Ethanol modulation of mammalian BK channels in excitable tissues: molecular targets and their possible contribution to alcohol-induced altered behavior

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Alex M. Dopico

2014-12-01

Full Text Available In most tissues, the function of calcium- and voltage-gated potassium (BK channels is modified in response to ethanol concentrations reached in human blood during alcohol intoxication. In general, modification of BK current from ethanol-naïve preparations in response to brief ethanol exposure results from changes in channel open probability without modification of unitary conductance or change in BK protein levels in the membrane. Protracted and/or repeated ethanol exposure, however, may evoke changes in BK expression. The final ethanol effect on BK open probability leading to either BK current potentiation or BK current reduction is determined by an orchestration of molecular factors, including levels of activating ligand (cytosolic calcium, BK subunit composition and posttranslational modifications, and the channel’s lipid microenvironment. These factors seem to allosterically regulate a direct interaction between ethanol and a recognition pocket of discrete dimensions recently mapped to the channel-forming (slo1 subunit. Type of ethanol exposure also plays a role in the final BK response to the drug: in several central nervous system regions (e.g., striatum, primary sensory neurons, and supraoptic nucleus, acute exposure to ethanol reduces neuronal excitability by enhancing BK activity. In contrast, protracted or repetitive ethanol administration may alter BK subunit composition and membrane expression, rendering the BK complex insensitive to further ethanol exposure. In neurohypophysial axon terminals, ethanol potentiation of BK channel activity leads to a reduction in neuropeptide release. In vascular smooth muscle, however, ethanol inhibition of BK current leads to cell contraction and vascular constriction.

Probing the Geometry of the Inner Vestibule of BK Channels with Sugars

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Brelidze, Tinatin I.; Magleby, Karl L.

2005-01-01

The geometry of the inner vestibule of BK channels was probed by examining the effects of different sugars in the intracellular solution on single-channel current amplitude (unitary current). Glycerol, glucose, and sucrose decreased unitary current through BK channels in a concentration- and size-dependent manner, in the order sucrose > glucose > glycerol, with outward currents being reduced more than inward currents. The fractional decrease of outward current was more directly related to the fractional hydrodynamic volume occupied by the sugars than to changes in osmolality. For concentrations of sugars ≤1 M, the i/V plots for outward currents in the presence and absence of sugar superimposed after scaling, and increasing K+ i from 150 mM to 2 M increased the magnitudes of the i/V plots with little effect on the shape of the scaled curves. These observations suggest that sugars ≤1 M reduce outward currents mainly by entering the inner vestibule and reducing the movement of K+ through the vestibule, rather than by limiting diffusion-controlled access of K+ to the vestibule. With 2 M sucrose, the movement of K+ into the inner vestibule became diffusion limited for 150 mM K+ i and voltages >+100 mV. Increasing K+ i then relieved the diffusion limitation. An estimate of the capture radius based on the 5 pA diffusion-limited current for channels without the ring of negative charge at the entrance to the inner vestibule was 2.2 Å. Adding the radius of a hydrated K+ (6–8 Å) then gave an effective radius for the entrance to the inner vestibule of 8–10 Å. Such a functionally wide entrance to the inner vestibule together with our observation that even small concentrations of sugar in the inner vestibule reduce unitary current suggest that a wide inner vestibule is required for the large conductance of BK channels. PMID:16043773

KCNMA1 encoded cardiac BK channels afford protection against ischemia-reperfusion injury

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Soltysinska, Ewa; Bentzen, Bo Hjorth; Barthmes, Maria

2014-01-01

Mitochondrial potassium channels have been implicated in myocardial protection mediated through pre-/postconditioning. Compounds that open the Ca2+- and voltage-activated potassium channel of big-conductance (BK) have a pre-conditioning-like effect on survival of cardiomyocytes after ischemia/rep...

Differential Regulation of Action Potential Shape and Burst-Frequency Firing by BK and Kv2 Channels in Substantia Nigra Dopaminergic Neurons.

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Kimm, Tilia; Khaliq, Zayd M; Bean, Bruce P

2015-12-16

Little is known about the voltage-dependent potassium currents underlying spike repolarization in midbrain dopaminergic neurons. Studying mouse substantia nigra pars compacta dopaminergic neurons both in brain slice and after acute dissociation, we found that BK calcium-activated potassium channels and Kv2 channels both make major contributions to the depolarization-activated potassium current. Inhibiting Kv2 or BK channels had very different effects on spike shape and evoked firing. Inhibiting Kv2 channels increased spike width and decreased the afterhyperpolarization, as expected for loss of an action potential-activated potassium conductance. BK inhibition also increased spike width but paradoxically increased the afterhyperpolarization. Kv2 channel inhibition steeply increased the slope of the frequency-current (f-I) relationship, whereas BK channel inhibition had little effect on the f-I slope or decreased it, sometimes resulting in slowed firing. Action potential clamp experiments showed that both BK and Kv2 current flow during spike repolarization but with very different kinetics, with Kv2 current activating later and deactivating more slowly. Further experiments revealed that inhibiting either BK or Kv2 alone leads to recruitment of additional current through the other channel type during the action potential as a consequence of changes in spike shape. Enhancement of slowly deactivating Kv2 current can account for the increased afterhyperpolarization produced by BK inhibition and likely underlies the very different effects on the f-I relationship. The cross-regulation of BK and Kv2 activation illustrates that the functional role of a channel cannot be defined in isolation but depends critically on the context of the other conductances in the cell. This work shows that BK calcium-activated potassium channels and Kv2 voltage-activated potassium channels both regulate action potentials in dopamine neurons of the substantia nigra pars compacta. Although both

Functional validation of Ca2+-binding residues from the crystal structure of the BK ion channel.

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Kshatri, Aravind S; Gonzalez-Hernandez, Alberto J; Giraldez, Teresa

2018-04-01

BK channels are dually regulated by voltage and Ca 2+ , providing a cellular mechanism to couple electrical and chemical signalling. Intracellular Ca 2+ concentration is sensed by a large cytoplasmic region in the channel known as "gating ring", which is formed by four tandems of regulator of conductance for K + (RCK1 and RCK2) domains. The recent crystal structure of the full-length BK channel from Aplysia californica has provided new information about the residues involved in Ca 2+ coordination at the high-affinity binding sites located in the RCK1 and RCK2 domains, as well as their cooperativity. Some of these residues have not been previously studied in the human BK channel. In this work we have investigated, through site directed mutagenesis and electrophysiology, the effects of these residues on channel activation by voltage and Ca 2+ . Our results demonstrate that the side chains of two non-conserved residues proposed to coordinate Ca 2+ in the A. californica structure (G523 and E591) have no apparent functional role in the human BK Ca 2+ sensing mechanism. Consistent with the crystal structure, our data indicate that in the human channel the conserved residue R514 participates in Ca 2+ coordination in the RCK1 binding site. Additionally, this study provides functional evidence indicating that R514 also interacts with residues E902 and Y904 connected to the Ca 2+ binding site in RCK2. Interestingly, it has been proposed that this interaction may constitute a structural correlate underlying the cooperative interactions between the two high-affinity Ca 2+ binding sites regulating the Ca 2+ dependent gating of the BK channel. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain. Copyright © 2017 Elsevier B.V. All rights reserved.

The BK(Ca) channels deficiency as a possible reason for radiation-induced vascular hypercontractility.

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Kyrychenko, Sergii; Tishkin, Sergey; Dosenko, Victor; Ivanova, Irina; Novokhatska, Tatiana; Soloviev, Anatoly

2012-01-01

It is likely that large-conductance Ca²⁺-activated K⁺ (BK(Ca)) channels channelopathy tightly involved in vascular malfunctions and arterial hypertension development. In the present study, we compared the results of siRNAs-induced α-BK(Ca) gene silencing and vascular abnormalities produced by whole-body ionized irradiation in rats. The experimental design comprised RT-PCR and patch clamp technique, thoracic aorta smooth muscle (SM) contractile recordings and arterial blood pressure (BP) measurements on the 30th day after whole body irradiation (6Gy) and following siRNAs KCNMA1 gene silencing in vivo. The expression profile of BK(Ca) mRNA transcripts in SM was significantly decreased in siRNAs-treated rats in a manner similar to irradiated SM. In contrast, the mRNA levels of K(v) and K(ATP) were significantly increased while L-type calcium channels mRNA transcripts demonstrated tendency to increment. The SMCs obtained from irradiated animals and after KCNMA1 gene silencing showed a significant decrease in total K⁺ current density amplitude. Paxilline (500 nM)-sensitive components of outward current were significantly decreased in both irradiated and gene silencing SMCs. KCNMA1 gene silencing increased SM sensitivity to norepinephrine while Ach-induced relaxation had decreased. The silencing of KCNMA1 had no significant effect on BP while radiation produced sustained arterial hypertension. Therefore, radiation alters the form and function of the BK(Ca) channel and this type of channelopathy may contribute to related vascular abnormalities. Nevertheless, it is unlikely that BK(Ca) can operate as a crucial factor for radiation-induced arterial hypertension. Copyright © 2012 Elsevier Inc. All rights reserved.

The Role of Ca2+ and BK Channels of Locus Coeruleus (LC) Neurons as a Brake to the CO2 Chemosensitivity Response of Rats.

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Imber, Ann N; Patrone, Luis G A; Li, Ke-Yong; Gargaglioni, Luciane H; Putnam, Robert W

2018-06-15

The cellular mechanisms by which LC neurons respond to hypercapnia are usually attributed to an "accelerator" whereby hypercapnic acidosis causes an inhibition of K + channels or activation of Na + and Ca +2 channels to depolarize CO 2 -sensitive neurons. Nevertheless, it is still unknown if this "accelerator" mechanism could be controlled by a brake phenomenon. Whole-cell patch clamping, fluorescence imaging microscopy and plethysmography were used to study the chemosensitive response of the LC neurons. Hypercapnic acidosis activates L-type Ca 2+ channels and large conductance Ca-activated K + (BK) channels, which function as a "brake" on the chemosensitive response of LC neurons. Our findings indicate that both Ca 2+ and BK currents develop over the first 2 weeks of postnatal life in rat LC slices and that this brake pathway may cause the developmental decrease in the chemosensitive firing rate response of LC neurons to hypercapnic acidosis. Inhibition of this brake by paxilline (BK channel inhibitor) returns the magnitude of the chemosensitive firing rate response from LC neurons in rats older than P10 to high values similar to those in LC neurons from younger rats. Inhibition of BK channels in LC neurons by bilateral injections of paxilline into the LC results in a significant increase in the hypercapnic ventilatory response of adult rats. Our findings indicate that a BK channel-based braking system helps to determine the chemosensitive respiratory drive of LC neurons and contributes to the hypercapnic ventilatory response. Perhaps, abnormalities of this braking system could result in hypercapnia-induced respiratory disorders and panic responses. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Relative transmembrane segment rearrangements during BK channel activation resolved by structurally assigned fluorophore–quencher pairing

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Pantazis, Antonios

2012-01-01

Voltage-activated proteins can sense, and respond to, changes in the electric field pervading the cell membrane by virtue of a transmembrane helix bundle, the voltage-sensing domain (VSD). Canonical VSDs consist of four transmembrane helices (S1–S4) of which S4 is considered a principal component because it possesses charged residues immersed in the electric field. Membrane depolarization compels the charges, and by extension S4, to rearrange with respect to the field. The VSD of large-conductance voltage- and Ca-activated K+ (BK) channels exhibits two salient inconsistencies from the canonical VSD model: (1) the BK channel VSD possesses an additional nonconserved transmembrane helix (S0); and (2) it exhibits a “decentralized” distribution of voltage-sensing charges, in helices S2 and S3, in addition to S4. Considering these unique features, the voltage-dependent rearrangements of the BK VSD could differ significantly from the standard model of VSD operation. To understand the mode of operation of this unique VSD, we have optically tracked the relative motions of the BK VSD transmembrane helices during activation, by manipulating the quenching environment of site-directed fluorescent labels with native and introduced Trp residues. Having previously reported that S0 and S4 diverge during activation, in this work we demonstrate that S4 also diverges from S1 and S2, whereas S2, compelled by its voltage-sensing charged residues, moves closer to S1. This information contributes spatial constraints for understanding the BK channel voltage-sensing process, revealing the structural rearrangements in a non-canonical VSD. PMID:22802360

Differential expression of BK channel isoforms and beta-subunits in rat neuro-vascular tissues

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Poulsen, Asser Nyander; Wulf, Helle; Hay-Schmidt, Anders

2009-01-01

We investigated the expression of splice variants and beta-subunits of the BK channel (big conductance Ca(2+)-activated K(+) channel, Slo1, MaxiK, K(Ca)1.1) in rat cerebral blood vessels, meninges, trigeminal ganglion among other tissues. An alpha-subunit splice variant X1(+24) was found expresse...

Overexpression of the Large-Conductance, Ca2+-Activated K+ (BK) Channel Shortens Action Potential Duration in HL-1 Cardiomyocytes.

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Stimers, Joseph R; Song, Li; Rusch, Nancy J; Rhee, Sung W

2015-01-01

Long QT syndrome is characterized by a prolongation of the interval between the Q wave and the T wave on the electrocardiogram. This abnormality reflects a prolongation of the ventricular action potential caused by a number of genetic mutations or a variety of drugs. Since effective treatments are unavailable, we explored the possibility of using cardiac expression of the large-conductance, Ca2+-activated K+ (BK) channel to shorten action potential duration (APD). We hypothesized that expression of the pore-forming α subunit of human BK channels (hBKα) in HL-1 cells would shorten action potential duration in this mouse atrial cell line. Expression of hBKα had minimal effects on expression levels of other ion channels with the exception of a small but significant reduction in Kv11.1. Patch-clamped hBKα expressing HL-1 cells exhibited an outward voltage- and Ca2+-sensitive K+ current, which was inhibited by the BK channel blocker iberiotoxin (100 nM). This BK current phenotype was not detected in untransfected HL-1 cells or in HL-1 null cells sham-transfected with an empty vector. Importantly, APD in hBKα-expressing HL-1 cells averaged 14.3 ± 2.8 ms (n = 10), which represented a 53% reduction in APD compared to HL-1 null cells lacking BKα expression. APD in the latter cells averaged 31.0 ± 5.1 ms (n = 13). The shortened APD in hBKα-expressing cells was restored to normal duration by 100 nM iberiotoxin, suggesting that a repolarizing K+ current attributed to BK channels accounted for action potential shortening. These findings provide initial proof-of-concept that the introduction of hBKα channels into a cardiac cell line can shorten APD, and raise the possibility that gene-based interventions to increase hBKα channels in cardiac cells may hold promise as a therapeutic strategy for long QT syndrome.

Neuronal fast activating and meningeal silent modulatory BK channel splice variants cloned from rat

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Poulsen, Asser Nyander; Jansen-Olesen, Inger; Olesen, Jes

2011-01-01

The big conductance calcium-activated K(+) channel (BK) is involved in regulating neuron and smooth muscle cell excitability. Functional diversity of BK is generated by alpha-subunit splice variation and co-expression with beta subunits. Here, we present six different splice combinations cloned...... and RCK2 (4 aa at SS1) and upstream of the calcium "bowl" (27 aa at SS4). Two other truncated variants, X2(92) and X2(188), lacking the intracellular C-terminal (stop downstream of S6), were cloned from cerebral vascular/meningeal tissue. They appear non-functional as no current expression was observed...

Cell volume and membrane stretch independently control K+ channel activity

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Bomholtz, Sofia Hammami; Willumsen, Niels J; Olsen, Hervør L

2009-01-01

A number of potassium channels including members of the KCNQ family and the Ca(2+) activated IK and SK, but not BK, are strongly and reversibly regulated by small changes in cell volume. It has been argued that this general regulation is mediated through sensitivity to changes in membrane stretch...... was not affected by membrane stretch. The results indicate that (1) activation of BK channels by local membrane stretch is not mimicked by membrane stress induced by cell swelling, and (2) activation of KCNQ1 channels by cell volume increase is not mediated by local tension in the cell membrane. We conclude....... To test this hypothesis we have studied the regulation of KCNQ1 and BK channels after expression in Xenopus oocytes. Results from cell-attached patch clamp studies (approximately 50 microm(2) macropatches) in oocytes expressing BK channels demonstrate that the macroscopic volume-insensitive BK current...

Mechanism of the modulation of BK potassium channel complexes with different auxiliary subunit compositions by the omega-3 fatty acid DHA.

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Hoshi, Toshinori; Tian, Yutao; Xu, Rong; Heinemann, Stefan H; Hou, Shangwei

2013-03-19

Large-conductance Ca(2+)- and voltage-activated K(+) (BK) channels are well known for their functional versatility, which is bestowed in part by their rich modulatory repertoire. We recently showed that long-chain omega-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA) found in oily fish lower blood pressure by activating vascular BK channels made of Slo1+β1 subunits. Here we examined the action of DHA on BK channels with different auxiliary subunit compositions. Neuronal Slo1+β4 channels were just as well activated by DHA as vascular Slo1+β1 channels. In contrast, the stimulatory effect of DHA was much smaller in Slo1+β2, Slo1+LRRC26 (γ1), and Slo1 channels without auxiliary subunits. Mutagenesis of β1, β2, and β4 showed that the large effect of DHA in Slo1+β1 and Slo1+β4 is conferred by the presence of two residues, one in the N terminus and the other in the first transmembrane segment of the β1 and β4 subunits. Transfer of this amino acid pair from β1 or β4 to β2 introduces a large response to DHA in Slo1+β2. The presence of a pair of oppositely charged residues at the aforementioned positions in β subunits is associated with a large response to DHA. The Slo1 auxiliary subunits are expressed in a highly tissue-dependent fashion. Thus, the subunit composition-dependent stimulation by DHA demonstrates that BK channels are effectors of omega-3 fatty acids with marked tissue specificity.

Differential contribution of Ca2+ sources to day and night BK current activation in the circadian clock.

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Whitt, Joshua P; McNally, Beth A; Meredith, Andrea L

2018-02-05

Large conductance K + (BK) channels are expressed widely in neurons, where their activation is regulated by membrane depolarization and intracellular Ca 2+ (Ca 2+ i ). To enable this regulation, BK channels functionally couple to both voltage-gated Ca 2+ channels (VGCCs) and channels mediating Ca 2+ release from intracellular stores. However, the relationship between BK channels and their specific Ca 2+ source for particular patterns of excitability is not well understood. In neurons within the suprachiasmatic nucleus (SCN)-the brain's circadian clock-BK current, VGCC current, and Ca 2+ i are diurnally regulated, but paradoxically, BK current is greatest at night when VGCC current and Ca 2+ i are reduced. Here, to determine whether diurnal regulation of Ca 2+ is relevant for BK channel activation, we combine pharmacology with day and night patch-clamp recordings in acute slices of SCN. We find that activation of BK current depends primarily on three types of channels but that the relative contribution changes between day and night. BK current can be abrogated with nimodipine during the day but not at night, establishing that L-type Ca 2+ channels (LTCCs) are the primary daytime Ca 2+ source for BK activation. In contrast, dantrolene causes a significant decrease in BK current at night, suggesting that nighttime BK activation is driven by ryanodine receptor (RyR)-mediated Ca 2+ i release. The N- and P/Q-type Ca 2+ channel blocker ω-conotoxin MVIIC causes a smaller reduction of BK current that does not differ between day and night. Finally, inhibition of LTCCs, but not RyRs, eliminates BK inactivation, but the BK β2 subunit was not required for activation of BK current by LTCCs. These data reveal a dynamic coupling strategy between BK channels and their Ca 2+ sources in the SCN, contributing to diurnal regulation of SCN excitability. © 2018 Whitt et al.

Statin therapy exacerbates alcohol-induced constriction of cerebral arteries via modulation of ethanol-induced BK channel inhibition in vascular smooth muscle.

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Simakova, Maria N; Bisen, Shivantika; Dopico, Alex M; Bukiya, Anna N

2017-12-01

Statins constitute the most commonly prescribed drugs to decrease cholesterol (CLR). CLR is an important modulator of alcohol-induced cerebral artery constriction (AICAC). Using rats on a high CLR diet (2% CLR) we set to determine whether atorvastatin administration (10mg/kg daily for 18-23weeks) modified AICAC. Middle cerebral arteries were pressurized in vitro at 60mmHg and AICAC was evoked by 50mM ethanol, that is within the range of blood alcohol detected in humans following moderate-to-heavy drinking. AICAC was evident in high CLR+atorvastatin group but not in high CLR diet+placebo. Statin exacerbation of AICAC persisted in de-endothelialized arteries, and was blunted by CLR enrichment in vitro. Fluorescence imaging of filipin-stained arteries showed that atorvastatin decreased vascular smooth muscle (VSM) CLR when compared to placebo, this difference being reduced by CLR enrichment in vitro. Voltage- and calcium-gated potassium channels of large conductance (BK) are known VSM targets of ethanol, with their beta1 subunit being necessary for ethanol-induced channel inhibition and resulting AICAC. Ethanol-induced BK inhibition in excised membrane patches from freshly isolated myocytes was exacerbated in the high CLR diet+atorvastatin group when compared to high CLR diet+placebo. Unexpectedly, atorvastatin decreased the amount and function of BK beta1 subunit as documented by immunofluorescence imaging and functional patch-clamp studies. Atorvastatin exacerbation of ethanol-induced BK inhibition disappeared upon artery CLR enrichment in vitro. Our study demonstrates for the first time statin's ability to exacerbate the vascular effect of a widely consumed drug of abuse, this exacerbation being driven by statin modulation of ethanol-induced BK channel inhibition in the VSM via CLR-mediated mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

Expression of BK_Ca channels and the modulatory ß-subunits in the rat and porcine trigeminal ganglion

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Wulf-Johansson, Helle; Hay-Schmidt, Anders; Poulsen, Asser Nyander

2009-01-01

Large conductance calcium-activated potassium (BK(Ca)) channels contribute to electrical impulses, proper signal transmission of information and regulation of neurotransmitter release. Migraine has been proposed to be a trigeminovascular disease involving the sensory trigeminal pathways and the c...

The first transmembrane domain (TM1) of β2-subunit binds to the transmembrane domain S1 of α-subunit in BK potassium channels

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Morera, Francisco J.; Alioua, Abderrahmane; Kundu, Pallob; Salazar, Marcelo; Gonzalez, Carlos; Martinez, Agustin D.; Stefani, Enrico; Toro, Ligia; Latorre, Ramon

2012-01-01

The BK channel is one of the most broadly expressed ion channels in mammals. In many tissues, the BK channel pore-forming α-subunit is associated to an auxiliary β-subunit that modulates the voltage- and Ca2+-dependent activation of the channel. Structural components present in β-subunits that are important for the physical association with the α-subunit are yet unknown. Here, we show through co-immunoprecipitation that the intracellular C-terminus, the second transmembrane domain (TM2) and the extracellular loop of the β2-subunit are dispensable for association with the α-subunit pointing transmembrane domain 1 (TM1) as responsible for the interaction. Indeed, the TOXCAT assay for transmembrane protein–protein interactions demonstrated for the first time that TM1 of the β2-subunit physically binds to the transmembrane S1 domain of the α-subunit. PMID:22710124

Local calcium signalling is mediated by mechanosensitive ion channels in mesenchymal stem cells

International Nuclear Information System (INIS)

Chubinskiy-Nadezhdin, Vladislav I.; Vasileva, Valeria Y.; Pugovkina, Natalia A.; Vassilieva, Irina O.; Morachevskaya, Elena A.; Nikolsky, Nikolay N.; Negulyaev, Yuri A.

2017-01-01

Mechanical forces are implicated in key physiological processes in stem cells, including proliferation, differentiation and lineage switching. To date, there is an evident lack of understanding of how external mechanical cues are coupled with calcium signalling in stem cells. Mechanical reactions are of particular interest in adult mesenchymal stem cells because of their promising potential for use in tissue remodelling and clinical therapy. Here, single channel patch-clamp technique was employed to search for cation channels involved in mechanosensitivity in mesenchymal endometrial-derived stem cells (hMESCs). Functional expression of native mechanosensitive stretch-activated channels (SACs) and calcium-sensitive potassium channels of different conductances in hMESCs was shown. Single current analysis of stretch-induced channel activity revealed functional coupling of SACs and BK channels in plasma membrane. The combination of cell-attached and inside-out experiments have indicated that highly localized Ca 2+ entry via SACs triggers BK channel activity. At the same time, SK channels are not coupled with SACs despite of high calcium sensitivity as compared to BK. Our data demonstrate novel mechanism controlling BK channel activity in native cells. We conclude that SACs and BK channels are clusterized in functional mechanosensitive domains in the plasma membrane of hMESCs. Co-clustering of ion channels may significantly contribute to mechano-dependent calcium signalling in stem cells. - Highlights: • Stretch-induced channel activity in human mesenchymal stem cells was analyzed. • Functional expression of SACs and Ca 2+ -sensitive BK and SK channels was shown. • Local Ca 2+ influx via stretch-activated channels triggers BK channel activity. • SK channels are not coupled with SACs despite higher sensitivity to [Ca 2+ ] i . • Functional clustering of SACs and BK channels in stem cell membrane is proposed.

Polyomavirus specific cellular immunity: from BK-virus-specific cellular immunity to BK-virus-associated nephropathy ?

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manon edekeyser

2015-06-01

Full Text Available In renal transplantation, BK-virus-associated nephropathy has emerged as a major complication, with a prevalence of 5–10% and graft loss in >50% of cases. BK-virus is a member of the Polyomavirus family and rarely induces apparent clinical disease in the general population. However, replication of polyomaviruses, associated with significant organ disease, is observed in patients with acquired immunosuppression, which suggests a critical role for virus-specific cellular immunity to control virus replication and prevent chronic disease. Monitoring of specific immunity combined with viral load could be used to individually assess the risk of viral reactivation and virus control. We review the current knowledge on BK-virus specific cellular immunity and, more specifically, in immunocompromised patients. In the future, immune-based therapies could allow us to treat and prevent BK-virus-associated nephropathy.

Cholesterol tuning of BK ethanol response is enantioselective, and is a function of accompanying lipids.

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Chunbo Yuan

Full Text Available In the search to uncover ethanol's molecular mechanisms, the calcium and voltage activated, large conductance potassium channel (BK has emerged as an important molecule. We examine how cholesterol content in bilayers of 1,2-dioleoyl-3-phosphatidylethanolamine (DOPE/sphingomyelin (SPM and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylethanolamine (POPE/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS affect the function and ethanol sensitivity of BK. In addition, we examine how manipulation of cholesterol in biological membranes modulates ethanol's actions on BK. We report that cholesterol levels regulate the change in BK channel open probability elicited by 50 mM ethanol. Low levels of cholesterol (<20%, molar ratio supports ethanol activation, while high levels of cholesterol leads to ethanol inhibition of BK. To determine if cholesterol affects BK and its sensitivity to ethanol through a direct cholesterol-protein interaction or via an indirect action on the lipid bilayer, we used the synthetic enantiomer of cholesterol (ent-CHS. We found that 20% and 40% ent-CHS had little effect on the ethanol sensitivity of BK, when compared with the same concentration of nat-CHS. We accessed the effects of ent-CHS and nat-CHS on the molecular organization of DOPE/SPM monolayers at the air/water interface. The isotherm data showed that ent-CHS condensed DOPE/SPM monolayer equivalently to nat-CHS at a 20% concentration, but slightly less at a 40% concentration. Atomic force microscopy (AFM images of DOPE/SPM membranes in the presence of ent-CHS or nat-CHS prepared with LB technique or vesicle deposition showed no significant difference in topographies, supporting the interpretation that the differences in actions of nat-CHS and ent-CHS on BK channel are not likely from a generalized action on bilayers. We conclude that membrane cholesterol influences ethanol's modulation of BK in a complex manner, including an interaction with the channel protein

Astaxanthin and Docosahexaenoic Acid Reverse the Toxicity of the Maxi-K (BK Channel Antagonist Mycotoxin Penitrem A

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Amira A. Goda

2016-11-01

Full Text Available Penitrem A (PA is a food mycotoxin produced by several terrestrial and few marine Penicillium species. PA is a potent tremorgen through selective antagonism of the calcium-dependent potassium BK (Maxi-K channels. Discovery of natural products that can prevent the toxic effects of PA is important for food safety. Astaxanthin (AST is a marine natural xanthophyll carotenoid with documented antioxidant activity. Unlike other common antioxidants, AST can cross blood brain barriers (BBBs, inducing neuroprotective effects. Docosahexaenoic acid (DHA is polyunsaturated ω-3 fatty acid naturally occurring in fish and algae. DHA is essential for normal neurological and cellular development. This study evaluated the protective activity of AST and DHA against PA-induced toxicity, in vitro on Schwann cells CRL-2765 and in vivo in the worm Caenorhbitidis elegans and Sprague Dawley rat models. PA inhibited the viability of Schwann cells, with an IC50 of 22.6 μM. Dose-dependent treatments with 10–100 μM DHA significantly reversed the PA toxicity at its IC50 dose, and improved the survival of Schwann cells to 70.5%–98.8%. Similarly, dose-dependent treatments with 10–20 μM AST reversed the PA toxicity at its IC50 dose and raised these cells’ survival to 61.7%–70.5%. BK channel inhibition in the nematode C. elegans is associated with abnormal reversal locomotion. DHA and AST counteracted the in vivo PA BK channel antagonistic activity in the C. elegans model. Rats fed a PA-contaminated diet showed high levels of glutamate (GLU, aspartate (ASP, and gamma amino butyric acid (GABA, with observed necrosis or absence of Purkinjie neurons, typical of PA-induced neurotoxicity. Dopamine (DA, serotonin (5-HT, and norepinephrine (NE levels were abnormal, Nitric Oxide (NO and Malondialdehyde (MDA levels were significantly increased, and total antioxidant capacity (TAC level in serum and brain homogenates was significantly decreased in PA-treated rats. DHA and AST

[β-estradiol activates BK(Ca) in mesenteric artery smooth muscle cells of post-menopause women].

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Cheng, Jun; Zeng, Xiao-Rong; Li, Peng-Yun; Lu, Ting-Ting; Tan, Xiao-Qiu; Wen, Jing; Yang, Yan

2012-04-25

The aim of the present study was to study the effect of β-estradiol (β-E(2)) on the large-conductance Ca(2+)-activated potassium (BK(Ca)) channel in mesenteric artery smooth muscle cells (SMCs). The mesenteric arteries were obtained from post-menopause female patients with abdominal surgery, and the SMCs were isolated from the arteries using an enzymatic disassociation. According to the sources, the SMCs were divided into non-hypertension (NH) and essential hypertension (EH) groups. Single channel patch clamp technique was used to investigate the effect of β-E(2) and ICI 182780 (a specific blocker of estrogen receptor) on BK(Ca) in the SMCs. The results showed the opening of BK(Ca) in the SMCs was voltage and calcium dependent, and could be blocked by IbTX. β-E(2) (100 μmol/L) significantly increased open probability (Po) of BK(Ca) in both NH and EH groups. After β-E(2) treatment, NH group showed higher Po of BK(Ca) compared with EH group. ICI 182780 could inhibit the activating effect of β-E(2) on BK(Ca) in no matter NH or EH groups. These results suggest β-E(2) activates BK(Ca) in mesenteric artery SMCs from post-menopause women via estrogen receptor, but hypertension may decline the activating effect of β-E(2) on BK(Ca).

Neurogenic detrusor overactivity is associated with decreased expression and function of the large conductance voltage- and Ca(2+-activated K(+ channels.

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Kiril L Hristov

Full Text Available Patients suffering from a variety of neurological diseases such as spinal cord injury, Parkinson's disease, and multiple sclerosis often develop neurogenic detrusor overactivity (NDO, which currently lacks a universally effective therapy. Here, we tested the hypothesis that NDO is associated with changes in detrusor smooth muscle (DSM large conductance Ca(2+-activated K(+ (BK channel expression and function. DSM tissue samples from 33 patients were obtained during open bladder surgeries. NDO patients were clinically characterized preoperatively with pressure-flow urodynamics demonstrating detrusor overactivity, in the setting of a clinically relevant neurological condition. Control patients did not have overactive bladder and did not have a clinically relevant neurological disease. We conducted quantitative polymerase chain reactions (qPCR, perforated patch-clamp electrophysiology on freshly-isolated DSM cells, and functional studies on DSM contractility. qPCR experiments revealed that DSM samples from NDO patients showed decreased BK channel mRNA expression in comparison to controls. Patch-clamp experiments demonstrated reduced whole cell and transient BK currents (TBKCs in freshly-isolated DSM cells from NDO patients. Functional studies on DSM contractility showed that spontaneous phasic contractions had a decreased sensitivity to iberiotoxin, a selective BK channel inhibitor, in DSM strips isolated from NDO patients. These results reveal the novel finding that NDO is associated with decreased DSM BK channel expression and function leading to increased DSM excitability and contractility. BK channel openers or BK channel gene transfer could be an alternative strategy to control NDO. Future clinical trials are needed to evaluate the value of BK channel opening drugs or gene therapies for NDO treatment and to identify any possible adverse effects.

Fragile X mental retardation protein controls ion channel expression and activity.

Science.gov (United States)

Ferron, Laurent

2016-10-15

Fragile X-associated disorders are a family of genetic conditions resulting from the partial or complete loss of fragile X mental retardation protein (FMRP). Among these disorders is fragile X syndrome, the most common cause of inherited intellectual disability and autism. FMRP is an RNA-binding protein involved in the control of local translation, which has pleiotropic effects, in particular on synaptic function. Analysis of the brain FMRP transcriptome has revealed hundreds of potential mRNA targets encoding postsynaptic and presynaptic proteins, including a number of ion channels. FMRP has been confirmed to bind voltage-gated potassium channels (K v 3.1 and K v 4.2) mRNAs and regulates their expression in somatodendritic compartments of neurons. Recent studies have uncovered a number of additional roles for FMRP besides RNA regulation. FMRP was shown to directly interact with, and modulate, a number of ion channel complexes. The sodium-activated potassium (Slack) channel was the first ion channel shown to directly interact with FMRP; this interaction alters the single-channel properties of the Slack channel. FMRP was also shown to interact with the auxiliary β4 subunit of the calcium-activated potassium (BK) channel; this interaction increases calcium-dependent activation of the BK channel. More recently, FMRP was shown to directly interact with the voltage-gated calcium channel, Ca v 2.2, and reduce its trafficking to the plasma membrane. Studies performed on animal models of fragile X syndrome have revealed links between modifications of ion channel activity and changes in neuronal excitability, suggesting that these modifications could contribute to the phenotypes observed in patients with fragile X-associated disorders. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels

Science.gov (United States)

Hei, Hongya; Li, Fangping; Wang, Yunman; Peng, Wen; Zhang, Xuemei

2015-01-01

Large conductance Ca2+-activated potassium channels (BK) are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α) and BK (α+β1) currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α) in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1). Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms. PMID:26672753

Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels.

Directory of Open Access Journals (Sweden)

Qijing Chen

Full Text Available Large conductance Ca2+-activated potassium channels (BK are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α and BK (α+β1 currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1. Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms.

Efficacy of levofloxacin in the treatment of BK viremia: a multicenter, double-blinded, randomized, placebo-controlled trial.

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Lee, Belinda T; Gabardi, Steven; Grafals, Monica; Hofmann, R Michael; Akalin, Enver; Aljanabi, Aws; Mandelbrot, Didier A; Adey, Deborah B; Heher, Eliot; Fan, Pang-Yen; Conte, Sarah; Dyer-Ward, Christine; Chandraker, Anil

2014-03-01

BK virus reactivation in kidney transplant recipients can lead to progressive allograft injury. Reduction of immunosuppression remains the cornerstone of treatment for active BK infection. Fluoroquinolone antibiotics are known to have in vitro antiviral properties, but the evidence for their use in patients with BK viremia is inconclusive. The objective of the study was to determine the efficacy of levofloxacin in the treatment of BK viremia. Enrollment in this prospective, multicenter, double-blinded, placebo-controlled trial occurred from July 2009 to March 2012. Thirty-nine kidney transplant recipients with BK viremia were randomly assigned to receive levofloxacin, 500 mg daily, or placebo for 30 days. Immunosuppression in all patients was adjusted on the basis of standard clinical practices at each institution. Plasma BK viral load and serum creatinine were measured monthly for 3 months and at 6 months. At the 3-month follow-up, the percentage reductions in BK viral load were 70.3% and 69.1% in the levofloxacin group and the placebo group, respectively (P=0.93). The percentage reductions in BK viral load were also equivalent at 1 month (58% versus and 67.1%; P=0.47) and 6 months (82.1% versus 90.5%; P=0.38). Linear regression analysis of serum creatinine versus time showed no difference in allograft function between the two study groups during the follow-up period. A 30-day course of levofloxacin does not significantly improve BK viral load reduction or allograft function when used in addition to overall reduction of immunosuppression.

Quantification and distribution of big conductance Ca2+-activated K+ channels in kidney epithelia

DEFF Research Database (Denmark)

Grunnet, Morten; Hay-Schmidt, Anders; Klaerke, Dan A

2005-01-01

and immunohistochemical studies. In cortical collecting ducts, BK channels were exclusively located in principal cells while no channels could be found in intercalated cells. The abundant and distinct distribution in kidney epithelia talks in favor for BK channels being important contributors in maintaining salt......Big conductance Ca2+ activated K+ channels (BK channels) is an abundant channel present in almost all kind of tissue. The accurate quantity and especially the precise distribution of this channel in kidney epithelia are, however, still debated. The aim of the present study has therefore been...... to examine the presence of BK channels in kidney epithelia and determine the actual number and distribution of these channels. For this purpose, a selective peptidyl ligand for BK channels called iberiotoxin or the radiolabeled double mutant analog 125I-IbTX-D19Y/Y36F has been employed. The presence of BK...

Structure of the (0+,1+) mesons Bs0 and Bs1, and the strong coupling constant gBs0BK and gBs1B*K

International Nuclear Information System (INIS)

Wang, Z. G.

2008-01-01

In this article, we take the point of view that the bottomed (0 + ,1 + ) mesons B s0 and B s1 are the conventional bs meson and calculate the strong coupling constants g B s0 BK and g B s1 B*K with the light-cone QCD sum rules. The numerical values of strong coupling constants g B s1 B*K and g B s0 BK are very large and support the hadronic dressing mechanism. Just like the scalar mesons f 0 (980), a 0 (980), D s0 and axial-vector meson D s1 , the (0 + ,1 + ) bottomed mesons B s0 and B s1 may have small bs kernels of the typical bs meson size. The strong couplings to the hadronic channels (or the virtual mesons loops) may result in smaller masses than the conventional bs mesons in the potential quark models and enrich the pure bs states with other components.

Large-conductance Ca2+-activated K+ channel β1-subunit knockout mice are not hypertensive

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Garver, Hannah; Galligan, James J.; Fink, Gregory D.

2011-01-01

Large-conductance Ca2+-activated K+ (BK) channels are composed of pore-forming α-subunits and accessory β1-subunits that modulate Ca2+ sensitivity. BK channels regulate arterial myogenic tone and renal Na+ clearance/K+ reabsorption. Previous studies using indirect or short-term blood pressure measurements found that BK channel β1-subunit knockout (BK β1-KO) mice were hypertensive. We evaluated 24-h mean arterial pressure (MAP) and heart rate in BK β1-KO mice using radiotelemetry. BK β1-KO mice did not have a higher 24-h average MAP when compared with wild-type (WT) mice, although MAP was ∼10 mmHg higher at night. The dose-dependent peak declines in MAP by nifedipine were only slightly larger in BK β1-KO mice. In BK β1-KO mice, giving 1% NaCl to mice to drink for 7 days caused a transient (5 days) elevation of MAP (∼5 mmHg); MAP returned to pre-saline levels by day 6. BK β1-KO mesenteric arteries in vitro demonstrated diminished contractile responses to paxilline, increased reactivity to Bay K 8644 and norepinephrine (NE), and maintained relaxation to isoproterenol. Paxilline and Bay K 8644 did not constrict WT or BK β1-KO mesenteric veins (MV). BK β1-subunits are not expressed in MV. The results indicate that BK β1-KO mice are not hypertensive on normal or high-salt intake. BK channel deficiency increases arterial reactivity to NE and L-type Ca2+ channel function in vitro, but the L-type Ca2+ channel modulation of MAP is not altered in BK β1-KO mice. BK and L-type Ca2+ channels do not modulate murine venous tone. It appears that selective loss of BK channel function in arteries only is not sufficient to cause sustained hypertension. PMID:21131476

Potassium channels in brain mitochondria.

Science.gov (United States)

Bednarczyk, Piotr

2009-01-01

Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium

DEFF Research Database (Denmark)

Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E

2008-01-01

Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work...... was to investigate the functional and molecular expression of BK in the eel intestine, which is a useful experimental model for cell volume regulation research. In the present paper using rat BK channel-specific primer, a RT-PCR signal of 696 pb cDNA was detected in eel intestine, whole nucleotide sequence showed...... high similarity (83%) to the alpha subunit of BK channel family. BK channel protein expression was verified by immunoblotting and confocal microscopy, while the functional role of BK channels in epithelial ion transport mechanisms and cell volume regulation was examined by electrophysiological...

Large-conductance calcium-dependent potassium channels prevent dendritic excitability in neocortical pyramidal neurons.

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Benhassine, Narimane; Berger, Thomas

2009-03-01

Large-conductance calcium-dependent potassium channels (BK channels) are homogeneously distributed along the somatodendritic axis of layer 5 pyramidal neurons of the rat somatosensory cortex. The relevance of this conductance for dendritic calcium electrogenesis was studied in acute brain slices using somatodendritic patch clamp recordings and calcium imaging. BK channel activation reduces the occurrence of dendritic calcium spikes. This is reflected in an increased critical frequency of somatic spikes necessary to activate the distal initiation zone. Whilst BK channels repolarise the somatic spike, they dampen it only in the distal dendrite. Their activation reduces dendritic calcium influx via glutamate receptors. Furthermore, they prevent dendritic calcium electrogenesis and subsequent somatic burst discharges. However, the time window for coincident somatic action potential and dendritic input to elicit dendritic calcium events is not influenced by BK channels. Thus, BK channel activation in layer 5 pyramidal neurons affects cellular excitability primarily by establishing a high threshold at the distal action potential initiation zone.

Homogeneous distribution of large-conductance calcium-dependent potassium channels on soma and apical dendrite of rat neocortical layer 5 pyramidal neurons.

