

    2013-01-01

    We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based-upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (ne = 1 cm^-3) and finite (ne=10^10 ...

  5. Line defect induced conductance suppression in graphene nanojunction

    Science.gov (United States)

    Li, Haidong; Li, Ruixue; Yu, Qiongyan; Kang, Xiubao; Ding, Jun

    2016-05-01

    Line defect induced conductance suppression in graphene nanojunction is investigated by means of Landauer-Bütikker formula and the nonequilibrium Green's function technique. With the increase of the longitudinal size of the device region, the conductance value decreases and tends to form two conductance valleys. Then we prove that the line defect can lead to localize states in the device region, which contributes to conductance valley at the point far away from Dirac point. And the zero conductance at the Dirac point is associated with the edge state localized at the zigzag-edged shoulder of the nanojunctions. The staggered potential can change energy spectrum structure of the device region, and produce strong conductance suppression. The line defect can efficiently enhance the conductance suppression, which can be utilized to realize the electron transport manipulation.

  6. Suppression of phase synchronisation in network based on cat's brain

    Science.gov (United States)

    Lameu, Ewandson L.; Borges, Fernando S.; Borges, Rafael R.; Iarosz, Kelly C.; Caldas, Iberê L.; Batista, Antonio M.; Viana, Ricardo L.; Kurths, Jürgen

    2016-04-01

    We have studied the effects of perturbations on the cat's cerebral cortex. According to the literature, this cortex structure can be described by a clustered network. This way, we construct a clustered network with the same number of areas as in the cat matrix, where each area is described as a sub-network with a small-world property. We focus on the suppression of neuronal phase synchronisation considering different kinds of perturbations. Among the various controlling interventions, we choose three methods: delayed feedback control, external time-periodic driving, and activation of selected neurons. We simulate these interventions to provide a procedure to suppress undesired and pathological abnormal rhythms that can be associated with many forms of synchronisation. In our simulations, we have verified that the efficiency of synchronisation suppression by delayed feedback control is higher than external time-periodic driving and activation of selected neurons of the cat's cerebral cortex with the same coupling strengths.

  7. Vibration suppression of composite laminated plate with nonlinear energy sink

    Science.gov (United States)

    Zhang, Ye-Wei; Zhang, Hao; Hou, Shuai; Xu, Ke-Fan; Chen, Li-Qun

    2016-06-01

    The composite laminated plate is widely used in supersonic aircraft. So, there are many researches about the vibration suppression of composite laminated plate. In this paper, nonlinear energy sink (NES) as an effective method to suppress vibration is studied. The coupled partial differential governing equations of the composite laminated plate with the nonlinear energy sink (NES) are established by using the Hamilton principle. The fourth-order Galerkin discrete method is used to truncate the partial differential equations, which are solved by numerical integration method. Meanwhile study about the precise effectiveness of the nonlinear energy sink (NES) by discussing the different installation location of the nonlinear energy sink (NES) at the same speed. The results indicate that the nonlinear energy sink (NES) can significantly suppress the severe vibration of the composite laminated plate with speed wind loadings in to protect the composite laminated plate from excessive vibration.

  8. Holographic Lifshitz fermions and exponentially suppressed spectral weight

    CERN Document Server

    Kim, Youngshin

    2016-01-01

    One of the unusual features of Lifshitz holography is the presence of a tunneling barrier that arises from the bulk geometry for probes carrying large transverse momentum. This leads to a decoupling of the horizon from the boundary, and in particular gives rise to an exponential suppression of spectral weight in the large transverse momentum limit. We compute the spin-1/2 holographic Green's function and show that this suppression has the same origin as in the scalar case. We furthermore demonstrate that the suppression factor is universal in the $\\hat\\omega\\to0$ limit where $\\hat\\omega=\\omega/|\\vec k|^z$. In particular, it depends only on $\\hat\\omega$ and the critical exponent $z$, and is independent of scaling dimension and spin.

  9. Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments

    CERN Document Server

    Cucoanes, Andi; Cabrera, Anatael; Fallot, Muriel; Onillon, Anthony; Obolensky, Michel; Yermia, Frederic

    2015-01-01

    This publication provides a coherent treatment for the reactor neutrino flux uncertainties suppression, specially focussed on the latest $\\theta_{13}$ measurement. The treatment starts with single detector in single reactor site, most relevant for all reactor experiments beyond $\\theta_{13}$. We demonstrate there is no trivial error cancellation, thus the flux systematic error can remain dominant even after the adoption of multi-detector configurations. However, three mechanisms for flux error suppression have been identified and calculated in the context of Double Chooz, Daya Bay and RENO sites. Our analysis computes the error {\\it suppression fraction} using simplified scenarios to maximise relative comparison among experiments. We have validated the only mechanism exploited so far by experiments to improve the precision of the published $\\theta_{13}$. The other two newly identified mechanisms could lead to total error flux cancellation under specific conditions and are expected to have major implications o...

  10. Subradiant spontaneous undulator emission through collective suppression of shot noise

    Science.gov (United States)

    Ratner, D.; Hemsing, E.; Gover, A.; Marinelli, A.; Nause, A.

    2015-05-01

    The phenomenon of Dicke's subradiance, in which the collective properties of a system suppress radiation, has received broad interest in atomic physics. Recent theoretical papers in the field of relativistic electron beams have proposed schemes to achieve subradiance through suppression of shot noise current fluctuations. The resulting "quiet" beam generates less spontaneous radiation than emitted even by a shot noise beam when oscillating in an undulator. Quiet beams could have diverse accelerator applications, including lowering power requirements for seeded free-electron lasers and improving efficiency of hadron cooling. In this paper we present experimental observation of a strong reduction in undulator radiation, demonstrating the feasibility of noise suppression as a practical tool in accelerator physics.

  11. Long-term health benefits of appetite suppressants remain unproven

    Directory of Open Access Journals (Sweden)

    Francisco José Roma Paumgartten

    2011-12-01

    Full Text Available Because of the increasing prevalence of obesity, prevention and treatment of overweight has become a major public health concern. In addition to diet and exercise, drugs are needed for patients who failed to lose weight with behavioral treatment. The current article aimed to summarize recent concerns on the safety and efficacy of appetite suppressants. Several appetite suppressants have been banned for safety reasons. In 2010, sibutramine was withdrawn from the market because a long-term study showed it increased the risks of cardiovascular events. So far no study with a sufficiently large sample size has demonstrated that appetite suppressants can reduce morbidity and mortality associated with overweight. The withdrawal of sibutramine highlights that guidelines for the evaluation of weight control drugs must be more stringent, and studies on their long-term health benefits are needed prior to their marketing.

  12. Suppression of extraneous thermal noise in cavity optomechanics

    CERN Document Server

    Zhao, Yi; Ni, Kang-Kuen; Kimble, H Jeff

    2011-01-01

    Extraneous thermal motion can limit displacement sensitivity and radiation pressure effects, such as optical cooling, in a cavity-optomechanical system. Here we present an active noise suppression scheme and its experimental implementation. The main challenge is to selectively sense and suppress extraneous thermal noise without affecting motion of the oscillator. Our solution is to monitor two modes of the optical cavity, each with different sensitivity to the oscillator's motion but similar sensitivity to the extraneous thermal motion. This information is used to imprint "anti-noise" onto the frequency of the incident laser field. In our system, based on a nano-mechanical membrane coupled to a Fabry-P\\'{e}rot cavity, simulation and experiment demonstrate that extraneous thermal noise can be selectively suppressed and that the associated limit on optical cooling can be reduced.

  13. Stimulus-dependent suppression of chaos in recurrent neural networks

    International Nuclear Information System (INIS)

    Neuronal activity arises from an interaction between ongoing firing generated spontaneously by neural circuits and responses driven by external stimuli. Using mean-field analysis, we ask how a neural network that intrinsically generates chaotic patterns of activity can remain sensitive to extrinsic input. We find that inputs not only drive network responses, but they also actively suppress ongoing activity, ultimately leading to a phase transition in which chaos is completely eliminated. The critical input intensity at the phase transition is a nonmonotonic function of stimulus frequency, revealing a 'resonant' frequency at which the input is most effective at suppressing chaos even though the power spectrum of the spontaneous activity peaks at zero and falls exponentially. A prediction of our analysis is that the variance of neural responses should be most strongly suppressed at frequencies matching the range over which many sensory systems operate.

  14. Study of Ion Back Flow suppression with thick COBRA GEM

    International Nuclear Information System (INIS)

    Ion Back Flow (IBF) suppression is essential to avoid a space-charge distortion of the electric field under a high rate condition in the Time Projection Chamber (TPC). A GEM technology is one possible solution to achieve a small IBF and to keep a good performance in terms of particle tracking and particle identification at high rates in TPC. We developed Thick COBRA GEMs to investigate the capability of further IBF suppression. It was found that the COBRA GEM can suppress IBF more effectively compared to a standard GEM. IBF reaches about 0.1–0.5% with a stack configuration consisting of one standard GEM facing to the drift field and two COBRA GEMs. In this paper, the current status of development of COBRA GEM is described

  15. CAREM 25: Suppression pool cooling and purification system

    International Nuclear Information System (INIS)

    The suppression pool cooling and purification system has the following main functions: purify and cool water from the suppression pool, cool and send water to the residual heat extraction system, and transfer water to the fuel element transference channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the suppression pool to the spray network, thus cooling and reducing pressure in the primary containment. The system has been designed in accordance with the requirements of the following standards: ANSI/ANS 52.1; ANSI/ANS 57.2; ANSI/ANS 56.2; ANSI/ANS 59.1; ANSI/ANS 58.3; ANSI/ANS 58.9; and ANSI/ANS 56.5. The design of the system fulfils all the assigned functions. (author)

  16. CAREM-25. Suppression Pool Cooling and Purification System

    International Nuclear Information System (INIS)

    The Suppression Pool Cooling and Purification System has the following main functions: purify and cool water from the Suppression Pool, cool and send water to the Residual Heat Extraction System, and transfer water to the Fuel Element Transference Channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the Suppression Pool to the spray network, thus cooling and reducing pressure in the primary containment.The system has been designed in accordance with the requirements of the following standards ANSI/ANS 52.1 [1], ANSI/ANS 57.2 [2], ANSI/ANS 56.2 [3], ANSI/ANS 59.1 [4] ANSI/ANS 58.3 [5], ANSI/ANS 58.9 [6], and ANSI/ANS 56.5 [7]. The design of the system fulfils all the assigned functions

  17. Thought suppression and treatment outcome in late-life depression.

    Science.gov (United States)

    Rosenthal, M Z; Cheavens, J S; Compton, J S; Thorp, S R; Lynch, T R

    2005-01-01

    This study examined severity of depression, age of onset, and thought suppression as predictors of treatment outcome. Measures were taken pre-treatment, post-treatment, and at six-month follow-up in 34 depressed older adults receiving the treatment protocol described in Lynch, Morse, Mendelson & Robins (Dialectical behavior therapy for depressed older adults, American Journal of Geriatric Psychiatry, 11, 33-45, 2003). Severity and chronicity of depression and higher levels of thought suppression were associated with higher depressive symptoms six months after treatment. Findings are consistent with research suggesting that severity and chronicity of depression predict poor clinical outcome. In addition, these results provide preliminary evidence that the tendency to cope with unwanted thoughts by deliberate attempts to not experience such thoughts may be an important pre-treatment predictor of outcome among depressed older adults. Larger studies are needed to explore whether thought suppression mediates long-term recovery from depression. PMID:15841830

  18. Technology Assessment of Dust Suppression Techniques Applied During Structural Demolition

    Energy Technology Data Exchange (ETDEWEB)

    Boudreaux, J.F.; Ebadian, M.A.; Williams, P.T.; Dua, S.K.

    1998-10-20

    Hanford, Fernald, Savannah River, and other sites are currently reviewing technologies that can be implemented to demolish buildings in a cost-effective manner. In order to demolish a structure properly and, at the same time, minimize the amount of dust generated from a given technology, an evaluation must be conducted to choose the most appropriate dust suppression technology given site-specific conditions. Thus, the purpose of this research, which was carried out at the Hemispheric Center for Environmental Technology (HCET) at Florida International University, was to conduct an experimental study of dust aerosol abatement (dust suppression) methods as applied to nuclear D and D. This experimental study targeted the problem of dust suppression during the demolition of nuclear facilities. The resulting data were employed to assist in the development of mathematical correlations that can be applied to predict dust generation during structural demolition.

  19. Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

    International Nuclear Information System (INIS)

    The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and 3H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by α-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S2 episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. 3H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system

  20. Noise Suppression for Dual-Energy CT Through Entropy Minimization.

    Science.gov (United States)

    Petrongolo, Michael; Zhu, Lei

    2015-11-01

    In dual energy CT (DECT), noise amplification during signal decomposition significantly limits the utility of basis material images. Since clinically relevant objects typically contain a limited number of different materials, we propose an Image-domain Decomposition method through Entropy Minimization (IDEM) for noise suppression in DECT. Pixels of decomposed images are first linearly transformed into 2D clusters of data points, which are highly asymmetric due to strong signal correlation. An optimal axis is identified in the 2D space via numerical search such that the projection of data clusters onto the axis has minimum entropy. Noise suppression is performed on each image pixel by estimating the center-of-mass value of each data cluster along the direction perpendicular to the projection axis. The IDEM method is distinct from other noise suppression techniques in that it does not suppress pixel noise by reducing spatial variation between neighboring pixels. As supported by studies on Catphan©600 and anthropomorphic head phantoms, this feature endows our algorithm with a unique capability of reducing noise standard deviation on DECT decomposed images by approximately one order of magnitude while preserving spatial resolution and image noise power spectra (NPS). Compared with a filtering method and recently developed iterative method at the same level of noise suppression, the IDEM algorithm obtains high-resolution images with less artifacts. It also maintains accuracy of electron density measurements with less than 2% bias error. The IDEM method effectively suppresses noise of DECT for quantitative use, with appealing features on preservation of image spatial resolution and NPS. PMID:25955585

  1. Genetic identification of a neural circuit that suppresses appetite.

    Science.gov (United States)

    Carter, Matthew E; Soden, Marta E; Zweifel, Larry S; Palmiter, Richard D

    2013-11-01

    Appetite suppression occurs after a meal and in conditions when it is unfavourable to eat, such as during illness or exposure to toxins. A brain region proposed to play a role in appetite suppression is the parabrachial nucleus, a heterogeneous population of neurons surrounding the superior cerebellar peduncle in the brainstem. The parabrachial nucleus is thought to mediate the suppression of appetite induced by the anorectic hormones amylin and cholecystokinin, as well as by lithium chloride and lipopolysaccharide, compounds that mimic the effects of toxic foods and bacterial infections, respectively. Hyperactivity of the parabrachial nucleus is also thought to cause starvation after ablation of orexigenic agouti-related peptide neurons in adult mice. However, the identities of neurons in the parabrachial nucleus that regulate feeding are unknown, as are the functionally relevant downstream projections. Here we identify calcitonin gene-related peptide-expressing neurons in the outer external lateral subdivision of the parabrachial nucleus that project to the laterocapsular division of the central nucleus of the amygdala as forming a functionally important circuit for suppressing appetite. Using genetically encoded anatomical, optogenetic and pharmacogenetic tools, we demonstrate that activation of these neurons projecting to the central nucleus of the amygdala suppresses appetite. In contrast, inhibition of these neurons increases food intake in circumstances when mice do not normally eat and prevents starvation in adult mice whose agouti-related peptide neurons are ablated. Taken together, our data demonstrate that this neural circuit from the parabrachial nucleus to the central nucleus of the amygdala mediates appetite suppression in conditions when it is unfavourable to eat. This neural circuit may provide targets for therapeutic intervention to overcome or promote appetite. PMID:24121436

  2. Suppression of oscillations in mean-field diffusion

    Indian Academy of Sciences (India)

    Neeraj Kumar Kamal; Pooja Rani Sharma; Manish Dev Shrimali

    2015-02-01

    We study the role of mean-field diffusive coupling on suppression of oscillations for systems of limit cycle oscillators. We show that this coupling scheme not only induces amplitude death (AD) but also oscillation death (OD) in coupled identical systems. The suppression of oscillations in the parameter space crucially depends on the value of mean-field diffusion parameter. It is also found that the transition from oscillatory solutions to OD in conjugate coupling case is different from the case when the coupling is through similar variable. We rationalize our study using linear stability analysis.