Science.gov (United States)

Benhassine, Narimane; Berger, Thomas

2005-02-01

Voltage-gated conductances on dendrites of layer 5 pyramidal neurons participate in synaptic integration and output generation. We investigated the properties and the distribution of large-conductance calcium-activated potassium channels (BK channels) in this cell type using excised patches in acute slice preparations of rat somatosensory cortex. BK channels were characterized by their large conductance and sensitivity to the specific blockers paxilline and iberiotoxin. BK channels showed a pronounced calcium-dependence with a maximal opening probability of 0.69 at 10 microm and 0.42 at 3 microm free calcium. Their opening probability and transition time constants between open and closed states are voltage-dependent. At depolarized potentials, BK channel gating is described by two open and one closed states. Depolarization increases the opening probability due to a prolongation of the open time constant and a shortening of the closed time constant. Calcium-dependence and biophysical properties of somatic and dendritic BK channels were identical. The presence of BK channels on the apical dendrite of layer 5 pyramidal neurons was shown by immunofluorescence. Patch-clamp recordings revealed a homogeneous density of BK channels on the soma and along the apical dendrite up to 850 microm with a mean density of 1.9 channels per microm(2). BK channels are expressed either isolated or in clusters containing up to four channels. This study shows the presence of BK channels on dendrites. Their activation might modulate the shape of sodium and calcium action potentials, their propagation along the dendrite, and thereby the electrotonic distance between the somatic and dendritic action potential initiation zones.

Reactivation of BK polyomavirus in patients with multiple sclerosis receiving natalizumab therapy.

LENUS (Irish Health Repository)

Lonergan, Roisin M

2012-02-01

Natalizumab therapy in multiple sclerosis has been associated with JC polyomavirus-induced progressive multifocal leucoencephalopathy. We hypothesized that natalizumab may also lead to reactivation of BK, a related human polyomavirus capable of causing morbidity in immunosuppressed groups. Patients with relapsing remitting multiple sclerosis treated with natalizumab were prospectively monitored for reactivation of BK virus in blood and urine samples, and for evidence of associated renal dysfunction. In this cohort, JC and BK DNA in blood and urine; cytomegalovirus (CMV) DNA in blood and urine; CD4 and CD8 T-lymphocyte counts and ratios in peripheral blood; and renal function were monitored at regular intervals. BK subtyping and noncoding control region sequencing was performed on samples demonstrating reactivation. Prior to commencement of natalizumab therapy, 3 of 36 patients with multiple sclerosis (8.3%) had BK viruria and BK reactivation occurred in 12 of 54 patients (22.2%). BK viruria was transient in 7, continuous in 2 patients, and persistent viruria was associated with transient viremia. Concomitant JC and CMV viral loads were undetectable. CD4:CD8 ratios fluctuated, but absolute CD4 counts did not fall below normal limits. In four of seven patients with BK virus reactivation, transient reductions in CD4 counts were observed at onset of BK viruria: these resolved in three of four patients on resuppression of BK replication. No renal dysfunction was observed in the cohort. BK virus reactivation can occur during natalizumab therapy; however, the significance in the absence of renal dysfunction is unclear. We propose regular monitoring for BK reactivation or at least for evidence of renal dysfunction in patients receiving natalizumab.

Membrane potential and cation channels in rat juxtaglomerular cells

DEFF Research Database (Denmark)

Friis, U G; Jørgensen, F; Andreasen, D

2004-01-01

The relationship between membrane potential and cation channels in juxtaglomerular (JG) cells is not well understood. Here we review electrophysiological and molecular studies of JG cells demonstrating the presence of large voltage-sensitive, calcium-activated potassium channels (BK(Ca)) of the Z......The relationship between membrane potential and cation channels in juxtaglomerular (JG) cells is not well understood. Here we review electrophysiological and molecular studies of JG cells demonstrating the presence of large voltage-sensitive, calcium-activated potassium channels (BK...

Evaluation of fluoroquinolones for the prevention of BK viremia after renal transplantation.

Science.gov (United States)

Gabardi, Steven; Waikar, Sushrut S; Martin, Spencer; Roberts, Keri; Chen, Jie; Borgi, Lea; Sheashaa, Hussein; Dyer, Christine; Malek, Sayeed K; Tullius, Stefan G; Vadivel, Nidyanandh; Grafals, Monica; Abdi, Reza; Najafian, Nader; Milford, Edgar; Chandraker, Anil

2010-07-01

Nearly 30% of renal transplant recipients develops BK viremia, a prerequisite for BK nephropathy. Case reports have evaluated treatment options for BK virus, but no controlled studies have assessed prophylactic therapies. Fluoroquinolone antibiotics were studied for prevention of BK viremia after renal transplantation. This retrospective analysis evaluated adult renal transplant recipients with at least one BK viral load (blood) between 90 and 400 days after transplantation. Six to 12 months of co-trimoxazole was used for Pneumocystis prophylaxis. In sulfa-allergic/-intolerant patients, 6 to 12 months of atovaquone with 1 month of a fluoroquinolone was used. Fluoroquinolones can inhibit BK DNA topoisomerase. The two groups studied were those that received 30 days of levofloxacin or ciprofloxacin after transplantation and those that did not. The primary endpoint was BK viremia rates at 1 year. Of note, of the 160 patients not receiving fluoroquinolone prophylaxis, 40 received a fluoroquinolone for treatment of a bacterial infection within 3 months after transplantation. Subgroup analysis evaluating these 40 patients against the 120 who had no exposure to fluoroquinolones was completed. A 1-month fluoroquinolone course after transplantation was associated with significantly lower rates of BK viremia at 1 year compared with those with no fluoroquinolone. In the subgroup analysis, exposure to fluoroquinolone for treatment of bacterial infections within 3 months after transplantation was associated with significantly lower 1-year rates of BK viremia. This analysis demonstrates that fluoroquinolones are effective at preventing BK viremia after renal transplantation.

Localization of Ca2+ -activated big-conductance K+ channels in rabbit distal colon

DEFF Research Database (Denmark)

Hay-Schmidt, Anders; Grunnet, Morten; Abrahamse, Salomon L

2003-01-01

Big-conductance Ca(2+)-activated K(+) channels (BK channels) may play an important role in the regulation of epithelial salt and water transport, but little is known about the expression level and the precise localization of BK channels in epithelia. The aim of the present study was to quantify a...

Regulation of cloned, Ca2+-activated K+ channels by cell volume changes

DEFF Research Database (Denmark)

Grunnet, Morten; MacAulay, Nanna; Jorgensen, Nanna K

2002-01-01

Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2+ into the ooc...

Apelin-13 inhibits large-conductance Ca2+-activated K+ channels in cerebral artery smooth muscle cells via a PI3-kinase dependent mechanism.

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Amit Modgil

Full Text Available Apelin-13 causes vasoconstriction by acting directly on APJ receptors in vascular smooth muscle (VSM cells; however, the ionic mechanisms underlying this action at the cellular level remain unclear. Large-conductance Ca(2+-activated K(+ (BKCa channels in VSM cells are critical regulators of membrane potential and vascular tone. In the present study, we examined the effect of apelin-13 on BK(Ca channel activity in VSM cells, freshly isolated from rat middle cerebral arteries. In whole-cell patch clamp mode, apelin-13 (0.001-1 μM caused concentration-dependent inhibition of BK(Ca in VSM cells. Apelin-13 (0.1 µM significantly decreased BK(Ca current density from 71.25 ± 8.14 pA/pF to 44.52 ± 7.10 pA/pF (n=14 cells, P<0.05. This inhibitory effect of apelin-13 was confirmed by single channel recording in cell-attached patches, in which extracellular application of apelin-13 (0.1 µM decreased the open-state probability (NPo of BK(Ca channels in freshly isolated VSM cells. However, in inside-out patches, extracellular application of apelin-13 (0.1 µM did not alter the NPo of BK(Ca channels, suggesting that the inhibitory effect of apelin-13 on BKCa is not mediated by a direct action on BK(Ca. In whole cell patches, pretreatment of VSM cells with LY-294002, a PI3-kinase inhibitor, markedly attenuated the apelin-13-induced decrease in BK(Ca current density. In addition, treatment of arteries with apelin-13 (0.1 µM significantly increased the ratio of phosphorylated-Akt/total Akt, indicating that apelin-13 significantly increases PI3-kinase activity. Taken together, the data suggest that apelin-13 inhibits BK(Ca channel via a PI3-kinase-dependent signaling pathway in cerebral artery VSM cells, which may contribute to its regulatory action in the control of vascular tone.

Molecular studies of BKCa channels in intracranial arteries

DEFF Research Database (Denmark)

Wulf, Helle; Hay-Schmidt, Anders; Poulsen, Asser Nyander

2008-01-01

expression of the BK(Ca) channel in rat basilar, middle cerebral, and middle meningeal arteries by reverse transcription polymerase chain reaction (RT-PCR), quantitative real-time PCR, and Western blotting. Distribution patterns were investigated using in situ hybridization and immunofluorescence studies. RT......  Large conductance calcium-activated potassium channels (BK(ca)) are crucial for the regulation of cerebral vascular basal tone and might be involved in cerebral vasodilation relevant to migraine and stroke. We studied the differential gene expression of mRNA transcript levels and protein......-PCR and quantitative real-time PCR detected the expression of the BK(Ca) channel mRNA transcript in rat basilar, middle cerebral, and middle meningeal arteries, with the transcript being expressed more abundantly in rat basilar arteries than in middle cerebral and middle meningeal arteries. Western blotting detected...

Levels of 250Cf populated in the decay of 250Bk

International Nuclear Information System (INIS)

Uecke, J.W.

1975-06-01

The nuclide 250 Bk undergoes β-decay with a half-life of 3.2 h to 13.1 y 250 Cf. A study is undertaken of the excited states in 250 Cf populated by 250 Bk decay which results from the α-decay of 276d 254 Es. The general features of published level schemes for these nuclei are consistent with predictions of the Nilsson and collective models; however, there remain many undiscovered transitions and ambiguous or uncertain level assignments. In an attempt to confirm predictions of current theoretical models which account for nuclear level assignments in this nucleus, these gamma transitions and their levels have been studied. Twenty-eight new γ-rays were determined. The decay of 250 Bk is investigated primarily by high resolution gamma-ray singles spectrometry and supported in part by two-parameter gamma-gamma coincidence spectrometry. The equipment, comprised of a Ge(HP) and a large volume Ge(Li) detector, a 4096-channel two-parameter analyzer, and a PDP-8/e computer system, permitted significant improvement in sensitivity and accuracy over previous investigations on this nucleus. (11 figures, 2 tables) (U.S.)

Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca2+-Activated K+ Channels In Vitro.

Science.gov (United States)

Su, Fang; Guo, An-Chen; Li, Wei-Wei; Zhao, Yi-Long; Qu, Zheng-Yi; Wang, Yong-Jun; Wang, Qun; Zhu, Yu-Lan

2017-02-01

Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion; however, the underlying mechanism has not been elucidated. In the present study, we showed that expression of the neuronal large-conductance, Ca 2+ -activated K + channel (BK Ca ) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) compared with controls. Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R, attenuated the OGD/R-induced elevation of cytosolic Ca 2+ levels, and reduced the number of apoptotic neurons. Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax. The protective effect of ethanol preconditioning was antagonized by a BK Ca channel inhibitor, paxilline. Inside-out patches in primary neurons also demonstrated the direct activation of the BK Ca channel by 10 mmol/L ethanol. The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca 2+ and preventing neuronal apoptosis, and this is mediated by BK Ca channel activation.

Melatonin mediates vasodilation through both direct and indirect activation of BKCa channels.

Science.gov (United States)

Zhao, T; Zhang, H; Jin, C; Qiu, F; Wu, Y; Shi, L

2017-10-01

Melatonin, synthesized primarily by the pineal gland, is a neuroendocrine hormone with high membrane permeability. The vascular effects of melatonin, including vasoconstriction and vasodilation, have been demonstrated in numerous studies. However, the mechanisms underlying these effects are not fully understood. Large-conductance Ca 2+ -activated K + (BK Ca ) channels are expressed broadly on smooth muscle cells and play an important role in vascular tone regulation. This study explored the mechanisms of myocyte BK Ca channels and endothelial factors underlying the action of melatonin on the mesenteric arteries (MAs). Vascular contractility and patch-clamp studies were performed on myocytes of MAs from Wistar rats. Melatonin induced significant vasodilation on MAs. In the presence of N ω -nitro-l-arginine methyl ester (l-NAME), a potent endothelial oxide synthase (eNOS) inhibitor, melatonin elicited concentration-dependent relaxation, with lowered pIC 50 The effect of melatonin was significantly attenuated in the presence of BK Ca channel blocker iberiotoxin or MT1/MT2 receptor antagonist luzindole in both (+) l-NAME and (-) l-NAME groups. In the (+) l-NAME group, iberiotoxin caused a parallel rightward shift of the melatonin concentration-relaxation curve, with pIC 50 lower than that of luzindole. Both inside-out and cell-attached patch-clamp recordings showed that melatonin significantly increased the open probability, mean open time and voltage sensitivity of BK Ca channels. In a cell-attached patch-clamp configuration, the melatonin-induced enhancement of BK Ca channel activity was significantly suppressed by luzindole. These findings indicate that in addition to the activation of eNOS, melatonin-induced vasorelaxation of MAs is partially attributable to its direct (passing through the cell membrane) and indirect (via MT1/MT2 receptors) activation of the BK Ca channels on mesenteric arterial myocytes. © 2017 Society for Endocrinology.

Hydrophobic interaction between contiguous residues in the S6 transmembrane segment acts as a stimuli integration node in the BK channel

Science.gov (United States)

Carrasquel-Ursulaez, Willy; Contreras, Gustavo F.; Sepúlveda, Romina V.; Aguayo, Daniel; González-Nilo, Fernando

2015-01-01

Large-conductance Ca2+- and voltage-activated K+ channel (BK) open probability is enhanced by depolarization, increasing Ca2+ concentration, or both. These stimuli activate modular voltage and Ca2+ sensors that are allosterically coupled to channel gating. Here, we report a point mutation of a phenylalanine (F380A) in the S6 transmembrane helix that, in the absence of internal Ca2+, profoundly hinders channel opening while showing only minor effects on the voltage sensor active–resting equilibrium. Interpretation of these results using an allosteric model suggests that the F380A mutation greatly increases the free energy difference between open and closed states and uncouples Ca2+ binding from voltage sensor activation and voltage sensor activation from channel opening. However, the presence of a bulky and more hydrophobic amino acid in the F380 position (F380W) increases the intrinsic open–closed equilibrium, weakening the coupling between both sensors with the pore domain. Based on these functional experiments and molecular dynamics simulations, we propose that F380 interacts with another S6 hydrophobic residue (L377) in contiguous subunits. This pair forms a hydrophobic ring important in determining the open–closed equilibrium and, like an integration node, participates in the communication between sensors and between the sensors and pore. Moreover, because of its effects on open probabilities, the F380A mutant can be used for detailed voltage sensor experiments in the presence of permeant cations. PMID:25548136

Molecular studies of BKCa channels in intracranial arteries: presence and localization

DEFF Research Database (Denmark)

Johansson, Helle Wulf; Hay-Schmidt, Anders; Poulsen, Asser Nyander

2008-01-01

of the BK(Ca) channel in rat basilar, middle cerebral, and middle meningeal arteries by reverse transcription polymerase chain reaction (RT-PCR), quantitative real-time PCR, and Western blotting. Distribution patterns were investigated using in situ hybridization and immunofluorescence studies. RT......Large conductance calcium-activated potassium channels (BK(ca)) are crucial for the regulation of cerebral vascular basal tone and might be involved in cerebral vasodilation relevant to migraine and stroke. We studied the differential gene expression of mRNA transcript levels and protein expression......-PCR and quantitative real-time PCR detected the expression of the BK(Ca) channel mRNA transcript in rat basilar, middle cerebral, and middle meningeal arteries, with the transcript being expressed more abundantly in rat basilar arteries than in middle cerebral and middle meningeal arteries. Western blotting detected...

Calcium Activated K+ Channels in The Electroreceptor of the Skate Confirmed by Cloning. Details of Subunits and Splicing

Science.gov (United States)

King, Benjamin L.; Shi, Ling Fang; Kao, Peter; Clusin, William T.

2015-01-01

Elasmobranchs detect small potentials using excitable cells of the ampulla of Lorenzini which have calcium-activated K+ channels, first described in l974. A distinctive feature of the outward current in voltage clamped ampullae is its apparent insensitivity to voltage. The sequence of a BK channel α isoform expressed in the ampulla of the skate was characterized. A signal peptide is present at the beginning of the gene. When compared to human isoform 1 (the canonical sequence), the largest difference was absence of a 59 amino acid region from the S8-S9 intracellular linker that contains the strex regulatory domain. The ampulla isoform was also compared with the isoform predicted˜ in late skate embryos where strex was also absent. The BK voltage sensors were conserved in both skate isoforms. Differences between the skate and human BK channel included alternative splicing. Alternative splicing occurs at seven previously defined sites that are characteristic for BK channels in general and hair cells in particular. Skate BK sequences were highly similar to the Australian ghost shark and several other vertebrate species. Based on alignment of known BK sequences with the skate genome and transcriptome, there are at least two isoforms of Kcnma1α expressed in the skate. One of the β subunits (β4), which is known to decrease voltage sensitivity, was also identified in the skate genome and transcriptome and in the ampulla. These studies advance our knowledge of BK channels and suggest further studies in the ampulla and other excitable tissues. PMID:26687710

Distribution, expression and functional effects of small conductance Ca-activated potassium (SK) channels in rat myometrium.

Science.gov (United States)

Noble, Karen; Floyd, Rachel; Shmygol, Andre; Shmygol, Anatoly; Mobasheri, A; Wray, Susan

2010-01-01

Calcium-activated potassium channels are important in a variety of smooth muscles, contributing to excitability and contractility. In the myometrium previous work has focussed on the large conductance channels (BK), and the role of small conductance channels (SK) has received scant attention, despite the finding that over-expression of an SK channel isoform (SK3) results in uterine dysfunction and delayed parturition. This study therefore characterises the expression of the three SK channel isoforms (SK1-3) in rat myometrium throughout pregnancy and investigates their effect on cytosolic [Ca] and force and compares this with that of BK channels. Consistent expression of all SK isoform transcripts and clear immunostaining of SK1-3 was found. Inhibition of SK1-3 channels (apamin, scyllatoxin) significantly inhibited outward current, caused membrane depolarisation and elicited action potentials in previously quiescent cells. Apamin or scyllatoxin increased the amplitude of [Ca] and force in spontaneously contracting myometrial strips throughout gestation. The functional effect of SK inhibition was larger than that of BK channel inhibition. Thus we show for the first time that SK1-3 channels are expressed and translated throughout pregnancy and contribute to outward current, regulate membrane potential and hence Ca signals in pregnant rat myometrium. They contribute more to quiescence that BK channels. 2009 Elsevier Ltd. All rights reserved.

Hydralazine-induced vasodilation involves opening of high conductance Ca2+-activated K+ channels

DEFF Research Database (Denmark)

Bang, Lone; Nielsen-Kudsk, J E; Gruhn, N

1998-01-01

The purpose of this study was to investigate whether high conductance Ca2+-activated K+ channels (BK(Ca)) are mediating the vasodilator action of hydralazine. In isolated porcine coronary arteries, hydralazine (1-300 microM), like the K+ channel opener levcromakalim, preferentially relaxed......M) suppressed this response by 82% (P opening of BK(Ca) takes part in the mechanism whereby...

Calcium activated K⁺ channels in the electroreceptor of the skate confirmed by cloning. Details of subunits and splicing.

Science.gov (United States)

King, Benjamin L; Shi, Ling Fang; Kao, Peter; Clusin, William T

2016-03-01

Elasmobranchs detect small potentials using excitable cells of the ampulla of Lorenzini which have calcium-activated K(+) channels, first described in 1974. A distinctive feature of the outward current in voltage clamped ampullae is its apparent insensitivity to voltage. The sequence of a BK channel α isoform expressed in the ampulla of the skate was characterized. A signal peptide is present at the beginning of the gene. When compared to human isoform 1 (the canonical sequence), the largest difference was absence of a 59 amino acid region from the S8-S9 intra-cellular linker that contains the strex regulatory domain. The ampulla isoform was also compared with the isoform predicted in late skate embryos where strex was also absent. The BK voltage sensors were conserved in both skate isoforms. Differences between the skate and human BK channel included alternative splicing. Alternative splicing occurs at seven previously defined sites that are characteristic for BK channels in general and hair cells in particular. Skate BK sequences were highly similar to the Australian ghost shark and several other vertebrate species. Based on alignment of known BK sequences with the skate genome and transcriptome, there are at least two isoforms of Kcnma1α expressed in the skate. One of the β subunits (β4), which is known to decrease voltage sensitivity, was also identified in the skate genome and transcriptome and in the ampulla. These studies advance our knowledge of BK channels and suggest further studies in the ampulla and other excitable tissues. Copyright © 2015 Elsevier B.V. All rights reserved.

Absorption of 249Bk from the gastrointestinal tract

International Nuclear Information System (INIS)

Zalikin, G.A.; Nisimov, P.G.

1988-01-01

In experimets with albino mongrel female rats a study was made of the absorption of 249 Bk from the gastrointestinal tract after a single per os administration. The bulk of 249 Bk (96 per cent) administered either intravenously or per os was mainly deposited in the skeleton and liver. The value of 249 Bk absorption from the gastrointestinal trat by days 4 and 8 following administration was 0.05 per cent

Dynamics of Db isotopes formed in reactions induced by 238U, 248Cm, and 249Bk across the Coulomb barrier

Science.gov (United States)

Kaur, Gurjit; Sandhu, Kirandeep; Kaur, Amandeep; Sharma, Manoj K.

2018-05-01

The dynamical cluster decay model is employed to investigate the decay of *265Db and *267Db nuclei, formed in the 27Al+238U , 18O+249Bk , and 19F+248Cm hot fusion reactions at energies around the Coulomb barrier. First, the fission dynamics of the 27Al+238U reaction is explored by investigating the fragmentation and preformation yield of the reaction. The symmetric mass distribution of the fission fragments is observed for *265Db nucleus, when static β2 i deformations are used within hot optimum orientation approach. However, the mass split gets broaden for the use of β2 i-dynamical hot configuration of the fragments and becomes clearly asymmetric for the cold-static-deformed approach. Within the application of cold orientations of fragments, a new fission channel is observed at mass asymmetry η =0.29 . In addition to 238U-induced reaction, the work is carried out to address the fission and neutron evaporation cross sections of *267Db nucleus formed via 19F+248Cm and 18O+249Bk reactions, besides a comprehensive analysis of fusion and capture processes. Higher fusion cross sections and compound nucleus formation probabilities (PCN) are obtained for the 18O+249Bk reaction, as larger mass asymmetry in the entrance channel leads to reduced Coulomb factor. Finally, the role of sticking (IS) and nonsticking (INS) moments of inertia is analyzed for the 4 n and 5 n channels of *267Db nuclear system.

Agnoprotein Is an Essential Egress Factor during BK Polyomavirus Infection

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Margarita-Maria Panou

2018-03-01

Full Text Available BK polyomavirus (BKPyV; hereafter referred to as BK causes a lifelong chronic infection and is associated with debilitating disease in kidney transplant recipients. Despite its importance, aspects of the virus life cycle remain poorly understood. In addition to the structural proteins, the late region of the BK genome encodes for an auxiliary protein called agnoprotein. Studies on other polyomavirus agnoproteins have suggested that the protein may contribute to virion infectivity. Here, we demonstrate an essential role for agnoprotein in BK virus release. Viruses lacking agnoprotein fail to release from host cells and do not propagate to wild-type levels. Despite this, agnoprotein is not essential for virion infectivity or morphogenesis. Instead, agnoprotein expression correlates with nuclear egress of BK virions. We demonstrate that the agnoprotein binding partner α-soluble N-ethylmaleimide sensitive fusion (NSF attachment protein (α-SNAP is necessary for BK virion release, and siRNA knockdown of α-SNAP prevents nuclear release of wild-type BK virions. These data highlight a novel role for agnoprotein and begin to reveal the mechanism by which polyomaviruses leave an infected cell.

Localization of large conductance calcium-activated potassium channels and their effect on calcitonin gene-related peptide release in the rat trigemino-neuronal pathway

DEFF Research Database (Denmark)

Wulf-Johansson, H.; Amrutkar, D.V.; Hay-Schmidt, Anders

2010-01-01

Large conductance calcium-activated potassium (BK(Ca)) channels are membrane proteins contributing to electrical propagation through neurons. Calcitonin gene-related peptide (CGRP) is a neuropeptide found in the trigeminovascular system (TGVS). Both BK(Ca) channels and CGRP are involved in migrai...

BK Virus-Associated Nephropathy without Viremia in an Adolescent Kidney Transplant Recipient

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Kraisoon Lomjansook, M.D.

2017-09-01

Full Text Available BK virus can reactivate in kidney transplant recipients leading to BK virus-associated nephropathy (BKVAN and allograft dysfunction. Pathogenesis begins with viral replication, follows by viruria, viremia and nephropathy. Screening tools recommended for viral detection are urine and blood BK viral load. Viremia has higher positive predictive value than viruria, thus several guidelines recommend using viremia to determine whether renal biopsy, a gold standard for diagnosis of BKVAN is needed. We present a 16-year-old boy who developed BKVAN five months after deceased donor kidney transplantation. He had increased serum creatinine with negative blood BK viral load. BK nephropathy was diagnosed in kidney graft biopsy. The urine showed BK viruria. Immunosuppressant was reduced and ciprofloxacin given. Viruria disappeared and repeated graft biopsy was normal 4 months later. BK viremia was negative through 1 year follow up. We conclude that BKVAN may occur even without viremia and BK viruria may be considered for screening tool.

Perbedaan Pemahaman Guru BK Tentang Konseling Kelompok antara Alumni Unnes dan Non-Unnes

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Desta Rizky Budiarti

2014-10-01

Full Text Available Tujuan penelitian ini untuk mengetahui gambaran pemahaman guru BK alumni Unnes dan guru BK alumni non-Unnes tentang konseling kelompok, dan perbedaan pemahaman diantara keduanya. Jenis penelitian adalah penelitian survey komparatif. Populasi penelitian ini yaitu guru BK di SMP Negeri se-Kota Semarang. Teknik sampling yang digunakan adalah Cluster Proportional Random Sampling. Metode pengumpulan data menggunakan tes tentang pemahaman konseling kelompok. Analisis datanya menggunakan analisis kuantitatif yang mencakup deskriptif prosentase dan uji beda t-test polled varian. Hasil penelitian menunjukkan bahwa ada perbedaan yang signifikan, dimana pemahaman guru BK alumni Unnes tentang konseling kelompok berada pada kategori sangat tinggi dengan persentase 84,26% dibandingkan dengan guru BK alumni non-Unnes yang memiliki persentase 63,9% berada pada kategori sedang. Simpulan dari penelitian ini, pemahaman guru BK tentang konseling kelompok antara alumni Unnes lebih tinggi daripada guru BK alumni non-Unnes. The purpose of this study to describe the understanding of BK teacher Unnes graduate and BK teacher non - Unnes graduates about group counseling, and understanding the differences between them . This type of research is a comparative survey research. The population of this study are in Junior High School teacher BK as the city of Semarang. The sampling technique used is proportional cluster random sampling. Methods of data collection using test on understanding group counseling. Analysis of the data using descriptive quantitative analysis that includes the percentage and t - test different test variants polled. The results showed that there were significant differences, where the understanding of BK teacher Unnes graduate  abaout  the counseling group in the category with a very high percentage of 84.26 % compared to a BK teacher non - Unnes graduates who have a percentage only 63.9 % are in the medium category. The conclusions of this study

BK channel activators and their therapeutic perspectives

DEFF Research Database (Denmark)

Bentzen, Bo Hjorth; Olesen, Søren-Peter; Rønn, Lars C B

2014-01-01

in intracellular calcium to outward hyperpolarizing potassium currents. Consequently, the channel has many important physiological roles including regulation of smooth muscle tone, neurotransmitter release and neuronal excitability. Additionally, cardioprotective roles have been revealed in recent years. After...

Pharmacological investigation of the role of ion channels in salivary secretion

DEFF Research Database (Denmark)

Stummann, Tina C; Poulsen, Jørgen H; Hay-Schmidt, Anders

2003-01-01

The role of K+ and Cl- channels in salivary secretion was investigated, with emphasis on the potential role of Ca2+ -activated K+ channels. Ligand saturation kinetic assays and autoradiography showed large-conductance (BK) K+ channels to be highly expressed in rat submandibular and parotid glands...

Inhibition of CUG-binding protein 1 and activation of caspases are critically involved in piperazine derivative BK10007S induced apoptosis in hepatocellular carcinoma cells.

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Ju-Ha Kim

Full Text Available Though piperazine derivative BK10007S was known to induce apoptosis in pancreatic cancer xenograft model as a T-type CaV3.1 a1G isoform calcium channel blocker, its underlying antitumor mechanism still remains unclear so far. Thus, in the present study, the antitumor mechanism of BK10007S was elucidated in hepatocellular carcinoma cells (HCCs. Herein, BK10007S showed significant cytotoxicity by 3-[4,5-2-yl]-2,5-diphenyltetra-zolium bromide (MTT assay and anti-proliferative effects by colony formation assay in HepG2 and SK-Hep1 cells. Also, apoptotic bodies and terminal deoxynucleotidyl transferase (TdT dUTP Nick End Labeling (TUNEL positive cells were observed in BK10007S treated HepG2 and SK-Hep1 cells by 4',6-diamidino-2-phenylinodole (DAPI staining and TUNEL assay, respectively. Consistently, BK10007S increased sub G1 population in HepG2 and SK-Hep1 cells by cell cycle analysis. Furthermore, Western blotting revealed that BK10007S activated the caspase cascades (caspase 8, 9 and 3, cleaved poly (ADP-ribose polymerase (PARP, and downregulated the expression of cyclin D1, survivin and for CUG-binding protein 1 (CUGBP1 or CELF1 in HepG2 and SK-Hep1 cells. Conversely, overexpression of CUGBP1 reduced cleavages of PARP and caspase 3, cytotoxicity and subG1 population in BK10007S treated HepG2 cells. Overall, these findings provide scientific evidences that BK10007S induces apoptosis via inhibition of CUGBP1 and activation of caspases in hepatocellular carcinomas as a potent anticancer candidate.

The role of voltage-gated potassium channels in the regulation of mouse uterine contractility

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Abel Peter W

2007-11-01

Full Text Available Abstract Background Uterine smooth muscle cells exhibit ionic currents that appear to be important in the control of uterine contractility, but how these currents might produce the changes in contractile activity seen in pregnant myometrium has not been established. There are conflicting reports concerning the role of voltage-gated potassium (Kv channels and large-conductance, calcium-activated potassium (BK channels in the regulation of uterine contractility. In this study we provide molecular and functional evidence for a role for Kv channels in the regulation of spontaneous contractile activity in mouse myometrium, and also demonstrate a change in Kv channel regulation of contractility in pregnant mouse myometrium. Methods Functional assays which evaluated the effects of channel blockers and various contractile agonists were accomplished by quantifying contractility of isolated uterine smooth muscle obtained from nonpregnant mice as well as mice at various stages of pregnancy. Expression of Kv channel proteins in isolated uterine smooth muscle was evaluated by Western blots. Results The Kv channel blocker 4-aminopyridine (4-AP caused contractions in nonpregnant mouse myometrium (EC50 = 54 micromolar, maximal effect at 300 micromolar but this effect disappeared in pregnant mice; similarly, the Kv4.2/Kv4.3 blocker phrixotoxin-2 caused contractions in nonpregnant, but not pregnant, myometrium. Contractile responses to 4-AP were not dependent upon nerves, as neither tetrodotoxin nor storage of tissues at room temperature significantly altered these responses, nor were responses dependent upon the presence of the endometrium. Spontaneous contractions and contractions in response to 4-AP did not appear to be mediated by BK, as the BK channel-selective blockers iberiotoxin, verruculogen, or tetraethylammonium failed to affect either spontaneous contractions or 4-AP-elicited responses. A number of different Kv channel alpha subunit proteins were

Study of the properties of the superheavy nuclei Z=117 produced in the 249Bk + 48Ca reaction

International Nuclear Information System (INIS)

Oganessian, Y.T.; Abdullin, F.S.; Dmitriev, S.N.; Itkis, M.G.; Polyakov, A.N.; Sagaidak, R.N.; Shirokovsky, I.V.; Shumeiko, M.V.; Subbotin, V.G.; Sukhov, A.M.; Tsyganov, Y.S.; Utyonkov, V.K.; Voinov, A.A.; Vostokin, G.K.; Alexander, C.; Binder, J.; Boll, R.A.; Ezold, J.; Felker, K.; Miernik, K.; Roberto, J.B.; Rykaczewski, K.P.; Gostic, J.M.; Henderson, R.A.; Moody, K.J.; Shaughnessy, D.H.; Stoyer, M.A.; Stoyer, N.J.; Grzywacz, R.K.; Miller, D.; Hamilton, J.H.; Ramayya, A.V.; Ryabinin, M.A.

2014-01-01

The reaction of 249 Bk with 48 Ca have been reinvestigated to provide new evidence for the discovery of element 117 on a larger number of events. The experiments were performed at five projectile energies and with a total beam dose of 48 Ca of about 4.6*10 19 . Two isotopes 293,294 117 were synthesized in the 249 Bk+ 48 Ca reaction, providing excitation functions and α-decay spectra of the produced isotopes that establishes these nuclei to be the products of the 4n- and 3n-evaporation channels, respectively. Decay properties of 293,294 117 and of all the daughter products agree with the data of the experiment in which these nuclei were synthesized for the first time in 2010. The new 289 115 events, populated by a decay of 293 117, demonstrate the same decay properties as those observed for 289 115 produced in the 243 Am( 48 Ca,2n) reaction thus providing cross-bombardment evidence. In addition, a single decay of 294 118 was observed from the reaction with 249 Cf - a result of the in-growth of 249 Cf in the 249 Bk target. (authors)

Compartmentalized beta subunit distribution determines characteristics and ethanol sensitivity of somatic, dendritic, and terminal large-conductance calcium-activated potassium channels in the rat central nervous system.

Science.gov (United States)

Wynne, P M; Puig, S I; Martin, G E; Treistman, S N

2009-06-01

Neurons are highly differentiated and polarized cells, whose various functions depend upon the compartmentalization of ion channels. The rat hypothalamic-neurohypophysial system (HNS), in which cell bodies and dendrites reside in the hypothalamus, physically separated from their nerve terminals in the neurohypophysis, provides a particularly powerful preparation in which to study the distribution and regional properties of ion channel proteins. Using electrophysiological and immunohistochemical techniques, we characterized the large-conductance calcium-activated potassium (BK) channel in each of the three primary compartments (soma, dendrite, and terminal) of HNS neurons. We found that dendritic BK channels, in common with somatic channels but in contrast to nerve terminal channels, are insensitive to iberiotoxin. Furthermore, analysis of dendritic BK channel gating kinetics indicates that they, like somatic channels, have fast activation kinetics, in contrast to the slow gating of terminal channels. Dendritic and somatic channels are also more sensitive to calcium and have a greater conductance than terminal channels. Finally, although terminal BK channels are highly potentiated by ethanol, somatic and dendritic channels are insensitive to the drug. The biophysical and pharmacological properties of somatic and dendritic versus nerve terminal channels are consistent with the characteristics of exogenously expressed alphabeta1 versus alphabeta4 channels, respectively. Therefore, one possible explanation for our findings is a selective distribution of auxiliary beta1 subunits to the somatic and dendritic compartments and beta4 to the terminal compartment. This hypothesis is supported immunohistochemically by the appearance of distinct punctate beta1 or beta4 channel clusters in the membrane of somatic and dendritic or nerve terminal compartments, respectively.

Infección por virus BK en paciente pediátrico trasplantado renal BK virus infection in a pediatric renal transplant recipient

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R. Bonaventura

2005-09-01

Full Text Available El poliomavirus humano BK causa infección primaria asintomática en la niñez, estableciendo latencia principalmente en el tracto urinario. En individuos con alteración en la inmunidad celular se puede producir su reactivación desencadenando patología a nivel renal. Por estas razones es particularmente importante en la población pediátrica trasplantada renal, en la que puede producir la infección primaria cuando el paciente está inmunosuprimido. En nuestro trabajo se realizó el seguimiento de un paciente de 5 años trasplantado renal en octubre de 2003 que 45 días post-trasplante sufrió un deterioro del órgano injertado. Desde la fecha del trasplante hasta junio de 2004 se produjeron 3 episodios de alteración en la función renal, durante los cuales se analizaron muestras de sangre, orina, biopsia renal y líquido de linfocele. Para el diagnóstico difererencial entre rechazo agudo versus causa infecciosa se emplearon técnicas de detección para los virus BK, CMV y ADV, además del estudio citológico del tejido renal. Los resultados obtenidos junto con la clínica del paciente indican un probable caso de infección por BK. La importancia de realizar el diagnóstico diferencial entre rechazo agudo y la infección por BK radica en que la conducta en cuanto a la terapia inmunosupresora es opuesta en cada caso.BK Human Polyomavirus causes an asymptomatic primary infection in children, then establishing latency mainly in the urinary tract. Viral reactivation can lead to renal pathology in individuals with impaired cellular immune response. This is particularly important in pediatric transplant recipients, who can suffer a primary infection when immunosupressed. We followed up the case of a 5 years old patient who received a renal transplant in October 2003, and presented damaged graft 45 days after the intervention. The patient suffered 3 episodes of renal function failure between October 2003 and June 2004. Blood, urine, renal biopsy

A Precise determination of B(K) in quenched QCD

CERN Document Server

Dimopoulos, P.; Palombi, F.; Pena, C.; Sint, S.; Vladikas, A.

2006-01-01

The $B_K$ parameter is computed in quenched lattice QCD with Wilson twisted mass fermions. Two variants of tmQCD are used; in both of them the relevant $\\Delta S = 2$ four-fermion operator is renormalised multiplicatively. The renormalisation adopted is non-perturbative, with a Schroedinger functional renormalisation condition. Renormalisation group running is also non-perturbative, up to very high energy scales. In one of the two tmQCD frameworks the computations have been performed at the physical $K$-meson mass, thus eliminating the need of mass extrapolations. Simulations have been performed at several lattice spacings and the continuum limit was reached by combining results from both tmQCD regularisations. Finite volume effects have been partially checked and turned out to be small. Exploratory studies have also been performed with non-degenerate valence flavours. The final result for the RGI bag parameter, with all sources of uncertainty (except quenching) under control, is $\\hat B_K =0.789 \\pm 0.046$.

Inflammatory mediator bradykinin increases population of sensory neurons expressing functional T-type Ca(2+) channels.

Science.gov (United States)

Huang, Dongyang; Liang, Ce; Zhang, Fan; Men, Hongchao; Du, Xiaona; Gamper, Nikita; Zhang, Hailin

2016-04-29

T-type Ca(2+) channels are important regulators of peripheral sensory neuron excitability. Accordingly, T-type Ca(2+) currents are often increased in various pathological pain conditions, such as inflammation or nerve injury. Here we investigated effects of inflammation on functional expression of T-type Ca(2+) channels in small-diameter cultured dorsal root ganglion (DRG) neurons. We found that overnight treatment of DRG cultures with a cocktail of inflammatory mediators bradykinin (BK), adenosine triphosphate (ATP), norepinephrine (NE) and prostaglandin E2 (PGE2) strongly increased the population size of the small-diameter neurons displaying low-voltage activated (LVA, T-type) Ca(2+) currents while having no effect on the peak LVA current amplitude. When applied individually, BK and ATP also increased the population size of LVA-positive neurons while NE and PGE2 had no effect. The PLC inhibitor U-73122 and B2 receptor antagonist, Hoe-140, both abolished the increase of the population of LVA-positive DRG neurons. Inflammatory treatment did not affect CaV3.2 mRNA or protein levels in DRG cultures. Furthermore, an ubiquitination inhibitor, MG132, did not increase the population of LVA-positive neurons. Our data suggest that inflammatory mediators BK and ATP increase the abundance of LVA-positive DRG neurons in total neuronal population by stimulating the recruitment of a 'reserve pool' of CaV3.2 channels, particularly in neurons that do not display measurable LVA currents under control conditions. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A comparison of HK-CONWIP and BK-CONWIP control strategies in a multi-product manufacturing system

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Chukwunonyelum Emmanuel Onyeocha

2015-12-01

Full Text Available This paper evaluates the performance of the Hybrid Kanban Constant Work-In-Process control strategy and Basestock Kanban Constant Work-In-Process control strategy operating Shared Kanban Allocation Policy (S-KAP and Dedicated Kanban Allocation Policy (D-KAP in a multi-product serial flow line. We explored the effect of an increase of product types on the WIP inventory in the system. A simulation-based optimisation technique was used in determining the optimal settings for the strategies. The strategies were compared via pairwise comparison technique and Nelson’s ranking and selection procedure. S-KAP responds quicker to demand than D-KAP. BK-CONWIP outperforms HK-CONWIP in a serial manufacturing system. It was shown that an increase in the number of product-type increases the number of PAC and WIP inventory.

Outcomes of renal transplant recipients with BK virus infection and BK virus surveillance in the Auckland region from 2006 to 2012.

Science.gov (United States)

Hsiao, Chun-Yuan; Pilmore, Helen L; Zhou, Lifeng; de Zoysa, Janak R

2016-11-06

To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy (BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus (BKV) surveillance programme. A cohort of 226 patients who received their renal transplants from 2006 to 2012 was retrospectively reviewed. Seventy-six recipients (33.6%) had a BK viral load (BKVL) test and 9 patients (3.9%) developed BKVN. Cold ischaemia time (HR = 1.18, 95%CI: 1.04-1.35) was found to be a risk factor for BKVN. Four recipients with BKVN had complete resolution of their BKV infection; 1 recipient had BKVL less than 625 copies/mL; 3 recipients had BKVL more than 1000 copies/mL and 1 had graft failure from BKVN. BKVN has a negative impact on graft function [median estimated glomerular filtration rate (eGFR) 22.5 (IQR 18.5-53.0) mL/min per 1.73 m 2 , P = 0.015), but no statistically significant difference ( P = 0.374) in renal allograft function was found among negative BK viraemia group [median eGFR 60.0 (IQR 48.5-74.2) mL/min per 1.73 m 2 ), positive BK viraemia without BKVN group [median eGFR 55.0 (IQR 47.0-76.0) mL/min per 1.73 m 2 ] and unknown BKV status group [median eGFR 54.0 (IQR 43.8-71.0) mL/min per 1.73 m 2 ]. The incidence and treatment outcomes of BKVN were similar to some centres with BKV surveillance programmes. Recipients with BVKN have poorer graft function. Although active surveillance for BKV has been shown to be effective in reducing incidence of BKVN, it should be tailored specifically to that transplant centre based on its epidemiology and outcomes of BKVN, particularly in centres with limited resources.

Numerical solution of incompressible flow through branched channels

Czech Academy of Sciences Publication Activity Database

Louda, Petr; Kozel, K.; Příhoda, Jaromír; Beneš, L.; Kopáček, T.

2011-01-01

Roč. 46, č. 1 (2011), s. 318-324 ISSN 0045-7930 R&D Projects: GA ČR GA103/09/0977; GA ČR GAP101/10/1230 Institutional research plan: CEZ:AV0Z20760514 Keywords : channel flow * branched channel * EARSM turbulence model Subject RIV: BK - Fluid Dynamics Impact factor: 1.810, year: 2011 http://www.sciencedirect.com/science/article/pii/S0045793010003506

Phase 1b randomized trial and follow-up study in Uganda of the blood-stage malaria vaccine candidate BK-SE36.

Science.gov (United States)

Palacpac, Nirianne Marie Q; Ntege, Edward; Yeka, Adoke; Balikagala, Betty; Suzuki, Nahoko; Shirai, Hiroki; Yagi, Masanori; Ito, Kazuya; Fukushima, Wakaba; Hirota, Yoshio; Nsereko, Christopher; Okada, Takuya; Kanoi, Bernard N; Tetsutani, Kohhei; Arisue, Nobuko; Itagaki, Sawako; Tougan, Takahiro; Ishii, Ken J; Ueda, Shigeharu; Egwang, Thomas G; Horii, Toshihiro

2013-01-01

Up to now a malaria vaccine remains elusive. The Plasmodium falciparum serine repeat antigen-5 formulated with aluminum hydroxyl gel (BK-SE36) is a blood-stage malaria vaccine candidate that has undergone phase 1a trial in malaria-naive Japanese adults. We have now assessed the safety and immunogenicity of BK-SE36 in a malaria endemic area in Northern Uganda. We performed a two-stage, randomized, single-blinded, placebo-controlled phase 1b trial (Current Controlled trials ISRCTN71619711). A computer-generated sequence randomized healthy subjects for 2 subcutaneous injections at 21-day intervals in Stage1 (21-40 year-olds) to 1-mL BK-SE36 (BKSE1.0) (n = 36) or saline (n = 20) and in Stage2 (6-20 year-olds) to BKSE1.0 (n = 33), 0.5-mL BK-SE36 (BKSE0.5) (n = 33), or saline (n = 18). Subjects and laboratory personnel were blinded. Safety and antibody responses 21-days post-second vaccination (Day42) were assessed. Post-trial, to compare the risk of malaria episodes 130-365 days post-second vaccination, Stage2 subjects were age-matched to 50 control individuals. Nearly all subjects who received BK-SE36 had induration (Stage1, n = 33, 92%; Stage2, n = 63, 96%) as a local adverse event. No serious adverse event related to BK-SE36 was reported. Pre-existing anti-SE36 antibody titers negatively correlated with vaccination-induced antibody response. At Day42, change in antibody titers was significant for seronegative adults (1.95-fold higher than baseline [95% CI, 1.56-2.43], p = 0.004) and 6-10 year-olds (5.71-fold [95% CI, 2.38-13.72], p = 0.002) vaccinated with BKSE1.0. Immunogenicity response to BKSE0.5 was low and not significant (1.55-fold [95% CI, 1.24-1.94], p = 0.75). In the ancillary analysis, cumulative incidence of first malaria episodes with ≥5000 parasites/µL was 7 cases/33 subjects in BKSE1.0 and 10 cases/33 subjects in BKSE0.5 vs. 29 cases/66 subjects in the control group. Risk ratio for BKSE1.0 was 0.48 (95% CI, 0

Pelaksanaan Asas-Asas BK dalam Pelayanan BK (Ditinjau dari Persepsi Siswa

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Yasinta Nur Miftakhul Jannah

2015-09-01

Full Text Available Penelitian ini didasarkan pada data dan fenomena yang ditemukan di lapangan yang menunjukkan rendahnya pelaksanaan asas-asas bimbingan dan konseling oleh konselor di sekolah. Penelitian ini bertujuan untuk mengetahui gambaran pelaksanaan asas-asas BK dalam pelayanan BK di SMA Negeri se-Kabupaten Pati (ditinjau dari persepsi siswa kelas XI Tahun Ajaran 2014/2015. Populasi penelitian ini adalah siswa kelas XI di SMA Negeri se-Kabupaten Pati. Pengambilan sampel penelitian dilakukan dengan menggunakan teknik proportionale homogen random sampling dengan sampel sebesar 307 siswa kelas XI. Metode pengumpulan data menggunakan skala psikologis dalam bentuk skala persepsi. Metode analisis data menggunakan statistik deskriptif persentase. Hasil dari penelitian menunjukkan, gambaran pelaksanaan asas-asas BK secara umum sudah masuk pada kategori baik dengan persentase sebesar 73,45%. Asas yang paling tinggi pelaksanaannya yaitu asas kegiatan dengan persentase sebesar 79,80%. Asas yang masih tergolong rendah persentase pelaksanaannya yaitu asas kekinian dengan persentase sebesar 68,80% dan asas alih tangan dengan persentase sebesar 69,10%. This research is based on data and phenomena found in a field that shows low  implementation of guidance and counseling principles by counselor at school. This research aims to find out the implementation of guidance and counseling principles in counseling services toward public senior high school throughout Pati Regency (reviewed from grade XI students’ perceptions Academic Year 2014/2015. Population of this research are grade XI public senior high school students throughout Pati Regency. Sampling in this research is done by using proportionale homogen random sampling technique with the number of samples 307 of grade IX. Collecting data method using psychological scale in the form of scale perception. Data analysis method which used is descriptive percentage. The result shows description of the implementation of

The oncogenic potential of BK-polyomavirus is linked to viral integration into the human genome.

Science.gov (United States)

Kenan, Daniel J; Mieczkowski, Piotr A; Burger-Calderon, Raquel; Singh, Harsharan K; Nickeleit, Volker

2015-11-01

It has been suggested that BK-polyomavirus is linked to oncogenesis via high expression levels of large T-antigen in some urothelial neoplasms arising following kidney transplantation. However, a causal association between BK-polyomavirus, large T-antigen expression and oncogenesis has never been demonstrated in humans. Here we describe an investigation using high-throughput sequencing of tumour DNA obtained from an urothelial carcinoma arising in a renal allograft. We show that a novel BK-polyomavirus strain, named CH-1, is integrated into exon 26 of the myosin-binding protein C1 gene (MYBPC1) on chromosome 12 in tumour cells but not in normal renal cells. Integration of the BK-polyomavirus results in a number of discrete alterations in viral gene expression, including: (a) disruption of VP1 protein expression and robust expression of large T-antigen; (b) preclusion of viral replication; and (c) deletions in the non-coding control region (NCCR), with presumed alterations in promoter feedback loops. Viral integration disrupts one MYBPC1 gene copy and likely alters its expression. Circular episomal BK-polyomavirus gene sequences are not found, and the renal allograft shows no productive polyomavirus infection or polyomavirus nephropathy. These findings support the hypothesis that integration of polyomaviruses is essential to tumourigenesis. It is likely that dysregulation of large T-antigen, with persistent over-expression in non-lytic cells, promotes cell growth, genetic instability and neoplastic transformation. © 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Bk and Cf chromatographic separation and 249Bk/248Cm and 249Cf/248Cm elemental ratios determination by inductively coupled plasma quadrupole mass spectrometry

International Nuclear Information System (INIS)

Gourgiotis, A.; Isnard, H.; Nonell, A.; Aubert, M.; Stadelmann, G.; Dupont, E.; AlMahamid, I.; Tiang, G.; Rao, L.; Lukens, W.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.

2013-01-01

The French Atomic Energy Commission has carried out several experiments for the study of minor-actinide transmutation processes in high intensity thermal neutron flux. In this context a Cm sample enriched in 248 Cm (97%) was irradiated in a thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). The precise and accurate determination of Cf isotope ratios and of 249 Bk/ 248 Cm and 249 Cf/ 248 Cm elemental ratios in the 248 Cm irradiated sample is crucial for the calculation of actinide neutron capture cross-sections.This work describes an analytical procedure for the separation and the isotope ratio measurement of Bk and Cf in the irradiated sample.The Bk and Cf separation is based on a lanthanides separation protocol previously developed by the laboratory. Well-defined retention times for Bk and Cf were obtained by coupling the Ionic Chromatography (IC) with an ICP-QMS. All conditions of element separation by IC and the different steps of the analytical protocol in order to obtain the isotopic and elemental ratios are presented. Relative uncertainties of Cf isotopic ratios range from 0.3% to 0.5% and the uncertainty of the 249 Bk/ 248 Cm and 249 Cf/ 248 Cm elemental ratios are respectively 6.1% and 3.2%.This level of uncertainty for both isotopic and elemental ratios is in perfect agreement with the requirement for transmutation studies. (authors)

Urinary BK virus excretion in children newly diagnosed with acute lymphoblastic leukemia

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Nahid Raeesi

2012-01-01

Conclusion: To demonstrate the role of BK virus in inducing ALL or increasing the number of relapses, prospective studies on larger scale of population and evaluating both serum and urine for BK virus are recommended.

Molecular mapping of qBK1 WD , a major QTL for bakanae disease resistance in rice.

Science.gov (United States)

Lee, Sais-Beul; Hur, Yeon-Jae; Cho, Jun-Hyeon; Lee, Jong-Hee; Kim, Tae-Heon; Cho, Soo-Min; Song, You-Chun; Seo, Young-Su; Lee, Jungkwan; Kim, Tae-Sung; Park, Yong-Jin; Oh, Myung-Kyu; Park, Dong-Soo

2018-01-10

Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring bakanae disease resistance from the highly resistant japonica variety Wonseadaesoo. A primary QTL study using the genotypes/phenotypes of the recombinant inbred lines (RILs) indicated that the locus qBK1 WD conferring resistance to bakanae disease from Wonseadaesoo was located in a 1.59 Mb interval delimited on the physical map between chr01_13542347 (13.54 Mb) and chr01_15132528 (15.13 Mb). The log of odds (LOD) score of qBK1 WD was 8.29, accounting for 20.2% of the total phenotypic variation. We further identified a gene pyramiding effect of two QTLs, qBK WD and previously developed qBK1. The mean proportion of healthy plant for 31 F 4 RILs that had no resistance genes was 35.3%, which was similar to that of the susceptible check variety Ilpum. The proportion of healthy plants for the lines with only qBK WD or qBK1 was 66.1% and 55.5%, respectively, which was significantly higher than that of the lines without resistance genes and that of Ilpum. The mean proportion of the healthy plant for 15 F 4 RILs harboring both qBK WD and qBK1 was 80.2%, which was significantly higher than that of the lines with only qBK WD or qBK1. Introducing qBK WD or pyramiding the QTLs qBK WD and qBK1 could provide effective tools for breeding rice with bakanae disease resistance. To our knowledge, this is the first report on a gene pyramiding effect that provides higher resistance against bakanae disease.

Vascular ATP-sensitive potassium channels are over-expressed and partially regulated by nitric oxide in experimental septic shock.

Science.gov (United States)

Collin, Solène; Sennoun, Nacira; Dron, Anne-Gaëlle; de la Bourdonnaye, Mathilde; Montemont, Chantal; Asfar, Pierre; Lacolley, Patrick; Meziani, Ferhat; Levy, Bruno

2011-05-01

To study the activation and expression of vascular (aorta and small mesenteric arteries) potassium channels during septic shock with or without modulation of the NO pathway. Septic shock was induced in rats by peritonitis. Selective inhibitors of vascular K(ATP) (PNU-37883A) or BK(Ca) [iberiotoxin (IbTX)] channels were used to demonstrate their involvement in vascular hyporeactivity. Vascular response to phenylephrine was measured on aorta and small mesenteric arteries mounted on a wire myograph. Vascular expression of potassium channels was studied by PCR and Western blot, in the presence or absence of 1400W, an inducible NO synthase (iNOS) inhibitor. Aortic activation of the transcriptional factor nuclear factor-kappaB (NF-κB) was assessed by electrophoretic mobility shift assay. Arterial pressure as well as in vivo and ex vivo vascular reactivity were reduced by sepsis and improved by PNU-37883A but not by IbTX. Sepsis was associated with an up-regulation of mRNA and protein expression of vascular K(ATP) channels, while expression of vascular BK(Ca) channels remained unchanged. Selective iNOS inhibition blunted the sepsis-induced increase in aortic NO, decreased NF-κB activation, and down-regulated vascular K(ATP) channel expression. Vascular K(ATP) but not BK(Ca) channels are activated, over-expressed, and partially regulated by NO via NF-κB activation during septic shock. Their selective inhibition restores arterial pressure and vascular reactivity and decreases lactate concentration. The present data suggest that selective vascular K(ATP) channel inhibitors offer potential therapeutic perspectives for septic shock.

Impact of two different commercial DNA extraction methods on BK virus viral load

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Massimiliano Bergallo

2016-03-01

Full Text Available Background and aim: BK virus, a member of human polyomavirus family, is a worldwide distributed virus characterized by a seroprevalence rate of 70-90% in adult population. Monitoring of viral replication is made by evaluation of BK DNA by quantitative polymerase chain reaction. Many different methods can be applied for extraction of nucleic acid from several specimens. The aim of this study was to assess the impact of two different DNA extraction procedure on BK viral load. Materials and methods: DNA extraction procedure including the Nuclisens easyMAG platform (bioMerieux, Marcy l’Etoile, France and manual QIAGEN extraction (QIAGEN Hilden, Germany. BK DNA quantification was performed by Real Time TaqMan PCR using a commercial kit. Result and discussion: The samples capacity, cost and time spent were compared for both systems. In conclusion our results demonstrate that automated nucleic acid extraction method using Nuclisense easyMAG was superior to manual protocol (QIAGEN Blood Mini kit, for the extraction of BK virus from serum and urine specimens.

Identification of the new isotope sup 2 sup 4 sup 1 Bk

CERN Document Server

Asai, M; Ichikawa, S; Nagame, Y; Nishinaka, I; Akiyama, K; Toyoshima, A; Kaneko, T; Sakama, M; Haba, H; Oura, Y; Kojima, Y; Shibata, M

2003-01-01

A new neutron-deficient berkelium isotope sup 2 sup 4 sup 1 Bk produced in the sup 2 sup 3 sup 9 Pu( sup 6 Li, 4n) reaction has been identified using a gas-jet coupled on-line isotope separator. Cm K and L X-rays associated with the EC decay of sup 2 sup 4 sup 1 Bk were observed in the mass-241 fraction, and three gamma transitions were attributed to the EC decay of sup 2 sup 4 sup 1 Bk through X-gamma coincidences. The half-life of sup 2 sup 4 sup 1 Bk was determined to be 4.6+-0.4 min which is 1/2-1/4 of that of theoretical predictions. The half-life value and the observed gamma transitions can be consistently explained as a consequence of the allowed EC transition of pi 7/2 sup + [633] -> nu 7/2 sup + [624]. (orig.)

Bifurcating channels supplying "numbered-up" microreactors

Czech Academy of Sciences Publication Activity Database

Tesař, Václav

2011-01-01

Roč. 89, č. 12A (2011), s. 2507-2020 ISSN 0263-8762 R&D Projects: GA ČR(CZ) GCP101/11/J019 Institutional research plan: CEZ:AV0Z20760514 Keywords : microfluidics * branched channels * geometric self-similarity Subject RIV: BK - Fluid Dynamics Impact factor: 1.968, year: 2011 http://www.sciencedirect.com/science/article/pii/S0263876211001821

Control of a channel-flow behind a backward-facing step by suction/blowing

Czech Academy of Sciences Publication Activity Database

Uruba, Václav; Jonáš, Pavel; Mazur, Oton

2007-01-01

Roč. 28, č. 4 (2007), s. 665-672 ISSN 0142-727X R&D Projects: GA AV ČR IAA2076403 Institutional research plan: CEZ:AV0Z20760514 Keywords : boundary layer separation * boundary layer reattachement * control Subject RIV: BK - Fluid Dynamics Impact factor: 1.283, year: 2007

Mitochondrial BK Channel Openers CGS7181 and CGS7184 Exhibit Cytotoxic Properties

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Bartłomiej Augustynek

2018-01-01

Full Text Available Potassium channel openers (KCOs have been shown to play a role in cytoprotection through the activation of mitochondrial potassium channels. Recently, in several reports, a number of data has been described as off-target actions for KCOs. In the present study, we investigated the effects of BKCa channel openers CGS7181, CGS7184, NS1619, and NS004 in neuronal cells. For the purpose of this research, we used a rat brain, the mouse hippocampal HT22 cells, and the human astrocytoma U-87 MG cell line. We showed that CGS7184 activated the mitochondrial BKCa (mitoBKCa channel in single-channel recordings performed on astrocytoma mitoplasts. Moreover, when applied to the rat brain homogenate or isolated rat brain mitochondria, CGS7184 increased the oxygen consumption rate, and can thus be considered a potentially cytoprotective agent. However, experiments on intact neuronal HT22 cells revealed that both CGS7181 and CGS7184 induced HT22 cell death in a concentration- and time-dependent manner. By contrast, we did not observe cell death when NS1619 or NS004 was applied. CGS7184 toxicity was not abolished by BKCa channel inhibitors, suggesting that the observed effects were independent of a BKCa-type channel activity. CGS7184 treatment resulted in an increase of cytoplasmic Ca2+ concentration that likely involved efflux from internal calcium stores and the activation of calpains (calcium-dependent proteases. The cytotoxic effect of the channel opener was partially reversed by a calpain inhibitor. Our data show that KCOs under study not only activate mitoBKCa channels from brain tissue, but also induce cell death when used in cellular models.

Rapid detection of urinary polyomavirus BK by heterodyne-based surface plasmon resonance biosensor

Science.gov (United States)

Su, Li-Chen; Tian, Ya-Chung; Chang, Ying-Feng; Chou, Chien; Lai, Chao-Sung

2014-01-01

In renal transplant patients, immunosuppressive therapy may result in the reactivation of polyomavirus BK (BKV), leading to polyomavirus-associated nephropathy (PVAN), which inevitably causes allograft failure. Since the treatment outcomes of PVAN remain unsatisfactory, early identification and continuous monitoring of BKV reactivation and reduction of immunosuppressants are essential to prevent PVAN development. The present study demonstrated that the developed dual-channel heterodyne-based surface plasmon resonance (SPR) biosensor is applicable for the rapid detection of urinary BKV. The use of a symmetrical reference channel integrated with the poly(ethylene glycol)-based low-fouling self-assembled monolayer to reduce the environmental variations and the nonspecific noise was proven to enhance the sensitivity in urinary BKV detection. Experimentally, the detection limit of the biosensor for BKV detection was estimated to be around 8500 copies/mL. In addition, urine samples from five renal transplant patients were tested to rapidly distinguish PVAN-positive and PVAN-negative renal transplant patients. By virtue of its simplicity, rapidity, and applicability, the SPR biosensor is a remarkable potential to be used for continuous clinical monitoring of BKV reactivation.

An ERG channel inhibitor from the scorpion Buthus eupeus

DEFF Research Database (Denmark)

Korolkova, Y.V.; Kozlov, S.A.; Lipkin, A.V.

2001-01-01

and the three mutants partly inhibited the native M-like current in NG108-15 at 100 nm. The effect of the recombinant BeKm-1 on different K(+) channels was also studied. BeKm-1 inhibited hERG1 channels with an IC(50) of 3.3 nm, but had no effect at 100 nm on hEAG, hSK1, rSK2, hIK, hBK, KCNQ1/KCNE1, KCNQ2/KCNQ3......, KCNQ4 channels, and minimal effect on rELK1. Thus, BeKm-1 was shown to be a novel specific blocker of hERG1 potassium channels....

Diagnosis of BK viral nephropathy in the renal allograft biopsy: role of fluorescence in situ hybridization.

Science.gov (United States)

Wang, Zhen; Portier, Bryce P; Hu, Bo; Chiesa-Vottero, Andres; Myles, Jonathan; Procop, Gary W; Tubbs, Raymond R

2012-09-01

Early recognition of BK viral nephropathy is essential for successful management. Our aim in this study was to evaluate a novel fluorescence in situ hybridization (FISH) assay for detection of BK virus in renal transplant biopsies in the context of standard detection methods. Renal allograft biopsies (n = 108) were analyzed via H&E, immunohistochemistry (IHC) for simian virus 40, and FISH for BK virus. BK virus was detected in 16 (14.8%) cases by H&E, 13 (12%) cases by IHC, 18 (16.6%) cases by FISH, and 19 (17.6%) cases by real-time PCR; 24 of 108 showed a discrepancy in ≥1 testing modalities. Comparison of H&E, IHC, and FISH showed no statistical difference in detection of BK virus. However, performing comparisons between the different tissue-based assays in the context of plasma or urine real-time PCR results showed significant improvement in detection of BK by FISH over H&E (P = 0.02) but not IHC (P = 0.07). This novel FISH-based approach for BK virus identification in renal allograft biopsy tissue mirrored real-time PCR results and showed superior performance to detection of inclusions by H&E. Therefore, use of FISH for BK virus detection in the setting of renal allograft biopsy is a useful and sensitive detection method and could be adopted in any laboratory that currently performs FISH analysis. Copyright © 2012 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Identification of pyrolysis products of the new psychoactive substance 2-amino-1-(4-bromo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-B) and its iodo analogue bk-2C-I.

Science.gov (United States)

Texter, Kelly B; Waymach, Rachel; Kavanagh, Pierce V; O'Brien, John E; Talbot, Brian; Brandt, Simon D; Gardner, Elizabeth A

2018-01-01

2-Amino-1-(4-bromo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-B) has recently emerged as a new psychoactive substance (NPS). It is most commonly consumed orally, although there are indications that it might also be ingested by inhalation or 'smoking'. Information about the stability of bk-2C-B when exposed to heat is unavailable and the potential for pyrolytic degradation and formation of unknown substances available for inhalation prompted an investigation using a simulated 'meth pipe' scenario. Twelve products following pyrolysis of bk-2C-B were detected and verified by organic synthesis of the corresponding standards. In addition, 2-amino-1-(4-iodo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-I) was characterized for the first time and subjected to pyrolysis as well. Similar products were formed, which indicated that the replacement of the bromo with the iodo substituent did not affect the pyrolysis pattern under the conditions used. Two additional products were detected in the bk-2C-I pyrolates, namely 1-(2,5-dimethoxyphenyl)-ethanone and 1-iodo-4-ethenyl-5-methoxyphenol. The potential ingestion of pyrolysis products with unknown toxicity adds an element of concern. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

BK Virus Load Associated with Serum Levels of sCD30 in Renal Transplant Recipients

Science.gov (United States)

Malik, Salma N.; Al-Saffer, Jinan M.; Jawad, Rana S.

2016-01-01

Background. Rejection is the main drawback facing the renal transplant operations. Complicated and overlapping factors, mainly related to the immune system, are responsible for this rejection. Elevated serum levels of sCD30 were frequently recorded as an indicator for renal allograft rejection, while BV virus is considered as one of the most serious consequences for immunosuppressive treatment of renal transplant recipients (RTRs). Aims. This study aimed to determine the association of BK virus load with serum levels of sCD30 in RTRs suffering from nephropathy. Patients and Methods. A total of 50 RTRs with nephropathy and 30 age-matched apparently healthy individuals were recruited for this study. Serum samples were obtained from each participant. Real-time PCR was used to quantify BK virus load in RTRs serum, while ELISA technique was employed to estimate serum levels of sCD30. Results. Twenty-two percent of RTRs had detectable BKV with mean viral load of 1.094E + 06 ± 2.291E + 06. RTRs showed higher mean serum level of sCD30 (20.669 ± 18.713 U/mL) than that of controls (5.517 ± 5.304 U/mL) with significant difference. BK virus load had significant positive correlation with the serum levels of sCD30 in RTRs group. Conclusion. These results suggest that serum levels of sCD30 could be used as an indicator of BK viremia, and accordingly the immunosuppressive regime should be adjusted. PMID:27051424

Production and decay of the heaviest odd-Z nuclei in the 249Bk + 48Ca reaction

International Nuclear Information System (INIS)

Oganessian, Yu Ts; Abdullin, F Sh; Dmitriev, S N; Itkis, M G; Polyakov, A N; Alexander, C; Binder, J; Boll, R A; Ezold, J; Felker, K; Grzywacz, R K; Miernik, K; Roberto, J B; Gostic, J M; Henderson, R A; Moody, K J; Hamilton, J H; Ramayya, A V; Miller, D; Ryabinin, M A

2015-01-01

The reaction of 249 Bk with 48 Ca has been investigated with an aim of synthesizing and studying the decay properties of isotopes of the new element 117. The experiments were performed at five projectile energies (in two runs, in 2009-2010 and 2012) and with a total beam dose of 48 Ca ions of about 9x10 19 The experiments yielded data on a-decay characteristics and excitation functions of the produced nuclei that establish these to be 293 117 and 294 117 – the products of the 4n- and 3n-evaporation channels, respectively. In total, we have observed 20 decay chains of Z=117 nuclides. The cross sections were measured to be 1.1 pb for the 3n and 2.4 pb for the 4n-reaction channel. The new 289 115 events, populated by α decay of 117, demonstrate the same decay properties as those observed for 115 produced in the 243 Am( 48 Ca,2n) reaction thus providing cross-bombardment evidence. In addition, a single decay of 294 118 was observed from the reaction with 249 Cf – a result of the in-growth of 249 Cf in the 249 Bk target. The observed decay chain of 294 118 is in good agreement with decay properties obtained in 2002-2005 in the experiments with the reaction 249 Cf( 48 Ca,3n) 294 118. The energies and half-lives of the odd-Z isotopes observed in the 117 decay chains together with the results obtained for lower-Z superheavy nuclei demonstrate enhancement of nuclear stability with increasing neutron number towards the predicted new magic number N=184

Time-resolved resonance Raman spectroscopy of intermediates of bacteriorhodopsin: The bK(590) intermediate.

Science.gov (United States)

Terner, J; Hsieh, C L; Burns, A R; El-Sayed, M A

1979-07-01

We have combined microbeam and flow techniques with computer subtraction methods to obtain the resonance Raman spectrum of the short lived batho-intermediate (bK(590)) of bacteriorhodopsin. Comparison of the spectra obtained in (1)H(2)O and (2)H(2)O, as well as the fact that the bK(590) intermediate shows large optical red shifts, suggests that the Schiff base linkage of this intermediate is protonated. The fingerprint region of the spectrum of bK(590), sensitive to the isomeric configuration of the retinal chromophore, does not resemble the corresponding region of the parent bR(570) form. The resonance Raman spectrum of bK(590) as well as the spectra of all of the other main intermediates in the photoreaction cycle of bacteriorhodopsin are discussed and compared with resonance Raman spectra of published model compounds.

Surveillance of polyomavirus BK in relation to immunosuppressive therapy in kidney transplantation

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Cristina Costa

2012-03-01

Full Text Available Introduction. Reactivation of polyomavirus BK in kidney transplant recipients has been associated to the development of nephropathy (polyomavirus-associated nephropathy, PVAN, possibly leading to the loss of the transplanted organ. Immunosuppression is the condicio sine qua non for the onset of PVAN; however, a lower incidence of BK viremia has been reported with low-level tacrolimus based immunosuppressive protocols in comparison to cyclosporine A.Aim of this study was to compare the two immunosuppressive protocols. Methods. Virological monitoring of BK was performed in 468 consecutive renal transplant patients over a period of 3 years (2370 urine e 2370 serum specimens: in particular, 1780 specimens from 362 patients treated with tacrolimus and 590 from 106 treated with cyclosporine A. Results. BK viremia was evidenced in 124 (7.0% and 12 (2.0% specimens from 40 (11.0% and 11 (10.4% patients treated with tacrolimus and cyclosporine A, respectively; similarly, BK viruria in 289 (16.2% and 58 (9.8% specimens from 67 (18.5% and 27 (25.5% patients, being the difference of incidence highly significant (p <0.0001 for both viremia and viruria at comparison between specimens and not significant for patients. No case of PVAN was diagnosed at histophatology evaluation. Conclusions. The incidence of viremia and viruria was similar to that previously reported. Our results evidenced that with low-level tacrolimus-based protocols the overall incidence of reactivation in renal transplant patients is not significantly different and there is no increased risk of PVAN, nevertheless the higher incidence of episodes of reactivation.

Modelling of supercritical turbulent flow over transversal ribs in an open channel

Czech Academy of Sciences Publication Activity Database

Příhoda, Jaromír; Šulc, J.; Sedlář, M.; Zubík, P.

2009-01-01

Roč. 16, č. 1 (2009), s. 65-74 ISSN 1802-1484 R&D Projects: GA ČR GA103/06/0461 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbulent flow in open channels * flow over obstacles Subject RIV: BK - Fluid Dynamics

Preliminary study on rotary ultrasonic machining of Bk-7 optical glass rod

International Nuclear Information System (INIS)

Hamzah, E.; Izman, S.; Khoo, C.Y.; Zainal Abidin, N.N.

2007-01-01

This paper presents an experimental observation on rotary ultrasonic machining (RUM) of BK7 optical glass rod. BK7 is a common technical optical glass for high quality optical components due to its high linear optical transmission in the visible range and is chemically stable. RUM is a hybrid machining process that combines the material removal mechanisms of diamond grinding and ultrasonic machining (USM) and it is non-thermal, non-chemical, creates no change in the microstructure, chemical or physical properties of the work piece. In the RUM, a controlled static load is applied to the rotating core drill with metal bonded diamond abrasive and is ultrasonically vibrated in the axial direction. A water-soluble coolant was used to cool the tool and sample during machining processes. By using DOE (Design of Experiment) approach, the effect of spindle speed and feed rate to the ultrasonic machinability had been developed. The main effects and two-factor interactions of process parameters (spindle speed) and feed rate) on output variables (MRR, surface roughness, opaqueness, chipping thickness and chipping size) are studied. (author)

Persepsi Guru BK Tentang Kompetensi Konselor di Sekolah Dasar Swasta Kota Semarang

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Restu Setyoningtyas

2014-10-01

Full Text Available Tujuan penelitian ini adalah untuk mengetahui tentang persepsi guru BK tentang kompetensi konselor di sekolah dasar swasta Kota Semarang. Penelitian ini bersifat kuantitatif, responden penelitian adalah guru BK sekolah dasar swasta, teknik pengumpulan data berupa skala psikologi dan dokumentasi. Analisis data menggunakan Analisis Deskriptif Persentase. Hasil penelitian menunjukkan persepsi guru BK tentang kompetensi konselor mendapatkan hasil yang positif. Kompetensi pedagogik yaitu positif, kepribadian yaitu kurang positif, sosial yaitu kurang positif, profesional yaitu cukup positif. Kesimpulan dari penelitian ini adalah persepsi guru BK tentang kompetensi konselor di sekolah dasar swasta Kota Semarang pada umumnya positif. The purpose of this research is determine perception guidance and counseling teacher about counselor competence in private elementary school on Semarang city. This research is quantitative. Respondens is guidance and counseling teacher from private elementary school, techniques of data collection are psychology scale and documentation. The data analysis using Analysis Descriptive Percentage. Result showed that research is perception  guidance and counseling teacher about counselor competence is positive. Pedagogic competence is positive, personality is not positive enough, social is not positive enough, professional is positive enough. The conclusion of this research is perception guidance and counseling teacher about counselor competence in private elementary school on Semarang city in general is positive.

On the flow around Glauert-Goldschmied body in the narrow channel and separation control strategy

Czech Academy of Sciences Publication Activity Database

Procházka, Pavel P.; Uruba, Václav

2016-01-01

Roč. 16, č. 1 (2016), s. 643-644 ISSN 1617-7061 R&D Projects: GA ČR(CZ) GP14-25354P Institutional support: RVO:61388998 Keywords : PIV * active flow control * Glauert-Goldschmied body Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/doi/10.1002/pamm.201610310/full

Molecular cloning of a K+ channel from the malaria parasite Plasmodium falciparum

DEFF Research Database (Denmark)

Ellekvist, Peter; Ricke, Christina Høier; Litman, Thomas

2004-01-01

In most living cells, K(+) channels are important for the generation of the membrane potential and for volume regulation. The parasite Plasmodium falciparum, which causes malignant malaria, must be able to deal with large variations in the ambient K(+) concentration: it is exposed to high...... concentrations of K(+) when inside the erythrocyte and low concentrations when in plasma. In the recently published genome of P. falciparum, we have identified a gene, pfkch1, encoding a potential K(+) channel, which to some extent resembles the big-conductance (BK) K(+) channel. We have cloned the approximately...

Pemahaman Guru BK Tentang Pelaksanaan Layanan Peminatan pada Kurikulum 2013

Directory of Open Access Journals (Sweden)

Finda Marsetyana

2015-04-01

Full Text Available Penelitian ini dilakukan berdasar fenomena yaitu belum adanya kesiapan tentang program peminatan di SMK Negeri se-Kota Semarang. Tujuan penelitian secara umum untuk mengetahui pemahaman guru BK tentang pelaksanaan layanan peminatan pada kurikulum 2013 di SMK Negeri se-Kota Semarang. Medote pengumpulan data yaitu angket tertutup yang diberikan kepada 44 orang guru BK SMK Negeri se Kota Semarang. Analisis data menggunakan analisis deskriptif persentase. Hasil penelitian dari Pemahaman Guru BK Tentang Pelaksanaan Layanan Peminatan Pada Kurikulum 2013 Di SMK Negeri Se-Kota Semarang termasuk dalam kategori tinggi (71.59% dengan perincian indikator variabel yaitu pemahaman guru BK tentang kurikulum 2013 persentase sebesar 75.04% (tinggi, konsep dan strategi pelayanan bimbingan dan konseling pada kurikulum 2013 sebesar 69.31% (sedang, lingkup layanan peminatan sebesar 70.57% (tinggi, dan pelaksanaan layanan peminatan 72.22% (tinggi. Simpulan penelitian ini yakni guru BK SMK Negeri se-Kota Semarang telah mempunyai pemahaman tentang pelaksanaan layanan peminatan pada kurikulum 2013 dengan kriteria tinggi. This research was conducted based on the phenomenon that is there was no readiness about the students’ interest program vocational high schools in around Semarang.The general objective of this research was to know the counseling’s teachers deals with the implementation of students’ interest service towards the 2013 curriculum vocational high schools in around Semarang. Method of data collection is used closed questionnaire and it was given to 44 students vocational high schools in around Semarang in which the data obtained was analysed trough descriptive percentages. The research finding from counseling’s teachers about the implementation of students’ interest in the 2013 curriculum vocational high schools in around Semarang are in a high category (71.59%, with the details of the indicator variable are as follows; the understanding of

Faktor-Faktor Hambatan Profesionalisasi Guru BK di SMA Negeri se- Kota Purwokerto

Directory of Open Access Journals (Sweden)

Cahya Dewi Rizkiwati

2014-10-01

Full Text Available Tujuan penelitian ini yaitu untuk mendeskripsikan tentang faktor-faktor hambatan yang terjadi dalam profesionalisasi guru BK. Jenis penelitian ini merupakan penelitian survey. Penelitian ini dilaksanakan di SMA Negeri se-Kota Purwokerto. Penelitian ini adalah penelitian populasi atau sensus karena populasi guru BK berjumlah 25 orang. Metode yang digunakan dalam penelitian ini adalah  inventori dalam bentuk daftar cek masalah. Instrumen tersebut telah diuji validitasnya menggunakan rumus point biserial, sedangkan reliabilitas instrumen digunakan rumus KR-20. Data yang telah diperoleh dianalisis dengan menggunakan teknik deskriptif prosentase. Hasil dari penelitian ini menunjukkan hambatan yang berasal dari faktor internal mendapat prosentase lebih tinggi daripada faktor eksternal. Faktor internal yang paling mempengaruhi profesionalisasi guru BK antara lain latar belakang pendidikan, pengalaman kerja, motivasi kerja, kompetensi guru BK. Sedangkan faktor eksternal yang paling mempengaruhi profesionalisasi guru BK adalah sarana dan prasarana. The purpose of this research is to describe problems  occur in the professionalization of guidance and counseling teachers. The type of the research is survey research . This research was conducted in all of Senior High School in Purwokerto. Population research or census were used as sampling method, since  the population of guidance and counseling teachers were 25 people. Data collection technique was  using inventory with list of issues. The instrument validity has been tested using point biserial formula, whilst its reliability was tested using KR-20 formula. The data was analyzed using descriptive percentage techniques. The results of this research indicate that internal factors get higher percentage than external factors. Internal factors that have the most influence in the professionalization of guidance and counseling teachers include educational background, working experience , motivation, teacher�

Diagnóstico y clasificación molecular del virus BK en receptores de trasplante renal

OpenAIRE

Riva, Omar; Cobos, Marisa; Raimondi, J. Clemente

2010-01-01

La infección primaria por virus BK ocurre durante la infancia permaneciendo latente en el tracto urogenital. En individuos que presentan alteraciones en la inmunidad celular, el virus se reactiva haciendo posible su detección en orina y sangre. En receptores de trasplante renal, la nefropatía producida por el virus BK puede llevar a la pérdida de la función del injerto. El virus BK es miembro de la familia Polyomaviridae, presenta un genoma de ADN circular doble cadena unido en forma covalent...

Experimental and numerical modelling of turbulent flow over an inclined backward-facing step in an open channel

Czech Academy of Sciences Publication Activity Database

Příhoda, Jaromír; Zubík, P.; Šulc, J.; Sedlář, M.

2012-01-01

Roč. 14, 4a (2012), s. 6-12 ISSN 1335-4205 R&D Projects: GA ČR GA103/09/0977 Institutional support: RVO:61388998 Keywords : open channel flow * inclined backward-facing step Subject RIV: BK - Fluid Dynamics

Characterization of self-assembled virus-like particles of human polyomavirus BK generated by recombinant baculoviruses

International Nuclear Information System (INIS)

Li, T.-C.; Takeda, Naokazu; Kato, Kenzo; Nilsson, Josefina; Xing Li; Haag, Lars; Cheng, R. Holland; Miyamura, Tatsuo

2003-01-01

The major structural protein of the human polyomavirus BK (BKV), VP1, was expressed by using recombinant baculoviruses. A large amount of protein with a molecular mass of about 42 kDa was synthesized and identified by Western blotting. The protein was detected exclusively in the nuclei by immunofluorescent analysis and it was released into culture medium. The expressed BKV VP1 protein was self-assembled into virus-like particles (BK-VLPs) with two different sizes (50 and 26 nm in diameter), which migrated into four different bands in CsCl gradient with buoyant densities of 1.29, 1.30, 1.33, and 1.35 g/cm 3 . The immunological studies on the BK-VLPs suggested that they have similar antigenicity with those of authentic BKV particles. Cryoelectron microscopy and 3D image analysis further revealed that the larger BK-VLPs were composed of 72 capsomers which all were pentamers arranged in a T = 7 surface lattice. This system provides useful information for detailed studies of viral morphogenesis and the structural basis for the antigenicity of BKV

Activation of human IK and SK Ca2+ -activated K+ channels by NS309 (6,7-dichloro-1H-indole-2,3-dione 3-oxime)

DEFF Research Database (Denmark)

Strøbaek, Dorte; Teuber, Lene; Jørgensen, Tino D

2004-01-01

We have identified and characterized the compound NS309 (6,7-dichloro-1H-indole-2,3-dione 3-oxime) as a potent activator of human Ca2+ -activated K+ channels of SK and IK types, whereas it is devoid of effect on BK type channels. IK- and SK-channels have previously been reported to be activated...

The new secondary channel control system at TRIUMF

International Nuclear Information System (INIS)

Keitel, R.; Bishop, D.; Dale, D.; England, N.; Harrison, D.

1990-01-01

The control of the secondary channels at TRIUMF has been decentralized. Each channel is now controlled through a single CAMAC crate from an IBM PC in the experimental counting room. Intelligent motor controllers were developed to replace the ageing slit control system. Advanced features of the control software package TICS, such as computer optimization of channel parameters and high-voltage conditioning of the dc separators, are described. (orig.)

Two-channel recoder for magnetometer with energy-independent mass memory device

International Nuclear Information System (INIS)

Korzinin, V.N.; Selivanov, A.M.

1993-01-01

The paper describes a two-channel digit-to-analog recorder designed for converting the sequence of pulses from proton magnetometer (MMH-203) outlet; the device enables processing of the pulses and their recording in RAM and on the tape of the analog recorder. The availability of nonvolotile RAM allows to transmit digit information to a computer (BK-0010) for its further processing

Effect of temperature on surface error and laser damage threshold for self-healing BK7 glass.

Science.gov (United States)

Wang, Chu; Wang, Hongxiang; Shen, Lu; Hou, Jing; Xu, Qiao; Wang, Jian; Chen, Xianhua; Liu, Zhichao

2018-03-20

Cracks caused during the lapping and polishing process can decrease the laser-induced damage threshold (LIDT) of the BK7 glass optical elements, which would shorten the lifetime and limit the output power of the high-energy laser system. When BK7 glass is heated under appropriate conditions, the surface cracks can exhibit a self-healing phenomenon. In this paper, based on thermodynamics and viscous fluid mechanics theory, the mechanisms of crack self-healing are explained. The heat-healing experiment was carried out, and the effect of water was analyzed. The multi-spatial-frequency analysis was used to investigate the effect of temperature on surface error for self-healing BK7 glass, and the lapped BK7 glass specimens before and after heat healing were detected by an interferometer and atomic force microscopy. The low-spatial-frequency error was analyzed by peak to valley and root mean square, the mid-spatial-frequency error was analyzed by power spectral density, and the high-spatial-frequency error was analyzed by surface roughness. The results showed that the optimal heating temperature for BK7 was 450°C, and when the heating temperature was higher than the glass transition temperature (555°C), the surface quality decreased a lot. The laser damage test was performed, and the specimen heated at 450°C showed an improvement in LIDT.

Universal features of JIMWLK and BK evolution at small x

CERN Document Server

Rummukainen, K; Rummukainen, Kari; Weigert, Heribert

2004-01-01

In this paper we present the results of numerical studies of the JIMWLK and BK equations with a particular emphasis on the universal scaling properties and phase space structure involved. The results are valid for near zero impact parameter in DIS. We demonstrate IR safety due to the occurrence of a rapidity dependent saturation scale Q_s(\\tau). Within the set of initial conditions chosen both JIMWLK and BK equations show remarkable agreement. We point out the crucial importance of running coupling corrections to obtain consistency in the UV. Despite the scale breaking induced by the running coupling we find that evolution drives correlators towards an asymptotic form with near scaling properties. We discuss asymptotic features of the evolution, such as the \\tau- and A-dependence of Q_s away from the initial condition.