  3. Overnight Dexamethasone Suppression Test in the Diagnosis of Cushing's Disease

    Directory of Open Access Journals (Sweden)

    Fatemeh Esfahanian

    2010-08-01

    Full Text Available Realizing the cause of Cushing's Syndrome (CS is one of the most challenging processes in clinical endocrinology. The long high dose dexamethasone suppression test (standard test is costly and need an extended inpatient stay. In this study we want to show the clinical utility of the overnight 8 mg dexamethasone suppression test (DST for differential diagnosis of CS in a referral center. Retrospectively from 2002-2005 we selected the patients of endocrinology ward in Imam hospital who were admitted with the diagnosis of Cushing syndrome and had 8 mg DST (modified test along with classic DST. In modified test a decrease in an 8 AM serum cortisol level of 50% or more is thought to indicate suppression and we compared the results of modified test with standard test. This test had been done on 42 patients: 10 male (23% and 32 female (76%. The mean age of patients was 31.39 (15-63, 32 with proven pituitary Cushing's disease, 7 with primary adrnal tumors and 3 with ectopic ACTH syndrome. The standard test according to 50% suppression of UFC had 90.62% sensitivity, and according to 90% suppression had 43.75% sensitivity. The sensitivity of this test was 71.85% for serum cortisol suppression. The modified test (8 mg overnight DST had 78% sensitivity. All of these tests had 100% specificity for the diagnosis of Cushing's disease. The positive predictive vale (PPV of all of these tests was 100%. The negative predictive value (NPV of modified test for the diagnosis of Cushing's disease was 58.82%. In standard test the NPV of serum cortisol was 52.6%, UFC 50% had 76.9% NPV and UFC 90% had 35.7% NPV. The results of serum cortisol suppression in modified test is better than standard test. Although 50% suppression of UFC in standard test had greater sensitivity than modified test, collecting of urine is difficult, time consuming and needing hospitalization, so we advice modified test that is much simpler and more convenient instead of standard test in the first

  4. Molecular mechanisms of growth suppression by pharmacologically activated p53

    OpenAIRE

    Hedström, Elisabeth

    2009-01-01

    The tumor suppressor p53 is a transcription factor that is crucial for protecting cells from cancer development. The importance of p53 tumor suppression function is highlighted by the fact that the p53 pathway is inactivated in most, if not all cancers. Mutation of the p53 gene occurs in about 50% of all tumors, whereas in the tumors which retain wild-type p53, the function of p53 is abolished due to deregulation of the p53 pathway. Due to the potency of p53 in suppressing t...

  5. Strong-field-ionization suppression by light-field control

    DEFF Research Database (Denmark)

    Räsänen, Esa; Madsen, Lars Bojer

    2012-01-01

    In recent attempts to control strong-field phenomena such as molecular dissociation, undesired ionization sometimes seriously limited the outcome. In this work we examine the capability of quantum optimal control theory to suppress the ionization by rational pulse shaping. Using a simple model...... system and the ground-state occupation as the target functional, we show that optimal control generally leads to a significant suppression of the ionization, although the fluence and the pulse length are kept fixed. In the low-frequency regime the ionization is reduced mainly by avoiding high peaks in...

  6. Suppressing the QCD axion abundance by hidden monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Masahiro [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Takahashi, Fuminobu [Tokyo Univ., Miyagi (Japan). Dept. of Physics; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Yamada, Masaki [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; DESY Hamburg (Germany)

    2015-11-15

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10{sup 12} GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  7. Enhanced J/$\\psi$ suppression due to gluon depletion

    CERN Document Server

    Hwa, R C; Pisútová, N

    1998-01-01

    The nonlinear effect of gluon depletion in the collision of large nuclei can be large. It is due to multiple scatterings among comoving partons initiated by primary scattering of partons in the colliding nuclei. The effect can give rise to substantial suppression of $J/\\psi$ production in very large nuclei, even if the linear depletion effect is insignificant for the collisions of nuclei of smaller sizes. This mechanism offers a natural explanation of the enhanced suppression in the Pb-Pb data recently observed by NA50.

  8. Social class affects Mu-suppression during action observation.

    Science.gov (United States)

    Varnum, Michael E W; Blais, Chris; Brewer, Gene A

    2016-08-01

    Socioeconomic status (SES) has been linked to differences in the degree to which people are attuned to others. Those who are lower in SES also tend to be more interpersonally attuned. However, to date, this work has not been demonstrated using neural measures. In the present electroencephalogram study, we found evidence that lower SES was linked to stronger Mu-suppression during action observation. This finding adds to the growing literature on factors that affect Mu-suppression and suggests that the mirror neuron system may be influenced by one's social class. PMID:26458132

  9. Thermopower signatures and spectroscopy of the canyon of conductance suppression

    Science.gov (United States)

    Kiršanskas, G.; Hammarberg, S.; Karlström, O.; Wacker, A.

    2016-07-01

    Interference effects in quantum dots between different transport channels can lead to a strong suppression of conductance, which cuts like a canyon through the common conductance plot [Phys. Rev. Lett. 104, 186804 (2010), 10.1103/PhysRevLett.104.186804]. In the present work we consider the thermoelectric transport properties of the canyon of conductance suppression using the second-order von Neumann approach. We observe a characteristic signal for the zeros of the thermopower. This demonstrates that thermoelectric measurements are an interesting complimentary tool to study complex phenomena for transport through confined systems.

  10. Suppression of 0ν2β decay from CP violation

    International Nuclear Information System (INIS)

    The observed phenomenon of neutrino oscillations is interpreted as the proof that neutrinos must have mass. As this is true for the neutrinos in the mass basis, the mass matrix in the flavor (weak) basis may still contain zeros. This can happen if the CP violating phases, usually neglected, come into play and result in suppression of processes which half-life depends on the masses of νe, νμ, or ντ. In the present paper we investigate the possibility of such suppression of the neutrinoless double beta decay (0ν2β). (author)

  11. Suppressing proton decay in theories with localised fermions

    International Nuclear Information System (INIS)

    We calculate the contribution to the proton decay amplitude from Kaluza-Klein lepto-quarks in theories with extra dimensions, localised fermions and gauge fields which propagate in the bulk. Such models naturally occur within the context of M theory. In SU(5) models we show that carefully including all such modes gives a distinctive pattern of decays through various channels including a strong suppression of decays into neutrinos or right handed positrons. By contrast there is no such suppression for SO(10). (author)

  12. Applications of a Compton suppression spectrometer in nuclear spectroscopy

    International Nuclear Information System (INIS)

    This thesis describes some studies in nuclear physics performed with a Compton-suppression spectrometer. Examples are given in three different research areas: an investigation of a decay to an odd-odd nucleus, an investigation of high-spin states excited by a nuclear reaction, and an investigation of nuclear excitation as a result of pion capture. Besides the measurements with the suppression spectrometer, γ-γ-time coincidence measurements and conversion-electron measurements were also performed. Theoretical interpretations of the experimental results are given. (Auth.)

  13. Alumina Paste Sublimation Suppression Barrier for Thermoelectric Device

    Science.gov (United States)

    Paik, Jong-Ah (Inventor); Caillat, Thierry (Inventor)

    2014-01-01

    Alumina as a sublimation suppression barrier for a Zintl thermoelectric material in a thermoelectric power generation device operating at high temperature, e.g. at or above 1000K, is disclosed. The Zintl thermoelectric material may comprise Yb.sub.14MnSb.sub.11. The alumina may be applied as an adhesive paste dried and cured on a substantially oxide free surface of the Zintl thermoelectric material and polished to a final thickness. The sublimation suppression barrier may be finalized by baking out the alumina layer on the Zintl thermoelectric material until it becomes substantially clogged with ytterbia.