Analýza marketingové komunikace sportovního klubu BK Lokomotiva Karlovy Vary

OpenAIRE

Houdková, Jana

2012-01-01

ANALYSIS OF MARKETING COMMUNICATIONS BK LOKOMOTIVA KARLOVY VARY SPORTS CLUB Objectives: The aim of this work is to analyze the current state of marketing communication with the audience and sponsors for women's basketball club BK Lokomotiva Karlovy Vary and propose a strategy for improving marketing communications. Methods: In this thesis were performed using the methods of observation and personal interviews examined subjects Results: An analysis of marketing communication club, thanks to wh...

Hydronephrosis Resulting from Bilateral Ureteral Stenosis: A Late Complication of Polyoma BK Virus Cystitis?

OpenAIRE

Basara, N.; Rasche, F.-M.; Schwalenberg, T.; Wickenhauser, C.; Maier, M.; Ivovic, J.; Niederwieser, D.; Lindner, T. H.

2010-01-01

We report here a case of acute lymphoblastic leukemia in remission presenting a late-onset bilateral hydronephrosis probably due to polyoma BK virus-induced proliferation of bladder endothelium on both ostii. The diagnosis was made virologically by BK virus Polymerase Chain Reaction (PCR) detection in the absence of any other bladder disease. Awareness of this late complication is necessary not only in patients after renal transplantation but also in patients after hematopoietic stem cell tra...

BK/TD models for analyzing in vitro impedance data on cytotoxicity.

Science.gov (United States)

Teng, S; Barcellini-Couget, S; Beaudouin, R; Brochot, C; Desousa, G; Rahmani, R; Pery, A R R

2015-06-01

The ban of animal testing has enhanced the development of new in vitro technologies for cosmetics safety assessment. Impedance metrics is one such technology which enables monitoring of cell viability in real time. However, analyzing real time data requires moving from static to dynamic toxicity assessment. In the present study, we built mechanistic biokinetic/toxicodynamic (BK/TD) models to analyze the time course of cell viability in cytotoxicity assay using impedance. These models account for the fate of the tested compounds during the assay. BK/TD models were applied to analyze HepaRG cell viability, after single (48 h) and repeated (4 weeks) exposures to three hepatotoxic compounds (coumarin, isoeugenol and benzophenone-2). The BK/TD models properly fit the data used for their calibration that was obtained for single or repeated exposure. Only for one out of the three compounds, the models calibrated with a single exposure were able to predict repeated exposure data. We therefore recommend the use of long-term exposure in vitro data in order to adequately account for chronic hepatotoxic effects. The models we propose here are capable of being coupled with human biokinetic models in order to relate dose exposure and human hepatotoxicity. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Hydronephrosis Resulting from Bilateral Ureteral Stenosis: A Late Complication of Polyoma BK Virus Cystitis?

Science.gov (United States)

Basara, N; Rasche, F-M; Schwalenberg, T; Wickenhauser, C; Maier, M; Ivovic, J; Niederwieser, D; Lindner, T H

2010-01-01

We report here a case of acute lymphoblastic leukemia in remission presenting a late-onset bilateral hydronephrosis probably due to polyoma BK virus-induced proliferation of bladder endothelium on both ostii. The diagnosis was made virologically by BK virus Polymerase Chain Reaction (PCR) detection in the absence of any other bladder disease. Awareness of this late complication is necessary not only in patients after renal transplantation but also in patients after hematopoietic stem cell transplantation from matched unrelated donor.

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly; Pettersson, Gustav M.; Kostina, Victoria; Hassibi, Babak

2017-01-01

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly

2017-01-05

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel\\'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Hydronephrosis Resulting from Bilateral Ureteral Stenosis: A Late Complication of Polyoma BK Virus Cystitis?

Science.gov (United States)

Basara, N.; Rasche, F.-M.; Schwalenberg, T.; Wickenhauser, C.; Maier, M.; Ivovic, J.; Niederwieser, D.; Lindner, T. H.

2010-01-01

We report here a case of acute lymphoblastic leukemia in remission presenting a late-onset bilateral hydronephrosis probably due to polyoma BK virus-induced proliferation of bladder endothelium on both ostii. The diagnosis was made virologically by BK virus Polymerase Chain Reaction (PCR) detection in the absence of any other bladder disease. Awareness of this late complication is necessary not only in patients after renal transplantation but also in patients after hematopoietic stem cell transplantation from matched unrelated donor. PMID:20936157

Hydronephrosis Resulting from Bilateral Ureteral Stenosis: A Late Complication of Polyoma BK Virus Cystitis?

Directory of Open Access Journals (Sweden)

N. Basara

2010-01-01

Full Text Available We report here a case of acute lymphoblastic leukemia in remission presenting a late-onset bilateral hydronephrosis probably due to polyoma BK virus-induced proliferation of bladder endothelium on both ostii. The diagnosis was made virologically by BK virus Polymerase Chain Reaction (PCR detection in the absence of any other bladder disease. Awareness of this late complication is necessary not only in patients after renal transplantation but also in patients after hematopoietic stem cell transplantation from matched unrelated donor.

Control system design for concrete irrigation channels

OpenAIRE

Strecker, Timm; Aamo, Ole Morten; Cantoni, Michael

2017-01-01

Concrete channels find use at the periphery of irrigation networks, for expansion and to replace small earthen channels given the relative ease of maintenance and elimination of seepage losses. In design, it is important to account for control system performance when dimensioning the channel infrastructure. In this paper, the design of a distributed controller is investigated in terms managing water-levels, and thereby the depth profile (i.e., amount of concrete) needed to support peak flow l...

BK virus has tropism for human salivary gland cells in vitro: Implications for transmission

International Nuclear Information System (INIS)

Jeffers, Liesl K.; Madden, Vicki; Webster-Cyriaque, Jennifer

2009-01-01

Background: In this study, it was determined that BKV is shed in saliva and an in vitro model system was developed whereby BKV can productively infect both submandibular (HSG) and parotid (HSY) salivary gland cell lines. Results: BKV was detected in oral fluids using quantitative real-time PCR (QRTPCR). BKV infection was determined using quantitative RT-PCR, immunofluorescence and immunoblotting assays. The infectivity of BKV was inhibited by pre-incubation of the virus with gangliosides that saturated the major capsid protein, VP1, halting receptor mediated BKV entry into salivary gland cells. Examination of infected cultures by transmission electron microscopy revealed 45-50 nm BK virions clearly visible within the cells. Subsequent to infection, encapsidated BK virus was detected in the supernatant. Conclusion: We thus demonstrated that BKV was detected in oral fluids and that BK infection and replication occur in vitro in salivary gland cells. These data collectively suggest the potential for BKV oral route of transmission and oral pathogenesis.

BK Virus-Associated Nephropathy: Current Situation in a Resource-Limited Country.

Science.gov (United States)

Yooprasert, P; Rotjanapan, P

Data on BK virus-associated nephropathy (BKVAN) and treatment strategy in a resource-limited country are scarce. This study aimed to evaluate epidemiology of BKVAN and its situation in Thailand. A retrospective analysis was conducted among adult kidney transplant recipients at Ramathibodi Hospital from October 2011 to September 2016. Patients' demographic data, information on kidney transplantation, immunosuppressive therapy, cytomegalovirus and BK virus infections, and allograft outcomes were retrieved and analyzed. This study included 623 kidney transplant recipients. Only 327 patients (52.49%) received BK virus infection screening, and 176 of 327 patients had allograft dysfunction as a trigger for screening. BKVAN was identified in 39 of 327 patients (11.93%). Deceased donor transplantation and cytomegalovirus infection were associated with a higher risk of BKVAN (odds ratio = 2.2, P = .024, 95% confidence intervals [1.1, 4.43], and odds ratio = 2.6, P = .006, 95% confidence intervals [1.29, 5.26], respectively). BKVAN patients were at significantly higher risk for allograft rejection (P < .001) and allograft failure (P = .036). At the end of the study, 4 graft losses were documented (12.12%). BKVAN was associated with high rate of allograft rejection and failure. However, surveillance of its complications has been underperformed at our facility. Implementing a formal practice guideline may improve allograft outcome in resource-limited countries. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Tungstate-targeting of BKαβ1 channels tunes ERK phosphorylation and cell proliferation in human vascular smooth muscle.

Directory of Open Access Journals (Sweden)

Ana Isabel Fernández-Mariño

Full Text Available Despite the substantial knowledge on the antidiabetic, antiobesity and antihypertensive actions of tungstate, information on its primary target/s is scarce. Tungstate activates both the ERK1/2 pathway and the vascular voltage- and Ca2+-dependent large-conductance BKαβ1 potassium channel, which modulates vascular smooth muscle cell (VSMC proliferation and function, respectively. Here, we have assessed the possible involvement of BKαβ1 channels in the tungstate-induced ERK phosphorylation and its relevance for VSMC proliferation. Western blot analysis in HEK cell lines showed that expression of vascular BKαβ1 channels potentiates the tungstate-induced ERK1/2 phosphorylation in a Gi/o protein-dependent manner. Tungstate activated BKαβ1 channels upstream of G proteins as channel activation was not altered by the inhibition of G proteins with GDPβS or pertussis toxin. Moreover, analysis of Gi/o protein activation measuring the FRET among heterologously expressed Gi protein subunits suggested that tungstate-targeting of BKαβ1 channels promotes G protein activation. Single channel recordings on VSMCs from wild-type and β1-knockout mice indicated that the presence of the regulatory β1 subunit was essential for the tungstate-mediated activation of BK channels in VSMCs. Moreover, the specific BK channel blocker iberiotoxin lowered tungstate-induced ERK phosphorylation by 55% and partially reverted (by 51% the tungstate-produced reduction of platelet-derived growth factor (PDGF-induced proliferation in human VSMCs. Our observations indicate that tungstate-targeting of BKαβ1 channels promotes activation of PTX-sensitive Gi proteins to enhance the tungstate-induced phosphorylation of ERK, and inhibits PDGF-stimulated cell proliferation in human vascular smooth muscle.

Decay properties of ${}_{97}{}^{243}\mathrm{<span\; class="hlt">Bk</span>}$ and ${}_{97}{}^{244}\mathrm{<span\; class="hlt">Bk</span>}$

Energy Technology Data Exchange (ETDEWEB)

Ahmad, I.; Kondev, F. G.; Greene, J. P.; Zhu, S.

2018-01-01

Electron capture decays of Bk-243 and Bk-244 have been studied by measuring the gamma-ray spectra of mass-separated sources and level structures of Cm-243 and Cm-244 have been deduced. In Cm-243, the electron capture population to the ground state, 1/2(+)[631], and 1/2(+)[620] Nilsson states have been observed. The octupole K-pi = 2(-) band was identified in Cm-244 at 933.6 keV. In addition, spins and parities were deduced for several other states and two-quasiparticle configurations have been tentatively assigned to them

Flow over back-facing step in a narrow channel

Czech Academy of Sciences Publication Activity Database

Uruba, Václav; Jonáš, Pavel

2012-01-01

Roč. 12, č. 1 (2012), s. 501-502 ISSN 1617-7061. [Annual Meeting of the International Association of Applied Mathematics and Mechanics /83./. Darmstadt, 26.03.2012-30.03.2012] R&D Projects: GA ČR GAP101/10/1230; GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : channel flow * backward facing step * PIV Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1617-7061

Dynamics of reattachment region behind backward-facing step in a narrow channel

Czech Academy of Sciences Publication Activity Database

Uruba, Václav

2014-01-01

Roč. 14, č. 1 (2014), s. 641-642 ISSN 1617-7061. [Annual Meeting of the International Association of Applied Mathematics and Mechanics /85./. Erlangen, 10.03.2014-14.03.2014] R&D Projects: GA ČR GAP101/10/1230 Institutional support: RVO:61388998 Keywords : backward facing step * reattachment * channel flow Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/doi/10.1002/pamm.201410305/abstract

BK virus infection in a renal transplant Saudi child

International Nuclear Information System (INIS)

Maghrabi, M.; Marwan, D.; Osoba, Abimbola O.

2007-01-01

BK human polyomavirus (BKV) causes an asymptomatic primary infection in children, but later, establishes latency mainly in the urinary tract. Virus-host interactions influencing persistence and pathogenicity are not well-understood. We present here a 12-year-old Saudi boy, who had renal transplant in Egypt. Seven months later, he was admitted to our Pediatric Nephrology Unit as a case of renal impairment. He developed BKV infection, diagnosed and successfully managed in our hospital. This case demonstrates the expanding clinical importance of BKV in a post renal transplant patient. This virus can be detected in transitional cells in the urine (decoy cells) using cytology. Testing for BKV deoxyribonucleic acid in urine and blood is an early detection assay, and can be used as a screening test in the early stages. The early reduction of immunosuppression can improve the prognosis. No specific antiviral treatment has been established yet. This is the first report of detecting BK virus in a Saudi post-transplant child in urine and blood specimens by using polymerase chain reaction. (author)

Mārketinga komunikācijas pielietojums atjaunotā BK "VEF Rīga" zīmola virzīšanā

OpenAIRE

Līcis, Mārtiņš

2014-01-01

Darba tēma ir „Mārketinga komunikācijas pielietojums atjaunotā BK „VEF Rīga” zīmola virzīšanā”. Darba mērķis ir noskaidrot mārketinga komunikācijas pielietojumu atjaunotā BK „VEF Rīga” zīmola virzīšanā. Uzdevumi ir izstudēt nepieciešamo teoriju, izanalizēt mārketinga komunikācijas instrumentu pielietojumu, noskaidrot BK „VEF Rīga”, sporta mārketinga speciālista un sabiedrības viedokli par BK „VEF Rīga” zīmolu. Teoriju veido: zīmols, zīmolvedība, mārketinga komunikācija, sociālo mediju mārketi...

NS19504

DEFF Research Database (Denmark)

Nausch, Bernhard; Rode, Frederik; Jørgensen, Susanne

2014-01-01

channel activators and identified a small-molecule positive modulator, NS19504 (5-[(4-bromophenyl)methyl]-1,3-thiazol-2-amine), which activated the BK channel with an EC50 value of 11.0 ± 1.4 µM. Hit validation was performed using high-throughput electrophysiology (QPatch), and further characterization......19504 activated BK channels in native smooth muscle cells from guinea pig urinary bladder. In guinea pig urinary bladder strips, NS19504 (1 µM) reduced spontaneous phasic contractions, an effect that was significantly inhibited by the specific BK channel blocker iberiotoxin. In contrast, NS19504 (1 µ......M) only modestly inhibited nerve-evoked contractions and had no effect on contractions induced by a high K(+) concentration consistent with a K(+) channel-mediated action. Collectively, these results show that NS19504 is a positive modulator of BK channels and provide support for the role of BK channels...

Dwarf Elliptical Galaxies in the M81 Group: The Structure and Stellar Populations of BK5N and F8D1

OpenAIRE

Caldwell, Nelson; Armandroff, Taft E.; Da Costa, G. S.; Seitzer, Patrick

1997-01-01

We have obtained HST WFPC2 images through the F555W and F814W filters of two M81 group dE's: BK5N and a new system, designated F8D1. The resulting color-magnitude diagrams show the upper two magnitudes of the red giant branch. Surface brightness and total magnitude measurements indicate that BK5N and F8D1 have similar central surface brightness (24.5 and 25.4 mag/arcsec^2 in V, respectively), but F8D1's larger length scale results in it being 3 magnitudes more luminous than BK5N. BK5N lies on...

In-pile behavior of controlled beta-quenched fuel channels

Energy Technology Data Exchange (ETDEWEB)

Moeckel, Andreas; Pflaum, Wolfgang; Cremer, Ingo [AREVA NP GmbH, Erlangen (Germany); Zbib, Ali A. [AREVA NP Inc., Richland, WA (United States)

2011-07-01

Dimensional stability during in-reactor service is the major requirement that is put on fuel channels to provide good moderation and power distribution, and to guarantee unrestricted movement of the control blades during operation. High corrosion resistance and low hydrogen pick-up are required as well. The latter are usually not considered to be life limiting, but may contribute to channel deformation since increased oxide layers due to shadow corrosion on the control blade sides of a channel result in differential oxide thickness and differential volume expansion due to hydride formation. This would be in addition to the well known effects of irradiation induced channel deformation, especially channel growth and bow. In order to meet the trend toward increased fuel assembly discharge burnup levels and the industry wide need for improved dimensional stability of fuel channels, AREVA NP has developed the Controlled Beta-Quenching of fuel channels. The process combines the positive effect of randomization of the crystallographic texture by beta-quenching with the optimization of the microstructure for good corrosion resistance by providing intermetallic phase particles in the optimum size range. The Controlled Beta-Quenching is a continuous heat treatment operation. Its key features are the two-step induction heating to uniformly reach the target temperature, the tight control of the quench rate by cooling the fuel channel from the outer surface using a controlled argon mass flow for quenching, and the protection of the inner surface from oxidation by providing an argon atmosphere. Due to the utilization of argon, the surfaces of the channels remain metal bright after beta-quenching. All in all, the Controlled Beta-Quenching provides an overall 'clean' and environment friendly operation without the need of additional surface conditioning. The first set of beta-quenched fuel channels, exhibiting these optimized material properties, were inserted in the core

Some experimental results on flow in a diverging 2D channel

Czech Academy of Sciences Publication Activity Database

Antoš, Pavel; Hladík, Ondřej; Jonáš, Pavel; Uruba, Václav

2013-01-01

Roč. 13, č. 1 (2013), s. 297-298 ISSN 1617-7061. [Annual Meeting of the International Association of Applied Mathematics and Mechanics /84./. Novi Sad, 18.03.2013-22.03.2013] R&D Projects: GA ČR GAP101/12/1271 Institutional support: RVO:61388998 Keywords : free stream turbulence * negative pressure gradient * diverging 2D channel Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/doi/10.1002/pamm.201310144/pdf

Intermittent losartan administration triggers cardiac post-conditioning in isolated rat hearts: role of BK2 receptors.

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Luca Sgarra

Full Text Available The angiotensin (Ang and bradykinin (BK tissue-system plays a pivotal role in post-conditioning, but the efficacy of angiotensin type 1 receptor (AT1R blockers (ARBs in post-ischemic strategies is still under investigation. We evaluated functional and morphological outcomes, together with activation of cytosolic RISK pathway kinases, in rat hearts subjected to losartan (LOS or irbesartan (IRB post-ischemic administration.Isolated rat hearts underwent 30 min ischemia and 120 min reperfusion. Post-conditioning was obtained by intermittent (10 s/each or continuous drug infusion during the first 3 min of reperfusion. Left ventricular end-diastolic pressure (LVEDP, left ventricular developed pressure (dLVP, coronary flow (CF, and left ventricular infarct mass (IM were measured together with the activation status of RISK kinases Akt, p42/44 MAPK and GSK3β.When compared to hearts subjected to ischemia/reperfusion (iI/R alone, continuous IRB or LOS administration did not significantly reduce total infarct mass (cIRB or cLOS vs. iI/R, p = 0.2. Similarly, intermittent IRB (iIRB was not able to enhance cardioprotection. Conversely, intermittent LOS administration (iLOS significantly ameliorated cardiac recovery (iLOS vs iI/R, p<0.01. Differences between iLOS and iIRB persisted under continuous blockade of AT2R (iLOS+cPD vs. iIRB+cPD, p<0.05. Interestingly, iLOS cardioprotection was lost when BK2R was simultaneously blocked (iLOS+cHOE vs. iI/R, p = 0.6, whereas concurrent administration of iBK and iIRB replicated iLOS effects (iIRB+iBK vs. iLOS, p = 0.7. At the molecular level, iIRB treatment did not significantly activate RISK kinases, whereas both iLOS and iBK treatments were associated with activation of the Akt/GSK3β branch of the RISK pathways (p<0.05 vs. iI/R, for both.Our results suggest that intermittent losartan is effective in mediating post-conditioning cardioprotection, whereas irbesartan is not. The infarct mass reduction by intermittent

Regulation of KV channel voltage-dependent activation by transmembrane β subunits

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Xiaohui eSun

2012-04-01

Full Text Available Voltage-activated K+ (KV channels are important for shaping action potentials and maintaining resting membrane potential in excitable cells. KV channels contain a central pore-gate domain (PGD surrounded by four voltage-sensing domains (VSD. The VSDs will change conformation in response to alterations of the membrane potential thereby inducing the opening of the PGD. Many KV channels are heteromeric protein complexes containing auxiliary β subunits. These β subunits modulate channel expression and activity to increase functional diversity and render tissue specific phenotypes. This review focuses on the KV β subunits that contain transmembrane (TM segments including the KCNE family and the β subunits of large conductance, Ca2+- and voltage-activated K+ (BK channels. These TM β subunits affect the voltage-dependent activation of KV α subunits. Experimental and computational studies have described the structural location of these β subunits in the channel complexes and the biophysical effects on VSD activation, PGD opening and VSD-PGD coupling. These results reveal some common characteristics and mechanistic insights into KV channel modulation by TM β subunits.

Hopping control channel MAC protocol for opportunistic spectrum access networks

Institute of Scientific and Technical Information of China (English)

FU Jing-tuan; JI Hong; MAO Xu

2010-01-01

Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

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J. Konki

2017-01-01

Full Text Available The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion–evaporation reaction 209Bi(34S,3n240Es. Half-lives of 6(2s and 22−6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα=8.19(3MeV and 8.09(3MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16(6 and 0.04(2 were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

On the Operator ⨁Bk Related to Bessel Heat Equation

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Wanchak Satsanit

2010-01-01

Full Text Available We study the equation (∂/∂tu(x,t=c2⊕Bku(x,t with the initial condition u(x,0=f(x for x∈Rn+. The operator ⊕Bk is the operator iterated k-times and is defined by ⊕Bk=((∑i=1pBxi4-(∑j=p+1p+qBxi4k, where p+q=n is the dimension of the Rn+, Bxi=∂2/∂xi2+(2vi/xi(∂/∂xi, 2vi=2αi+1, αi>-1/2, i=1,2,3,…,n, and k is a nonnegative integer, u(x,t is an unknown function for (x,t=(x1,x2,…,xn,t∈Rn+×(0,∞, f(x is a given generalized function, and c is a positive constant. We obtain the solution of such equation, which is related to the spectrum and the kernel, which is so called Bessel heat kernel. Moreover, such Bessel heat kernel has interesting properties and also related to the kernel of an extension of the heat equation.

A multi-channel AC power supply controller

International Nuclear Information System (INIS)

Su Hong; Li Xiaogang; Ma Xiaoli; Zhou Bo; Yin Weiwei

2003-01-01

A multi-channel ac power supply controller developed recently by authors is introduced briefly in this paper. This controller is a computer controlled multi-electronic-switch device. This controller was developed for the automatic control and monitoring system of a 220 V ac power supply system, it is a key front-end device of the automatic control and monitoring system. There is an electronic switch in each channel, the rated load power is ≤1 kW/each channel. Another function is to sample the 220 V ac output voltage so that computer can monitor the operation state of each electronic switch. Through these switches, the 220 V ac power supply is applied to some device or apparatus that need to be powered by 220 V ac power supply. In the design, a solid-state relay was employed as an electronic switch. This controller can be connected in cascade mode. There are 8 boxes at most can be connected in cascade mode. The length of control word is 8 bit, which contains addressing information and electronic switch state setting information. The sampling output of the controller is multiplexed. It is only one bit that indicates the operating state of an electronic switch. This controller has been used in an automatic control and monitoring system for 220 V ac power supply system

Comprehensive benchmarking reveals H2BK20 acetylation as a distinctive signature of cell-state-specific enhancers and promoters.

Science.gov (United States)

Kumar, Vibhor; Rayan, Nirmala Arul; Muratani, Masafumi; Lim, Stefan; Elanggovan, Bavani; Xin, Lixia; Lu, Tess; Makhija, Harshyaa; Poschmann, Jeremie; Lufkin, Thomas; Ng, Huck Hui; Prabhakar, Shyam

2016-05-01

Although over 35 different histone acetylation marks have been described, the overwhelming majority of regulatory genomics studies focus exclusively on H3K27ac and H3K9ac. In order to identify novel epigenomic traits of regulatory elements, we constructed a benchmark set of validated enhancers by performing 140 enhancer assays in human T cells. We tested 40 chromatin signatures on this unbiased enhancer set and identified H2BK20ac, a little-studied histone modification, as the most predictive mark of active enhancers. Notably, we detected a novel class of functionally distinct enhancers enriched in H2BK20ac but lacking H3K27ac, which was present in all examined cell lines and also in embryonic forebrain tissue. H2BK20ac was also unique in highlighting cell-type-specific promoters. In contrast, other acetylation marks were present in all active promoters, regardless of cell-type specificity. In stimulated microglial cells, H2BK20ac was more correlated with cell-state-specific expression changes than H3K27ac, with TGF-beta signaling decoupling the two acetylation marks at a subset of regulatory elements. In summary, our study reveals a previously unknown connection between histone acetylation and cell-type-specific gene regulation and indicates that H2BK20ac profiling can be used to uncover new dimensions of gene regulation. © 2016 Kumar et al.; Published by Cold Spring Harbor Laboratory Press.

Ion Channel Trafficking: Control of Ion Channel Density as a Target for Arrhythmias?

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Elise Balse

2017-10-01

Full Text Available The shape of the cardiac action potential (AP is determined by the contributions of numerous ion channels. Any dysfunction in the proper function or expression of these ion channels can result in a change in effective refractory period (ERP and lead to arrhythmia. The processes underlying the correct targeting of ion channels to the plasma membrane are complex, and have not been fully characterized in cardiac myocytes. Emerging evidence highlights ion channel trafficking as a potential causative factor in certain acquired and inherited arrhythmias, and therapies which target trafficking as opposed to pore block are starting to receive attention. In this review we present the current evidence for the mechanisms which underlie precise control of cardiac ion channel trafficking and targeting.

On the influence of plasma DBD actuator on the flow in a rectangular channel

Czech Academy of Sciences Publication Activity Database

Procházka, Pavel P.; Uruba, Václav

2014-01-01

Roč. 14, č. 1 (2014), s. 727-728 ISSN 1617-7061. [Annual Meeting of the International Association of Applied Mathematics and Mechanics /85./. Erlangen, 10.03.2014-14.03.2014] R&D Projects: GA ČR(CZ) GP14-25354P Institutional support: RVO:61388998 Keywords : plasma DBD * boundary layer * channel flow Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/doi/10.1002/pamm.201410346/abstract

Altered Potassium Ion Channel Function as a Possible Mechanism of Increased Blood Pressure in Rats Fed Thermally Oxidized Palm Oil Diets.

Science.gov (United States)

Nkanu, Etah E; Owu, Daniel U; Osim, Eme E

2017-12-27

Intake of thermally oxidized palm oil leads to cytotoxicity and alteration of the potassium ion channel function. This study investigated the effects of fresh and thermally oxidized palm oil diets on blood pressure and potassium ion channel function in blood pressure regulation. Male Wistar rats were randomly divided into three groups of eight rats. Control group received normal feed; fresh palm oil (FPO) and thermally oxidized palm oil (TPO) groups were fed a diet mixed with 15% (weight/weight) fresh palm oil and five times heated palm oil, respectively, for 16 weeks. Blood pressure was measured; blood samples, hearts, and aortas were collected for biochemical and histological analyses. Thermally oxidized palm oil significantly elevated basal mean arterial pressure (MAP). Glibenclamide (10 -5 mmol/L) and tetraethylammonium (TEA; 10 -3 mmol/L) significantly raised blood pressure in TPO compared with FPO and control groups. Levcromakalim (10 -6 mmol/L) significantly (p palm oil increases MAP probably due to the attenuation of adenosine triphosphate-sensitive potassium (K ATP ) and large-conductance calcium-dependent potassium (BK Ca ) channels, tissue peroxidation, and altered histological structures of the heart and blood vessels.

A single-center epidemiological study of BK virus infection and analysis of risk factors in patients with renal transplantation

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Ji-gang LI

2014-10-01

Full Text Available Objective　To investigate the epidemiological characteristics of BK virus (BKV infection in living renal transplantation patients, and analyze the risk factors of BKV infection and BKV nephropathy (BKVN. Methods　The BKV DNA load in urine and blood samples of 43 renal transplant recipients, who had received renal transplantation in 309 Hospital from Feb. 2012 to Feb. 2013, was determined at preoperative period and 0.5, 1, 3, 6, 9, 12 and 15 months after transplantation. Meanwhile, the biopsy of grafted kidney was performed in those patients with continuously elevated serum creatinine and those with higher BKV DNA load. Patients were divided into 3 groups as follows according to the test results: BK viruria group, BK viremia group and pathologically diagnosed BKVN group. Data of each group were then recorded, including gender, age, postoperative diabetes (PTDM, acute rejection (AR, delayed recovery of graft function (DGF, postoperative pulmonary infection, preoperative immune induction therapy, postoperative immunosuppressive regimen, and other information. The risk factors for postoperative BKV infection and BKVN were analyzed. Results　After an average of 15-month follow-up, it was found that the incidence of BKV viruria was 46.5%, that of BKV viremia was 14.0%, and that of BKVN was 2.3%. Sixth month after transplantation was found to be the peak time of viruria and viremia. FK506 was significantly associated with viremia in living donor renal transplantation. The immunosuppressive regimen was the immune related independent risk factor for BK viremia developing BKVN after living renal transplantation. Conclusion　The incidence of BK viremia and BKVN is lower in living donor renal transplantation than in cadaver renal transplantation, but that of viruria is similar in both groups. Immunosuppressive scheme based on FK506 is an immune related independent risk factor leading to BK viremia proceeding to BKVN in living donor kidney

Mitigation of Control Channel Jamming via Combinatorial Key Distribution

Science.gov (United States)

Falahati, Abolfazl; Azarafrooz, Mahdi

The problem of countering control channel jamming against internal adversaries in wireless ad hoc networks is addressed. Using combinatorial key distribution, a new method to secure the control channel access is introduced. This method, utilizes the established keys in the key establishment phase to hide the location of control channels without the need for a secure BS. This is in obtained by combination of a collision free one-way function and a combinatorial key establishment method. The proposed scheme can be considered as a special case of the ALOHA random access schemes which uses the common established keys as its seeds to generate the pattern of transmission.

Increase in cortical pyramidal cell excitability accompanies depression-like behavior in mice: a transcranial magnetic stimulation study.

Science.gov (United States)

Sun, Peng; Wang, Furong; Wang, Li; Zhang, Yu; Yamamoto, Ryo; Sugai, Tokio; Zhang, Qing; Wang, Zhengda; Kato, Nobuo

2011-11-09

Clinical evidence suggests that cortical excitability is increased in depressives. We investigated its cellular basis in a mouse model of depression. In a modified version of forced swimming (FS), mice were initially forced to swim for 5 consecutive days and then were treated daily with repetitive transcranial magnetic stimulation (rTMS) or sham treatment for the following 4 weeks without swimming. On day 2 through day 5, the mice manifested depression-like behaviors. The next and last FS was performed 4 weeks later, which revealed a 4 week maintenance of depression-like behavior in the sham mice. In slices from the sham controls, excitability in cingulate cortex pyramidal cells was elevated in terms of membrane potential and frequencies of spikes evoked by current injection. Depolarized resting potential was shown to depend on suppression of large conductance calcium-activated potassium (BK) channels. This BK channel suppression was confirmed by measuring spike width, which depends on BK channels. Chronic rTMS treatment during the 4 week period significantly reduced the depression-like behavior. In slices obtained from the rTMS mice, normal excitability and BK channel activity were recovered. Expression of a scaffold protein Homer1a was reduced by the FS and reversed by rTMS in the cingulate cortex. Similar recovery in the same behavioral, electrophysiological, and biochemical features was observed after chronic imipramine treatment. The present study demonstrated that manifestation and disappearance of depression-like behavior are in parallel with increase and decrease in cortical neuronal excitability in mice and suggested that regulation of BK channels by Homer1a is involved in this parallelism.

Control channels in the brain and their influence on brain executive functions

Science.gov (United States)

Meng, Qinglei; Choa, Fow-Sen; Hong, Elliot; Wang, Zhiguang; Islam, Mohammad

2014-05-01

In a computer network there are distinct data channels and control channels where massive amount of visual information are transported through data channels but the information streams are routed and controlled by intelligent algorithm through "control channels". Recent studies on cognition and consciousness have shown that the brain control channels are closely related to the brainwave beta (14-40 Hz) and alpha (7-13 Hz) oscillations. The high-beta wave is used by brain to synchronize local neural activities and the alpha oscillation is for desynchronization. When two sensory inputs are simultaneously presented to a person, the high-beta is used to select one of the inputs and the alpha is used to deselect the other so that only one input will get the attention. In this work we demonstrated that we can scan a person's brain using binaural beats technique and identify the individual's preferred control channels. The identified control channels can then be used to influence the subject's brain executive functions. In the experiment, an EEG measurement system was used to record and identify a subject's control channels. After these channels were identified, the subject was asked to do Stroop tests. Binaural beats was again used to produce these control-channel frequencies on the subject's brain when we recorded the completion time of each test. We found that the high-beta signal indeed speeded up the subject's executive function performance and reduced the time to complete incongruent tests, while the alpha signal didn't seem to be able to slow down the executive function performance.

On a multi-channel transportation loss system with controlled input and controlled service

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Jewgeni Dshalalow

1987-01-01

Full Text Available A multi-channel loss queueing system is investigated. The input stream is a controlled point process. The service in each of m parallel channels depends on the state of the system at certain moments of time when input and service may be controlled. To obtain explicitly the limiting distribution of the main process (Zt (the number of busy channels in equilibrium, an auxiliary three dimensional process with two additional components (one of them is a semi-Markov process is treated as semi-regenerative process. An optimization problem is discussed. Simple expressions for an objective function are derived.

Chemical consequences of radioactive decay. 1. Study of 249Cf ingrowth into crystalline 249BkBr3: a new crystalline phase of CfBr3

International Nuclear Information System (INIS)

Young, J.P.; Haire, R.G.; Peterson, J.R.; Ensor, D.D.; Fellows, R.L.

1980-01-01

Spectrophotometric and x-ray powder diffraction methods have been applied to a study of the ingrowth of californium-249 by β - decay of berkelium-249 in crystalline 249 BkBr 3 . It was found that the Cf daughter grows in with the same oxidation state and crystal structure as the parent. Thus, six-coordinate BkBr 3 (AlCl 3 -type monoclinic structure) generates six-coordinate CfBr 3 , and eight-coordinate BkBr 3 (PuBr 3 -type orthorhombic structure) generates eight-coordinate CfBr 3 , a previously unknown form of CfBr 3 . It was also found that the daughter Cf(III) in the BkBr 3 parent compound can be reduced to Cf(II) by treatment with H 2 , as it can in pure CfBr 3 . 5 figures

24-channel dual microcontroller-based voltage controller for ion optics remote control

Science.gov (United States)

Bengtsson, L.

2018-05-01

The design of a 24-channel voltage control instrument for Wenzel Elektronik N1130 NIM modules is described. This instrument is remote controlled from a LabVIEW GUI on a host Windows computer and is intended for ion optics control in electron affinity measurements on negative ions at the CERN-ISOLDE facility. Each channel has a resolution of 12 bits and has a normally distributed noise with a standard deviation of <1 mV. The instrument is designed as a standard 2-unit NIM module where the electronic hardware consists of a printed circuit board with two asynchronously operating microcontrollers.

ASAI ISOLAT BAKTERI KITINOLITIK BACILLUS SP. BK17 PADA MEDIA PEMBAWA TANAH GAMBUT DAN KOMPOS JANJANG KELAPA SAWIT DALAM MENGHAMBAT PERTUMBUHAN JAMUR PATOGEN SCLEROTIUM ROLFSII DAN FUSARIUM OXYSPORUM PADA KECAMBAH CABAI

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Deswidya Hutauruk

2016-10-01

Full Text Available Assay of chitinolytic bacterial isolate of Bacillus sp. Bk17 in peat and palm oil bunch compost as carrier media in inhibiting Sclerotium rolfsii and Fusarium oxysporum of chilli seedlings. Sclerotium rolfsii and Fusarium oxysporum have been known as causal agents of seedling-off of chilli. Biological control has been used as an alternative control to replace chemical control. This study was aimed to determine the viability and ability of chitinolityc bacteria Bacillus sp. BK17 in carrier media of peat and palm oil bunch compost and in growing media to control seedling-off caused by S. rolfsii dan F. oxysporum of chilli. Our previous study showed that Bacillus sp. BK17 could reduce disease severity and intensity. Bacterial viability was measured as colony number grown after 90 days of storage in minimum salt medium with colloidal chitin as sole C source. Reduction of disease infection was measured as seedling number infected by S. rolfsii dan F. oxysporum. Seedling performances were measured as seedling height, leaf number and dry-weight after 30-days of growth. The result showed that bacterial cell viability was still high in both peat and palm oil bunch compost both with and without colloidal chitin addition after 90 days of storage. It was also shown that during application bacterial cell could grow. Seedling performaces i.e. seedling height, leaf number and dry-weight showed to be normal or even increase compared to those of pathogenic fungal inoculation only and (- control.

High-level viruria as a screening tool for BK virus nephropathy in renal transplant recipients

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W. James Chon

2016-09-01

Conclusion: The presence of high-grade viruria is an early marker for developing BK viremia/BKVN. Detection of high-grade viruria should prompt early allograft biopsy and/or preemptive reduction in immunosuppression.

Time domain passivity controller for 4-channel time-delay bilateral teleoperation.

Science.gov (United States)

Rebelo, Joao; Schiele, Andre

2015-01-01

This paper presents an extension of the time-domain passivity control approach to a four-channel bilateral controller under the effects of time delays. Time-domain passivity control has been used successfully to stabilize teleoperation systems with position-force and position-position controllers; however, the performance with such control architectures is sub-optimal both with and without time delays. This work extends the network representation of the time-domain passivity controller to the four-channel architecture, which provides perfect transparency to the user without time delay. The proposed architecture is based on modelling the controllers as dependent voltage sources and using only series passivity controllers. The obtained results are shown on a one degree-of-freedom setup and illustrate the stabilization behaviour of the proposed controller when time delay is present in the communication channel.

A multi-channel humidity control system based on LabVIEW

International Nuclear Information System (INIS)

Zhang Aiwu; Xie Yuguang; Liu Hongbang; Liu Yingbiao; Cai Xiao; Yu Boxiang; Lu Junguang; Zhou Li

2011-01-01

A real time multi-channel humidity control system was designed based on LabVIEW, using the dry air branch of BESⅢ drying system. The hardware of this control system consist of mini humidity and temperature sensors, intelligent collection module, switch quantity controller and electromagnetic valves. The humidity can be controlled at arbitrary value from air humidity to 3% with accuracy better than 2%. Multi microenvironment with different humidity can be easily controlled and monitored in real time by this system. It can also be extended to hybrid control of multi channel humidity and temperature. (authors)

Effects of Nonlinear Absorption in BK7 and Color Glasses at 355 nm

International Nuclear Information System (INIS)

Adams, J J; McCarville, T; Bruere, J; McElroy, J; Peterson, J

2003-01-01

We have demonstrated a simple experimental technique that can be used to measure the nonlinear absorption coefficients in glasses. We determine BK7, UG1, and UG11 glasses to have linear absorption coefficients of 0.0217 ± 10% cm -1 , 1.7 ± 10% cm -1 , and 0.82 ± 10% cm -1 , respectively, two-photon absorption cross-sections of 0.025 ± 20% cm/GW, 0.035 ± 20% cm/GW, and 0.047 ± 20% cm/GW, respectively, excited-state absorption cross-sections of 8.0 x 10 -18 ± 20% cm 2 , 2.8 x 10 -16 ± 20% cm 2 , and 5 x 10 -17 ± 20% cm 2 , respectively, and solarization coefficients of 8.5 x 10 -20 ± 20% cm 2 , 2.5 x 10 -18 ± 20% cm 2 , and 1.3 x 10 -19 ± 20% cm 2 , respectively. For our application, nonlinear effects in 10-cm of BK7 are small ((le) 2%) for 355-nm fluences 2 for flat-top pulses. However, nonlinear effects are noticeable for 355-nm fluences at 0.8 J/cm 2 . In particular, we determine a 20% increase in the instantaneous absorption from linear, a solarization rate of 4% per 100 shots, and a 10% temporal droop introduced in the pulse, for 355-nm flat-top pulses at a fluence of 0.8 J/cm 2 . For 0.5-cm of UG1 absorbing glass the non-linear absorption has a similar effect as that from 10-cm of BK7 on the pulse shape; however, the effects in UG11 are much smaller

Vaccine for BK Polyomavirus-associated Infections in Transplant Recipients | NCI Technology Transfer Center | TTC

Science.gov (United States)

NCI researches identified a BK polyomavirus (BKV) virulent strain that causes chronic urinary tract infections, and the development of vaccine and therapeutic methods that would block BKV pathogenesis. The NCI Laboratory of Cellular Oncology, seek parties to license or co-develop this technology.

Mechanisms of Gain Control by Voltage-Gated Channels in Intrinsically-Firing Neurons

Science.gov (United States)

Patel, Ameera X.; Burdakov, Denis

2015-01-01

Gain modulation is a key feature of neural information processing, but underlying mechanisms remain unclear. In single neurons, gain can be measured as the slope of the current-frequency (input-output) relationship over any given range of inputs. While much work has focused on the control of basal firing rates and spike rate adaptation, gain control has been relatively unstudied. Of the limited studies on gain control, some have examined the roles of synaptic noise and passive somatic currents, but the roles of voltage-gated channels present ubiquitously in neurons have been less explored. Here, we systematically examined the relationship between gain and voltage-gated ion channels in a conductance-based, tonically-active, model neuron. Changes in expression (conductance density) of voltage-gated channels increased (Ca2+ channel), reduced (K+ channels), or produced little effect (h-type channel) on gain. We found that the gain-controlling ability of channels increased exponentially with the steepness of their activation within the dynamic voltage window (voltage range associated with firing). For depolarization-activated channels, this produced a greater channel current per action potential at higher firing rates. This allowed these channels to modulate gain by contributing to firing preferentially at states of higher excitation. A finer analysis of the current-voltage relationship during tonic firing identified narrow voltage windows at which the gain-modulating channels exerted their effects. As a proof of concept, we show that h-type channels can be tuned to modulate gain by changing the steepness of their activation within the dynamic voltage window. These results show how the impact of an ion channel on gain can be predicted from the relationship between channel kinetics and the membrane potential during firing. This is potentially relevant to understanding input-output scaling in a wide class of neurons found throughout the brain and other nervous systems

Unraveling hominin behavior at another anthropogenic site from Olduvai Gorge (Tanzania): new archaeological and taphonomic research at BK, Upper Bed II.