  14. Development of underwater surface inspection system for BWR suppression chamber

    International Nuclear Information System (INIS)

    In order to inspect underwater paints surface of BWR suppression chamber as an in-service inspection, the underwater surface inspection system has been developed, which consists of magnetic crawler, crud recovery nozzles and special camera unit. The system can move on wall surface of pressure suppression chamber with magnetic crawler to inspect surface paints films under the muddy water with special camera unit after removing surface cruds. Based on inspection results, the paint films inspection criteria to assess degradation of paints films were proposed. (T. Tanaka)

  15. Bifurcation suppression of nonlinear systems via dynamic output feedback and its applications to rotating stall control

    Institute of Scientific and Technical Information of China (English)

    Pengnian CHEN; Huashu QIN; Shengwei MEI

    2005-01-01

    This paper deals with the problems of bifurcation suppression and bifurcation suppression with stability of nonlinear systems. Necessary conditions and sufficient conditions for bifurcation suppression via dynamic output feedback are presented;Sufficient conditions for bifurcation suppression with stability via dynamic output feedback are obtained. As an application, a dynamic compensator, which guarantees that the bifurcation point of rotating stall in axial flow compressors is stably suppressed, is constructed.

  16. Emotional suppression and well-being in immigrants and majority group members in the Netherlands

    OpenAIRE

    Stupar, S.; van de Vijver, FJR; Fontaine, Johnny

    2014-01-01

    We were interested in interethnic differences in emotional suppression. We propose a model in which suppression of specific emotional experiences (suppressive behaviours during interactions with others) mediates the relationship between emotional suppression tendency (intention to suppress emotions) and well-being, operationalised as mood disturbance, life dissatisfaction and depressive and physical symptoms. The sample consisted of 427 majority group members and 344 non-Western and 465 Weste...

  17. Perfluorooctanoic Acid Exposure Suppresses T-independent Antibody Responses

    Science.gov (United States)

    Exposure to  3.75mg/kg of perfluoroocatnoic acid (PFOA) for 15d suppresses T-dependent antibody responses (TDAR), suggesting that T helper cells and/or B cells/plasma cells may be impacted. This study evaluated effects of PFOA exposure on the T cell-independent antibody response...

  18. Quantum origin of suppression for vacuum fluctuations of energy

    Science.gov (United States)

    Balitsky, Ja. V.; Kiselev, V. V.

    2014-12-01

    By using a model with a spatially global scalar field, we show that the energy density of zero-point modes is exponentially suppressed by an average number of field quanta in a finite volume with respect to the energy density in the stationary state of minimal energy. We describe cosmological implications of the mechanism.

  19. Maturation of cognitive control: delineating response inhibition and interference suppression.

    Directory of Open Access Journals (Sweden)

    Christopher R Brydges

    Full Text Available Cognitive control is integral to the ability to attend to a relevant task whilst suppressing distracting information or inhibiting prepotent responses. The current study examined the development of these two subprocesses by examining electrophysiological indices elicited during each process. Thirteen 18 year-old adults and thirteen children aged 8-11 years (mean=9.77 years completed a hybrid Go/Nogo flanker task while continuous EEG data were recorded. The N2 topography for both response inhibition and interference suppression changed with increasing age. The neural activation associated with response inhibition became increasingly frontally distributed with age, and showed decreases of both amplitude and peak latency from childhood to adulthood, possibly due to reduced cognitive demands and myelination respectively occurring during this period. Interestingly, a significant N2 effect was apparent in adults, but not observed in children during trials requiring interference suppression. This could be due to more diffuse activation in children, which would require smaller levels of activation over a larger region of the brain than is reported in adults. Overall, these results provide evidence of distinct maturational processes occurring throughout late childhood and adolescence, highlighting the separability of response inhibition and interference suppression.

  20. Intravenous lidocaine as a suppressant of coughing during tracheal intubation.

    Science.gov (United States)

    Yukioka, H; Yoshimoto, N; Nishimura, K; Fujimori, M

    1985-12-01

    Effects of intravenously administered lidocaine on cough suppression during tracheal intubation under general anesthesia were evaluated in two studies. In study 1, 100 patients received either a placebo or 0.5, 1.0, 1.5, or 2.0 mg/kg lidocaine intravenously 1 min before tracheal intubation. All visible coughs were classified as coughing. The incidence of coughing decreased as the dose of lidocaine increased. A dose of 1 mg/kg or more of intravenous lidocaine suppressed the cough reflex significantly (P less than 0.01). Coughing was suppressed completely by 2 mg/kg of intravenous lidocaine. In study 2, 108 patients received 2 mg/kg lidocaine intravenously or a placebo 1, 3, 5, 7, 10, or 15 min before intubation. The same criteria for determining whether a patient did or did not cough during tracheal intubation were used as in study 1. The incidence of coughing decreased significantly (P less than 0.01) when 2 mg/kg of lidocaine was injected intravenously between 1 and 5 min before our attempting intubation. Cough reflex was suppressed completely by plasma concentrations of lidocaine in excess of 3 micrograms/ml. PMID:4061901

  1. Using multiple perspectives to suppress information and complexity

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, R.L. [Los Alamos National Lab., NM (US)]|[New Mexico State Univ., Las Cruces, NM (US). Computer Science Dept.; Webster, R.B. [Los Alamos National Lab., NM (US); Hartley, R.T. [New Mexico State Univ., Las Cruces, NM (US). Computer Science Dept.

    1998-09-01

    Dissemination of battlespace information involves getting information to particular warfighters that is both useful and in a form that facilitates the tasks of those particular warfighters. There are two issues which motivate this problem of dissemination. The first issue deals with disseminating pertinent information to a particular warfighter. This can be thought of as information suppression. The second issue deals with facilitating the use of the information by tailoring the computer interface to the specific tasks of an individual warfighter. This can be thought of as interface complexity suppression. This paper presents a framework for suppressing information using an object-based knowledge representation methodology. This methodology has the ability to represent knowledge and information in multiple perspectives. Information can be suppressed by creating a perspective specific to an individual warfighter. In this way, only the information pertinent and useful to a warfighter is made available to that warfighter. Information is not removed, lost, or changed, but spread among multiple perspectives. Interface complexity is managed in a similar manner. Rather than have one generalized computer interface to access all information, the computer interface can be divided into interface elements. Interface elements can then be selected and arranged into a perspective-specific interface. This is done in a manner to facilitate completion of tasks contained in that perspective. A basic battlespace domain containing ground and air elements and associated warfighters is used to exercise the methodology.

  2. Sequential Analysis of the Numerical Stroop Effect Reveals Response Suppression

    Science.gov (United States)

    Kadosh, Roi Cohen; Gevers, Wim; Notebaert, Wim

    2011-01-01

    Automatic processing of irrelevant stimulus dimensions has been demonstrated in a variety of tasks. Previous studies have shown that conflict between relevant and irrelevant dimensions can be reduced when a feature of the irrelevant dimension is repeated. The specific level at which the automatic process is suppressed (e.g., perceptual repetition,…

  3. Rudder gap cavitation: Fundamental understanding and its suppression devices

    International Nuclear Information System (INIS)

    With the increasing size and speed of cargo ships, which results in high speed flow in propeller slipstream, cavitation is frequently observed on and around the rudder system. Among the various types of cavitation on the rudder system, the rudder gap cavitation is the most difficult one to control and suppress. For the development of rudder gap cavitation suppression devices, both experimental and numerical analyses of the physical phenomenon are warranted. In the present study, experiments of the incipient cavitation and pressure measurement were carried out for typical cargo ship rudder sections with and without the suppression devices, which were suggested by the author. The experiments were simulated using computational fluid dynamics tools and the results were compared in terms of the cavitation inception and surface pressure distribution. Fundamental understanding of the rudder gap cavitation inception was obtained along with its relevance to the surface pressure distribution. It is confirmed that the gap flow blocking devices effectively suppress the rudder gap cavitation and, at the same time, augment lift.

  4. Fission-suppressed hybrid reactor: the fusion breeder

    International Nuclear Information System (INIS)

    Results of a conceptual design study of a 233U-producing fusion breeder are presented. The majority of the study was devoted to conceptual design and evaluation of a fission-suppressed blanket and to fuel cycle issues such as fuel reprocessing, fuel handling, and fuel management. Studies in the areas of fusion engineering, reactor safety, and economics were also performed

  5. Suppression of the two-neutrino double β decay

    International Nuclear Information System (INIS)

    Two-neutrino ββ decay rates of 76Ge, 82Se, 128,130Te are calculated in the quasi-particle random phase approximation using a realistic effective NN interaction. The decays are strongly suppressed, in agreement with the experimental data, when a reasonable amount of particle-particle interaction is taken into account. (orig.)

  6. Compton continuum suppression by digital pulse shape analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aspacher, B. (Univ. of Florida, Inst. for Astrophysics and Planetary Exploration, Alachua, FL (United States)); Coldwell, R.L. (Univ. of Florida, Inst. for Astrophysics and Planetary Exploration, Alachua, FL (United States)); Rester, A.C. (Univ. of Florida, Inst. for Astrophysics and Planetary Exploration, Alachua, FL (United States))

    1993-06-10

    We present experimental results on a technique for flattening the Compton edges and suppressing the Compton continuum in gamma ray spectra with digital pulse shape analysis. The peak-to-Compton ratio can be improved by more than a factor 2. (orig.)

  7. Compton continuum suppression by digital pulse shape analysis

    International Nuclear Information System (INIS)

    We present experimental results on a technique for flattening the Compton edges and suppressing the Compton continuum in gamma ray spectra with digital pulse shape analysis. The peak-to-Compton ratio can be improved by more than a factor 2. (orig.)

  8. Matairesinol inhibits angiogenesis via suppression of mitochondrial reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Boram; Kim, Ki Hyun; Jung, Hye Jin [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer Matairesinol suppresses mitochondrial ROS generation during hypoxia. Black-Right-Pointing-Pointer Matairesinol exhibits potent anti-angiogenic activity both in vitro and in vivo. Black-Right-Pointing-Pointer Matairesinol could be a basis for the development of novel anti-angiogenic agents. -- Abstract: Mitochondrial reactive oxygen species (mROS) are involved in cancer initiation and progression and function as signaling molecules in many aspects of hypoxia and growth factor-mediated signaling. Here we report that matairesinol, a natural small molecule identified from the cell-based screening of 200 natural plants, suppresses mROS generation resulting in anti-angiogenic activity. A non-toxic concentration of matairesinol inhibited the proliferation of human umbilical vein endothelial cells. The compound also suppressed in vitro angiogenesis of tube formation and chemoinvasion, as well as in vivo angiogenesis of the chorioallantoic membrane at non-toxic doses. Furthermore, matairesinol decreased hypoxia-inducible factor-1{alpha} in hypoxic HeLa cells. These results demonstrate that matairesinol could function as a novel angiogenesis inhibitor by suppressing mROS signaling.

  9. String Clustering and J/Psi Suppression in Nuclear Collisions

    OpenAIRE

    Nardi, M; Satz, H.

    1998-01-01

    We study the clustering of colour strings in the transverse plane of nucleus-nucleus collisions and argue that deconfinement sets in when the string density within a cluster reaches a critical value. We show that this implies a minimal cluster size at the onset of deconfinement, which in turn results in discontinuous behaviour for J/Psi suppression.

  10. Suppression Pool Mixing and Condensation Tests in PUMA Facility

    International Nuclear Information System (INIS)

    Condensation of steam with non-condensable in the form of jet flow or bubbly flow inside the suppression pool is an important phenomenon on determining the containment pressure of a passively safe boiling water reactor. 32 cases of pool mixing and condensation test have been performed in Purdue University Multi-Dimensional Integral Test Assembly (PUMA) facility under the sponsor of the U.S. Nuclear Regulatory Commission to investigate thermal stratification and pool mixing inside the suppression pool during the reactor blowdown period. The test boundary conditions, such as the steam flow rate, the noncondensable gas flow rate, the initial water temperature, the pool initial pressure and the vent opening submergence depth, which covers a wide range of prototype (SBWR-600) conditions during Loss of Coolant Accident (LOCA) were obtained from the RELAP5 calculation. The test results show that steam is quickly condensed at the exit of the vent opening. For pure steam injection or low noncondensable injection cases, only the portion above the vent opening in the suppression pool is heated up by buoyant plumes. The water below the vent opening can be heated up slowly through conduction. The test results also show that the degree of thermal stratification in suppression pool is affected by the vent opening submergence depth, the pool initial pressure and the steam injection rate. And it is slightly affected by the initial water temperature. From these tests it is concluded that the pool mixing is strongly affected by the noncondensable gas flow rate. (authors)

  11. Nicotinamide Cofactors Suppress Active-Site Labeling of Aldehyde Dehydrogenases.

    Science.gov (United States)

    Stiti, Naim; Chandrasekar, Balakumaran; Strubl, Laura; Mohammed, Shabaz; Bartels, Dorothea; van der Hoorn, Renier A L

    2016-06-17

    Active site labeling by (re)activity-based probes is a powerful chemical proteomic tool to globally map active sites in native proteomes without using substrates. Active site labeling is usually taken as a readout for the active state of the enzyme because labeling reflects the availability and reactivity of active sites, which are hallmarks for enzyme activities. Here, we show that this relationship holds tightly, but we also reveal an important exception to this rule. Labeling of Arabidopsis ALDH3H1 with a chloroacetamide probe occurs at the catalytic Cys, and labeling is suppressed upon nitrosylation and oxidation, and upon treatment with other Cys modifiers. These experiments display a consistent and strong correlation between active site labeling and enzymatic activity. Surprisingly, however, labeling is suppressed by the cofactor NAD(+), and this property is shared with other members of the ALDH superfamily and also detected for unrelated GAPDH enzymes with an unrelated hydantoin-based probe in crude extracts of plant cell cultures. Suppression requires cofactor binding to its binding pocket. Labeling is also suppressed by ALDH modulators that bind at the substrate entrance tunnel, confirming that labeling occurs through the substrate-binding cavity. Our data indicate that cofactor binding adjusts the catalytic Cys into a conformation that reduces the reactivity toward chloroacetamide probes. PMID:26990764

  12. Calebin A downregulates osteoclastogenesis through suppression of RANKL signalling.

    Science.gov (United States)

    Tyagi, Amit K; Prasad, Sahdeo; Majeed, Muhammed; Aggarwal, Bharat B

    2016-03-01

    Osteoporosis is a bone disease that is exacerbated by aging and age-associated chronic diseases such as cancer. Cancer-induced bone loss is usually treated with bisphosphonates or denosumab, an antibody against receptor activator of nuclear factor (NF)-κB ligand (RANKL). Because these drugs are expensive and have numerous side effects and high rates of toxicity, safer, more effective, and more affordable therapies for osteoporosis are still needed. We identified a compound, calebin A (CA), derived from turmeric (Curcuma longa) that affects osteoclastogenesis through modulation of the RANKL signalling pathway. The CA's effect on NF-κB activation was examined by electrophoretic mobility shift assay. Using mouse macrophages in vitro model, we found that CA suppressed RANKL-induced osteoclast differentiation of macrophages into osteoclasts, and downregulate RANKL-induced osteoclastogenesis-related marker gene expression, including NFATc-1, TRAP, CTR, and cathepsin K. CA also suppressed the osteoclastogenesis induced by multiple myeloma and breast cancer cells. This effect of CA was correlated with suppression of the phosphorylation and degradation of inhibitor of κB and, thus, inhibition of NF-κB activation. Furthermore, we found that an NF-κB-specific inhibitory peptide blocked RANKL-induced osteoclastogenesis, demonstrating that the NF-κB signalling pathway is mandatory for RANKL-induced osteoclastogenesis. Our results conclusively indicate that CA downmodulates the osteoclastogenesis induced by RANKL and by tumour cells through suppression of NF-κB pathway. PMID:26874195

  13. Fission-suppressed hybrid reactor: the fusion breeder

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.; Lee, J.D.; Coops, M.S.

    1982-12-01

    Results of a conceptual design study of a /sup 233/U-producing fusion breeder are presented. The majority of the study was devoted to conceptual design and evaluation of a fission-suppressed blanket and to fuel cycle issues such as fuel reprocessing, fuel handling, and fuel management. Studies in the areas of fusion engineering, reactor safety, and economics were also performed.