Science.gov (United States)

Domínguez-Rodrigo, M; Mabulla, A; Bunn, H T; Barba, R; Diez-Martín, F; Egeland, C P; Espílez, E; Egeland, A; Yravedra, J; Sánchez, P

2009-09-01

New archaeological excavations and research at BK, Upper Bed II (Olduvai Gorge, Tanzania) have yielded a rich and unbiased collection of fossil bones. These new excavations show that BK is a stratified deposit formed in a riverine setting close to an alluvial plain. The present taphonomic study reveals the second-largest collection of hominin-modified bones from Olduvai, with abundant cut marks found on most of the anatomical areas preserved. Meat and marrow exploitation is reconstructed using the taphonomic signatures left on the bones by hominins. Highly cut-marked long limb shafts, especially those of upper limb bones, suggest that hominins at BK were actively engaged in acquiring small and middle-sized animals using strategies other than passive scavenging. The exploitation of large-sized game (Pelorovis) by Lower Pleistocene hominins, as suggested by previous researchers, is supported by the present study.

Adrenaline-induced colonic K+ secretion is mediated by KCa1.1 (BK) channels

DEFF Research Database (Denmark)

Sørensen, Mads Vaarby; Sausbier, Matthias; Ruth, Peter

2010-01-01

. However, the secretory K(+) channel responsible for cAMP-induced K(+) secretion remains to be defined. In this study we used the Ussing chamber to identify adrenaline-induced electrogenic K(+) secretion. We found that the adrenaline-induced electrogenic ion secretion is a compound effect dominated...... variants in colonic enterocytes (STREX and ZERO). Importantly, the ZERO variant known to be activated by cAMP is differentially up-regulated in enterocytes from animals on a high K(+) diet. In summary, these results strongly suggest that the adrenaline-induced distal colonic K(+) secretion is mediated...

Characterization of an extracellular lipase by Pseudomonas koreensis BK-L07 isolated from soil.

Science.gov (United States)

Anbu, Periasamy

2014-01-01

Screening using spirit blue agar revealed that strain BK-L07 had the highest lipase activity. Furthermore, the isolated strain was identified as Pseudomonas sp. based on morphological, physiological, biochemical, and molecular analyses. The 16S rRNA gene sequence of strain BK-L07 shared a high similarity with that of Pseudomonas koreensis (99%). The nutritional conditions and physicochemical properties were influenced by P. koreensis BK-L07. The maximum lipase production was obtained in tryptic soy broth medium at pH 8.0 and a temperature of 25°C after 36 hr of incubation. In addition, the lipase activity was determined using different carbon sources and lipase inducers. The lipase production was greatest when 1% maltose was used as the carbon source and olive oil was used as the lipase inducer. The lipase production was significantly increased approximately threefold in the optimized medium when compared with the original medium. Further, the lipase was purified by ammonium sulfate precipitation and gel filtration chromatography with a purification yield of 10.8%. The molecular mass of lipase was 45 kDa. The optimum temperature and pH were 40°C and 8.0, respectively. The enzyme was stable up to 50°C and at pH from 7 to 9. In addition, the enzyme activity was stimulated by MgSO4 and completely inhibited by ethylenediamine tetraacetic acid (EDTA), indicating the metalloenzyme type. The lipase activity was toward medium to long chain length of fatty acids (C10 to C18). Supplemental materials are available for this article. Go to the publisher's online edition of Preparative Biochemistry and Biotechnology to view the supplemental file.

Pore dimensions and the role of occupancy in unitary conductance of Shaker K channels

Science.gov (United States)

Díaz-Franulic, Ignacio; Sepúlveda, Romina V.; Navarro-Quezada, Nieves; González-Nilo, Fernando

2015-01-01

conductance of the large conductance K (BK) channel (the K channel of highest conductance), reducing the energy gap between their K+ transport rates to ∼1 kT. Thus, although Shaker’s pore sustains ion translocation as the BK channel’s does, higher energetic costs of ion stabilization or higher friction with the ion’s rigid hydration cage in its narrower aqueous cavity may entail higher resistance. PMID:26216859

Sediment and Vegetation Controls on Delta Channel Networks

Science.gov (United States)

Lauzon, R.; Murray, A. B.; Piliouras, A.; Kim, W.

2016-12-01

Numerous factors control the patterns of distributary channels formed on a delta, including water and sediment discharge, grain size, sea level rise rates, and vegetation type. In turn, these channel networks influence the shape and evolution of a delta, including what types of plant and animal life - such as humans - it can support. Previous fluvial modeling and flume experiments, outside of the delta context, have addressed how interactions between sediment and vegetation, through their influence on lateral transport of sediment, determine what type of channel networks develops. Similar interactions likely also shape delta flow patterns. Vegetation introduces cohesion, tending to reduce channel migration rates and strengthen existing channel banks, reinforcing existing channels and resulting in localized, relatively stable flow patterns. On the other hand, sediment transport processes can result in lateral migration and frequent switching of active channels, resulting in flow resembling that of a braided stream. While previous studies of deltas have indirectly explored the effects of vegetation through the introduction of cohesive sediment, we directly incorporate key effects of vegetation on flow and sediment transport into the delta-building model DeltaRCM to explore how these effects influence delta channel network formation. Model development is informed by laboratory flume experiments at UT Austin. Here we present initial results of experiments exploring the effects of sea level rise rate, sediment grain size, vegetation type, and vegetation growth rate on delta channel network morphology. These results support the hypothesis that the ability for lateral transport of sediment to occur plays a key role in determining the evolution of delta channel networks and delta morphology.

哈维氏弧菌黑鲷分离株BK-1培养条件优化研究%Studies on the Optimal Culture Conditions of Vibrio harveyi BK-1 from Sparus macrocephalus

Institute of Scientific and Technical Information of China (English)

潘晓艺; 沈锦玉; 尹文林; 曹铮; 马海其; 常抗美

2005-01-01

从患病黑鲷Sparus macrocephalus 的肾脏分离到一致病菌株BK-1,经鉴定为哈维氏弧菌.对哈维氏弧菌BK-1株的最佳生长条件及培养基优化进行了测定.结果表明:不同的培养条件和培养基成份均会影响其产量.哈维氏弧菌最适宜生长条件为:盐度为2%、pH8、温度为30℃;最佳培养基成份为:蛋白胨0.5%,牛肉膏0.75%,甘油0.05%,CuSO40.15 mg/L,CaCl2 0.01 g/L.

Aperiodic linear networked control considering variable channel delays: application to robots coordination.

Science.gov (United States)

Santos, Carlos; Espinosa, Felipe; Santiso, Enrique; Mazo, Manuel

2015-05-27

One of the main challenges in wireless cyber-physical systems is to reduce the load of the communication channel while preserving the control performance. In this way, communication resources are liberated for other applications sharing the channel bandwidth. The main contribution of this work is the design of a remote control solution based on an aperiodic and adaptive triggering mechanism considering the current network delay of multiple robotics units. Working with the actual network delay instead of the maximum one leads to abandoning this conservative assumption, since the triggering condition is fixed depending on the current state of the network. This way, the controller manages the usage of the wireless channel in order to reduce the channel delay and to improve the availability of the communication resources. The communication standard under study is the widespread IEEE 802.11g, whose channel delay is clearly uncertain. First, the adaptive self-triggered control is validated through the TrueTime simulation tool configured for the mentioned WiFi standard. Implementation results applying the aperiodic linear control laws on four P3-DX robots are also included. Both of them demonstrate the advantage of this solution in terms of network accessing and control performance with respect to periodic and non-adaptive self-triggered alternatives.

Aperiodic Linear Networked Control Considering Variable Channel Delays: Application to Robots Coordination

Directory of Open Access Journals (Sweden)

Carlos Santos

2015-05-01

Full Text Available One of the main challenges in wireless cyber-physical systems is to reduce the load of the communication channel while preserving the control performance. In this way, communication resources are liberated for other applications sharing the channel bandwidth. The main contribution of this work is the design of a remote control solution based on an aperiodic and adaptive triggering mechanism considering the current network delay of multiple robotics units. Working with the actual network delay instead of the maximum one leads to abandoning this conservative assumption, since the triggering condition is fixed depending on the current state of the network. This way, the controller manages the usage of the wireless channel in order to reduce the channel delay and to improve the availability of the communication resources. The communication standard under study is the widespread IEEE 802.11g, whose channel delay is clearly uncertain. First, the adaptive self-triggered control is validated through the TrueTime simulation tool configured for the mentioned WiFi standard. Implementation results applying the aperiodic linear control laws on four P3-DX robots are also included. Both of them demonstrate the advantage of this solution in terms of network accessing and control performance with respect to periodic and non-adaptive self-triggered alternatives.

CALCULATION METHODS OF OPTIMAL ADJUSTMENT OF CONTROL SYSTEM THROUGH DISTURBANCE CHANNEL

Directory of Open Access Journals (Sweden)

I. M. Golinko

2014-01-01

Full Text Available In the process of automatic control system debugging the great attention is paid to determining formulas’ parameters of optimal dynamic adjustment of regulators, taking into account the dynamics of Objects control. In most cases the known formulas are oriented on design of automatic control system through channel “input-output definition”. But practically in all continuous processes the main task of all regulators is stabilization of output parameters. The Methods of parameters calculation for dynamic adjustment of regulations were developed. These methods allow to optimize the analog and digital regulators, taking into account minimization of regulated influences. There were suggested to use the fact of detuning and maximum value of regulated influence. As the automatic control system optimization with proportional plus reset controllers on disturbance channel is an unimodal task, the main algorithm of optimization is realized by Hooke – Jeeves method. For controllers optimization through channel external disturbance there were obtained functional dependences of parameters calculations of dynamic proportional plus reset controllers from dynamic characteristics of Object control. The obtained dependences allow to improve the work of controllers (regulators of automatic control on external disturbance channel and so it allows to improve the quality of regulation of transient processes. Calculation formulas provide high accuracy and convenience in usage. In suggested method there are no nomographs and this fact expels subjectivity of investigation in determination of parameters of dynamic adjustment of proportional plus reset controllers. Functional dependences can be used for calculation of adjustment of PR controllers in a great range of change of dynamic characteristics of Objects control.

Properties of optical breakdown in BK7 glass induced by an extended-cavity femtosecond laser oscillator.

Science.gov (United States)

Do, Binh T; Phillips, Mark C; Miller, Paul A; Kimmel, Mark W; Britsch, Justin; Cho, Seong-Ho

2009-02-16

Using an extended-cavity femtosecond oscillator, we investigated optical breakdown in BK7 glass caused by the accumulated action of many laser pulses. By using a pump-probe experiment and collecting the transmitted pump along with the reflected pump and the broadband light generated by the optical breakdown, we measured the build-up time to optical breakdown as a function of the pulse energy, and we also observed the instability of the plasma due to the effect of defocusing and shielding created by the electron gas. The spectrum of the broadband light emitted by the optical breakdown and the origin of the material modification in BK7 glass was studied. We developed a simple model of electromagnetic wave propagation in plasma that is consistent with the observed behavior of the reflection, absorption, and transmission of the laser light.

Optimal coding-decoding for systems controlled via a communication channel

Science.gov (United States)

Yi-wei, Feng; Guo, Ge

2013-12-01

In this article, we study the problem of controlling plants over a signal-to-noise ratio (SNR) constrained communication channel. Different from previous research, this article emphasises the importance of the actual channel model and coder/decoder in the study of network performance. Our major objectives include coder/decoder design for an additive white Gaussian noise (AWGN) channel with both standard network configuration and Youla parameter network architecture. We find that the optimal coder and decoder can be realised for different network configuration. The results are useful in determining the minimum channel capacity needed in order to stabilise plants over communication channels. The coder/decoder obtained can be used to analyse the effect of uncertainty on the channel capacity. An illustrative example is provided to show the effectiveness of the results.

[Occupational Hearing Loss (BK-No. 2301) - A Retrospective Analysis of 100 Consecutive Cases].

Science.gov (United States)

Reiter, R; Brosch, S

2016-10-01

Introduction: In order for a diagnosis of Occupational Hearing Loss (BK-no. 2301) to be made certain criteria must be fulfilled to establish that the hearing loss is occupational in origin. This work compares 2 groups, those who fulfil the criteria (BKE) and those who do not (BKNE). Methods: A 100 consecutive reports ("Lärmgutachten BK-no. 2301") written by the authors were examined retrospectively. These recorded audiometric examination, an analysis of any tinnitus and noise exposure plus use of hearing protection. Pre- and post-noise exposure status together with an expert assessment of work limitations was made to produce a 7 point score. Results: 67% of the group fulfilled the conditions for occupational hearing loss (9% were entitled to compensation). In the BKE group 82% showed typical audiometric signs of noise damage with 75% of them fulfilling at least 6 criteria of occupational disease no. 2301. Tinnitus typical for noise exposure was found in 26%. Discussion: A 7 point score could be useful in the future as a method of helping distinguish hearing loss and tinnitus from occupational as opposed to other causes. © Georg Thieme Verlag KG Stuttgart · New York.

Controlled beta-quenching of fuel channels using inert gas

Energy Technology Data Exchange (ETDEWEB)

Moeckel, Andreas; Cremer, Ingo; Kratzer, Anton; Walter, Dirk [AREVA NP (Germany)

2008-07-01

The trend towards higher fuel assembly discharge burnups poses new challenges for fuel channels in terms of their dimensional behavior and corrosion resistance. This led AREVA NP to develop a new technique for beta quenching of fuel channels that combines the effect of beta-quenching with the optimization of the microstructure. The first set of fuel channels with these optimized material properties have been placed in the core of a German boiling water reactor (BWR) nuclear power plant in spring of 2004. Some more channels have been sited in the core of a Scandinavian BWR in fall of 2007 to broaden the in-pile experience with these channels. Dimensional stability is the major requirement that is applied to fuel channels. High corrosion resistance and low hydrogen pickup are certainly required as well. However, corrosion and hydrogen pickup are usually not life limiting factors due to the large wall thickness of the material. Since thick layers of oxide may spall off extensively at high burnup and cause increase of the dose rate for the personnel, high corrosion resistance of fuel channels is mandatory. The fuel channels which surround BWR fuel assemblies are exposed to neutron irradiation as well as to loads induced by the reactor coolant flowing through them. These service conditions induce material growth and creep which cause permanent changes in the dimensions of the channels. Especially, fuel channel bow is of certain interest as increased channel bow may lead to some friction with control blades. Fuel channel bow is mainly induced by fluence gradients. However, there may be additional influences such as oxidation and hydrogen uptake to cause increased channel bow. The effect of hydrogen is currently discussed in the nuclear community to explain the unexpected high fuel channel bow that has been observed in some nuclear power plants. (orig.)

Electronic structure and spectral properties of heavy actinides Pu, Am, Cm and Bk

International Nuclear Information System (INIS)

Shick, Alexander B; Kolorenc, Jindrich; Lichtenstein, Alexander I; Havela, Ladislav

2010-01-01

Selected electronic properties of Pu, Am, Cm and Bk are calculated with the aid of charge self-consistent LDA + Hubbard I method. Presented all-electron calculations are performed in the full-potential LAPW basis and incorporate spin-orbit interaction. The results are found to be in good agreement with experimental valence photoelectron spectra as well as with core XAS/EELS spectra of heavy actinides.

Stability and linearity control of spectrometric channels of the Cherenkov counters using controllable units

International Nuclear Information System (INIS)

Kollar, D.; Kollarova, L.; Khorvat, P.

1976-01-01

A system is elaborated to control stability and linearity of the Cherenkov counter spectrometric channels in an experiment on a magnetic monopole search. Linearity of a light characteristic of a photoelectric multiplier is checked with the help of the calibrated light-strikings of light emitting diodes with flare intensity adjusted by controlling generator voltage across the mercury body. A program algorithm is presented for checking stability and linearity of the Cherenkov counter spectrometric channels which helps to consider the fatigue effects of the photoelectric multiplier resulting from the considerable loads

PENGEMBANGAN INSTRUMEN ASESMEN KEBUTUHAN PERKEMBANGAN UNTUK PENYUSUNAN KURIKULUM DAN EVALUASI PROGRAM BK

Directory of Open Access Journals (Sweden)

Gendon Barus

2013-01-01

Full Text Available Penelitian pengembangan ini bertujuan menghasilkan instrumen asesmen kebutuhan peserta didik, disebut Invantori Kebutuhan Perkembangan Murid (IKPM. Penelitian mengikuti model Plomp (1999 dengan lima fase. Reliabilitas instrumen diestimasi dengan teknik Alpha Cronbach, validitas isi diperiksa oleh pakar dan telaah praktisi melalui FGD. Validitas empirik dan kecocokan model pengukuran dibuktikan dengan analisis faktor konfirmatori (CFA dengan program Lisrel 8.30. Telaah praktisi melibatkan 60 orang guru kelas V dan VI SD dalam dua tahap FGD, sedangkan uji coba empirik dan implementasi melibatkan murid kelas V dan VI. Hasil penelitian pengembang-an ini adalah: 1 IKPM dapat digunakan untuk menghimpun data kebutuhan perkembangan sebagai dasar penyusunan kurikulum bimbingan dan melaksanakan evaluasi program, bimbingan dan alat ukur evaluasi program bimbingan klasikal di sekolah dasar dan 2 teridentifikasi butir-butir kebutuhan per-kembangan murid yang intens dan sangat intens untuk dipenuhi melalui layanan bimbingan klasikal. Kata kunci: instrumen asesmen kebutuhan, kurikulum bimbingan, instrument evaluasi program BK ______________________________________________________________ DEVELOPMENT OF DEVELOPMENTAL NEEDS ASSESSMENT INSTRUMENT FOR CURRICULUM ARRANGEMENT AND EVALUATION OF BK PROGRAM Abstract The goal of this research is to produce a developmental needs assessment instrument, called Student’s Developmental Needs Inventory, which can be use to reveal the needs of students in elementary school. The research method follows the model of Research and Development (R & D by Plomp (1999 with five phases. The instrument which is developed in this study guidance and counseling (Bimbingan Konseling, BK in elementary school. Instrument reliability is estimated using by Alpha Cronbach technique, it content validity is checked by experts judgment and practitioner’s assessment with FGD technique. Furthermore, empirical validity and the goodness of fit

Ion channel gene expressions in infertile men: A case-control study

Directory of Open Access Journals (Sweden)

Serkan Carkci

2017-12-01

Full Text Available Background: Infertility is described as not receiving pregnancy despite unprotected and regular sexual intercourse in a 1 yr period. It is detected by 15% of the couples. Male and female factor in the etiology may be detected in similar rates. Objective: The present study aims to investigate ion channel gene expression in semen samples of infertile male compared with fertile men. Materials and Methods: A total of 150 men who applied to the urology clinic due to infertility were divided into five equal groups: asthenozoospermia, oligozoospermia, oligoasthenoteratozoospermia, teratozoospermia, and normozoospermia (control. All paticipants were evaluated with Cation Channel Spermia (CatSper 1, 2, 3, 4, Proton Voltage Gated Ion Channel1 (Hv1, Potassium Channel Subfamily U1 (KCNU1, and transmembrane protein (TMEM16A gene expression in semen samples. Results: “CatSper1, 4, HV1, KCNU1, and TMEM16A gene expression were detected higher in the oligozoospermia group compared to the controls. CatSper1, 2, 3, 4, KCNU1, and TMEM16A gene expression in the asthenozoospermia group and CatSper1, 2, 3, 4, KCNU1, and TMEM16A gene expression in the teratozoospermia group were detected lower compared to the controls. CatSper1, 4, HV1, and TMEM16A gen expression were higher in the oligoasthenoteratozoospermia men than the controls while CatSper3 gen expression was detected as lower.” Conclusion: It was detected that these ion channels have an effect on sperm progressive motility and morphology. It may be considered that mutations in these ion channels may result in infertility

TRPV5: an ingeniously controlled calcium channel.

NARCIS (Netherlands)

Groot, T. de; Bindels, R.J.M.; Hoenderop, J.G.J.

2008-01-01

Body Ca(2+) homeostasis is tightly controlled and slight disturbances in renal Ca(2+) reabsorption can lead to excessive urine Ca(2+) excretion and promote kidney stone formation. The epithelial Ca(2+) channel TRPV5 constitutes the rate-limiting step of active Ca(2+) reabsorption in the kidney.

Groundwater controls on river channel pattern

Science.gov (United States)

Bätz, Nico; Colombini, Pauline; Cherubini, Paolo; Lane, Stuart N.

2017-04-01

reduction in flood disturbance, it was still sufficient to maintain a wandering/braided state. Thus, it appears that access to groundwater can control river channel pattern through its impact upon the "engineering effects" of vegetation. The results are important for river management as they highlight the non-linearity of developing vegetation in dynamic alluvial floodplains and the importance of considering the wider environmental setting and associated feedbacks between biotic and abiotic river components in defining long-term geomorphological river response.

Network device interface for digitally interfacing data channels to a controller via a network

Science.gov (United States)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

2009-01-01

A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

Science.gov (United States)

Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

2015-01-01

In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

Directory of Open Access Journals (Sweden)

Yuanfu Mo

Full Text Available In a vehicular ad hoc network (VANET, the periodic exchange of single-hop status information broadcasts (beacon frames produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

Channel box

International Nuclear Information System (INIS)

Tanabe, Akira.

1993-01-01

In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)

Channel selection for simultaneous and proportional myoelectric prosthesis control of multiple degrees-of-freedom

Science.gov (United States)

Hwang, Han-Jeong; Hahne, Janne Mathias; Müller, Klaus-Robert

2014-10-01

Objective. Recent studies have shown the possibility of simultaneous and proportional control of electrically powered upper-limb prostheses, but there has been little investigation on optimal channel selection. The objective of this study is to find a robust channel selection method and the channel subsets most suitable for simultaneous and proportional myoelectric prosthesis control of multiple degrees-of-freedom (DoFs). Approach. Ten able-bodied subjects and one person with congenital upper-limb deficiency took part in this study, and performed wrist movements with various combinations of two DoFs (flexion/extension and radial/ulnar deviation). During the experiment, high density electromyographic (EMG) signals and the actual wrist angles were recorded with an 8 × 24 electrode array and a motion tracking system, respectively. The wrist angles were estimated from EMG features with ridge regression using the subsets of channels chosen by three different channel selection methods: (1) least absolute shrinkage and selection operator (LASSO), (2) sequential feature selection (SFS), and (3) uniform selection (UNI). Main results. SFS generally showed higher estimation accuracy than LASSO and UNI, but LASSO always outperformed SFS in terms of robustness, such as noise addition, channel shift and training data reduction. It was also confirmed that about 95% of the original performance obtained using all channels can be retained with only 12 bipolar channels individually selected by LASSO and SFS. Significance. From the analysis results, it can be concluded that LASSO is a promising channel selection method for accurate simultaneous and proportional prosthesis control. We expect that our results will provide a useful guideline to select optimal channel subsets when developing clinical myoelectric prosthesis control systems based on continuous movements with multiple DoFs.

Depletion of intracellular calcium stores facilitates the influx of extracellular calcium in platelet derived growth factor stimulated A172 glioblastoma cells.

Science.gov (United States)

Vereb, G; Szöllösi, J; Mátyus, L; Balázs, M; Hyun, W C; Feuerstein, B G

1996-05-01

Calcium signaling in non-excitable cells is the consequence of calcium release from intracellular stores, at times followed by entry of extracellular calcium through the plasma membrane. To study whether entry of calcium depends upon the level of saturation of intracellular stores, we measured calcium channel opening in the plasma membrane of single confluent A172 glioblastoma cells stimulated with platelet derived growth factor (PDGF) and/or bradykinin (BK). We monitored the entry of extracellular calcium by measuring manganese quenching of Indo-1 fluorescence. PDGF raised intracellular calcium concentration ([Ca2+]i) after a dose-dependent delay (tdel) and then opened calcium channels after a dose-independent delay (tch). At higher doses (> 3 nM), BK increased [Ca2+]i after a tdel approximately 0 s, and tch decreased inversely with both dose and peak [Ca2+]i. Experiments with thapsigargin (TG), BK, and PDGF indicated that BK and PDGF share intracellular Ca2+ pools that are sensitive to TG. When these stores were depleted by treatment with BK and intracellular BAPTA, tdel did not change, but tch fell to almost 0 s in PDGF stimulated cells, indicating that depletion of calcium stores affects calcium channel opening in the plasma membrane. Our data support the capacitative model for calcium channel opening and the steady-state model describing quantal Ca2+ release from intracellular stores.

Draft Genome Sequence of an Invasive Multidrug-Resistant Strain, Pseudomonas aeruginosa BK1, Isolated from a Keratitis Patient

KAUST Repository

Jeganathan, Lakshmi Priya; Prakash, Logambiga; Neelamegam, Sivakumar; Antony, Aju; Alqarawi, Sami; Prajna, Lalitha; Devarajan, Bharanidharan; Mohankumar, Vidyarani

2014-01-01

Pseudomonas aeruginosa infections are difficult to treat due to the presence of a multitude of virulence factors and antibiotic resistance. Here, we report the draft genome sequence of P. aeruginosa BK1, an invasive and multidrug-resistant strain

Two-Channel Transparency-Optimized Control Architectures in Bilateral Teleoperation With Time Delay.

Science.gov (United States)

Kim, Jonghyun; Chang, Pyung Hun; Park, Hyung-Soon

2013-01-01

This paper introduces transparency-optimized control architectures (TOCAs) using two communication channels. Two classes of two-channel TOCAs are found, thereby showing that two channels are sufficient to achieve transparency. These TOCAs achieve a greater level of transparency but poorer stability than three-channel TOCAs and four-channel TOCAs. Stability of the two-channel TOCAs has been enhanced while minimizing transparency degradation by adding a filter; and a combined use of the two classes of two-channel TOCAs is proposed for both free space and constrained motion, which involve switching between two TOCAs for transition between free space and constrained motions. The stability condition of the switched teleoperation system is derived for practical applications. Through the one degree-of-freedom (DOF) experiment, the proposed two-channel TOCAs were shown to operate stably, while achieving better transparency under time delay than the other TOCAs.

Use of integrity control and automatic start of reserve in a multi-channel temperature and flow rate control device

International Nuclear Information System (INIS)

Strzalkowski, L.

1975-01-01

A way to increase reliability of process quantity control is control of the integrity of the control plants themselves. The possibilities of integrity control on control devices having simply duplicated control channels or working on the basis of the ''two-from-three'' principle are valued. A highly reliable integrity control is possible by use of test signals. For an appropriate control device, structure and function of the assemblies are described. The integrity control device may be used in the water coolant temperature and flow rate control system for all technological channels of the research reactor ''Maria''

MODELING OF TECHNICAL CHANNELS OF INFORMATION LEAKAGE AT DISTRIBUTED CONTROL OBJECTS

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Aleksander Vladimirovich Karpov

2018-05-01

Full Text Available The significant increase in requirements for distributed control objects’ functioning can’t be realized only at the expense of the widening and strengthening of security control measures. The first step in ensuring the information security at such objects is the analysis of the conditions of their functioning and modeling of technical channels of information leakage. The development of models of such channels is essentially the only method of complete study of their opportunities and it is pointed toward receiving quantitative assessments of the safe operation of compound objects. The evaluation data are necessary to make a decision on the degree of the information security from a leak according to the current criterion. The existing models are developed for the standard concentrated objects and allow to evaluate the level of information security from a leak on each of channels separately, what involves the significant increase in the required protective resource and time of assessment of information security on an object in general. The article deals with a logical-and-probabilistic method of a security assessment of structurally-compound objects. The model of a security leak on the distributed control objects is cited as an example. It is recommended to use a software package of an automated structurally-logistical modeling of compound systems, which allows to evaluate risk of information leakage in the loudspeaker. A possibility of information leakage by technical channels is evaluated and such differential characteristics of the safe operation of the distributed control objects as positive and negative contributions of the initiating events and conditions, which cause a leak are calculated. Purpose. The aim is a quantitative assessment of data risk, which is necessary for justifying the rational composition of organizational and technical protection measures, as well as a variant of the structure of the information security system from a

Two-Channel Transparency-Optimized Control Architectures in Bilateral Teleoperation With Time Delay

Science.gov (United States)

Kim, Jonghyun; Chang, Pyung Hun; Park, Hyung-Soon

2013-01-01

This paper introduces transparency-optimized control architectures (TOCAs) using two communication channels. Two classes of two-channel TOCAs are found, thereby showing that two channels are sufficient to achieve transparency. These TOCAs achieve a greater level of transparency but poorer stability than three-channel TOCAs and four-channel TOCAs. Stability of the two-channel TOCAs has been enhanced while minimizing transparency degradation by adding a filter; and a combined use of the two classes of two-channel TOCAs is proposed for both free space and constrained motion, which involve switching between two TOCAs for transition between free space and constrained motions. The stability condition of the switched teleoperation system is derived for practical applications. Through the one degree-of-freedom (DOF) experiment, the proposed two-channel TOCAs were shown to operate stably, while achieving better transparency under time delay than the other TOCAs. PMID:23833548

The mechanosensory calcium-selective ion channel: key component of a plasmalemmal control centre?

Science.gov (United States)

Pickard, B. G.; Ding, J. P.

1993-01-01

Mechanosensory calcium-selective ion channels probably serve to detect not only mechanical stress but also electrical, thermal, and diverse chemical stimuli. Because all stimuli result in a common output, most notably a shift in second messenger calcium concentration, the channels are presumed to serve as signal integrators. Further, insofar as second messenger calcium in turn gives rise to mechanical, electrical, and diverse chemical changes, the channels are postulated to initiate regulatory feedbacks. It is proposed that the channels and the feedback loops play a wide range of roles in regulating normal plant function, as well as in mediating disturbance of normal function by environmental stressors and various pathogens. In developing evidence for the physiological performance of the channel, a model for a cluster of regulatory plasmalemmal proteins and cytoskeletal elements grouped around a set of wall-to-membrane and transmembrane linkers has proved useful. An illustration of how the model might operate is presented. It is founded on the demonstration that several xenobiotics interfere both with normal channel behaviour and with gravitropic reception. Accordingly, the first part of the illustration deals with how the channels and the control system within which they putatively operate might initiate gravitropism. Assuming that gravitropism is an asymmetric expression of growth, the activities of the channels and the plasmalemmal control system are extrapolated to account for regulation of both rate and allometry of cell expansion. Finally, it is discussed how light, hormones, redox agents and herbicides could in principle affect growth via the putative plasmalemmal control cluster or centre.

Profil Siswa Agresif dan Peranan Guru BK

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Hafiz Hidayat

2013-06-01

Full Text Available Abstract: Teens have a positive and negative behavior. Negative behavior is not characteristic of normal adolescent development, adolescents are developing will exhibit positive behavior. One of the teens indicated negative behavior is aggressive behavior. It can be seen in SMA N 5 Padang is quarrelsome, like teasing, hitting, pinching her, saying rude, insulting. This study aimed to describe the type of aggressive behavior of students and the role of BK teachers to address students' aggressive behavior SMAN 5 Padang. This study used a descriptive approach. The study population was a high school student Padang N 5 340 people with a total sample amounted to 77 people. Questionnaire data collection techniques to use. Data were analyzed using Microsoft Office Excel 2007. The findings showed that students' views of the aggressive actions hurt people physically with a percentage of 35.32%, while the aggressive actions of the student views of hurting people verbally 41.30% and aggression seen from damaging and destroying property by 30 percent, 42%. This means that the presence of aggressive behavior in SMA N 5 Padang.

Networked control of discrete-time linear systems over lossy digital communication channels

Science.gov (United States)

Jin, Fang; Zhao, Guang-Rong; Liu, Qing-Quan

2013-12-01

This article addresses networked control problems for linear time-invariant systems. The insertion of the digital communication network inevitably leads to packet dropout, time delay and quantisation error. Due to data rate limitations, quantisation error is not neglected. In particular, the case where the sensors and controllers are geographically separated and connected via noisy, bandwidth-limited digital communication channels is considered. A fundamental limitation on the data rate of the channel for mean-square stabilisation of the closed-loop system is established. Sufficient conditions for mean-square stabilisation are derived. It is shown that there exists a quantisation, coding and control scheme to stabilise the unstable system over packet dropout communication channels if the data rate is larger than the lower bound proposed in our result. An illustrative example is given to demonstrate the effectiveness of the proposed conditions.

No evidence for infection of UK prostate cancer patients with XMRV, BK virus, Trichomonas vaginalis or human papilloma viruses.

Science.gov (United States)

Groom, Harriet C T; Warren, Anne Y; Neal, David E; Bishop, Kate N

2012-01-01

The prevalence of specific infections in UK prostate cancer patients was investigated. Serum from 84 patients and 62 controls was tested for neutralisation of xenotropic murine leukaemia virus-related virus (XMRV) Envelope. No reactivity was found in the patient samples. In addition, a further 100 prostate DNA samples were tested for XMRV, BK virus, Trichomonas vaginalis and human papilloma viruses by nucleic acid detection techniques. Despite demonstrating DNA integrity and assay sensitivity, we failed to detect the presence of any of these agents in DNA samples, bar one sample that was weakly positive for HPV16. Therefore we conclude that these infections are absent in this typical cohort of men with prostate cancer.

No evidence for infection of UK prostate cancer patients with XMRV, BK virus, Trichomonas vaginalis or human papilloma viruses.

Directory of Open Access Journals (Sweden)

Harriet C T Groom

Full Text Available The prevalence of specific infections in UK prostate cancer patients was investigated. Serum from 84 patients and 62 controls was tested for neutralisation of xenotropic murine leukaemia virus-related virus (XMRV Envelope. No reactivity was found in the patient samples. In addition, a further 100 prostate DNA samples were tested for XMRV, BK virus, Trichomonas vaginalis and human papilloma viruses by nucleic acid detection techniques. Despite demonstrating DNA integrity and assay sensitivity, we failed to detect the presence of any of these agents in DNA samples, bar one sample that was weakly positive for HPV16. Therefore we conclude that these infections are absent in this typical cohort of men with prostate cancer.

Pitch Channel Control of a REMUS AUV with Input Saturation and Coupling Disturbances

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Nailong Wu

2018-02-01

Full Text Available The motion of an underwater vehicle is prone to be affected by time-varying model parameters and the actuator limitation in control practice. Adaptive control is an effective method to deal with the general system dynamic uncertainties and disturbances. However, the effect of disturbances control on transient dynamics is not prominent. In this paper, we redesign the L 1 adaptive control architecture (L1AC with anti-windup (AW compensator to guarantee robust and fast adaption of the underwater vehicle with input saturation and coupling disturbances. To reduce the fluctuation of vehicle states, the Riccati-based AW compensator is utilized to compensate the output signal from L1AC controller via taking proper modification. The proposed method is applied to the pitch channel of REMUS vehicle’s six Degrees Of Freedom (DOF model with strong nonlinearities and compared with L1AC baseline controller. Simulations show the effectiveness of the proposed control strategy compared to the original L1AC. Besides, the fluctuation in roll channel coupled with pitch channel is suppressed according to the performances of control tests.

Vasoinhibins Prevent Bradykinin-Stimulated Endothelial Cell Proliferation by Inactivating eNOS via Reduction of both Intracellular Ca2+ Levels and eNOS Phosphorylation at Ser1179

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Carmen Clapp

2011-07-01

Full Text Available Vasoinhibins, a family of antiangiogenic peptides derived from prolactin proteolysis, inhibit the vascular effects of several proangiogenic factors, including bradykinin (BK. Here, we report that vasoinhibins block the BK-induced proliferation of bovine umbilical vein endothelial cells. This effect is mediated by the inactivation of endothelial nitric oxide synthase (eNOS, as the NO donor DETA-NONOate reverted vasoinhibin action. It is an experimentally proven fact that the elevation of intracellular Ca2+ levels ([Ca2+]i upon BK stimulation activates eNOS, and vasoinhibins blocked the BK-mediated activation of phospholipase C and the formation of inositol 1,4,5-triphosphate leading to a reduced release of Ca2+ from intracellular stores. The [Ca2+]i rise evoked by BK also involves the influx of extracellular Ca2+ via canonical transient receptor potential (TRPC channels. Vasoinhibins likely interfere with TRPC-mediated Ca2+ entry since La3+, which is an enhancer of TRPC4 and TRPC5 channel activity, prevented vasoinhibins from blocking the stimulation by BK of endothelial cell NO production and proliferation, and vasoinhibins reduced the BK-induced increase of TRPC5 mRNA expression. Finally, vasoinhibins prevented the BK-induced phosphorylation of eNOS at Ser1179, a post-translational modification that facilitates Ca2+-calmodulin activation of eNOS. Together, our data show that vasoinhibins, by lowering NO production through the inhibition of both [Ca2+]i mobilization and eNOS phosphorylation, prevent the BK-induced stimulation of endothelial cell proliferation. Thus, vasoinhibins help to regulate BK effects on angiogenesis and vascular homeostasis.

Nanosecond pulsed electric fields depolarize transmembrane potential via voltage-gated K+, Ca2+ and TRPM8 channels in U87 glioblastoma cells.

Science.gov (United States)

Burke, Ryan C; Bardet, Sylvia M; Carr, Lynn; Romanenko, Sergii; Arnaud-Cormos, Delia; Leveque, Philippe; O'Connor, Rodney P

2017-10-01

Nanosecond pulsed electric fields (nsPEFs) have a variety of applications in the biomedical and biotechnology industries. Cancer treatment has been at the forefront of investigations thus far as nsPEFs permeabilize cellular and intracellular membranes leading to apoptosis and necrosis. nsPEFs may also influence ion channel gating and have the potential to modulate cell physiology without poration of the membrane. This phenomenon was explored using live cell imaging and a sensitive fluorescent probe of transmembrane voltage in the human glioblastoma cell line, U87 MG, known to express a number of voltage-gated ion channels. The specific ion channels involved in the nsPEF response were screened using a membrane potential imaging approach and a combination of pharmacological antagonists and ion substitutions. It was found that a single 10ns pulsed electric field of 34kV/cm depolarizes the transmembrane potential of cells by acting on specific voltage-sensitive ion channels; namely the voltage and Ca2 + gated BK potassium channel, L- and T-type calcium channels, and the TRPM8 transient receptor potential channel. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Term Protection of Genetically Ablated Rabbit Retinal Degeneration by Sustained Transscleral Unoprostone Delivery.

Science.gov (United States)

Nagai, Nobuhiro; Koyanagi, Eri; Izumida, Yasuko; Liu, Junjun; Katsuyama, Aya; Kaji, Hirokazu; Nishizawa, Matsuhiko; Osumi, Noriko; Kondo, Mineo; Terasaki, Hiroko; Mashima, Yukihiko; Nakazawa, Toru; Abe, Toshiaki

2016-12-01

To evaluate the long-term protective effects of transscleral unoprostone (UNO) against retinal degeneration in transgenic (Tg) rabbits (Pro347Leu rhodopsin mutation). The UNO release devices (URDs) were implanted into the sclerae of Tg rabbits and ERG, optical coherence tomography (OCT), and ophthalmic examinations were conducted for 40 weeks. Unoprostone metabolites in retina, choroid/RPE, aqueous humor, and plasma from wild-type (Wt) rabbits were measured using liquid chromatography-tandem mass spectrometry. In situ hybridization and immunohistochemistry evaluated the retinal distribution of big potassium (BK) channels, and RT-PCR evaluated the expressions of BK channels and m-opsin at 1 week after URD treatment. The URD released UNO at a rate of 10.2 ±1.0 μg/d, and the release rate and amount of UNO decreased during 32 weeks. Higher ERG amplitudes were observed in the URD-treated Tg rabbits compared with the placebo-URD, or nontreated controls. At 24 weeks after implantation into the URD-treated Tg rabbits, OCT images showed preservation of retinal thickness, and histologic examinations (44 weeks) showed greater thickness of outer nuclear layers. Unoprostone was detected in the retina, choroid, and plasma of Wt rabbits. Retina/plasma ratio of UNO levels were 38.0 vs. 0.68 ng UNO*hour/mL in the URD-treated group versus control (topical UNO), respectively. Big potassium channels were observed in cone, cone ON-bipolar, and rod bipolar cells. Reverse-transcriptase PCR demonstrated BK channels and m-opsins increased in URD-treated eyes. In Tg rabbits, URD use slowed the decline of retinal function for more than 32 weeks, and therefore provides a promising tool for long-term treatment of RP.

Experience with ActiveX control for simple channel access

International Nuclear Information System (INIS)

Timossi, C.; Nishimura, H.; McDonald, J.

2003-01-01

Accelerator control system applications at Berkeley Lab's Advanced Light Source (ALS) are typically deployed on operator consoles running Microsoft Windows 2000 and utilize EPICS[2]channel access for data access. In an effort to accommodate the wide variety of Windows based development tools and developers with little experience in network programming, ActiveX controls have been deployed on the operator stations. Use of ActiveX controls for use in the accelerator control environment has been presented previously[1]. Here we report on some of our experiences with the use and development of these controls

Chemical control of channel interference in two-photon absorption processes.

Science.gov (United States)

Alam, Md Mehboob; Chattopadhyaya, Mausumi; Chakrabarti, Swapan; Ruud, Kenneth

2014-05-20

The two-photon absorption (TPA) process is the simplest and hence the most studied nonlinear optical phenomenon, and various aspects of this process have been explored in the past few decades, experimentally as well as theoretically. Previous investigations have shown that the two-photon (TP) activity of a molecular system can be tuned, and at present, performance-tailored TP active materials are easy to develop by monitoring factors such as length of conjugation, dimensionality of charge-transfer network, strength of donor-acceptor groups, polarity of solvents, self-aggregation, H-bonding, and micellar encapsulation to mention but a few. One of the most intriguing phenomena affecting the TP activity of a molecule is channel interference. The phrase "channel interference" implies that if the TP transition from one electronic state to another involves more than one optical pathway or channel, characterized by the corresponding transition dipole moment (TDM) vectors, the channels may interfere with each other depending upon the angles between the TDM vectors and hence can either increase (constructive interference) or decrease (destructive interference) the overall TP activity of a system to a significant extent. This phenomenon was first pointed out by Cronstrand, Luo, and Ågren [Chem. Phys. Lett. 2002, 352, 262-269] in two-dimensional systems (i.e., only involving two components of the transition moment vectors). For three-dimensional molecules, an extended version of this idea was required. In order to fill this gap, we developed a generalized model for describing and exploring channel interference, valid for systems of any dimensionality. We have in particular applied it to through-bond (TB) and through-space (TS) charge-transfer systems both in gas phase and in solvents with different polarities. In this Account, we will, in addition to briefly describing the concept of channel interference, discuss two key findings of our recent work: (1) how to control the

Engineered channel controls limiting spawning habitat rehabilitation success on regulated gravel-bed rivers

Science.gov (United States)

Brown, Rocko A.; Pasternack, Gregory B.