  14. Unidirectional Suppression of Anaplasma phagocytophilum Genotypes in Infected Lambs

    OpenAIRE

    Stuen, Snorre; Dahl, Hilde; Bergström, Karin; Moum, Truls

    2005-01-01

    Five-month-old lambs were simultaneously infected with different doses of two 16S rRNA genetic variants of Anaplasma phagocytophilum and thereafter followed for clinical observation and blood sampling. The result of the study indicates a unidirectional suppression of genotypes in infected lambs, at least during a certain period of an A. phagocytophilum infection.

  15. Discovery and early development of non-suppressed ion chromatography.

    Science.gov (United States)

    Fritz, James S; Gjerde, Douglas T

    2010-08-01

    This year marks the 30th anniversary of the publication of Non-Suppressed Ion Chromatography, which is a method for the rapid separation of anions with on-line conductimetric detection. In this method, the separation column is connected directly to the conductimetric detector. This single-column method is a simpler technique than the original suppressed ion chromatography method, which requires a large suppressor column to reduce the background conductance. In the new method, the background signal is reduced to a manageable level simply by using an ion-exchange separation column of low exchange capacity that lowers the eluent concentration needed for separation. The eluent ion used for separation is chosen based on having large, bulky structure, which lowers the equivalent conductance and facilitates detection of the sample anions. This is a personal account of the initial discovery and early development of non-suppressed ion chromatography. The circumstances for the discovery are recounted by the two authors. Methods are described for determination of anions, cations with indirect detection, and techniques for increasing detection sensitivity. A fundamental equation for the prediction of ion chromatography detector response is given, and the development of several types of detection schemes for ion chromatography is discussed. Finally, the impact of non-suppressed ion chromatography is discussed together with comments on the discovery process. PMID:20819275

  16. Modeling pressure suppression pool hydrodynamics in the ABWR containment

    International Nuclear Information System (INIS)

    Highlights: → Developed mechanistic model for prediction of suppression pool hydrodynamics parameters. → Vent clearance time, pool swell height, and bubble breakthrough elevation predicted within 10% of the experimental data. → Performed assessment of pressure suppression pool hydrodynamics in ABWR. → Reasonable agreement obtained between the model predictions and the licensing analyses. - Abstract: This paper focuses on the assessment of pressure suppression pool hydrodynamics in the advanced boiling water reactor (ABWR) containment under design-basis, loss-of-coolant accident (LOCA) conditions. The paper presents a mechanistic model for predicting various suppression pool hydrodynamics parameters. A phenomena identification and ranking table (PIRT) applicable to the ABWR containment pool hydrodynamics analysis is used as a basis for the development of the model. The highly ranked phenomena are represented by analytic equations or empirical correlations. The best estimate and several sensitivity calculations are performed for the ABWR containment using this model. Results of the sensitivity calculations are also presented that demonstrate the influence of key model parameters and assumptions on the pool hydrodynamics parameters. A comparison of model predictions to the results of the licensing analyses shows reasonable agreement. Comparison of the results of the proposed model to experimental data shows that the model predicted top vent clearance time, the pool swell height, and the bubble breakthrough elevation are within 10% of the data. The predicted pool surface velocity and the liquid slug thickness are within 30% of the measurements, which is considered adequate given the large uncertainties in the experimental measurements.

  17. Surface superconductivity and order parameter suppression in UPt$_3$

    OpenAIRE

    Agterberg, D. F.; Walker, M. B.

    1995-01-01

    We show that a recent measurement of surface superconductivity in UPt$_3$ (Keller {\\it et. al.}, Phys. Rev. Lett. {\\bf 73}, 2364 (1994)) can be understood if the superconducting pair wavefunction is suppressed anisotropically at a vacuum to superconductor interface. Further measurements of surface superconductivity can distinguish between the various phenomenological models of superconducting UPt$_3$.

  18. Managing Abiotic Factors of Compost to Increase Soilborne Disease Suppression

    Science.gov (United States)

    Griffin, Deirdre E.

    2012-01-01

    Soilborne pathogens can devastate crops, causing economic losses for farmers due to reduced yields and expensive management practices. Fumigants and fungicides have harmful impacts on the surrounding environment and can be toxic to humans. Therefore, alternative methods of disease management are important. The disease suppressive abilities of…

  19. Suppression of Pest Lepidoptera by Releasing Partially Sterile Males

    Science.gov (United States)

    Knipling. E. F.

    1970-01-01

    Uses population growth models to calculate the theoretical suppression of reproduction achieved by releasing irradiated male moths carrying genetic sterility factors. Shows that releasing partially sterile males should be more effective than releasing fully sterile males. Discusses the costs and advantages of applying this approach to the control…

  20. Rosmarinus officinalis extract suppresses Propionibacterium acnes-induced inflammatory responses.

    Science.gov (United States)

    Tsai, Tsung-Hsien; Chuang, Lu-Te; Lien, Tsung-Jung; Liing, Yau-Rong; Chen, Wei-Yu; Tsai, Po-Jung

    2013-04-01

    Propionibacterium acnes is a key pathogen involved in the progression of acne inflammation. The development of a new agent possessing antimicrobial and anti-inflammatory activity against P. acnes is therefore of interest. In this study, we investigated the inhibitory effect of rosemary (Rosmarinus officinalis) extract on P. acnes-induced inflammation in vitro and in vivo. The results showed that ethanolic rosemary extract (ERE) significantly suppressed the secretion and mRNA expression of proinflammatory cytokines, including interleukin (IL)-8, IL-1β, and tumor necrosis factor-α in P. acnes-stimulated monocytic THP-1 cells. In an in vivo mouse model, concomitant intradermal injection of ERE attenuated the P. acnes-induced ear swelling and granulomatous inflammation. Since ERE suppressed the P. acnes-induced nuclear factor kappa-B (NF-κB) activation and mRNA expression of Toll-like receptor (TLR) 2, the suppressive effect of ERE might be due, at least partially, to diminished NF-κB activation and TLR2-mediated signaling pathways. Furthermore, three major constituents of ERE, carnosol, carnosic acid, and rosmarinic acid, exerted different immumodulatory activities in vitro. In brief, rosmarinic acid significantly suppressed IL-8 production, while the other two compounds inhibited IL-1β production. Further study is needed to explore the role of bioactive compounds of rosemary in mitigation of P. acnes-induced inflammation. PMID:23514231

  1. Expectation Suppression in Early Visual Cortex Depends on Task Set

    Science.gov (United States)

    St. John-Saaltink, Elexa; Utzerath, Christian; Kok, Peter; Lau, Hakwan C.; de Lange, Floris P.

    2015-01-01

    Stimulus expectation can modulate neural responses in early sensory cortical regions, with expected stimuli often leading to a reduced neural response. However, it is unclear whether this expectation suppression is an automatic phenomenon or is instead dependent on the type of task a subject is engaged in. To investigate this, human subjects were presented with visual grating stimuli in the periphery that were either predictable or non-predictable while they performed three tasks that differently engaged cognitive resources. In two of the tasks, the predictable stimulus was task-irrelevant and spatial attention was engaged at fixation, with a high load on either perceptual or working memory resources. In the third task, the predictable stimulus was task-relevant, and therefore spatially attended. We observed that expectation suppression is dependent on the cognitive resources engaged by a subjects’ current task. When the grating was task-irrelevant, expectation suppression for predictable items was visible in retinotopically specific areas of early visual cortex (V1-V3) during the perceptual task, but it was abolished when working memory was loaded. When the grating was task-relevant and spatially attended, there was no significant effect of expectation in early visual cortex. These results suggest that expectation suppression is not an automatic phenomenon, but dependent on attentional state and type of available cognitive resources. PMID:26098331

  2. Economic Analysis of a Traveling Gun for Feedyard Dust Suppression

    OpenAIRE

    Amosson, Stephen H.; Bretz, Fran E.; New, Leon L.; Almas, Lal K.

    2007-01-01

    Dust created in feedyards can adversely affect cattle performance. Dust suppression can be accomplished by moistening pen surfaces with traveling gun(s) sprinklers, solid-set sprinklers, and water trucks. This study specifically addresses the fixed and operational costs associated with a traveling gun sprinkler system for various sized feedyards.