2008-05-01

In efforts to rehabilitate regulated rivers for ecological benefits, the flow regime has been one of the primary focal points of management strategies. However, channel engineering can impact channel geometry such that hydraulic and geomorphic responses to flow reregulation do not yield the sought for benefits. To illustrate and assess the impacts of structural channel controls and flow reregulation on channel processes and fish habitat quality in multiple life stages, a highly detailed digital elevation model was collected and analyzed for a river reach right below a dam using a suite of hydrologic, hydraulic, geomorphic, and ecological methods. Results showed that, despite flow reregulation to produce a scaled-down natural hydrograph, anthropogenic boundary controls have severely altered geomorphic processes associated with geomorphic self-sustainability and instream habitat availability in the case study. Given the similarity of this stream to many others, we concluded that the potential utility of natural flow regime reinstatement in regulated gravel-bed rivers is conditional on concomitant channel rehabilitation.

Conversion from tacrolimus-mycophenolate mofetil to tacrolimus-mTOR immunosuppression after kidney-pancreas transplantation reduces the incidence of both BK and CMV viremia.

Science.gov (United States)

Knight, Richard J; Graviss, Edward A; Nguyen, Duc T; Kuten, Samantha A; Patel, Samir J; Gaber, Lillian; Gaber, A Osama

2018-04-19

We sought to determine whether conversion from tacrolimus/mycophenolate mofetil (TAC-MMF) into tacrolimus/mTOR inhibitor (TAC-mTOR) immunosuppression would reduce the incidences of BK and CMV viremia after kidney/pancreas (KP) transplantation. In this single-center review, the TAC-mTOR cohort (n = 39) was converted at 1 month post-transplant to an mTOR inhibitor and reduced-dose tacrolimus. Outcomes were compared to a cohort of KP recipients (n = 40) maintained on TAC-MMF. At 3 years post-transplant, KP survivals and incidences of kidney/pancreas rejection were equivalent between mTOR and MMF-treated cohorts. (P = ns). BK viremia-free survival was better for the mTOR vs MMF-treated group (P = .004). In multivariate analysis, MMF vs mTOR immunosuppression was an independent risk factor for BK viremia (hazard ratio 12.27, P = .02). Similarly, mTOR-treated recipients displayed better CMV infection-free survival compared to the MMF-treated cohort (P = .01). MMF vs mTOR immunosuppression (hazard ratio 18.77, P = .001) and older recipient age (hazard ratio 1.13 per year, P = .006) were independent risk factors for CMV viremia. Mean estimated GFR and HgbA1c levels were equivalent between groups at 1, 2, and 3 years post-transplantation. Conversion from TAC/MMF into TAC/mTOR immunosuppression after KP transplantation reduced the incidences of BK and CMV viremia with an equivalent risk of acute rejection and similar renal/pancreas function. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

On the delay effects of different channels in Internet-based networked control systems

Science.gov (United States)

Zhao, Yun-Bo; Kim, Jongrae; Sun, Xi-Ming; Liu, Guo-Ping

2013-11-01

The sensor-to-controller and the controller-to-actuator delays in networked control systems (NCSs) are investigated for the first time with respect to their different effects on the system performance. This study starts with identifying the delay-independent and delay-dependent control laws in NCSs, and confirms that only two delay-dependent control laws can cause different delay effects in different channels. The conditions under which the different delays in different channels can cause different effects are then given for both delay-dependent control laws. The results are verified by numerical examples. Potentially, these results can be regarded as important design principles in the practical implementation of NCSs.

Perilaku Bullying dan Peranan Guru BK/Konselor dalam Pengentasannya (Studi Deskriptif terhadap Siswa SMP Negeri 3 Lubuk Basung

Directory of Open Access Journals (Sweden)

Ilfajri Yenes

2016-06-01

Full Text Available Bullying merupakan suatu situasi di mana terjadinya penyalahgunaan kekuatan/kekuasaan yang dilakukan oleh seseorang/kelompok. Perilaku bullying merupakan  salah satu bentuk kekerasan dan agresif siswa di sekolah. Penelitian ini adalah penelitian deskriptif yang bertujuan untuk mendeskripsikan perilaku bullying yang ditampilkan siswa SMPN 3 Lubuk Basung dan peranan guru BK/konselor dalam pengentasannya. Populasi penelitian adalah siswa di SMP Negeri 3 Lubuk Basung berjumlah  564 orang dengan sampel 138 orang diambil dengan menggunakan teknik propotonal stratified random. Teknik pengumpulan data dengan menggunakan angket. Temuan penelitian menunjukkan bahwa jenis perilaku bullying yang dominan terjadi yaitu menyakiti secara verbal dilanjutkan dengan menyakiti secara fisik kemudian menyakiti secara mental dengan faktor keluarga. Faktor teman sebaya merupakan faktor yang lebih dominan sebagai penyebab perilaku bullying siswa. Secara umum guru BK/konselor cukup berperan mengatasi perilaku bullyingdengan memberikan  layanan informasi sebagai layanan yang lebih dominan diberikan dilanjutkan dengan layanan bimbingan kelompok dan konseling kelompok serta pemberian layanan konseling individual.

Controlling Plasma Channels through Ultrashort Laser Pulse Filamentation

Science.gov (United States)

Ionin, Andrey; Seleznev, Leonid; Sunchugasheva, Elena

2013-09-01

A review of studies fulfilled at the Lebedev Institute in collaboration with the Moscow State University and Institute of Atmospheric Optics in Tomsk on influence of various characteristics of ultrashort laser pulse on plasma channels formed under its filamentation is presented. Filamentation of high-power laser pulses with wavefront controlled by a deformable mirror, with cross-sections spatially formed by various diaphragms and with different wavelengths was experimentally and numerically studied. An application of plasma channels formed due to filamentation of ultrashort laser pulse including a train of such pulses for triggering and guiding long electric discharges is discussed. The research was supported by RFBR Grants 11-02-12061-ofi-m and 11-02-01100, and EOARD Grant 097007 through ISTC Project 4073 P

Free-energy relationships in ion channels activated by voltage and ligand

Science.gov (United States)

Chowdhury, Sandipan

2013-01-01

Many ion channels are modulated by multiple stimuli, which allow them to integrate a variety of cellular signals and precisely respond to physiological needs. Understanding how these different signaling pathways interact has been a challenge in part because of the complexity of underlying models. In this study, we analyzed the energetic relationships in polymodal ion channels using linkage principles. We first show that in proteins dually modulated by voltage and ligand, the net free-energy change can be obtained by measuring the charge-voltage (Q-V) relationship in zero ligand condition and the ligand binding curve at highly depolarizing membrane voltages. Next, we show that the voltage-dependent changes in ligand occupancy of the protein can be directly obtained by measuring the Q-V curves at multiple ligand concentrations. When a single reference ligand binding curve is available, this relationship allows us to reconstruct ligand binding curves at different voltages. More significantly, we establish that the shift of the Q-V curve between zero and saturating ligand concentration is a direct estimate of the interaction energy between the ligand- and voltage-dependent pathway. These free-energy relationships were tested by numerical simulations of a detailed gating model of the BK channel. Furthermore, as a proof of principle, we estimate the interaction energy between the ligand binding and voltage-dependent pathways for HCN2 channels whose ligand binding curves at various voltages are available. These emerging principles will be useful for high-throughput mutagenesis studies aimed at identifying interaction pathways between various regulatory domains in a polymodal ion channel. PMID:23250866

Channel Control-Blade Interference Management at LaSalle 1 and 2 during 2007 and 2008

Energy Technology Data Exchange (ETDEWEB)

Cantonwine, Paul; Crawford, Doug; Downs, Mike [Global Nuclear Fuels, PO Box 780, Wilmington, NC 28402 (United States); Joe, Bertrum [GE-Hitachi, 1989 Little Orchard St., San Jose, CA 95125-1030 (United States); Bahensky, Ted [GE-Hitachi, PO Box 780, Wilmington, NC 28402 (United States); Reimer, John [Exelon Nuclear, 2601 North 21st Road, Marseilles, Il 61341-9757 (United States); Hoz, Carlos del la; Petersen, Ken [Exelon Nuclear, 4300 Winfield Road, Warrenville, IL 60555 (United States); Reitmeyer, Mike [Exelon Nuclear, 200 Exelon Way, Kennett Square, PA 19348 (United States); Morris, Jeff; Zbib, Ali [AREVA NP, 2101 Horn Rapids Road, Richland, WA. 99354 (United States)

2009-06-15

This paper provides a summary of the operational experience at LaSalle 1 and LaSalle 2 regarding channel control-blade interference that occurred in 2007 and 2008. Channel distortion data from LaSalle 1 provides a characterization of distortion in all four bundles in cells that experienced channel interference and cells that did not. Also, this paper provides a new channel distortion management strategy implemented at LaSalle 2 that avoided a mid-cycle outage. LaSalle 1 and LaSalle 2 are GE designed Boiling Water Reactors (BWR/5 Type) that generate 1195 MW electric. During 2007 and 2008, each core had 1. and 3. Cycle AREVA ATTRIUM{sup TM} 10 fuel with 100 mil Zr-2 channels and 2. Cycle GNF GE14 fuel with 120/75 mil Zr-2 channels. As a result of the channel control-blade interference observed in 2007 and 2008, two peripheral cells in LaSalle 1 and two (1 peripheral and 1 interior) cells in LaSalle 2 were declared inoperable. The first observations of channel control-blade friction occurred in September 2007 in LaSalle 1 about 6 months prior to the end of a 2-year cycle. LaSalle 2 had started up approximately 6 months earlier and had 18 months left the cycle. The initial observations (eventually seven cells with no-settle conditions were observed in LaSalle) were limited to the peripheral cells where fluence gradient-induced bow was the dominant distortion mechanism. However, near the end of cycle in LaSalle 1 in January 2008, a number of interior cells were unexpectedly found to not settle. These were later determined to be a result of shadow corrosion-induced bow. Further testing to determine the extent of condition found a total of nine interior cells that failed the no-settle criterion. These unexpected observations instigated a significant response that resulted in an extensive expansion of the work scope for the upcoming outage that began on February 4, 2008. Specifically, a large channel measurement campaign and a large re-channeling campaign were added. The

Performance of Downlink UTRAN LTE under Control Channel Constraints

DEFF Research Database (Denmark)

López Villa, Dimas; Úbeda Castellanos, Carlos; Kovács, István Z.

2008-01-01

Dynamic time-frequency domain packet scheduling algorithms in the shared channel of downlink orthogonal Frequency Division Multiple Access (OFDMA) systems have been shown to achieve high multi-user diversity scheduling gains. However, the flexibility is obtained at the cost of additional control ...

Role of KCNMA1 gene in breast cancer invasion and metastasis to brain

International Nuclear Information System (INIS)

Khaitan, Divya; Sankpal, Umesh T; Weksler, Babette; Meister, Edward A; Romero, Ignacio A; Couraud, Pierre-Olivier; Ningaraj, Nagendra S

2009-01-01

The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, large-conductance calcium- and voltage-activated potassium channel (BK Ca ) channels are significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene that encodes for the pore-forming α-subunit of BK Ca channels in breast cancer metastasis and invasion. We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer to brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of BK Ca channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A), non-metastatic breast cancer (MCF-7), non-brain metastatic breast cancer cells (MDA-MB-231), and brain-specific metastatic breast cancer cells (MDA-MB-361) to study whether BK Ca channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with Iberiotoxin (IBTX). The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BK Ca channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1. Determining the relative abundance of BK Ca channel expression in breast cancer metastatic to brain and the mechanism of its

Clinical polyomavirus BK variants with agnogene deletion are non-functional but rescued by trans-complementation

International Nuclear Information System (INIS)

Myhre, Marit Renee; Olsen, Gunn-Hege; Gosert, Rainer; Hirsch, Hans H.; Rinaldo, Christine Hanssen

2010-01-01

High-level replication of polyomavirus BK (BKV) in kidney transplant recipients is associated with the emergence of BKV variants with rearranged (rr) non-coding control region (NCCR) increasing viral early gene expression and cytopathology. Cloning and sequencing revealed the presence of a BKV quasispecies which included non-functional variants when assayed in a recombinant virus assay. Here we report that the rr-NCCR of BKV variants RH-3 and RH-12, both bearing a NCCR deletion including the 5' end of the agnoprotein coding sequence, mediated early and late viral reporter gene expression in kidney cells. However, in a recombinant virus they failed to produce infectious progeny despite large T-antigen and VP1 expression and the formation of nuclear virus-like particles. Infectious progeny was generated when the agnogene was reconstructed in cis or agnoprotein provided in trans from a co-existing BKV rr-NCCR variant. We conclude that complementation can rescue non-functional BKV variants in vitro and possibly in vivo.

Draft Genome Sequence of an Invasive Multidrug-Resistant Strain, Pseudomonas aeruginosa BK1, Isolated from a Keratitis Patient

KAUST Repository

Jeganathan, Lakshmi Priya

2014-03-27

Pseudomonas aeruginosa infections are difficult to treat due to the presence of a multitude of virulence factors and antibiotic resistance. Here, we report the draft genome sequence of P. aeruginosa BK1, an invasive and multidrug-resistant strain, isolated from a bacterial keratitis patient in southern India.

Sediment control - an appropriate solution for small irrigation channels

International Nuclear Information System (INIS)

Shoag, M.A.

2002-01-01

Sediment control is one of the key factors considered prior to the design of an irrigation channel. When the channel takes off from its headworks, its slope is usually smaller than that of the parent stream to obtain required head. If the sediment load is heavy then the channel can not maintain equilibrium since the high influx can not be transported fully due to its small gradient. This results in the deposition of part incoming sediment in the channel itself. A typical irrigation intake suitable for small schemes, which consists of a simple settling basin with double orifice: one at the inlet from the river and the other at the outlet to the canal. The basin is provided with a side spill weir near its downstream end, to discharge flows in excess of the maximum canal capacity. This paper deals with the experimental study of such an arrangement. Different flows were run covering a range of levels in the river, from minimum to flood flows to check the hydraulic performance of the layout and in particular to study its effectiveness in settling sediment at low flows and avoiding excessive sediment input to the canal during flood. (author)

Abnormal differentiation, hyperplasia and embryonic/perinatal lethality in BK5-T/t transgenic mice

Science.gov (United States)

Chen, Xin; Schneider-Broussard, Robin; Hollowell, Debra; McArthur, Mark; Jeter, Collene R.; Benavides, Fernando; DiGiovanni, John; Tang, Dean G.

2009-01-01

The cell-of-origin has a great impact on the types of tumors that develop and the stem/progenitor cells have long been considered main targets of malignant transformation. The SV40 large T and small t antigens (T/t), have been targeted to multiple differentiated cellular compartments in transgenic mice. In most of these studies, transgenic animals develop tumors without apparent defects in animal development. In this study, we used the bovine keratin 5 (BK5) promoter to target the T/t antigens to stem/progenitor cell-containing cytokeratin 5 (CK5) cellular compartment. A transgene construct, BK5-T/t, was made and microinjected into the male pronucleus of FVB/N mouse oocytes. After implanting ∼1700 embryos, only 7 transgenics were obtained, including 4 embryos (E9.5, E13, E15, and E20) and 3 postnatal animals, which died at P1, P2, and P18, respectively. Immunohistological analysis revealed aberrant differentiation and prominent hyperplasia in several transgenic CK5 tissues, especially the upper digestive organs (tongue, oral mucosa, esophagus, and forestomach) and epidermis, the latter of which also showed focal dysplasia. Altogether, these results indicate that constitutive expression of the T/t antigens in CK5 cellular compartment results in abnormal epithelial differentiation and leads to embryonic/perinatal animal lethality. PMID:19272531

A Fairness-Based Access Control Scheme to Optimize IPTV Fast Channel Changing

Directory of Open Access Journals (Sweden)

Junyu Lai

2014-01-01

Full Text Available IPTV services are typically featured with a longer channel changing delay compared to the conventional TV systems. The major contributor to this lies in the time spent on intraframe (I-frame acquisition during channel changing. Currently, most widely adopted fast channel changing (FCC methods rely on promptly transmitting to the client (conducting the channel changing a retained I-frame of the targeted channel as a separate unicasting stream. However, this I-frame acceleration mechanism has an inherent scalability problem due to the explosions of channel changing requests during commercial breaks. In this paper, we propose a fairness-based admission control (FAC scheme for the original I-frame acceleration mechanism to enhance its scalability by decreasing the bandwidth demands. Based on the channel changing history of every client, the FAC scheme can intelligently decide whether or not to conduct the I-frame acceleration for each channel change request. Comprehensive simulation experiments demonstrate the potential of our proposed FAC scheme to effectively optimize the scalability of the I-frame acceleration mechanism, particularly in commercial breaks. Meanwhile, the FAC scheme only slightly increases the average channel changing delay by temporarily disabling FCC (i.e., I-frame acceleration for the clients who are addicted to frequent channel zapping.

Experimental Investigation on Cutting Characteristics in Nanometric Plunge-Cutting of BK7 and Fused Silica Glasses.

Science.gov (United States)

An, Qinglong; Ming, Weiwei; Chen, Ming

2015-03-27

Ductile cutting are most widely used in fabricating high-quality optical glass components to achieve crack-free surfaces. For ultra-precision machining of brittle glass materials, critical undeformed chip thickness (CUCT) commonly plays a pivotal role in determining the transition point from ductile cutting to brittle cutting. In this research, cutting characteristics in nanometric cutting of BK7 and fused silica glasses, including machined surface morphology, surface roughness, cutting force and specific cutting energy, were investigated with nanometric plunge-cutting experiments. The same cutting speed of 300 mm/min was used in the experiments with single-crystal diamond tool. CUCT was determined according to the mentioned cutting characteristics. The results revealed that 320 nm was found as the CUCT in BK7 cutting and 50 nm was determined as the size effect of undeformed chip thickness. A high-quality machined surface could be obtained with the undeformed chip thickness between 50 and 320 nm at ductile cutting stage. Moreover, no CUCT was identified in fused silica cutting with the current cutting conditions, and brittle-fracture mechanism was confirmed as the predominant chip-separation mode throughout the nanometric cutting operation.

A combination of genistein and magnesium enhances the vasodilatory effect via an eNOS pathway and BK(Ca) current amplification.

Science.gov (United States)

Sun, Lina; Hou, Yunlong; Zhao, Tingting; Zhou, Shanshan; Wang, Xiaoran; Zhang, Liming; Yu, Guichun

2015-04-01

The phytoestrogen genistein (GST) and magnesium have been independently shown to regulate vascular tone; however, their individual vasodilatory effects are limited. The aim of this study was to examine the combined effects of GST plus magnesium on vascular tone in mesenteric arteries. The effects of pretreatment with GST (0-200 μmol/L), MgCl2 (0-4.8 mmol/L) and GST plus MgCl2 on 10 μmol/L phenylephrine (PE) precontracted mesenteric arteries in rats were assessed by measuring isometric force. BK(Ca) currents were detected by the patch clamp method. GST caused concentration- and partial endothelium-dependent relaxation. Magnesium resulted in dual adjustment of vascular tone. Magnesium-free solution eliminated the vasodilatation of GST in both endothelium-intact and denuded rings. GST (50 μmol/L) plus magnesium (4.8 mmol/L) caused stronger relaxation in both endothelium-intact and denuded rings. Pretreatment with the nitric oxide synthase (NOS) inhibitor L-N-nitroarginine methyl ester (L-NAME, 100 μmol/L) significantly inhibited the effects of GST, high magnesium, and the combination of GST and magnesium. BK(Ca) currents were amplified to a greater extent when GST (50 μmol/L) was combined with 4.8 versus 1.2 mmol/L Mg(2+). Our data suggest that GST plus magnesium provides enhanced vasodilatory effects in rat mesenteric arteries compared with that observed when either is used separately, which was related to an eNOS pathway and BK(Ca) current amplification.

Joint duplex mode selection, channel allocation, and power control for full-duplex cognitive femtocell networks

Directory of Open Access Journals (Sweden)

Mingjie Feng

2015-02-01

Full Text Available In this paper, we aim to maximize the sum rate of a full-duplex cognitive femtocell network (FDCFN as well as guaranteeing the quality of service (QoS of users in the form of a required signal to interference plus noise ratios (SINR. We first consider the case of a pair of channels, and develop optimum-achieving power control solutions. Then, for the case of multiple channels, we formulate joint duplex model selection, power control, and channel allocation as a mixed integer nonlinear problem (MINLP, and propose an iterative framework to solve it. The proposed iterative framework consists of a duplex mode selection scheme, a near-optimal distributed power control algorithm, and a greedy channel allocation algorithm. We prove the convergence of the proposed iterative framework as well as a lower bound for the greedy channel allocation algorithm. Numerical results show that the proposed schemes effectively improve the sum rate of FDCFNs.

Polyomavirus BK replication in renal transplant recipients: combined monitoring of viremia and VP1 mRNA in urine

Directory of Open Access Journals (Sweden)

Sara Astegiano

2010-06-01

Full Text Available Introduction. Human polyomavirus BK (BKV is worldwide distributed, with a seroprevalence rate of 70–90% in the adults. Following primary infection, BK remains latent in the renourinary tract as the epidemiologically most relevant latency site, and in B cell, brain, spleen and probably other tissues. Reactivation may occur in both immunocompetent subjects and immunocompromised patients. In renal transplantation, in the context of intense immunosuppression, viral replication may determine BKV-associated nephropathy (BKVAN with interstitial nephritis and/or ureteral stenosis in 1–10% of the patients and leading to graft failure and return to haemodialysis in 30 to 80% of the cases (5. Screening of BKV replication represents the basic strategy to predict early the onset of BKVAN and may allow for earlier intervention with reduced allograft loss (3, 4. Nowadays, replication of BKV is monitored by quantification of BKV-DNA in serum and urine (2. The aim of this study was to evaluated the role of BKV VP1 mRNA in urine as a marker of viral replication in renal transplant recipients.

Controllable transport of a skyrmion in a ferromagnetic narrow channel with voltage-controlled magnetic anisotropy

Science.gov (United States)

Wang, Junlin; Xia, Jing; Zhang, Xichao; Zhao, G. P.; Ye, Lei; Wu, Jing; Xu, Yongbing; Zhao, Weisheng; Zou, Zhigang; Zhou, Yan

2018-05-01

Magnetic skyrmions have potential applications in next-generation spintronic devices with ultralow energy consumption. In this work, the current-driven skyrmion motion in a narrow ferromagnetic nanotrack with voltage-controlled magnetic anisotropy (VCMA) is studied numerically. By utilizing the VCMA effect, the transport of skyrmion can be unidirectional in the nanotrack, leading to a one-way information channel. The trajectory of the skyrmion can also be modulated by periodically located VCMA gates, which protects the skyrmion from destruction by touching the track edge. In addition, the location of the skyrmion can be controlled by adjusting the driving pulse length in the presence of the VCMA effect. Our results provide guidelines for practical realization of the skyrmion-based information channel, diode, and skyrmion-based electronic devices such as racetrack memory.

The polyomavirus BK agnoprotein co-localizes with lipid droplets

International Nuclear Information System (INIS)

Unterstab, Gunhild; Gosert, Rainer; Leuenberger, David; Lorentz, Pascal; Rinaldo, Christine H.; Hirsch, Hans H.

2010-01-01

Agnoprotein encoded by human polyomavirus BK (BKV) is a late cytoplasmic protein of 66 amino acids (aa) of unknown function. Immunofluorescence microscopy revealed a fine granular and a vesicular distribution in donut-like structures. Using BKV(Dunlop)-infected or agnoprotein-transfected cells, we investigated agnoprotein co-localization with subcellular structures. We found that agnoprotein co-localizes with lipid droplets (LD) in primary human renal tubular epithelial cells as well as in other cells supporting BKV replication in vitro (UTA, Vero cells). Using agnoprotein-enhanced green fluorescent protein (EGFP) fusion constructs, we demonstrate that agnoprotein aa 20-42 are required for targeting LD, whereas aa 1-20 or aa 42-66 were not. Agnoprotein aa 22-40 are predicted to form an amphipathic helix, and mutations A25D and F39E, disrupting its hydrophobic domain, prevented LD targeting. However, changing the phosphorylation site serine-11 to alanine or aspartic acid did not alter LD co-localization. Our findings provide new clues to unravel agnoprotein function.

Perfect controlled joint remote state preparation independent of entanglement degree of the quantum channel

International Nuclear Information System (INIS)

An, Nguyen Ba; Bich, Cao Thi

2014-01-01

We construct a quantum circuit to produce a task-oriented partially entangled state and use it as the quantum channel for controlled joint remote state preparation. Unlike most previous works, where the parameters of the quantum channel are given to the receiver who can accomplish the task only probabilistically by consuming auxiliary resource, operation and measurement, here we give them to the supervisor. Thanks to the knowledge of the task-oriented quantum channel parameters, the supervisor can carry out proper complete projective measurement, which, combined with the feed-forward technique adapted by the preparers, not only much economizes (simplifies) the receiver's resource (operation) but also yields unit total success probability. Notably, such apparent perfection does not depend on the entanglement degree of the shared quantum channel. Our protocol is within the reach of current quantum technologies. - Highlights: • Controlled joint remote state preparation is considered. • Quantum circuit is proposed to produce task-oriented partially entangled channel. • The quantum channel parameter is given to the supervisor (not to the receiver). • Unit success probability without additional resource/operations/measurement. • Perfection is achieved regardless of the shared entanglement degree

Controlled beta-quench treatment of fuel channels

International Nuclear Information System (INIS)

Moeckel, Andreas; Cremer, Ingo; Kratzer, Anton; Walter, Dirk; Perkins, Richard A.

2007-01-01

The trend towards higher fuel assembly discharge burnups poses new challenges for fuel channels in terms of their dimensional behavior and corrosion resistance. Beta-quenching of fuel channels has been applied by the nuclear industry to improve the dimensional stability of this component. This led AREVA NP to develop a new technique for beta quenching of fuel channels that combines the effect of beta-quenching with the optimization of the microstructure in order to improve the dimensional behavior of fuel channels by randomizing the crystallographic texture, while maintaining the excellent corrosion behavior of the fuel channels by providing intermetallic phase particles of optimum average size. The first fuel channels with these optimized material properties have been placed in the core of a German boiling water reactor (BWR) nuclear power plant in spring of 2004. Some more channels will follow in 2007 to broaden in-pile experience and to receive irradiation feedback from two other nuclear power plants. (authors)

Electrically controlled wire-channel GaN/AlGaN transistor for terahertz plasma applications

Science.gov (United States)

Cywiński, G.; Yahniuk, I.; Kruszewski, P.; Grabowski, M.; Nowakowski-Szkudlarek, K.; Prystawko, P.; Sai, P.; Knap, W.; Simin, G. S.; Rumyantsev, S. L.

2018-03-01

We report on a design of fin-shaped channel GaN/AlGaN field-effect transistors developed for studying resonant terahertz plasma oscillations. Unlike common two dimensional FinFET transistor design, the gates were deposited only to the sides of the two dimensional electron gas channel, i.e., metal layers were not deposited on the top of the AlGaN. This side gate configuration allowed us to electrically control the conductivity of the channel by changing its width while keeping the carrier density and mobility virtually unchanged. Computer simulations and analytical model describe well the general shape of the characteristics. The side gate control of the channel width of these transistors allowed us to eliminate the so-called oblique plasma wave modes and paves the way towards future terahertz detectors and emitters using high quality factor plasma wave resonances.

Assessment of effect of SSSC stabilizer in different control channels on damping inter-area oscillations

Energy Technology Data Exchange (ETDEWEB)

Shakarami, M.R., E-mail: shakarami@iust.ac.i [Centre of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Kazemi, A. [Centre of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)

2011-03-15

A static synchronous series compensator (SSSC) is one of the series flexible ac transmission system (FACTS) devices that injects a balanced three-phase voltage in quadrature with the transmission line current. There are two channels for controlling of phase and magnitude of the voltage. When the SSSC is used for damping of inter-area oscillations, a SSSC-based stabilizer can be included in both channels. In this paper, the best location and suitable input control signal for SSSC in order to enhance the damping of inter-area oscillations are selected by residue analysis. A method by quadratic mathematic programming has been presented to the design of the stabilizer. By this method, the effect of the stabilizer in both control channels of the SSSC on damping of inter-area oscillations has been assessed. By considering the gain of stabilizer as a criterion, obtained results from studying on a small and a large multi-machine power system show that the stabilizer in the phase control channel is more effective for damping inter-are oscillations.

Experimental control of natural perturbations in channel flow

OpenAIRE

Juillet , Fabien; Mckeon , J.; Schmid , Peter J.

2014-01-01

International audience; A combined approach using system identification and feed-forward control design has been applied to experimental laminar channel flow in an effort to reduce the naturally occurring disturbance level. A simple blowing/suction strategy was capable of reducing the standard deviation of the measured sensor signal by 45 %, which markedly exceeds previously obtained results under comparable conditions. A comparable reduction could be verified over a significant streamwise ex...

The Activation Effect of Hainantoxin-I, a Peptide Toxin from the Chinese Spider, Ornithoctonus hainana, on Intermediate-Conductance Ca2+-Activated K+ Channels

Directory of Open Access Journals (Sweden)

Pengfei Huang

2014-08-01

Full Text Available Intermediate-conductance Ca2+-activated K+ (IK channels are calcium/calmodulin-regulated voltage-independent K+ channels. Activation of IK currents is important in vessel and respiratory tissues, rendering the channels potential drug targets. A variety of small organic molecules have been synthesized and found to be potent activators of IK channels. However, the poor selectivity of these molecules limits their therapeutic value. Venom-derived peptides usually block their targets with high specificity. Therefore, we searched for novel peptide activators of IK channels by testing a series of toxins from spiders. Using electrophysiological experiments, we identified hainantoxin-I (HNTX-I as an IK-channel activator. HNTX-I has little effect on voltage-gated Na+ and Ca2+ channels from rat dorsal root ganglion neurons and on the heterologous expression of voltage-gated rapidly activating delayed rectifier K+ channels (human ether-à-go-go-related gene; human ERG in HEK293T cells. Only 35.2% ± 0.4% of the currents were activated in SK channels, and there was no effect on BK channels. We demonstrated that HNTX-I was not a phrenic nerve conduction blocker or acutely toxic. This is believed to be the first report of a peptide activator effect on IK channels. Our study suggests that the activity and selectivity of HNTX-I on IK channels make HNTX-I a promising template for designing new drugs for cardiovascular diseases.

Volume Regulated Channels

DEFF Research Database (Denmark)

Klausen, Thomas Kjær

of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

Patterns and controls on historical channel change in the Willamette River, Oregon, USA

Science.gov (United States)

Jennifer Rose Wallick; Gordon E. Grant; Stephen T. Lancaster; John P. Bolte; Roger P. Denlinger

2007-01-01

Distinguishing human impacts on channel morphology from the natural behaviour of fluvial systems is problematic for large river basins. Large river basins, by virtue of their size, typically encompass wide ranges of geology and landforms resulting in diverse controls on channel form. They also inevitably incorporate long and complex histories of overlapping human and...

Sediment traps with guiding channel and hybrid check dams improve controlled sediment retention

Science.gov (United States)

Schwindt, Sebastian; Franca, Mário J.; Reffo, Alessandro; Schleiss, Anton J.

2018-03-01

Sediment traps with partially open check dams are crucial elements for flood protection in alpine regions. The trapping of sediment is necessary when intense sediment transport occurs during floods that may endanger urban areas at downstream river reaches. In turn, the unwanted permanent trapping of sediment during small, non-hazardous floods can result in the ecological and morphological degradation of downstream reaches. This study experimentally analyses a novel concept for permeable sediment traps. For ensuring the sediment transfer up to small floods, a guiding channel implemented in the deposition area of a sediment trap was systematically studied. The bankfull discharge of the guiding channel corresponds to a dominant morphological discharge. At the downstream end of the guiding channel, a permeable barrier (check dam) triggers sediment retention and deposition. The permeable barrier consists of a bar screen for mechanical deposition control, superposed to a flow constriction for the hydraulic control. The barrier obstructs hazardous sediment transport for discharges that are higher than the bankfull discharge of the guiding channel without the risk of unwanted sediment flushing (massive self-cleaning).

(-)-Epicatechin-induced relaxation of isolated human saphenous vein: Roles of K+ and Ca2+ channels.

Science.gov (United States)

Marinko, Marija; Jankovic, Goran; Nenezic, Dragoslav; Milojevic, Predrag; Stojanovic, Ivan; Kanjuh, Vladimir; Novakovic, Aleksandra

2018-02-01

In this study, we aimed to investigate relaxant effect of flavanol (-)-epicatechin on the isolated human saphenous vein (HSV), as a part of its cardioprotective action, and to define the mechanisms underlying this vasorelaxation. (-)-Epicatechin induced a concentration-dependent relaxation of HSV pre-contracted by phenylephrine. Among K + channel blockers, 4-aminopyridine, margatoxin, and iberiotoxin significantly inhibited relaxation of HSV, while glibenclamide considerably reduced effects of the high concentrations of (-)-epicatechin. Additionally, (-)-epicatechin relaxed contraction induced by 80 mM K + , whereas in the presence of nifedipine produced partial relaxation of HSV rings pre-contracted by phenylephrine. In Ca 2+ -free solution, (-)-epicatechin relaxed contraction induced by phenylephrine, but had no effect on contraction induced by caffeine. A sarcoplasmic reticulum Ca 2+ -ATPase inhibitor, thapsigargin, significantly reduced relaxation of HSV produced by (-)-epicatechin. These results demonstrate that (-)-epicatechin produces endothelium-independent relaxation of isolated HSV rings. Vasorelaxation to (-)-epicatechin probably involves activation of 4-aminopyridine- and margatoxin-sensitive K V channels, BK Ca channels, and at least partly, K ATP channels. In addition, not only the inhibition of extracellular Ca 2+ influx, but regulation of the intracellular Ca 2+ release, via inositol-trisphosphate receptors and reuptake into sarcoplasmic reticulum, via stimulation of Ca 2+ -ATPase, as well, most likely participate in (-)-epicatechin-induced relaxation of HSV. Copyright © 2017 John Wiley & Sons, Ltd.

Digital remote control system for power supplies of particle channel magnetooptical elements

International Nuclear Information System (INIS)

Vetrov, P.B.; Ermolina, G.P.; Kuznetsov, V.S.; Mojbenko, A.N.

1986-01-01

Current control of magnetooptical elements of accelerator particle channels is based on control of reference voltage of current stabilizers. Advent of industrial multidigit (12 bits) integral analog-to-digital converters permitted to develop simple digital sources of reference voltage. A digital control system of 30 spatially remoted power supplies of magnetooptical elements of particle channels on the basis of the ''Elektronika-60'' microcomputer is described. The microcomputer is connected by the standard communication line (20 mA) with the SM-4 computer. The ''Summa'' crate is connected with the microcomputer through the branch driver. Digit data are transmitted by the multibranch trunk of sequential communication (Manchester-2 code) at the rate of 0.5 Mband. Feedback was realized by connection of analog signals through the distributed commutator to the measuring line with a digital voltmeter

Integration of 128 channels for monitoring, acquisition and control with existing LHCD DAC system

International Nuclear Information System (INIS)

Joshi, Ramesh; Virani, Chetan; Wadhwani, Archana; Sharma, P.K.

2015-01-01

Lower Hybrid Current Drive (LHCD) data acquisition system needs to be upgraded for additional channel requirement. The existing VME based DAC has been used since long with 32 analog input channels for data monitoring and control. Additional 128 channels require integrating with existing DAC. There are four layers of waveguides which deliver final output power into tokamak. Each layer requires 32 channels for power measurement. For the same requirement 128 analog input channels have been integrated with the help of carrier board and IP modules. Acromag IP330 modules have been procured and finally integrated with additional carrier board with existing VME hardware. Each module provides 32 analog input channels. Device driver has been developed for each module and integrated with existing program. LHCD DAC system has been upgraded with additional 128 channels requirement. It has been successfully testing with recent SST-1 campaign. (author)

Range based power control for multi-radio multi-channel wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-08-01

Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in Wireless Mesh Networks (WMNs). In this paper, researchers present a range based dynamic power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified...

Control system devices : architectures and supply channels overview.

Energy Technology Data Exchange (ETDEWEB)

Trent, Jason; Atkins, William Dee; Schwartz, Moses Daniel; Mulder, John C.

2010-08-01

This report describes a research project to examine the hardware used in automated control systems like those that control the electric grid. This report provides an overview of the vendors, architectures, and supply channels for a number of control system devices. The research itself represents an attempt to probe more deeply into the area of programmable logic controllers (PLCs) - the specialized digital computers that control individual processes within supervisory control and data acquisition (SCADA) systems. The report (1) provides an overview of control system networks and PLC architecture, (2) furnishes profiles for the top eight vendors in the PLC industry, (3) discusses the communications protocols used in different industries, and (4) analyzes the hardware used in several PLC devices. As part of the project, several PLCs were disassembled to identify constituent components. That information will direct the next step of the research, which will greatly increase our understanding of PLC security in both the hardware and software areas. Such an understanding is vital for discerning the potential national security impact of security flaws in these devices, as well as for developing proactive countermeasures.

Potassium and ANO1/TMEM16A chloride channel profiles distinguish atypical and typical smooth muscle cells from interstitial cells in the mouse renal pelvis

Science.gov (United States)

Iqbal, Javed; Tonta, Mary A; Mitsui, Retsu; Li, Qun; Kett, Michelle; Li, Jinhua; Parkington, Helena C; Hashitani, Hikaru; Lang, Richard J

2012-01-01

BACKGROUND AND PURPOSE Although atypical smooth muscle cells (SMCs) in the proximal renal pelvis are thought to generate the pacemaker signals that drive pyeloureteric peristalsis, their location and electrical properties remain obscure. EXPERIMENTAL APPROACH Standard patch clamp, intracellular microelectrode and immunohistochemistry techniques were used. To unequivocally identify SMCs, transgenic mice with enhanced yellow fluorescent protein (eYFP) expressed in cells containing α-smooth muscle actin (α-SMA) were sometimes used. KEY RESULTS Atypical SMCs were distinguished from typical SMCs by the absence of both a transient 4-aminopyridine-sensitive K+ current (IKA) and spontaneous transient outward currents (STOCs) upon the opening of large-conductance Ca2+-activated K+ (BK) channels. Many typical SMCs displayed a slowly activating, slowly decaying Cl- current blocked by niflumic acid (NFA). Immunostaining for KV4.3 and ANO1/ TMEM16A Cl- channel subunits co-localized with α-SMA immunoreactive product predominately in the distal renal pelvis. Atypical SMCs fired spontaneous inward currents that were either selective for Cl- and blocked by NFA, or cation-selective and blocked by La3+. α-SMA- interstitial cells (ICs) were distinguished by the presence of a Xe991-sensitive KV7 current, BK channel STOCs and Cl- selective, NFA-sensitive spontaneous transient inward currents (STICs). Intense ANO1/ TMEM16A and KV7.5 immunostaining was present in Kit-α-SMA- ICs in the suburothelial and adventitial regions of the renal pelvis. CONCLUSIONS AND IMPLICATIONS We conclude that KV4.3+α-SMA+ SMCs are typical SMCs that facilitate muscle wall contraction, that ANO1/ TMEM16A and KV7.5 immunoreactivity may be selective markers of Kit- ICs and that atypical SMCs which discharge spontaneous inward currents are the pelviureteric pacemakers. PMID:22014103

Channel Deviation-Based Power Control in Body Area Networks.

Science.gov (United States)

Van, Son Dinh; Cotton, Simon L; Smith, David B

2018-05-01

Internet enabled body area networks (BANs) will form a core part of future remote health monitoring and ambient assisted living technology. In BAN applications, due to the dynamic nature of human activity, the off-body BAN channel can be prone to deep fading caused by body shadowing and multipath fading. Using this knowledge, we present some novel practical adaptive power control protocols based on the channel deviation to simultaneously prolong the lifetime of wearable devices and reduce outage probability. The proposed schemes are both flexible and relatively simple to implement on hardware platforms with constrained resources making them inherently suitable for BAN applications. We present the key algorithm parameters used to dynamically respond to the channel variation. This allows the algorithms to achieve a better energy efficiency and signal reliability in everyday usage scenarios such as those in which a person undertakes many different activities (e.g., sitting, walking, standing, etc.). We also profile their performance against traditional, optimal, and other existing schemes for which it is demonstrated that not only does the outage probability reduce significantly, but the proposed algorithms also save up to average transmit power compared to the competing schemes.

Channel control ASIC for the CMS hadron calorimeter front end readout module

International Nuclear Information System (INIS)

Ray Yarema et al.

2002-01-01

The Channel Control ASIC (CCA) is used along with a custom Charge Integrator and Encoder (QIE) ASIC to digitize signals from the hybrid photo diodes (HPDs) and photomultiplier tubes (PMTs) in the CMS hadron calorimeter. The CCA sits between the QIE and the data acquisition system. All digital signals to and from the QIE pass through the CCA chip. One CCA chip interfaces with two QIE channels. The CCA provides individually delayed clocks to each of the QIE chips in addition to various control signals. The QIE sends digitized PMT or HPD signals and time slice information to the CCA, which sends the data to the data acquisition system through an optical link

78 FR 68779 - Controlled Group Regulation Examples; Hearing Cancellation

Science.gov (United States)

2013-11-15

... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [REG-114122-12] RIN 1545-BK96 Controlled Group Regulation Examples; Hearing Cancellation AGENCY: Internal Revenue Service (IRS), Treasury... controlled group rules related to regulated investment companies. DATES: The public hearing originally...

Unfolding of a Temperature-Sensitive Domain Controls Voltage-Gated Channel Activation.