  3. Matairesinol inhibits angiogenesis via suppression of mitochondrial reactive oxygen species

    International Nuclear Information System (INIS)

    Highlights: ► Matairesinol suppresses mitochondrial ROS generation during hypoxia. ► Matairesinol exhibits potent anti-angiogenic activity both in vitro and in vivo. ► Matairesinol could be a basis for the development of novel anti-angiogenic agents. -- Abstract: Mitochondrial reactive oxygen species (mROS) are involved in cancer initiation and progression and function as signaling molecules in many aspects of hypoxia and growth factor-mediated signaling. Here we report that matairesinol, a natural small molecule identified from the cell-based screening of 200 natural plants, suppresses mROS generation resulting in anti-angiogenic activity. A non-toxic concentration of matairesinol inhibited the proliferation of human umbilical vein endothelial cells. The compound also suppressed in vitro angiogenesis of tube formation and chemoinvasion, as well as in vivo angiogenesis of the chorioallantoic membrane at non-toxic doses. Furthermore, matairesinol decreased hypoxia-inducible factor-1α in hypoxic HeLa cells. These results demonstrate that matairesinol could function as a novel angiogenesis inhibitor by suppressing mROS signaling.

  4. Hemodilution, vasopressin suppression, and diuresis during water immersion in man

    Science.gov (United States)

    Greenleaf, J. E.; Keil, L. C.; Shvartz, E.

    1981-01-01

    The possible role of hemodilution in the early stages of water immersion in the suppression of antidiuretic hormone (vasopressin) and subsequent diuresis in man is investigated. Parameters characterizing hemodilution as well as water balance and intercompartmental fluid levels were measured before, during and after the immersion of ten subjects in a semireclining position in tap water up to their necks at 34.6 C for 8 hr. Results indicate that hemodilution and the suppression of vasopressin and plasma renin activity were present by the second hour of immersion, with the early hemodilution due to a slight increase in plasma volume with no change in plasma sodium or osmotic contents, even though urine volume and osmotic excretion rates increased significantly. Hyponatremia, hyposmotemia and plasma renin activity suppression are observed to continue to the end of immersion, resulting in final decreases of 15.6% in plasma volume, 18.8% in extracellular volume, 19.6% in interstitial volume and 10.7% in red cell volume. Findings suggest the transfer of hypotonic fluid into the vascular system, which contributes to vasopressin suppression observed during immersion.

  5. Prostacyclin receptor suppresses cardiac fibrosis: role of CREB phosphorylation.

    Science.gov (United States)

    Chan, Elsa C; Dusting, Gregory J; Guo, Nancy; Peshavariya, Hitesh M; Taylor, Caroline J; Dilley, Rodney; Narumiya, Shuh; Jiang, Fan

    2010-08-01

    Cardiac fibrosis is a consequence of many cardiovascular diseases and contributes to impaired ventricular function. Activation of the prostacyclin receptor (IP) protects against cardiac fibrosis, but the molecular mechanisms are not totally understood. Using mouse cardiac fibroblasts, we found that IP activation with cicaprost suppressed expression of collagen I and other target genes of transforming growth factor-beta. This effect of cicaprost was unlikely to be mediated by inhibition of the Smad2/3 or mitogen-activated protein kinase (MAPK) activities, but was associated with cAMP elevation and phosphorylation of the transcription factor cAMP response element binding protein (CREB). Expression of a non-phosphorylated CREB mutant suppressed the inhibitory effect of cicaprost. It appears that phosphorylated CREB binds to and sequestrates the transcription coactivator CBP/p300 from binding to Smad. Inhibition of the intrinsic histone acetyl-transferase activity of CBP/p300 with garcinol significantly suppressed collagen I expression in fibroblasts. Using apolipoprotein E and IP double knockout mouse, we demonstrated that endogenous prostacyclin/IP signaling had an inhibitory effect on angiotensin II-induced cardiac fibrosis under hypercholesterolemic conditions. Taken together, our results suggest that the prostacyclin/IP pathway suppresses cardiac fibrosis, at least partly, by inducing CREB phosphorylation. PMID:20403362

  6. Suppression of thermal conduction in a mirror-unstable plasma

    CERN Document Server

    Komarov, S V; Kunz, M W; Schekochihin, A A

    2016-01-01

    The ICM plasma is subject to firehose and mirror instabilities at scales of order the ion Larmor radius. The mirror instability generates fluctuations of magnetic-field strength $\\delta B / B \\sim 1$. These fluctuations act as magnetic traps for the heat-conducting electrons, suppressing their transport. We calculate the effective parallel thermal conductivity in the ICM in the presence of the mirror fluctuations for different stages of the evolution of the instability. The mirror fluctuations are limited in amplitude by the maximum and minimum values of the field strength, with no large deviations from the mean value. This key property leads to a finite suppression of thermal conduction at large scales. We find suppression down to $\\approx 0.2$ of the Spitzer value for the secular phase of the perturbations' growth, and $\\approx 0.3$ for their saturated phase. The effect operates in addition to other suppression mechanisms and independently of them. Globally, fluctuations $\\delta B / B \\sim 1$ can be present...

  7. SUPPRESSION OF DIELECTRONIC RECOMBINATION DUE TO FINITE DENSITY EFFECTS

    International Nuclear Information System (INIS)

    We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (ne = 1 cm–3) and finite (ne = 1010 cm–3) densities. We find that the denser case is significantly more ionized due to suppression of DR, warranting further studies of density effects on DR by detailed collisional-radiative calculations which utilize state-of-the-art partial DR rate coefficients. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

  8. Diversity and activity of Lysobacter species from disease suppressive soils

    NARCIS (Netherlands)

    Gómez Expósito, Ruth; Postma, Joeke; Raaijmakers, Jos M; de Bruijn, Irene

    2015-01-01

    BACKGROUND: The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoct

  9. Diversity and Activity of Lysobacter Species from Disease Suppressive Soils

    NARCIS (Netherlands)

    Gomez Exposito, R.; Postma, J.; Raaijmakers, J.M.; Bruijn, de I.

    2015-01-01

    The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes, and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoctonia solani

  10. Does dexamethasone suppress the ACTH response in preterm babies?

    OpenAIRE

    Reynolds, G J; Yu, V Y; Doery, J

    1989-01-01

    Tests of adrenal stimulation with adrenocorticotrophic hormone (ACTH) were performed before and after commencing dexamethasone treatment in 12 infants. All except one of the tests performed showed the expected twofold rise in serum cortisol, suggesting that in this group of premature babies dexamethasone did not suppress the adrenal response.

  11. Suppression of galactic outflows by cosmological infall and circumgalactic medium

    CERN Document Server

    Singh, Priyanka; Bagla, Jasjeet S; Nath, Biman B

    2016-01-01

    We investigate the relative importance of two galactic outflow suppression mechanisms : a) Cosmological infall of the intergalactic gas onto the galaxy, and b) the existence of a hot circumgalactic medium (CGM). Considering only radial motion, the infall reduces the speed of outflowing gas and even halts the outflow, depending on the mass and redshift of the galaxy. For star forming galaxies there exists an upper mass limit beyond which outflows are suppressed by the gravitational field of the galaxy. We find that infall can reduce this upper mass limit approximately by a factor of two (independent of the redshift). Massive galaxies ($\\gtrsim 10^{12} M_{\\odot}$) host large reservoir of hot, diffuse CGM around the central part of the galaxy. The CGM acts as a barrier between the infalling and outflowing gas and provides an additional source of outflow suppression. We find that at low redshifts ($z\\lesssim3.5$), the CGM is more effective than the infall in suppressing the outflows. Together, these two processes...