Science.gov (United States)

Arrigoni, Cristina; Rohaim, Ahmed; Shaya, David; Findeisen, Felix; Stein, Richard A; Nurva, Shailika Reddy; Mishra, Smriti; Mchaourab, Hassane S; Minor, Daniel L

2016-02-25

Voltage-gated ion channels (VGICs) are outfitted with diverse cytoplasmic domains that impact function. To examine how such elements may affect VGIC behavior, we addressed how the bacterial voltage-gated sodium channel (BacNa(V)) C-terminal cytoplasmic domain (CTD) affects function. Our studies show that the BacNa(V) CTD exerts a profound influence on gating through a temperature-dependent unfolding transition in a discrete cytoplasmic domain, the neck domain, proximal to the pore. Structural and functional studies establish that the BacNa(V) CTD comprises a bi-partite four-helix bundle that bears an unusual hydrophilic core whose integrity is central to the unfolding mechanism and that couples directly to the channel activation gate. Together, our findings define a general principle for how the widespread four-helix bundle cytoplasmic domain architecture can control VGIC responses, uncover a mechanism underlying the diverse BacNa(V) voltage dependencies, and demonstrate that a discrete domain can encode the temperature-dependent response of a channel. Copyright © 2016 Elsevier Inc. All rights reserved.

Control of helium activity in the fuel reactor channels; Kontrola aktivnosti heliuma u tehnoloskim kanalima

Energy Technology Data Exchange (ETDEWEB)

Vidmar, M; Milosevic, M; Hadzic, S [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Yugoslavia)

1961-02-15

The objective of this task was to study the possibility of detecting a damaged fuel channel, and to introduce automated procedure for continuous control of reactor channels during operation. The existing control systems at the RA reactor (permanent control of heavy water and helium activity, radiation monitoring of heavy water and helium system, measurements of fire damp gas percent) are not sufficient for fast detection of fuel element failures. Since a 'hot' fuel channel cannot be removed from the core because it should be cooled in the core by heavy water circulation, it is not possible to prevent contamination of heavy water by fission products. It is concluded that it is not indispensable to detect the failed fuel element promptly, i.e. that tome is not a critical issue.

Multiparty-controlled teleportation of an arbitrary m-qudit state with a pure entangled quantum channel

International Nuclear Information System (INIS)

Zhou, Ping; Li, Xi-Han; Deng, Fu-Guo; Zhou, Hong-Yu

2007-01-01

We present a general scheme for multiparty-controlled teleportation of an arbitrary m-qudit (d-dimensional quantum system) state by using non-maximally entangled states as the quantum channel. The sender performs m generalized Bell-state measurements on her 2m particles, the controllers take some single-particle measurements with the measuring basis X d and the receiver only needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if he cooperates with all the controllers. All the parties can use some decoy photons to set up their quantum channel securely, which will forbid a dishonest party to eavesdrop freely. This scheme is optimal as the probability that the receiver obtains the originally unknown m-qudit state equals the entanglement of the quantum channel

BK polyomavirus genotypes Ia and Ib1 exhibit different biological properties in renal transplant recipients.

Science.gov (United States)

Varella, Rafael B; Zalona, Ana Carolina J; Diaz, Nuria C; Zalis, Mariano G; Santoro-Lopes, Guilherme

2018-01-02

BK polyomavirus (BKV) is an opportunist agent associated with nephropathy (BKVAN) in 1-10% of kidney transplant recipients. BKV is classified into genotypes or subgroups according to minor nucleotidic variations with unknown biological implications. Studies assessing the possible association between genotypes and the risk of BKVAN in kidney transplant patients have presented conflicting results. In these studies, genotype Ia, which is highly prevalent in Brazil, was less frequently found and, thus, comparative data on the biological properties of this genotype are lacking. In this study, BKV Ia and Ib1 genotypes were compared according to their viral load, genetic evolution (VP1 and NCCR) - in a cohort of renal transplant recipients. The patients infected with Ia (13/23; 56.5%) genotype exhibited higher viral loads in urine [>1.4 log over Ib1 (10/23; 43.5%); p=0.025]. In addition, genotype Ia was associated with diverse mutations at VP1 loops and sites under positive selection outside loops, which were totally absent in Ib1. Although the number of viremic patients was similar, the three patients who had BK nephropathy (BKVAN) were infected with Ia genotype. NCCR architecture (ww or rr) were not distinctive between Ia and Ib1 genotypes. Ia genotype, which is rare in other published BKV cohorts, presented some diverse biological properties in transplanted recipients in comparison to Ib1. Copyright © 2017 Elsevier B.V. All rights reserved.

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

Science.gov (United States)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-03-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

Detection of BK virus in urine from renal transplant subjects by mass spectrometry

Directory of Open Access Journals (Sweden)

Konietzny Rebecca

2012-04-01

Full Text Available Abstract Background The diagnosis and management of BK virus (BKV reactivation following renal transplantation continues to be a significant clinical problem. Following reactivation of latent virus, impaired cellular immunity enables sustained viral replication to occur in urothelial cells, which potentially leads to the development of BKV-associated nephropathy (BKVAN. Current guidelines recommend regular surveillance for BKV reactivation through the detection of infected urothelial cells in urine (decoy cells or viral nucleic acid in urine or blood. However, these methods have variable sensitivity and cannot routinely distinguish between different viral subtypes. We therefore asked whether mass spectrometry might be able to overcome these limitations and provide an additional non-invasive technique for the surveillance of BKV and identification of recipients at increased risk of BKVAN. Results Here we describe a mass spectrometry (MS-based method for the detection of BKV derived proteins directly isolated from clinical urine samples. Peptides detected by MS derived from Viral Protein 1 (VP1 allowed differentiation between subtypes I and IV. Using this approach, we observed an association between higher decoy cell numbers and the presence of the VP1 subtype Ib-2 in urine samples derived from a cohort of 20 renal transplant recipients, consistent with the hypothesis that certain viral subtypes may be associated with more severe BKVAN. Conclusions This is the first study to identify BK virus proteins in clinical samples by MS and that this approach makes it possible to distinguish between different viral subtypes. Further studies are required to establish whether this information could lead to stratification of patients at risk of BKVAN, facilitate distinction between BKVAN and acute rejection (AR, and ultimately improve patient treatment and outcomes.

Power Control for D2D Underlay Cellular Networks With Channel Uncertainty

KAUST Repository

Memmi, Amen

2016-12-26

Device-to-device (D2D) communications underlying the cellular infrastructure are a technology that have been proposed recently as a promising solution to enhance cellular network capabilities. It improves spectrum utilization, overall throughput, and energy efficiency while enabling new peer-to-peer and location-based applications and services. However, interference is the major challenge, since the same resources are shared by both systems. Therefore, interference management techniques are required to keep the interference under control. In this paper, in order to mitigate interference, we consider centralized and distributed power control algorithms in a one-cell random network model. Existing results on D2D underlay networks assume perfect channel state information (CSI). This assumption is usually unrealistic in practice due to the dynamic nature of wireless channels. Thus, it is of great interest to study and evaluate achievable performances under channel uncertainty. Differently from previous works, we are assuming that the CSI may be imperfect and include estimation errors. In the centralized approach, we derive the optimal powers that maximize the coverage probability and the rate of the cellular user while scheduling as many D2D links as possible. These powers are computed at the base station (BS) and then delivered to the users, and hence the name “centralized”. For the distributed method, the ON–OFF power control and the truncated channel inversion are proposed. Expressions of coverage probabilities are established in the function of D2D links intensity, pathloss exponent, and estimation error variance. Results show the important influence of CSI error on achievable performances and thus how crucial it is to consider it while designing networks and evaluating performances.

The Switching Generator: New Clock-Controlled Generator with Resistance against the Algebraic and Side Channel Attacks

Directory of Open Access Journals (Sweden)

Jun Choi

2015-06-01

Full Text Available Since Advanced Encryption Standard (AES in stream modes, such as counter (CTR, output feedback (OFB and cipher feedback (CFB, can meet most industrial requirements, the range of applications for dedicated stream ciphers is decreasing. There are many attack results using algebraic properties and side channel information against stream ciphers for hardware applications. Al-Hinai et al. presented an algebraic attack approach to a family of irregularly clock-controlled linear feedback shift register systems: the stop and go generator, self-decimated generator and alternating step generator. Other clock-controlled systems, such as shrinking and cascade generators, are indeed vulnerable against side channel attacks. To overcome these threats, new clock-controlled systems were presented, e.g., the generalized alternating step generator, cascade jump-controlled generator and mutual clock-controlled generator. However, the algebraic attack could be applied directly on these new systems. In this paper, we propose a new clock-controlled generator: the switching generator, which has resistance to algebraic and side channel attacks. This generator also preserves both security properties and the efficiency of existing clock-controlled generators.

Analytical model of nanoscale junctionless transistors towards controlling of short channel effects through source/drain underlap and channel thickness engineering

Science.gov (United States)

Roy, Debapriya; Biswas, Abhijit

2018-01-01

We develop a 2D analytical subthreshold model for nanoscale double-gate junctionless transistors (DGJLTs) with gate-source/drain underlap. The model is validated using well-calibrated TCAD simulation deck obtained by comparing experimental data in the literature. To analyze and control short-channel effects, we calculate the threshold voltage, drain induced barrier lowering (DIBL) and subthreshold swing of DGJLTs using our model and compare them with corresponding simulation value at channel length of 20 nm with channel thickness tSi ranging 5-10 nm, gate-source/drain underlap (LSD) values 0-7 nm and source/drain doping concentrations (NSD) ranging 5-12 × 1018 cm-3. As tSi reduces from 10 to 5 nm DIBL drops down from 42.5 to 0.42 mV/V at NSD = 1019 cm-3 and LSD = 5 nm in contrast to decrement from 71 to 4.57 mV/V without underlap. For a lower tSiDIBL increases marginally with increasing NSD. The subthreshold swing reduces more rapidly with thinning of channel thickness rather than increasing LSD or decreasing NSD.

Analysis and Improvement of Control Algorithm for Operation Mode Transition due to Input Channel Trouble in Control Systems

International Nuclear Information System (INIS)

Ahn, Myunghoon; Kim, Woogoon; Yim, Hyeongsoon

2016-01-01

The PI (Proportional plus Integral) controller, which is the essential functional block in control systems, can automatically perform the stable control of an important plant process while reducing the steady state error and improving the transient response. However, if the received input PV (Process Variable) is not normal due to input channel trouble, it will be difficult to control the system automatically. For this reason, many control systems are implemented to change the operation mode from automatic to manual mode in the PI controller when the failed input PV is detected. If the PI controller is in automatic mode for all the time, the control signal varies as the change of the input PV is continuously reflected in the control algorithm. In the other cases, since the controller changes into the manual mode at t=0, the control signal is fixed at the last PI controller output and thus the feedback control is not performed anymore until the operator takes an action such as the operation mode change. As a result of analysis and simulations for the controller’s operation modes in all the cases of input channel trouble, we discovered that it is more appropriate to maintain the automatic mode despite the bad quality in the PV. Therefore, we improved the control system algorithm reflecting the analysis results for the operator’s convenience and the stability of a control system

Analysis and Improvement of Control Algorithm for Operation Mode Transition due to Input Channel Trouble in Control Systems

Energy Technology Data Exchange (ETDEWEB)

Ahn, Myunghoon; Kim, Woogoon; Yim, Hyeongsoon [KEPCO Engineering and Construction Co., Deajeon (Korea, Republic of)

2016-10-15

The PI (Proportional plus Integral) controller, which is the essential functional block in control systems, can automatically perform the stable control of an important plant process while reducing the steady state error and improving the transient response. However, if the received input PV (Process Variable) is not normal due to input channel trouble, it will be difficult to control the system automatically. For this reason, many control systems are implemented to change the operation mode from automatic to manual mode in the PI controller when the failed input PV is detected. If the PI controller is in automatic mode for all the time, the control signal varies as the change of the input PV is continuously reflected in the control algorithm. In the other cases, since the controller changes into the manual mode at t=0, the control signal is fixed at the last PI controller output and thus the feedback control is not performed anymore until the operator takes an action such as the operation mode change. As a result of analysis and simulations for the controller’s operation modes in all the cases of input channel trouble, we discovered that it is more appropriate to maintain the automatic mode despite the bad quality in the PV. Therefore, we improved the control system algorithm reflecting the analysis results for the operator’s convenience and the stability of a control system.

Multiple-state based power control for multi-radio multi-channel wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-01-01

Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint...

Transmembrane proteoglycans control stretch-activated channels to set cytosolic calcium levels

DEFF Research Database (Denmark)

Gopal, Sandeep; Søgaard, Pernille; Multhaupt, Hinke A B

2015-01-01

show that syndecans regulate transient receptor potential canonical (TRPCs) channels to control cytosolic calcium equilibria and consequent cell behavior. In fibroblasts, ligand interactions with heparan sulfate of syndecan-4 recruit cytoplasmic protein kinase C to target serine714 of TRPC7...... with subsequent control of the cytoskeleton and the myofibroblast phenotype. In epidermal keratinocytes a syndecan-TRPC4 complex controls adhesion, adherens junction composition, and early differentiation in vivo and in vitro. In Caenorhabditis elegans, the TRPC orthologues TRP-1 and -2 genetically complement...

Toxin-antitoxin loci as stress-response-elements: ChpAK/MazF and ChpBK cleave translated RNAs and are counteracted by tmRNA

DEFF Research Database (Denmark)

Christensen, S.K.; Pedersen, K.; Hansen, Flemming G.

2003-01-01

Prokaryotic chromosomes encode toxin-antitoxin loci, often in multiple copies. In most cases, the function of these genes is not known. The chpA (mazEF) locus of Escherichia coli has been described as a cell killing module that induces bacterial apoptosis during nutritional stress. However, we...... found recently that ChpAK (MazF) does not confer cell killing but rather, induces a bacteriostatic condition from which the cells could be resuscitated. Results presented here yield a mechanistic explanation for the detrimental effect on cell growth exerted by ChpAK and the homologous ChpBK protein of E......AK cleaved tmRNA in its coding region. Thus, ChpAK and ChpBK inhibit translation by a mechanism very similar to that of E. coli RelE. On the basis of these results, we propose a model that integrates TA loci into general prokaryotic stress physiology....

1st International Conference on Hydraulic Design in Water Resources Engineering : Channels and Channel Control Structures

CERN Document Server

1984-01-01

The development of water resources has proceeded at an amazing speed around the world in the last few decades. The hydraulic engineer has played his part: in constructing much larger artificial channels than ever before, larger and more sophisticated control structures, and systems of irrigation, drainage and water supply channels in which the flow by its nature is complex and unsteady requiring computer-based techniques at both the design and operation stage. It seemed appropriate to look briefly at some of the developments in hydraulic design resulting from this situation. Hence the idea of the Conference was formed. The Proceedings of the Conference show that hydraulic engineers have been able to acquire a very substantial base of design capability from the experience of the period referred to. The most outstanding development to have occurred is in the combination of physical and mathematical modelling, which in hydraulic engineering has followed a parallel path to that in other branches of engineering sc...

Drag reduction in channel flow using nonlinear control

Science.gov (United States)

Keefe, Laurence R.

1993-01-01

Two nonlinear control schemes have been applied to the problem of drag reduction in channel flow. Both schemes have been tested using numerical simulations at a mass flux Reynolds numbers of 4408, utilizing 2D nonlinear neutral modes for goal dynamics. The OGY-method, which requires feedback, reduces drag to 60-80 percent of the turbulent value at the same Reynolds number, and employs forcing only within a thin region near the wall. The H-method, or model-based control, fails to achieve any drag reduction when starting from a fully turbulent initial condition, but shows potential for suppressing or retarding laminar-to-turbulent transition by imposing instead a transition to a low drag, nonlinear traveling wave solution to the Navier-Stokes equation. The drag in this state corresponds to that achieved by the OGY-method. Model-based control requires no feedback, but in experiments to date has required the forcing be imposed within a thicker layer than the OGY-method. Control energy expenditures in both methods are small, representing less than 0.1 percent of the uncontrolled flow's energy.

Marketingová situační analýza BK Lions Jindřichův Hradec

OpenAIRE

Hron, Patrik

2014-01-01

The aim of this bachelor thesis is to carry out an analysis of each part of marketing mix and the environment in which the BK Lions Jindřichův Hradec basketball club is situated. Suitable and applicable recommendations are suggested to make the marketing mix more effective based on analysis of marketing situation. The first part is focused on describing the marketing mix and marketing situational analysis at a theoretical level. The practical part describes particular marketing tools which ar...

Collective ion acceleration via laser controlled ionization channel

International Nuclear Information System (INIS)

Destler, W.W.; O'Shea, P.G.; Rodgers, J.; Segalov, Z.

1987-01-01

Initial results from a successful laser-controlled collective ion acceleration experiment at the University of Maryland are presented. In the experiment, positive ions are trapped in the potential well at the head of an intense relativistic electron beam injected at current levels above the space charge limit. Seed ions for acceleration are provided by puff valve injection of a neutral gas cloud localized to within 3 cm of the injection point. Control over the acceleration of the well and the ions is then achieved by means of a laser-generated ionization channel produced by passing the light from a Q-switched ruby laser through a series of partially and fully reflecting mirrors in such a way as to provide time-sequenced laser ionization of a target located on the drift tube wall. Using this system, controlled acceleration of protons at a rate of approximately 40 MV/m has been demonstrated over a distance of about 50 cm

Fragile X mental retardation protein controls synaptic vesicle exocytosis by modulating N-type calcium channel density

Science.gov (United States)

Ferron, Laurent; Nieto-Rostro, Manuela; Cassidy, John S.; Dolphin, Annette C.

2014-04-01

Fragile X syndrome (FXS), the most common heritable form of mental retardation, is characterized by synaptic dysfunction. Synaptic transmission depends critically on presynaptic calcium entry via voltage-gated calcium (CaV) channels. Here we show that the functional expression of neuronal N-type CaV channels (CaV2.2) is regulated by fragile X mental retardation protein (FMRP). We find that FMRP knockdown in dorsal root ganglion neurons increases CaV channel density in somata and in presynaptic terminals. We then show that FMRP controls CaV2.2 surface expression by targeting the channels to the proteasome for degradation. The interaction between FMRP and CaV2.2 occurs between the carboxy-terminal domain of FMRP and domains of CaV2.2 known to interact with the neurotransmitter release machinery. Finally, we show that FMRP controls synaptic exocytosis via CaV2.2 channels. Our data indicate that FMRP is a potent regulator of presynaptic activity, and its loss is likely to contribute to synaptic dysfunction in FXS.

TRP channels in calcium homeostasis: from hormonal control to structure-function relationship of TRPV5 and TRPV6.

Science.gov (United States)

van Goor, Mark K C; Hoenderop, Joost G J; van der Wijst, Jenny

2017-06-01

Maintaining plasma calcium levels within a narrow range is of vital importance for many physiological functions. Therefore, calcium transport processes in the intestine, bone and kidney are tightly regulated to fine-tune the rate of absorption, storage and excretion. The TRPV5 and TRPV6 calcium channels are viewed as the gatekeepers of epithelial calcium transport. Several calciotropic hormones control the channels at the level of transcription, membrane expression, and function. Recent technological advances have provided the first near-atomic resolution structural models of several TRPV channels, allowing insight into their architecture. While this field is still in its infancy, it has increased our understanding of molecular channel regulation and holds great promise for future structure-function studies of these ion channels. This review will summarize the mechanisms that control the systemic calcium balance, as well as extrapolate structural views to the molecular functioning of TRPV5/6 channels in epithelial calcium transport. Copyright © 2016. Published by Elsevier B.V.

On the ecogeomorphological feedbacks that control tidal channel network evolution in a sandy mangrove setting

Science.gov (United States)

van Maanen, B.; Coco, G.; Bryan, K. R.

2015-01-01

An ecomorphodynamic model was developed to study how Avicennia marina mangroves influence channel network evolution in sandy tidal embayments. The model accounts for the effects of mangrove trees on tidal flow patterns and sediment dynamics. Mangrove growth is in turn controlled by hydrodynamic conditions. The presence of mangroves was found to enhance the initiation and branching of tidal channels, partly because the extra flow resistance in mangrove forests favours flow concentration, and thus sediment erosion in between vegetated areas. The enhanced branching of channels is also the result of a vegetation-induced increase in erosion threshold. On the other hand, this reduction in bed erodibility, together with the soil expansion driven by organic matter production, reduces the landward expansion of channels. The ongoing accretion in mangrove forests ultimately drives a reduction in tidal prism and an overall retreat of the channel network. During sea-level rise, mangroves can potentially enhance the ability of the soil surface to maintain an elevation within the upper portion of the intertidal zone, while hindering both the branching and headward erosion of the landward expanding channels. The modelling results presented here indicate the critical control exerted by ecogeomorphological interactions in driving landscape evolution. PMID:26339195

Incidence and Factors Associated with De Novo DSA After BK Viremia in Renal Transplant Recipients.

Science.gov (United States)

Patel, Samir J; Kuten, Samantha A; Knight, Richard J; Graviss, Edward A; Nguyen, Duc; Gaber, A Osama

2016-01-01

BK polyomavirus infection and de novo donor-human leukocyte antigen (HLA) specific antibodies (dnDSA) are two well-known and distinct complications occurring after kidney transplantation. Recent literature suggests an association between the two events. This study aims to examine the relationship between BK viremia (BKV) and dnDSA and to identify potential risk factors for dnDSA following BKV in kidney transplant recipients. A retrospective review of 1019 recipients from Houston Methodist Hospital was conducted. All patients underwent routine screening for BKV and dnDSA. Median follow-up was 44 months. BKV was detected in 186 (18%) patients at a median of 107 (82-205) days post-transplant. dnDSA occurred in 283 (28%) patients at a median of 272 (62-575) days post-transplant. Of the 69 dnDSA-positive/BKV-positive patients, dnDSA detection occurred after BKV onset in 46 patients. Thus, 46 (28%) previously DSA-negative patients later became dnDSA-positive following BKV, not significantly different from the rate seen in BKV-negative patients (26%; p=0.5). Median time to DSA detection following BKV onset was 232 days (interquartile range, 119-460) post-BKV detection. Multivariate analysis revealed a greater number of HLA mismatches and viral clearance as risk factors for development of dnDSA following BKV, whereas delayed graft function was associated with a lower risk of dnDSA. In conclusion, despite being considered a result of over-immunosuppression, BKV can still be followed by dnDSA in a substantial proportion of patients. Monitoring for dnDSA in patients being managed for BKV may be warranted. Copyright© 2017 by the Terasaki Research Institute.

Light-activated control of protein channel assembly mediated by membrane mechanics

Science.gov (United States)

Miller, David M.; Findlay, Heather E.; Ces, Oscar; Templer, Richard H.; Booth, Paula J.

2016-12-01

Photochemical processes provide versatile triggers of chemical reactions. Here, we use a photoactivated lipid switch to modulate the folding and assembly of a protein channel within a model biological membrane. In contrast to the information rich field of water-soluble protein folding, there is only a limited understanding of the assembly of proteins that are integral to biological membranes. It is however possible to exploit the foreboding hydrophobic lipid environment and control membrane protein folding via lipid bilayer mechanics. Mechanical properties such as lipid chain lateral pressure influence the insertion and folding of proteins in membranes, with different stages of folding having contrasting sensitivities to the bilayer properties. Studies to date have relied on altering bilayer properties through lipid compositional changes made at equilibrium, and thus can only be made before or after folding. We show that light-activation of photoisomerisable di-(5-[[4-(4-butylphenyl)azo]phenoxy]pentyl)phosphate (4-Azo-5P) lipids influences the folding and assembly of the pentameric bacterial mechanosensitive channel MscL. The use of a photochemical reaction enables the bilayer properties to be altered during folding, which is unprecedented. This mechanical manipulation during folding, allows for optimisation of different stages of the component insertion, folding and assembly steps within the same lipid system. The photochemical approach offers the potential to control channel assembly when generating synthetic devices that exploit the mechanosensitive protein as a nanovalve.

KATP channels are not essential for pressure-dependent control of renin secretion

DEFF Research Database (Denmark)

Jensen, B L; Gambaryan, S; Scholz, H

1998-01-01

(IPRK). Cromakalim (0.1-10 muM) stimulated basal renin secretion up to threefold and caused vasorelaxation in the IPRK. Both effects of cromakalim were attenuated by glibenclamide. Cromakalim stimulated renin secretion from isolated juxtaglomerular (JG) cells and from microdissected afferent arterioles......This study aimed to investigate the functional role of ATP-sensitive K+ (KATP) channels in the control of renin secretion by renal perfusion pressure. We studied the effect of openers and blockers of KATP-channels on basal- and low-pressure-induced renin secretion from isolated perfused rat kidneys......, all of which suggests that KATP channel openers stimulate renin secretion at the level of JG cells. A decrease in the perfusion pressure from 13.3 to 9.33 kPa (100 mmHg to 70 mmHg) increased renin secretion twofold, and cromakalim further increased renin secretion. At 5.33 kPa (40 mmHg) renin...

Bathymetric survey of the Cayuga Inlet flood-control channel and selected tributaries in Ithaca, New York, 2016

Science.gov (United States)

Wernly, John F.; Nystrom, Elizabeth A.; Coon, William F.

2017-09-08

From July 14 to July 20, 2016, the U.S. Geological Survey, in cooperation with the City of Ithaca, New York, and the New York State Department of State, surveyed the bathymetry of the Cayuga Inlet flood-control channel and the mouths of selected tributaries to Cayuga Inlet and Cayuga Lake in Ithaca, N.Y. The flood-control channel, built by the U.S. Army Corps of Engineers between 1965 and 1970, was designed to convey flood flows from the Cayuga Inlet watershed through the City of Ithaca and minimize possible flood damages. Since that time, the channel has infrequently been maintained by dredging, and sediment accumulation and resultant shoaling have greatly decreased the conveyance of the channel and its navigational capability.U.S. Geological Survey personnel collected bathymetric data by using an acoustic Doppler current profiler. The survey produced a dense dataset of water depths that were converted to bottom elevations. These elevations were then used to generate a geographic information system bathymetric surface. The bathymetric data and resultant bathymetric surface show the current condition of the channel and provide the information that governmental agencies charged with maintaining the Cayuga Inlet for flood-control and navigational purposes need to make informed decisions regarding future maintenance measures.

Heat and mass transfer caused by a laminar channel flow equipped with a synthetic jet array

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Dančová, Petra; Kordík, Jozef; Vít, Tomáš; Pavelka, Miroslav

2011-01-01

Roč. 2, č. 4 (2011), 041006-041006 ISSN 1948-5085 R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GA101/09/1959 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * flow control * naphthalene sublimation Subject RIV: BK - Fluid Dynamics http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JTSEBV000002000004041006000001&idtype=cvips&gifs=yes

Direct numerical simulation of turbulent channel flow with spanwise alternatively distributed strips control

Science.gov (United States)

Ni, Weidan; Lu, Lipeng; Fang, Jian; Moulinec, Charles; Yao, Yufeng

2018-05-01

The effect of spanwise alternatively distributed strips (SADS) control on turbulent flow in a plane channel has been studied by direct numerical simulations to investigate the characteristics of large-scale streamwise vortices (LSSVs) induced by small-scale active wall actuation, and their potential in suppressing flow separation. SADS control is realized by alternatively arranging out-of-phase control (OPC) and in-phase control (IPC) wall actuations on the lower channel wall surface, in the spanwise direction. It is found that the coherent structures are suppressed or enhanced alternatively by OPC or IPC, respectively, leading to the formation of a vertical shear layer, which is responsible for the LSSVs’ presence. Large-scale low-speed region can also be observed above the OPC strips, which resemble large-scale low-speed streaks. LSSVs are found to be in a statistically-converged steady state and their cores are located between two neighboring OPC and IPC strips. Their motions contribute significantly to the momentum transport in the wall-normal and spanwise directions, demonstrating their potential ability to suppress flow separation.

First demonstration of single-mode MCF transport network with crosstalk-aware in-service optical channel control

DEFF Research Database (Denmark)

Pulverer, K.; Tanaka, T.; Häbel, U.

2017-01-01

We demonstrate the first crosstalk-aware traffic engineering as a use case in a multicore fibre transport network. With the help of a software-defined network controller, modulation format and channel route are adaptively changed using programmable devices with XT monitors.......We demonstrate the first crosstalk-aware traffic engineering as a use case in a multicore fibre transport network. With the help of a software-defined network controller, modulation format and channel route are adaptively changed using programmable devices with XT monitors....

Should they team up to make your brain clock?

Czech Academy of Sciences Publication Activity Database

Weiss, Norbert

2015-01-01

Roč. 36, č. 6 (2015), s. 2184-2185 ISSN 0197-4580 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : potassium channel * BK channel * circadian rhythm * calcium channel * T-type channel * SCN neuron * aging Subject RIV: CE - Biochemistry Impact factor: 5.153, year: 2015

Feedback power control strategies in wireless sensor networks with joint channel decoding.

Science.gov (United States)

Abrardo, Andrea; Ferrari, Gianluigi; Martalò, Marco; Perna, Fabio

2009-01-01

In this paper, we derive feedback power control strategies for block-faded multiple access schemes with correlated sources and joint channel decoding (JCD). In particular, upon the derivation of the feasible signal-to-noise ratio (SNR) region for the considered multiple access schemes, i.e., the multidimensional SNR region where error-free communications are, in principle, possible, two feedback power control strategies are proposed: (i) a classical feedback power control strategy, which aims at equalizing all link SNRs at the access point (AP), and (ii) an innovative optimized feedback power control strategy, which tries to make the network operational point fall in the feasible SNR region at the lowest overall transmit energy consumption. These strategies will be referred to as "balanced SNR" and "unbalanced SNR," respectively. While they require, in principle, an unlimited power control range at the sources, we also propose practical versions with a limited power control range. We preliminary consider a scenario with orthogonal links and ideal feedback. Then, we analyze the robustness of the proposed power control strategies to possible non-idealities, in terms of residual multiple access interference and noisy feedback channels. Finally, we successfully apply the proposed feedback power control strategies to a limiting case of the class of considered multiple access schemes, namely a central estimating officer (CEO) scenario, where the sensors observe noisy versions of a common binary information sequence and the AP's goal is to estimate this sequence by properly fusing the soft-output information output by the JCD algorithm.

Feedback Power Control Strategies inWireless Sensor Networks with Joint Channel Decoding

Directory of Open Access Journals (Sweden)

Fabio Perna

2009-11-01

Full Text Available In this paper, we derive feedback power control strategies for block-faded multiple access schemes with correlated sources and joint channel decoding (JCD. In particular, upon the derivation of the feasible signal-to-noise ratio (SNR region for the considered multiple access schemes, i.e., the multidimensional SNR region where error-free communications are, in principle, possible, two feedback power control strategies are proposed: (i a classical feedback power control strategy, which aims at equalizing all link SNRs at the access point (AP, and (ii an innovative optimized feedback power control strategy, which tries to make the network operational point fall in the feasible SNR region at the lowest overall transmit energy consumption. These strategies will be referred to as “balanced SNR” and “unbalanced SNR,” respectively. While they require, in principle, an unlimited power control range at the sources, we also propose practical versions with a limited power control range. We preliminary consider a scenario with orthogonal links and ideal feedback. Then, we analyze the robustness of the proposed power control strategies to possible non-idealities, in terms of residual multiple access interference and noisy feedback channels. Finally, we successfully apply the proposed feedback power control strategies to a limiting case of the class of considered multiple access schemes, namely a central estimating officer (CEO scenario, where the sensors observe noisy versions of a common binary information sequence and the AP’s goal is to estimate this sequence by properly fusing the soft-output information output by the JCD algorithm.

Online distribution channel increases article usage on Mendeley: a randomized controlled trial.

Science.gov (United States)

Kudlow, Paul; Cockerill, Matthew; Toccalino, Danielle; Dziadyk, Devin Bissky; Rutledge, Alan; Shachak, Aviv; McIntyre, Roger S; Ravindran, Arun; Eysenbach, Gunther

2017-01-01

Prior research shows that article reader counts (i.e. saves) on the online reference manager, Mendeley, correlate to future citations. There are currently no evidenced-based distribution strategies that have been shown to increase article saves on Mendeley. We conducted a 4-week randomized controlled trial to examine how promotion of article links in a novel online cross-publisher distribution channel (TrendMD) affect article saves on Mendeley. Four hundred articles published in the Journal of Medical Internet Research were randomized to either the TrendMD arm ( n  = 200) or the control arm ( n  = 200) of the study. Our primary outcome compares the 4-week mean Mendeley saves of articles randomized to TrendMD versus control. Articles randomized to TrendMD showed a 77% increase in article saves on Mendeley relative to control. The difference in mean Mendeley saves for TrendMD articles versus control was 2.7, 95% CI (2.63, 2.77), and statistically significant ( p  < 0.01). There was a positive correlation between pageviews driven by TrendMD and article saves on Mendeley (Spearman's rho r  = 0.60). This is the first randomized controlled trial to show how an online cross-publisher distribution channel (TrendMD) enhances article saves on Mendeley. While replication and further study are needed, these data suggest that cross-publisher article recommendations via TrendMD may enhance citations of scholarly articles.

Information-measurement and control system of the five-channel stellar spectrophotometer

International Nuclear Information System (INIS)

Granitskij, L.V.; Bukach, A.B.; Kaplin, Yu.V.; Bondarenko, V.P.; Smirnov, A.I.

1979-01-01

The multichannel information-measurement control system of the five-channel stellar spectrophotometer working in photon counting regime is described. The detecting part is synthesized taking into account the principles of multifunctional use of elements of the system. In the part of the photometer scanning mechanism control a discrete drive with the step motor is used. The data are detected on the punched tape, which is convenient for putting them into computer, into a digit printing device with the decimal code or on a diagram tape of the automatic potentiometer

Efficient uptake of blood-borne BK and JC polyomavirus-like particles in endothelial cells of liver sinusoids and renal vasa recta.

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Jaione Simon-Santamaria

Full Text Available Liver sinusoidal endothelial cells (LSECs are specialized scavenger cells that mediate high-capacity clearance of soluble waste macromolecules and colloid material, including blood-borne adenovirus. To explore if LSECs function as a sink for other viruses in blood, we studied the fate of virus-like particles (VLPs of two ubiquitous human DNA viruses, BK and JC polyomavirus, in mice. Like complete virions, VLPs specifically bind to receptors and enter cells, but unlike complete virions, they cannot replicate. 125I-labeled VLPs were used to assess blood decay, organ-, and hepatocellular distribution of ligand, and non-labeled VLPs to examine cellular uptake by immunohisto- and -cytochemistry. BK- and JC-VLPs rapidly distributed to liver, with lesser uptake in kidney and spleen. Liver uptake was predominantly in LSECs. Blood half-life (∼1 min, and tissue distribution of JC-VLPs and two JC-VLP-mutants (L55F and S269F that lack sialic acid binding affinity, were similar, indicating involvement of non-sialic acid receptors in cellular uptake. Liver uptake was not mediated by scavenger receptors. In spleen, the VLPs localized to the red pulp marginal zone reticuloendothelium, and in kidney to the endothelial lining of vasa recta segments, and the transitional epithelium of renal pelvis. Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta. The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia. We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation. In addition, we report the novel finding that a subpopulation of endothelial cells in kidney, the main organ of polyomavirus persistence, showed

Electrokinetic control of sample splitting at a channel bifurcation using isotachophoresis

International Nuclear Information System (INIS)

Persat, Alexandre; Santiago, Juan G

2009-01-01

We present a novel method for accurately splitting ionic samples at microchannel bifurcations. We leverage isotachophoresis (ITP) to focus and transport sample through a one-inlet, two-outlet microchannel bifurcation. We actively control the proportion of splitting by controlling potentials at end-channel reservoirs (and thereby controlling the current ratio). We explore the effect of buffer chemistry and local electric field on splitting dynamics and propose and validate a simple Kirchoff-type rule controlling the split ratio. We explore the effects of large applied electric fields on sample splitting and attribute a loss of splitting accuracy to electrohydrodynamic instabilities. We propose a scaling analysis to characterize the onset of this instability. This scaling is potentially useful for other electrokinetic flow problems with self-sharpening interfaces.

Automatic channel trimming for control systems: A concept

Science.gov (United States)

Vandervoort, R. J.; Sykes, H. A.

1977-01-01

Set of bias signals added to channel inputs automatically normalize differences between channels. Algorithm and second feedback loop compute trim biases. Concept could be applied to regulators and multichannel servosystems for remote manipulators in undersea mining.

The design of multi-channel pulse amplitude analyzer based on ARM micro controller

International Nuclear Information System (INIS)

Li Hai; Li Xiang; Liu Caixue

2010-01-01

It introduces the design of multi-channel pulse amplitude analyzer based on embedded ARM micro-controller. The embedded and real-time system μC/OS-II builds up the real-time and stability of the system and advances the integration. (authors)

Asynchronous, Decentralized DS-CDMA Using Feedback-Controlled Spreading Sequences for Time-Dispersive Channels

Science.gov (United States)

Miyatake, Teruhiko; Chiba, Kazuki; Hamamura, Masanori; Tachikawa, Shin'ichi

We propose a novel asynchronous direct-sequence codedivision multiple access (DS-CDMA) using feedback-controlled spreading sequences (FCSSs) (FCSS/DS-CDMA). At the receiver of FCSS/DS-CDMA, the code-orthogonalizing filter (COF) produces a spreading sequence, and the receiver returns the spreading sequence to the transmitter. Then the transmitter uses the spreading sequence as its updated version. The performance of FCSS/DS-CDMA is evaluated over time-dispersive channels. The results indicate that FCSS/DS-CDMA greatly suppresses both the intersymbol interference (ISI) and multiple access interference (MAI) over time-invariant channels. FCSS/DS-CDMA is applicable to the decentralized multiple access.

Kinetic properties and adrenergic control of TREK-2-like channels in rat medial prefrontal cortex (mPFC) pyramidal neurons.

Science.gov (United States)

Ładno, W; Gawlak, M; Szulczyk, P; Nurowska, E

2017-06-15

TREK-2-like channels were identified on the basis of electrophysiological and pharmacological tests performed on freshly isolated and enzymatically/mechanically dispersed pyramidal neurons of the rat medial prefrontal cortex (mPFC). Single-channel currents were recorded in cell-attached configuration and the impact of adrenergic receptors (α 1 , α 2 , β) stimulation on spontaneously appearing TREK-2-like channel activity was tested. The obtained results indicate that noradrenaline decreases the mean open probability of TREK-2-like channel currents by activation of β 1 but not of α 1 - and α 2 -adrenergic receptors. Mean open time and channel conductance were not affected. The system of intracellular signaling pathways depends on the activation of protein kinase A. We also show that adrenergic control of TREK-2-like channel currents by adrenergic receptors was similar in pyramidal neurons isolated from young, adolescent, and adult rats. Immunofluorescent confocal scans of mPFC slices confirmed the presence of the TREK-2 protein, which was abundant in layer V pyramidal neurons. The role of TREK-2-like channel control by adrenergic receptors is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Broadening of white-light continuum by filamentation in BK7 glass at its zero-dispersion point

International Nuclear Information System (INIS)

Jiang, Jiaming; Zhong, Yue; Zheng, Yinghui; Zeng, Zhinan; Ge, Xiaochun; Li, Ruxin

2015-01-01

Broadening of white-light continuum is observed by filamentation of near-infrared femtosecond laser pulses with peak power exceeding the megawatt level in BK7 glass with the presence of the zero-dispersion point. The simulated results show that, due to the low dispersion at the zero-dispersion point, the broadening of white-light continuum can be wider and the filament can persist in propagating stably longer distance. - Highlights: • We observed the white-light continuum by filamentation at the zero-dispersion point. • Peak power significantly exceeding the critical value of self-focusing was used. • Wider spectral broadening was obtained around the zero-dispersion point

Human BK Polyomavirus—The Potential for Head and Neck Malignancy and Disease

Directory of Open Access Journals (Sweden)

Raquel Burger-Calderon

2015-07-01

Full Text Available Members of the human Polyomaviridae family are ubiquitous and pathogenic among immune-compromised individuals. While only Merkel cell polyomavirus (MCPyV has conclusively been linked to human cancer, all members of the polyomavirus (PyV family encode the oncoprotein T antigen and may be potentially carcinogenic. Studies focusing on PyV pathogenesis in humans have become more abundant as the number of PyV family members and the list of associated diseases has expanded. BK polyomavirus (BKPyV in particular has emerged as a new opportunistic pathogen among HIV positive individuals, carrying harmful implications. Increasing evidence links BKPyV to HIV-associated salivary gland disease (HIVSGD. HIVSGD is associated with elevated risk of lymphoma formation and its prevalence has increased among HIV/AIDS patients. Determining the relationship between BKPyV, disease and tumorigenesis among immunosuppressed individuals is necessary and will allow for expanding effective anti-viral treatment and prevention options in the future.

Deficit of Kcnma1 mRNA expression in the dentate gyrus of epileptic rats

Science.gov (United States)

Ermolinsky, Boris; Arshadmansab, Massoud F.; Pacheco Otalora, Luis F.; Zarei, Masoud M.; Garrido-Sanabria, Emilio R.

2008-01-01

Epileptogenesis in mesial temporal lobe epilepsy is determined by several factors including abnormalities in the expression and function of ion channels. Here, we report a long-lasting deficit in gene expression of Kcnma1 coding for the large-conductance calcium-activated potassium (BK, MaxiK) channel α-subunits after pilocarpine-induced status epilepticus. By using comparative real-time PCR, Taqman gene expression assays, and the delta-delta comparative threshold method we detected a significant reduction in Kcnma1 expression in microdissected dentate gyrus at different intervals after status epilepticus (24 h, 10 days, 1 month, and more than 2 months). BK channels are key regulators of neuronal excitability and transmitter release. Hence, defective Kcnma1 expression may play a critical role in the pathogenesis of mesial temporal lobe epilepsy. PMID:18695509

Kaempferol stimulates large conductance Ca2+-activated K+ (BKCa) channels in human umbilical vein endothelial cells via a cAMP/PKA-dependent pathway

Science.gov (United States)

Xu, Y C; Leung, G P H; Wong, P Y D; Vanhoutte, P M; Man, R Y K

2008-01-01

Background and purpose: Kaempferol has been shown to possess a vasodilator effect but its mechanism of action remains unclear. In this study, experiments were carried out to study the effect of kaempferol on K+ channels in endothelial cells. Experimental approach: K+ channel activities in human umbilical vein endothelial cells (HUVECs) were studied by conventional whole cell and cell-attached patch-clamp electrophysiology. Key results: Kaempferol stimulated an outward-rectifying current in HUVECs in a dose-dependent manner with an EC50 value of 2.5±0.02 μM. This kaempferol-induced current was abolished by large conductance Ca2+-activated K+ (BKCa) channel blockers, such as iberiotoxin (IbTX) and charybdotoxin (ChTX), whereas the small conductance Ca2+-activated K+ (SKCa) channel blocker, apamin, and the voltage-dependent K+ (KV) channel blocker, 4-aminopyridine, had no effect. Cell-attached patches demonstrated that kaempferol increased the open probability of BkCa channels in HUVECs. Clamping intracellular Ca2+ did not prevent kaempferol-induced increases in outward current. In addition, the kaempferol-induced current was diminished by the adenylyl cyclase inhibitor SQ22536, the cAMP antagonist Rp-8-Br-cAMP and the PKA inhibitor KT5720, but was not affected by the guanylyl cyclase inhibitor ODQ, the cGMP antagonist Rp-8-Br-cGMP and the PKG inhibitor KT5823. The activation of BKCa channels by kaempferol caused membrane hyperpolarization of HUVECs. Conclusion and implications: These results demonstrate that kaempferol activates the opening of BKCa channels in HUVECs via a cAMP/PKA-dependent pathway, resulting in membrane hyperpolarization. This mechanism may partly account for the vasodilator effects of kaempferol. PMID:18493242

Process and device for controlling the operatability of a measuring channel in safety arrangements

International Nuclear Information System (INIS)

Edelmann, M.