  12. Suppression of developmental anomalies by maternal macrophages in mice

    International Nuclear Information System (INIS)

    We tested whether nonspecific tumoricidal immune cells can suppress congenital malformations by killing precursor cells destined to cause such defects. Pretreatment of pregnant ICR mice with synthetic (Pyran copolymer) and biological (Bacillus Calmette-Guerin) agents significantly suppressed radiation- and chemical-induced congenital malformations (cleft palate, digit anomalies, tail anomalies, etc.). Such suppressive effects were associated with the activation of maternal macrophages by these agents, but were lost either after the disruption of activated macrophages by supersonic waves or by inhibition of their lysosomal enzyme activity with trypan blue. These results indicate that a live activated macrophage with active lysosomal enzymes can be an effector cell to suppress maldevelopment. A similar reduction by activated macrophages was observed in strain CL/Fr, which has a high spontaneous frequency of cleft lips and palates. Furthermore, Pyran-activated maternal macrophages could pass through the placenta, and enhanced urethane-induced cell killing (but not somatic mutation) in the embryo. It is likely that a maternal immunosurveillance system eliminating preteratogenic cells allows for the replacement with normal totipotent blast cells during the pregnancy to protect abnormal development

  13. 'Patents and Downstream Innovation Suppression - Fact or Fiction?'

    DEFF Research Database (Denmark)

    Howells, John

    of that empirical evidence. They present alleged historical examples of downstream innovation suppression in such important technologies as: Edison's carbon filament light bulb; the automobile; radio; aircraft; the transistor; the computer. This paper presents a contrary interpretation of the role of patents...

  14. Human regulatory T cells suppress proliferation of B lymphoma cells.

    Science.gov (United States)

    Grygorowicz, Monika Anna; Biernacka, Marzena; Bujko, Mateusz; Nowak, Eliza; Rymkiewicz, Grzegorz; Paszkiewicz-Kozik, Ewa; Borycka, Ilona Sara; Bystydzienski, Zbigniew; Walewski, Jan; Markowicz, Sergiusz

    2016-08-01

    Activated regulatory T cells (Tregs) suppress proliferation and differentiation of normal B cells. In our study, allogeneic polyclonal CD4 (+) CD25 (+) Tregs and CD4 (+) CD25 (+) CD127(lo)Tregs expanded in vitro in the presence of rapamycin and low dose IL-2 suppressed proliferation of 11 out of 12 established lymphoma B-cell lines. The effect of expanded CD4 (+) CD25 (+) Tregs on survival of freshly isolated lymphoma B cells maintained in culture with soluble multimeric CD40L and IL-4 was variable across lymphoma entities. The survival of freshly isolated follicular lymphoma cells usually decreased in cocultures with CD4 (+) CD25 (+) Tregs. Treg effect on chronic lymphocytic leukemia/small lymphocytic lymphoma cells ranged from suppression to help in individual patients. CD4 (+) CD25 (+) Tregs or CD4 (+) CD25 (+) CD127(lo)Tregs expanded ex vivo with rapamycin could be used to suppress regrowth of residual lymphoma after autologous hematopoietic cell transplantation (HCT), and to counteract both graft-versus-host disease and lymphoma re-growth after allogeneic HCT in select patients with lymphoma susceptible to the regulation by Tregs. PMID:26758248

  15. Weight Suppression Predicts Time to Remission from Bulimia Nervosa

    Science.gov (United States)

    Lowe, Michael R.; Berner, Laura A.; Swanson, Sonja A.; Clark, Vicki L.; Eddy, Kamryn T.; Franko, Debra L.; Shaw, Jena A.; Ross, Stephanie; Herzog, David B.

    2011-01-01

    Objective: To investigate whether, at study entry, (a) weight suppression (WS), the difference between highest past adult weight and current weight, prospectively predicts time to first full remission from bulimia nervosa (BN) over a follow-up period of 8 years, and (b) weight change over time mediates the relationship between WS and time to first…

  16. On the Sudakov suppression and enhancement for electroweak reactions

    OpenAIRE

    Ermolaev, B. I.

    2002-01-01

    Accounting for the double-logarithmic (DL) contributions to amplitude of Z to f \\bar{f} leads to the Sudakov suppression. In contrast, resumming DL contributions to amplitudes of W to f \\bar{f}' results into an exponential with a positive exponent, i.e. into the enhancement. This effect is intrinsic property of the theories with non-Abelian gauge groups.

  17. Suppressing Spatiotemporal Chaos via Non-feedback Pinning Method

    Institute of Scientific and Technical Information of China (English)

    WU Shun-Guang; SANG Hai-Bo; HE Kai-Fen

    2001-01-01

    The spatiotemporal chaos in the system described by a one-dimensional nonlinear drift-wave equation is suppressed by the non-feedback pinning method. By adding additive external noise to the controlled state, we find that the deviation from the target spacetime pattern increases in a power law with noise intensity. The possible controlling mechanism is discussed.

  18. Spectral polarimetric radar clutter suppression to enhance atmospheric echoes

    NARCIS (Netherlands)

    Unal, C.M.H.

    2009-01-01

    The clutter present in the Doppler spectra of atmospheric targets can be removed by using polarimetry. The purpose is to suppress the Doppler velocity bins where spectral polarimetric parameters have atypical values. This procedure largely improves profiles of moments and polarimetric parameters of

  19. Rewriting and suppressing UMLS terms for improved biomedical term identification

    Directory of Open Access Journals (Sweden)

    Hettne Kristina M

    2010-03-01

    Full Text Available Abstract Background Identification of terms is essential for biomedical text mining.. We concentrate here on the use of vocabularies for term identification, specifically the Unified Medical Language System (UMLS. To make the UMLS more suitable for biomedical text mining we implemented and evaluated nine term rewrite and eight term suppression rules. The rules rely on UMLS properties that have been identified in previous work by others, together with an additional set of new properties discovered by our group during our work with the UMLS. Our work complements the earlier work in that we measure the impact on the number of terms identified by the different rules on a MEDLINE corpus. The number of uniquely identified terms and their frequency in MEDLINE were computed before and after applying the rules. The 50 most frequently found terms together with a sample of 100 randomly selected terms were evaluated for every rule. Results Five of the nine rewrite rules were found to generate additional synonyms and spelling variants that correctly corresponded to the meaning of the original terms and seven out of the eight suppression rules were found to suppress only undesired terms. Using the five rewrite rules that passed our evaluation, we were able to identify 1,117,772 new occurrences of 14,784 rewritten terms in MEDLINE. Without the rewriting, we recognized 651,268 terms belonging to 397,414 concepts; with rewriting, we recognized 666,053 terms belonging to 410,823 concepts, which is an increase of 2.8% in the number of terms and an increase of 3.4% in the number of concepts recognized. Using the seven suppression rules, a total of 257,118 undesired terms were suppressed in the UMLS, notably decreasing its size. 7,397 terms were suppressed in the corpus. Conclusions We recommend applying the five rewrite rules and seven suppression rules that passed our evaluation when the UMLS is to be used for biomedical term identification in MEDLINE. A software

  20. Weed-Suppressing Effect and Mechanism of Allelopathic Rice Accessions

    Institute of Scientific and Technical Information of China (English)

    HUFei; KONGChui-hua; XUXiao-hua; ZHANGChao-xian; CHENXiong-hui

    2004-01-01

    Two allelopathic rice accessions, PI312777 and Allelopathy i, significantly suppressed the growth of associated weeds in the field. Moreover, their weed-suppressing effects were correlated with the cultivation patterns. The weed-suppressing effects of throwing and transplanting were more effective than that of direct seeding. Furthermore, the amounts of allelochemicals (resorcinols, flavones and hydroxamic acids) produced and released from two allelopathic rice accessions were much higher than that from a nonallelopathic rice variety Hua-Jing-Xian i, and reached the maximum concentration at the 6th leaf stage. Differences in the weed-suppressing effects of rice accessions appear to result from the accessions producing and releasing different amounts of allelochemicals in the field. Further research confirmed that in PI312777 plants, allelochemicals were synthesized by the above-ground parts, and then secreted through the root tissues. Root tissues of PI312777 plants never produced the allelochemicals. Root exudates from PI312777 could significantly inhibit the growth of E. crus-galli surrounding rice plants in water culture. However, when activated carbon was added to the culture solution, which could absorb allelochemicals from root exudates, the growth of E. crus-galli was no longer significantly inhibited. Weed-suppressing effects of rice accessions depended on allelopathy, cultivation patterns and other factors in rice fields, while allelopathy was one of important factors. Interestingly, the amounts of allelochemicals produced and released from allelopathic rice plants may be induced by the presence of E. crus-galli.This suggests that there is a possible chemical recognition between rice and E. crus-galli.