1983-01-01

In addition to the neutron - and temperature - measuring channels, the detectors and thermocouples for active functional testing are also included in the safety circuits. The measuring parameter (neutron flux or coolant outlet temperature) is modulated by the output control system or output and/or coolant flow. This modulation is determined using an auxillary parameter (movement of control rods or neutron flux). To represent the actual value of the measuring parameter to be compared with the previously determined reference value, there is a division of the relative change of the neutron flux or the coolant outlet temperature by the change of control rod position or reactor output caused by it. The effect of the auxiliary parameter on the measured parameter is measured by the cross correlation of both of them and of the auxiliary parameter directly or by auto correlation. The coarse and fine monitoring of the measuring channels takes place with different time constants. (orig./PW)

Analytical characterization of three cathinone derivatives, 4-MPD, 4F-PHP and bk-EPDP, purchased as bulk powder from online vendors.

Science.gov (United States)

Apirakkan, Orapan; Frinculescu, Anca; Shine, Trevor; Parkin, Mark C; Cilibrizzi, Agostino; Frascione, Nunzianda; Abbate, Vincenzo

2018-02-01

Novel emerging drugs of abuse, also referred as new psychoactive substances, constitute an ever-changing mixture of chemical compounds designed to circumvent legislative controls by means of chemical modifications of previously banned recreational drugs. One such class, synthetic cathinones, namely β-keto derivatives of amphetamines, has been largely abused over the past decade. A number of new synthetic cathinones are detected each year, either in bulk powders/crystals or in biological matrices. It is therefore important to continuously monitor the supply of new synthetic derivatives and promptly report them. By using complementary analytical techniques (i.e. one- and two-dimensional NMR, FT-IR, GC-MS, HRMS and HPLC-UV), this study investigates the detection, identification and full characterization of 1-(4-methylphenyl)-2-(methylamino)pentanone (4-methylpentedrone, 4-MPD), 1-(4-fluorophenyl)-2-(pyrrolidin-1-yl)hexanone (4F-PHP) and 1-(1,3-benzodioxol-5-yl)-2-(ethylamino)-1-pentanone (bk-EPDP), three emerging cathinone derivatives. Copyright © 2017 John Wiley & Sons, Ltd.

Hemorrhagic Cystitis due to BK Reactivation in a Young Female Treated for Hodgkin-Disease

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R. Le Calloch

2011-01-01

Full Text Available Hodgkin's lymphoma is a disease with a high rate of curability under classic chemo-radiotherapy regimes. Complications due to chemotherapy could include viral reactivation due to chronic lymphopenia. BK virus (BKV is a polyoma virus belonging to the Papovaviridae family with antibody seroprevalences in healthy populations varying from 60% to 80%. Initial infections are asymptomatic usually occur in early childhood, after which the viruses remain latent in the kidneys or urothelium. Reactivation of BKV occurs in individuals with severe immunosuppression during HIV infections, transplantation or, exceptionally, after classical chemotherapy. BKV incidence is approximately 0% to 5% in immunocompetent individuals. Reactivation is associated with nephropathy and haemorrhagic cystitis. Herein, we present a case of a haemorrhagic cystitis due to BKV reactivation in a patient with Hodgkin's disease treated with chemotherapy.

Robust Finite-Dimensional LQG (Linear Quadric Gaussian)-Based Controllers for a Class of Distributed Parameter Systems.

Science.gov (United States)

1988-06-01

loop equations can be written in terms of the extended space XE = h ., where . C 7, to get SA = + G 0w(54 ) X K C A- BK - KfC j [0 K] 7] or in terms...C where in LQG notation C, = l,(sJ - (A - BK, - AfC))-’kj C = K (sl - (A - BK, - KfC ))-1K ! 44 Uy Recall that only Kf has to be approximated in...the oper- ators A-BK, and A- KfC both generate stable semigroups [24]. If (A+AA-BK) and (A + AA - 1’fC) also generale stable semigroups, then the

BK virus encephalopathy and sclerosing vasculopathy in a patient with hypohidrotic ectodermal dysplasia and immunodeficiency.

Science.gov (United States)

Darbinyan, Armine; Major, Eugene O; Morgello, Susan; Holland, Steven; Ryschkewitsch, Caroline; Monaco, Maria Chiara; Naidich, Thomas P; Bederson, Joshua; Malaczynska, Joanna; Ye, Fei; Gordon, Ronald; Cunningham-Rundles, Charlotte; Fowkes, Mary; Tsankova, Nadejda M

2016-07-13

Human BK polyomavirus (BKV) is reactivated under conditions of immunosuppression leading most commonly to nephropathy or cystitis; its tropism for the brain is rare and poorly understood. We present a unique case of BKV-associated encephalopathy in a man with hypohidrotic ectodermal dysplasia and immunodeficiency (HED-ID) due to IKK-gamma (NEMO) mutation, who developed progressive neurological symptoms. Brain biopsy demonstrated polyomavirus infection of gray and white matter, with predominant involvement of cortex and distinct neuronal tropism, in addition to limited demyelination and oligodendroglial inclusions. Immunohistochemistry demonstrated polyoma T-antigen in neurons and glia, but expression of VP1 capsid protein only in glia. PCR analysis on both brain biopsy tissue and cerebrospinal fluid detected high levels of BKV DNA. Sequencing studies further identified novel BKV variant and disclosed unique rearrangements in the noncoding control region of the viral DNA (BKVN NCCR). Neuropathological analysis also demonstrated an unusual form of obliterative fibrosing vasculopathy in the subcortical white matter with abnormal lysosomal accumulations, possibly related to the patient's underlying ectodermal dysplasia. Our report provides the first neuropathological description of HED-ID due to NEMO mutation, and expands the diversity of neurological presentations of BKV infection in brain, underscoring the importance of its consideration in immunodeficient patients with unexplained encephalopathy. We also document novel BKVN NCCR rearrangements that may be associated with the unique neuronal tropism in this patient.

A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

Joint power control has advantages of multi-user detection and power control; and it can combat the multi-access interference and the near-far problem. A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system was designed. Simulation results show that the algorithm can control the power not only quickly but also precisely with a time change. The method is useful for increasing system capacity.

Attitude Control of a Single Tilt Tri-Rotor UAV System: Dynamic Modeling and Each Channel's Nonlinear Controllers Design

Directory of Open Access Journals (Sweden)

Juing-Shian Chiou

2013-01-01

Full Text Available This paper has implemented nonlinear control strategy for the single tilt tri-rotor aerial robot. Based on Newton-Euler’s laws, the linear and nonlinear mathematical models of tri-rotor UAVs are obtained. A numerical analysis using Newton-Raphson method is chosen for finding hovering equilibrium point. Back-stepping nonlinear controller design is based on constructing Lyapunov candidate function for closed-loop system. By imitating the linguistic logic of human thought, fuzzy logic controllers (FLCs are designed based on control rules and membership functions, which are much less rigid than the calculations computers generally perform. Effectiveness of the controllers design scheme is shown through nonlinear simulation model on each channel.

Does calcium influx regulate melatonin production through the circadian pacemaker in chick pineal cells? Effects of nitrendipine, Bay K 8644, Co2+, Mn2+, and low external Ca2+.

Science.gov (United States)

Zatz, M; Mullen, D A

1988-11-01

We have recently described a system, using dispersed chick pineal cells in static culture, which displays a persistent, photosensitive, circadian rhythm of melatonin production and release. Here, we describe the effects of nitrendipine (NTR) (a dihydropyridine 'antagonist' of L-type calcium channels), Bay K 8644 (BK) (a dihydropyridine calcium channel 'agonist'), cobalt and manganese ions (both inorganic calcium channel blockers), and low external calcium concentrations, on the melatonin rhythm. NTR inhibited and BK stimulated melatonin output; they were potent and effective. Co2+, Mn2+, and low external Ca2+ markedly inhibited melatonin output. These results support a role for calcium influx through voltage-dependent calcium channels (L-type) in the regulation of melatonin production. Four or 8 h pulses of white light or darkness, in otherwise constant red light, cause, in addition to acute effects, phase-dependent phase shifts of the melatonin rhythm in subsequent cycles. Such phase shifts indicate an effect on (proximal to) the pacemaker generating the rhythm. Four or 8 h pulses of NTR, BK, Co2+, or low Ca2+, however, did not appreciably alter the phase of subsequent melatonin cycles. Neither did BK interfere with phase shifts induced by light pulses. Mn2+ pulses did induce phase-dependent phase shifts, but, unlike those evoked by light or dark pulses, these were all delays. Such effects of Mn2+ in other systems have been attributed to, and are characteristic of, 'metabolic inhibitors'. On balance, the results fail to support a prominent role for calcium influx in regulating the pacemaker underlying the circadian rhythm in chick pineal cells. Rather, calcium influx appears to regulate melatonin production primarily by acting on the melatonin-synthesizing apparatus, distal to the pacemaker.

Control of Excitation/Inhibition Balance in a Hippocampal Circuit by Calcium Sensor Protein Regulation of Presynaptic Calcium Channels.

Science.gov (United States)

Nanou, Evanthia; Lee, Amy; Catterall, William A

2018-05-02

Activity-dependent regulation controls the balance of synaptic excitation to inhibition in neural circuits, and disruption of this regulation impairs learning and memory and causes many neurological disorders. The molecular mechanisms underlying short-term synaptic plasticity are incompletely understood, and their role in inhibitory synapses remains uncertain. Here we show that regulation of voltage-gated calcium (Ca 2+ ) channel type 2.1 (Ca V 2.1) by neuronal Ca 2+ sensor (CaS) proteins controls synaptic plasticity and excitation/inhibition balance in a hippocampal circuit. Prevention of CaS protein regulation by introducing the IM-AA mutation in Ca V 2.1 channels in male and female mice impairs short-term synaptic facilitation at excitatory synapses of CA3 pyramidal neurons onto parvalbumin (PV)-expressing basket cells. In sharp contrast, the IM-AA mutation abolishes rapid synaptic depression in the inhibitory synapses of PV basket cells onto CA1 pyramidal neurons. These results show that CaS protein regulation of facilitation and inactivation of Ca V 2.1 channels controls the direction of short-term plasticity at these two synapses. Deletion of the CaS protein CaBP1/caldendrin also blocks rapid depression at PV-CA1 synapses, implicating its upregulation of inactivation of Ca V 2.1 channels in control of short-term synaptic plasticity at this inhibitory synapse. Studies of local-circuit function revealed reduced inhibition of CA1 pyramidal neurons by the disynaptic pathway from CA3 pyramidal cells via PV basket cells and greatly increased excitation/inhibition ratio of the direct excitatory input versus indirect inhibitory input from CA3 pyramidal neurons to CA1 pyramidal neurons. This striking defect in local-circuit function may contribute to the dramatic impairment of spatial learning and memory in IM-AA mice. SIGNIFICANCE STATEMENT Many forms of short-term synaptic plasticity in neuronal circuits rely on regulation of presynaptic voltage-gated Ca 2+ (Ca V

Alluvial cover controlling the width, slope and sinuosity of bedrock channels

Science.gov (United States)

Turowski, Jens Martin

2018-02-01

Bedrock channel slope and width are important parameters for setting bedload transport capacity and for stream-profile inversion to obtain tectonics information. Channel width and slope development are closely related to the problem of bedrock channel sinuosity. It is therefore likely that observations on bedrock channel meandering yields insights into the development of channel width and slope. Active meandering occurs when the bedrock channel walls are eroded, which also drives channel widening. Further, for a given drop in elevation, the more sinuous a channel is, the lower is its channel bed slope in comparison to a straight channel. It can thus be expected that studies of bedrock channel meandering give insights into width and slope adjustment and vice versa. The mechanisms by which bedrock channels actively meander have been debated since the beginning of modern geomorphic research in the 19th century, but a final consensus has not been reached. It has long been argued that whether a bedrock channel meanders actively or not is determined by the availability of sediment relative to transport capacity, a notion that has also been demonstrated in laboratory experiments. Here, this idea is taken up by postulating that the rate of change of both width and sinuosity over time is dependent on bed cover only. Based on the physics of erosion by bedload impacts, a scaling argument is developed to link bedrock channel width, slope and sinuosity to sediment supply, discharge and erodibility. This simple model built on sediment-flux-driven bedrock erosion concepts yields the observed scaling relationships of channel width and slope with discharge and erosion rate. Further, it explains why sinuosity evolves to a steady-state value and predicts the observed relations between sinuosity, erodibility and storm frequency, as has been observed for meandering bedrock rivers on Pacific Arc islands.

Alluvial cover controlling the width, slope and sinuosity of bedrock channels

Directory of Open Access Journals (Sweden)

J. M. Turowski

2018-02-01

Full Text Available Bedrock channel slope and width are important parameters for setting bedload transport capacity and for stream-profile inversion to obtain tectonics information. Channel width and slope development are closely related to the problem of bedrock channel sinuosity. It is therefore likely that observations on bedrock channel meandering yields insights into the development of channel width and slope. Active meandering occurs when the bedrock channel walls are eroded, which also drives channel widening. Further, for a given drop in elevation, the more sinuous a channel is, the lower is its channel bed slope in comparison to a straight channel. It can thus be expected that studies of bedrock channel meandering give insights into width and slope adjustment and vice versa. The mechanisms by which bedrock channels actively meander have been debated since the beginning of modern geomorphic research in the 19th century, but a final consensus has not been reached. It has long been argued that whether a bedrock channel meanders actively or not is determined by the availability of sediment relative to transport capacity, a notion that has also been demonstrated in laboratory experiments. Here, this idea is taken up by postulating that the rate of change of both width and sinuosity over time is dependent on bed cover only. Based on the physics of erosion by bedload impacts, a scaling argument is developed to link bedrock channel width, slope and sinuosity to sediment supply, discharge and erodibility. This simple model built on sediment-flux-driven bedrock erosion concepts yields the observed scaling relationships of channel width and slope with discharge and erosion rate. Further, it explains why sinuosity evolves to a steady-state value and predicts the observed relations between sinuosity, erodibility and storm frequency, as has been observed for meandering bedrock rivers on Pacific Arc islands.

Channel follower leakage restrictor

International Nuclear Information System (INIS)

Williamson, H.E.; Smith, B.A.

1977-01-01

An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures

Experimental Study of Tool Wear and Grinding Forces During BK-7 Glass Micro-grinding with Modified PCD Tool

Science.gov (United States)

Pratap, A.; Sahoo, P.; Patra, K.; Dyakonov, A. A.

2017-09-01

This study focuses on the improvement in grinding performance of BK-7 glass using polycrystalline diamond micro-tool. Micro-tools are modified using wire EDM and performance of modified tools is compared with that of as received tool. Tool wear of different types of tools are observed. To quantify the tool wear, a method based on weight loss of tool is introduced in this study. Modified tools significantly reduce tool wear in comparison to the normal tool. Grinding forces increase with machining time due to tool wear. However, modified tools produce lesser forces thus can improve life of the PCD micro-grinding tool.

VAX CAMAC channel

International Nuclear Information System (INIS)

Nelson, D.J.; Breidenbach, M.; Granieri, C.D.; Grund, J.E.; Patrick, J.F.; Weaver, L.J.

1980-10-01

A new generation CAMAC System has been developed for the Mark II Detector at SLAC's PEP storage ring. This flexible system can efficiently transfer data between a host computer and a very large set of CAMAC data acquisition and control modules. A bipolar microprocessor operates as a Channel interface by supervising the CAMAC system and minimizing the host computer's work. This programmable channel couples the host to a set of System Crates; each System Crate houses Branch Drivers that can directly control a set of crates or communicate over differential parallel highways to Branch Receivers for control of distant crates. A coherent software package integrates the high level programs, system driver level programs, and microcode control of the system

Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA

Science.gov (United States)

Heitmuller, Frank T.; Hudson, Paul F.; Asquith, William H.

2015-01-01

The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial–bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (high f values (most ≤ 0.45) that develop at sites with unit stream power values in excess of 200 watts per square meter (W/m2); and (vi) downstream convergence of hydraulic geometry exponents for bankfull and macrochannels, explained by co-increases of flood magnitude and noncohesive sandy sediments that collectively

Robust and Optimal Control of Magnetic Microparticles inside Fluidic Channels with Time-Varying Flow Rates

Directory of Open Access Journals (Sweden)

Islam S.M. Khalil

2016-06-01

Full Text Available Targeted therapy using magnetic microparticles and nanoparticles has the potential to mitigate the negative side-effects associated with conventional medical treatment. Major technological challenges still need to be addressed in order to translate these particles into in vivo applications. For example, magnetic particles need to be navigated controllably in vessels against flowing streams of body fluid. This paper describes the motion control of paramagnetic microparticles in the flowing streams of fluidic channels with time-varying flow rates (maximum flow is 35 ml.hr−1. This control is designed using a magnetic-based proportional-derivative (PD control system to compensate for the time-varying flow inside the channels (with width and depth of 2 mm and 1.5 mm, respectively. First, we achieve point-to-point motion control against and along flow rates of 4 ml.hr−1, 6 ml.hr−1, 17 ml.hr−1, and 35 ml.hr−1. The average speeds of single microparticle (with average diameter of 100 μm against flow rates of 6 ml.hr−1 and 30 ml.hr−1 are calculated to be 45 μm.s−1 and 15 μm.s−1, respectively. Second, we implement PD control with disturbance estimation and compensation. This control decreases the steady-state error by 50%, 70%, 73%, and 78% at flow rates of 4 ml.hr−1, 6 ml.hr−1, 17 ml.hr−1, and 35 ml.hr−1, respectively. Finally, we consider the problem of finding the optimal path (minimal kinetic energy between two points using calculus of variation, against the mentioned flow rates. Not only do we find that an optimal path between two collinear points with the direction of maximum flow (middle of the fluidic channel decreases the rise time of the microparticles, but we also decrease the input current that is supplied to the electromagnetic coils by minimizing the kinetic energy of the microparticles, compared to a PD control with disturbance compensation.

Marketing channels and control the distribution of products in the meat industry.

OpenAIRE

Sidorchuk, Roman

2010-01-01

The article deals with the formation of distribution channels in the meat industry. Question of finding channels. Awareness of the problem-added customer value in the channel. The task of shaping the company's own distribution channel products. The procedure of forming a channel of distribution. The main problem in forming their own distribution channel. Prospects of development of different channels

An optimal multi-channel memory controller for real-time systems

NARCIS (Netherlands)

Gomony, M.D.; Akesson, K.B.; Goossens, K.G.W.

2013-01-01

Optimal utilization of a multi-channel memory, such as Wide IO DRAM, as shared memory in multi-processor platforms depends on the mapping of memory clients to the memory channels, the granularity at which the memory requests are interleaved in each channel, and the bandwidth and memory capacity

Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA

Science.gov (United States)

Heitmuller, Frank T.; Hudson, Paul F.; Asquith, William H.

2015-01-01

The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial–bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (< 1.5-year return periods) that mobilize channel-bed material and less frequent events that determine bankfull channel (1.5- to 3-year return periods) and macrochannel (10- to 40-year return periods) dimensions; (v) macrochannels with high f values (most ≤ 0.45) that develop at sites with unit stream power values in excess

Reconfigurable virtual electrowetting channels.

Science.gov (United States)

Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

2012-02-21

Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

Quantum Channels With Memory

International Nuclear Information System (INIS)

Rybar, T.

2012-01-01

Quantum memory channels represent a very general, yet simple and comprehensible model for causal processes. As such they have attracted considerable research interest, mostly aimed on their transfer capabilities and structure properties. Most notably it was shown that memory channels can be implemented via physically naturally motivated collision models. We also define the concept of repeatable channels and show that only unital channels can be implemented repeat ably with pure memory channels. In the special case of qubit channels we also show that every unital qubit channel has a repeatable implementation. We also briefly explore the possibilities of stroboscopical simulation of channels and show that all random unitary channels can be stroboscopically simulated. Particularly in qubit case, all indivisible qubit channels are also random unitary, hence for qubit all indivisible channels can be stroboscopically simulated. Memory channels also naturally capture the framework of correlated experiments. We develop methods to gather and interpret data obtained in such setting and in detail examine the two qubit case. We also show that for control unitary interactions the measured data will never contradict a simple unitary evolution. Thus no memory effects can be spotted then. (author)

Skyrmion-based multi-channel racetrack

Science.gov (United States)

Song, Chengkun; Jin, Chendong; Wang, Jinshuai; Xia, Haiyan; Wang, Jianbo; Liu, Qingfang

2017-11-01

Magnetic skyrmions are promising for the application of racetrack memories, logic gates, and other nano-devices, owing to their topologically protected stability, small size, and low driving current. In this work, we propose a skyrmion-based multi-channel racetrack memory where the skyrmion moves in the selected channel by applying voltage-controlled magnetic anisotropy gates. It is demonstrated numerically that a current-dependent skyrmion Hall effect can be restrained by the additional potential of the voltage-controlled region, and the skyrmion velocity and moving channel in the racetrack can be operated by tuning the voltage-controlled magnetic anisotropy, gate position, and current density. Our results offer a potential application of racetrack memory based on skyrmions.

Noise control of subsonic cavity flows using plasma actuated receptive channels

International Nuclear Information System (INIS)

Gupta, Arnob Das; Roy, Subrata

2014-01-01

We introduce a passive receptive rectangular channel at the trailing edge of an open rectangular cavity to reduce the acoustic tones generated due to coherent shear layer impingement. The channel is numerically tested at Mach 0.3 using an unsteady three-dimensional large eddy simulation. Results show reduction in pressure fluctuations in the cavity due to which sound pressure levels are suppressed. Two linear dielectric barrier discharge plasma actuators are placed inside the channel to enhance the flow through it. Specifically, acoustic suppression of 7 dB was obtained for Mach 0.3 flow with the plasma actuated channel. Also, the drag coefficient for the cavity reduced by over three folds for the channel and over eight folds for the plasma actuated channel. Such a channel can be useful in noise and drag reduction for various applications, including weapons bay, landing gear and branched piping systems. (fast track communication)

``Large''- vs Small-scale friction control in turbulent channel flow

Science.gov (United States)

Canton, Jacopo; Örlü, Ramis; Chin, Cheng; Schlatter, Philipp

2017-11-01

We reconsider the ``large-scale'' control scheme proposed by Hussain and co-workers (Phys. Fluids 10, 1049-1051 1998 and Phys. Rev. Fluids, 2, 62601 2017), using new direct numerical simulations (DNS). The DNS are performed in a turbulent channel at friction Reynolds number Reτ of up to 550 in order to eliminate low-Reynolds-number effects. The purpose of the present contribution is to re-assess this control method in the light of more modern developments in the field, in particular also related to the discovery of (very) large-scale motions. The goals of the paper are as follows: First, we want to better characterise the physics of the control, and assess what external contribution (vortices, forcing, wall motion) are actually needed. Then, we investigate the optimal parameters and, finally, determine which aspects of this control technique actually scale in outer units and can therefore be of use in practical applications. In addition to discussing the mentioned drag-reduction effects, the present contribution will also address the potential effect of the naturally occurring large-scale motions on frictional drag, and give indications on the physical processes for potential drag reduction possible at all Reynolds numbers.

Calcium microdomains near R-type calcium channels control the induction of presynaptic LTP at parallel fiber to Purkinje cell synapses

Science.gov (United States)

Myoga, Michael H.; Regehr, Wade G.

2011-01-01

R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium-calmodulin sensitive potassium channel that in turn regulates postsynaptic hippocampal LTP. Here we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic LTP at parallel fiber to Purkinje cell synapses in the cerebellum (PF-LTP), which is mediated by calcium/calmodulin-stimulated adenylyl cyclases. Although most presynaptic calcium influx is through N-type and P/Q-type calcium channels, blocking these channels does not disrupt PF-LTP, but blocking R-type calcium channels does. Moreover, global calcium signaling cannot account for the calcium dependence of PF-LTP because R-type channels contribute modestly to overall calcium entry. These findings indicate that within presynaptic terminals, R-type calcium channels produce calcium microdomains that evoke presynaptic LTP at moderate frequencies that do not greatly increase global calcium levels,. PMID:21471358

Relative roughness controls on incipient sediment motion in steep channels

Science.gov (United States)

Prancevic, J.; Lamb, M. P.; Fuller, B. M.

2012-12-01

For over eight decades, researchers have noted an appreciable increase in the nondimensional shear stress (Shields number) at initiation of fluvial bedload transport with increasing bed slope. The precise cause of the trend, however, is obscured by the covariance of several factors with increased slope: a greater downstream component of the gravity acting on the grains and fluid, changes in bed morphology, increased grainsize relative to the channel width that may lead to grain bridging, and increased grainsize relative to flow depth (relative roughness) that may change flow hydraulics and particle buoyancy. Here, we report on ongoing laboratory experiments spanning a wide range of bed slopes (2% to 67%) designed to isolate these variables and determine the true cause of heightened critical Shields numbers on steep slopes. First, we eliminated bed morphology as a factor by using only planar beds. To investigate the effect of grain bridging, we used two different channel widths, representing width-to-grainsize ratios of 23:1 and 9:1. Finally, to separate the effects of slope from relative roughness, we compared incipient motion conditions for acrylic particles (submerged specific gravity of 0.15) to natural siliciclastic gravel (submerged specific gravity of 1.65). Different particle densities allowed us to explore incipient motion as a function of relative roughness, independent of channel slope, because lighter particles move at shallower flow depths than heavier ones of the same size. Results show that both materials exhibit a positive trend between bed slope and critical Shields number despite the existence of planar beds for all slopes. Furthermore, changing the grainsize-to-width ratio had a negligible effect on this trend. For all slopes, the critical Shields number for bedload transport was higher for the acrylic particles than for gravel, indicating that relative roughness has a strong control on incipient sediment motion independent of channel slope. These

Probabilistic Controlled Teleportation of a Triplet W State with Combined Channel of Non-Maximally Entangled Einstein–Podolsky–Rosen and Greenberger–Horne–Zeilinger States

International Nuclear Information System (INIS)

Jian, Dong; Jian-Fu, Teng

2009-01-01

A scheme for probabilistic controlled teleportation of a triplet W state using combined non-maximally entangled channel of two Einstein–Podolsky–Rosen (EPR) states and one Greenberger–Horne–Zeilinger (GHZ) state is proposed. In this scheme, an (m + 2)-qubit GHZ state serves not only as the control parameter but also as the quantum channel. The m control qubits are shared by m supervisors. With the aid of local operations and individual measurements, including Bell-state measurement, Von Neumann measurement, and mutual classical communication etc., Bob can faithfully reconstruct the original state by performing relevant unitary transformations. The total probability of successful teleportation is only dependent on channel coefficients of EPR states and GHZ, independent of the number of supervisor m. This protocol can also be extended to probabilistic controlled teleportation of an arbitrary N-qubit state using combined non-maximally entangled channel of N – 1 EPR states and one (m + 2)-qubit GHZ. (general)

Development of a loop-mediated isothermal amplification assay for rapid detection of BK virus.

Science.gov (United States)

Bista, Bipin Raj; Ishwad, Chandra; Wadowsky, Robert M; Manna, Pradip; Randhawa, Parmjeet Singh; Gupta, Gaurav; Adhikari, Meena; Tyagi, Rakhi; Gasper, Gina; Vats, Abhay

2007-05-01

Loop-mediated isothermal amplification (LAMP) is a novel method for rapid amplification of DNA. Its advantages include rapidity and minimal equipment requirement. The LAMP assay was developed for BK virus (BKV), which is a leading cause of morbidity in renal transplant recipients. The characteristics of the assay, including its specificity and sensitivity, were evaluated. BKV LAMP was performed using various incubation times with a variety of specimens, including unprocessed urine and plasma samples. A ladder pattern on gel electrophoresis, typical of successful LAMP reactions, was observed specifically only for BKV and not for other viruses. The sensitivity of the assay with 1 h of incubation was 100 copies/tube of a cloned BKV fragment. Additionally, a positive reaction was visually ascertained by a simple color reaction using SYBR green dye. BKV LAMP was also successful for urine and plasma specimens without the need for DNA extraction. Due to its simplicity and specificity, the LAMP assay can potentially be developed for "point of care" screening of BKV.

Channel access: A software bus for the LAACS

International Nuclear Information System (INIS)

Hill, J.O.

1990-01-01

The host processor for a code running within a distributed process control system is often predetermined by constraints built into the software architecture of the control system. Input/output (I/O) channels directly connected to the host processors are usually easier to access in software than channels on remote processors. It is often difficult to modernize selective parts of a control system's software while leaving the other parts unchanged. Likewise, software developed at one laboratory is often difficult to integrate into a control system developed at another laboratory. Software that runs in one machine or operating-system architecture is often unable to communicate with control-system software running on a different platform. For the Los Alamos Accelerator Control System (LAACS) we have attempted to address the above difficulties with a software communication facility which we call Channel Access. Channel Access provides a 'software bus' that allows programs to be connected through a network to I/O channels on real-time processors in a manner similar to the way in which hardware modules are integrated within a standardized hardware bus such as CAMAC or VME. We have already placed an operator interface on Channel Access and we are currently designing alarm, archiving and sequencing tools as well. Numerous application-specific programs use Channel Access. This paper describes the unique feature of this approach and its performance as an integral part of the Los Alamos Accelerator Control System. (orig.)

Transparency Trade-offs for a 3-channel Controller Revealed by the Bounded Environment Passivity Method

OpenAIRE

Willaert, Bert; Corteville, Brecht; Reynaerts, Dominiek; Van Brussel, Hendrik; Vander Poorten, Emmanuel

2010-01-01

In this paper, the Bounded Environment Passivity method [1] is applied to a 3-channel controller. This method enables the design of teleoperation controllers that show passive behaviour for interactions with a bounded range of environments. The resulting tuning guidelines, derived analytically, provide interesting tuning flexibility, which allows to focus on different aspects of transparency. As telesurgery is the motivation behind this work, the focus lies on correctly r...

Role of KCNMA1 in breast cancer.

Directory of Open Access Journals (Sweden)

Martin Oeggerli

Full Text Available KCNMA1 encodes the α-subunit of the large conductance, voltage and Ca(2+-activated (BK potassium channel and has been reported as a target gene of genomic amplification at 10q22 in prostate cancer. To investigate the prevalence of the amplification in other human cancers, the copy number of KCNMA1 was analyzed by fluorescence-in-situ-hybridization (FISH in 2,445 tumors across 118 different tumor types. Amplification of KCNMA1 was restricted to a small but distinct fraction of breast, ovarian and endometrial cancer with the highest prevalence in invasive ductal breast cancers and serous carcinoma of ovary and endometrium (3-7%. We performed an extensive analysis on breast cancer tissue microarrays (TMA of 1,200 tumors linked to prognosis. KCNMA1 amplification was significantly associated with high tumor stage, high grade, high tumor cell proliferation, and poor prognosis. Immunofluorescence revealed moderate or strong KCNMA1 protein expression in 8 out of 9 human breast cancers and in the breast cancer cell line MFM223. KCNMA1-function in breast cancer cell lines was confirmed by whole-cell patch clamp recordings and proliferation assays, using siRNA-knockdown, BK channel activators such as 17ß-estradiol and the BK-channel blocker paxilline. Our findings revealed that enhanced expression of KCNMA1 correlates with and contributes to high proliferation rate and malignancy of breast cancer.

"Legal highs"--toxicity in the clinical and medico-legal aspect as exemplified by suicide with bk-MBDB administration.

Science.gov (United States)

Rojek, Sebastian; Kłys, Małgorzata; Strona, Marcin; Maciów, Martyna; Kula, Karol

2012-10-10

The easily available "legal highs", which are products containing psychoactive substances, such as cathinones, piperazines and synthetic cannabinoids, are abused by adolescents in Poland and in the world as alternatives to classic drugs, such as amphetamines or marijuana. The majority of these potentially dangerous substances are still legal and they are associated with a risk of severe poisoning or even death, and provide new challenges in clinical and forensic toxicological practice. Investigations in the field of "designer drugs" may be well illustrated by the case of a suicide of a 21-year old male who ingested a specified dose of a preparation called "Amphi-bi-a" that contains bk-MBDB, chemically 2-methylamino-1-(3,4-methylenedioxyphenyl) butan-1-one, which belongs to the cathinone group, as a synthetic euphoric empathogen and psychoactive stimulant that is chemically similar to MDMA. It is one of more common components of "legal highs" examined in Poland and other countries. The documentation of the case includes a clinical assessment of the patient's health status performed during his almost 4-h hospitalization before death, autopsy and histological examinations supported by toxicological findings revealing bk-MBDB at extremely high concentrations (at 20 mg/l in the blood and 33 mg/kg in the liver); hence, this body of evidence contributes to knowledge in the field of "designer drugs". Inventions of designers of new psychoactive xenobiotics, which are much in demand, especially in view of the dynamic Internet marketing, which drums up narcobusiness, must be balanced by a national strategy developed by medical, legal and educational circles in the modern civilized world in order to prevent the spreading of the phenomenon. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A novel adaptive synchronization control of a class of master-slave large-scale systems with unknown channel time-delay

Science.gov (United States)

Shen, Qikun; Zhang, Tianping

2015-05-01

The paper addresses a practical issue for adaptive synchronization in master-slave large-scale systems with constant channel time-delay., and a novel adaptive synchronization control scheme is proposed to guarantee the synchronization errors asymptotically converge to the origin, in which the matching condition as in the related literatures is not necessary. The real value of channel time-delay can be estimated online by a proper adaptation mechanism, which removes the conditions that the channel time-delay should be known exactly as in existing works. Finally, simulation results demonstrate the effectiveness of the approach.

Coinfection with Epstein–Barr Virus (EBV), Human Papilloma Virus (HPV) and Polyoma BK Virus (BKPyV) in Laryngeal, Oropharyngeal and Oral Cavity Cancer

OpenAIRE

Drop, Bartłomiej; Strycharz-Dudziak, Małgorzata; Kliszczewska, Ewa; Polz-Dacewicz, Małgorzata

2017-01-01

Most research providing evidence for the role of oncogenic viruses in head and neck squamous cell carcinoma (SCC) development is focused on one type of virus without analyzing possible interactions between two or more types of viruses. The aim of this study was to analyse the prevalence of co-infection with human papillomavirus (HPV), Epstein–Barr virus (EBV) and polyoma BK virus (BKPyV) in oral, oropharyngeal and laryngeal squamous cell carcinomas in Polish patients. The correlations between...

Isotachophoresis system having larger-diameter channels flowing into channels with reduced diameter and with selectable counter-flow

Energy Technology Data Exchange (ETDEWEB)

Mariella, Jr., Raymond P.

2018-03-06

An isotachophoresis system for separating a sample containing particles into discrete packets including a flow channel, the flow channel having a large diameter section and a small diameter section; a negative electrode operably connected to the flow channel; a positive electrode operably connected to the flow channel; a leading carrier fluid in the flow channel; a trailing carrier fluid in the flow channel; and a control for separating the particles in the sample into discrete packets using the leading carrier fluid, the trailing carrier fluid, the large diameter section, and the small diameter section.

Multiple flow profiles for two-phase flow in single microfluidic channels through site-selective channel coating.

Science.gov (United States)

Logtenberg, Hella; Lopez-Martinez, Maria J; Feringa, Ben L; Browne, Wesley R; Verpoorte, Elisabeth

2011-06-21

An approach to control two-phase flow systems in a poly(dimethylsiloxane) (PDMS) microfluidic device using spatially selective surface modification is demonstrated. Side-by-side flows of ethanol : water solutions containing different polymers are used to selectively modify both sides of a channel by laminar flow patterning. Introduction of air pockets during modification allows for control over the length of the channel section that is modified. This approach makes it possible to achieve slug flow and side-by-side flow of water : 1-octanol simultaneously within the same PDMS channel, without the need of additional structural elements. A key finding is that conditioning of the PDMS channels with 1-octanol before polymer deposition is crucial to achieving stable side-by-side flows.

Cytomegalovirus and BK-Virus co-infection of a clinically non-functioning adrenal adenoma: innocent bystanders or new pathogenetic agents?

Science.gov (United States)

Pomara, G; Cappello, F; Barzon, L; Morelli, G; Rappa, F; Benvegna, L; Giannarini, G; Palù, G; Selli, C

2006-01-01

We report a case of a 64-year-old woman who underwent left adrenalectomy with removal of a 8,5 cm clinically non-functioning adrenocortical adenoma and a 4-cm myelolipoma. Molecular testing for viral infection demonstrated the presence of cytomegalovirus (CMV) DNA sequences in the adrenal adenoma, but not in the myelolipoma (confirmed by immunohistochemistry). Moreover, the adrenal adenoma was also positive for parvovirus B19, and both adrenal tumor samples were positive for polyomavirus BK (BKV) and adenovirus DNA sequences. This is the first report of co-infection of an adrenocortical adenoma by CMV and BKV. The role of these viruses in adrenal tumorigenesis was postulated.

Cytomegalovirus and BK-Virus co-infection of a clinically non-functioning adrenal adenoma: innocent bystanders or new pathogenetic agents?

Directory of Open Access Journals (Sweden)

G Pomara

2009-06-01

Full Text Available We report a case of a 64-year-old woman who underwent left adrenalectomy with removal of a 8,5 cm clinically non-functioning adrenocortical adenoma and a 4-cm myelolipoma. Molecular testing for viral infection demonstrated the presence of cytomegalovirus (CMV DNA sequences in the adrenal adenoma, but not in the myelolipoma (confirmed by immunohistochemistry. Moreover, the adrenal adenoma was also positive for parvovirus B19, and both adrenal tumor samples were positive for polyomavirus BK (BKV and adenovirus DNA sequences. This is the first report of co-infection of an adrenocortical adenoma by CMV and BKV. The role of these viruses in adrenal tumorigenesis was postulated.

Disease: H01258 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H01258 Generalized epilepsy and paroxysmal dyskinesia (GEPD) Epilepsy is one of th...BK channel causes this syndrome. Nervous system disease; Epilepsy KCNMA1 [HSA:3778] [KO:K04936] ... ICD-10

First demonstration of single-mode MCF transport network with crosstalk-aware in-service optical channel control

DEFF Research Database (Denmark)

Pulverer, K.; Tanaka, T.; Häbel, U.

2017-01-01

We demonstrate the first crosstalk-aware traffic engineering as a use case in a multicore fibre transport network. With the help of a software-defined network controller, modulation format and channel route are adaptively changed using programmable devices with XT monitors....

Control Problems in Distribution Channels: Empirical Evidence of Management Control Systems Contributions.

Directory of Open Access Journals (Sweden)

José M. Sánchez Vázqez

2006-12-01

Full Text Available As part of the supply chain, manufacturing firms are increasingly placing greater emphasis on the management of their outsourced distribution channels (DCs. However, the role that interorganizational Management Control Systems (MCS can play in managing DC problems is still not clearly understood. Through an exploratory case study, we show how intra-organizational control problems persist in an inter-organizational context, rooted in informational asymmetries and conflicts of interest and aggravated by interdependencies. Likewise, the case study illustrates the way in which MCS assists the manufacturing firm to communicate to its representatives what the organization wants from them, motivating them and transferring capabilities. Thus, MCS can help to complement and re-orientate inter-firm agreements and constitutes a key tool for managing DCs in a flexible way.Como parte de la cadena de suministros, las empresas productoras están poniendo mayor énfasis en la gestión de sus canales de distribución externalizados (DCs. Sin embargo, aún no existe una clara comprensión sobre el papel que los Sistemas de Control de Gestión inter-organizativos (MCS pueden desarrollar en la gestión de los problemas de los DCs. A través de un estudio de caso, se muestra cómo los problemas de control intra-organizativos persisten en un contexto inter-organizativo, causados por las asimetrías informativas y el conflicto de intereses, y agravándose por las interdependencias. Asimismo, se expone cómo los MCS ayudan a la empresa productora a comunicar a sus distribuidores lo que la organización desea de ellos, motivándolos y capacitándolos. De esta forma, los MCS pueden ayudar a completar y redirigir acuerdos entre firmas y constituir una herramienta clave en la gestión flexible de los DCs.

Capacity of the inflow river channels of the Krpelany and Hricov reservoirs with respect to flood control

International Nuclear Information System (INIS)

Capekova, Z.

2004-01-01

In this presentation author deals with the capacity of the inflow river channels of the Krpelany and Hricov reservoirs with respect to flood control (Vah River, Orava River, Kysuce River and Rajcianka River, Slovakia)

Lane fuzzy collision in channel with potential deformation by photon-phonon-electron excitation and sub-atomic control

International Nuclear Information System (INIS)

Shen Jing

1998-01-01

Collision between μ + and the μ - beams in the crystal are forbidden due to the two beams having different ''lanes'' in a channel. A laser pulse of ps-fs shocks lattice kernel vibration and dilates lattice electron distribution. It deforms the Lindhard's potential which is then expressed in a quantized form as the Huang-Zhu's potential[1]. The dynamic lanes can be made to overlap in a channel to allow collision without ductile fracture. This raises a new technology of sub-atomic information and control, which has been raised by T. D. Lee

Potassium channel and NKCC cotransporter involvement in ocular refractive control mechanisms.

Directory of Open Access Journals (Sweden)

Sheila G Crewther

Full Text Available Myopia affects well over 30% of adult humans globally. However, the underlying physiological mechanism is little understood. This study tested the hypothesis that ocular growth and refractive compensation to optical defocus can be controlled by manipulation of potassium and chloride ion-driven transretinal fluid movements to the choroid. Chicks were raised with +/-10D or zero power optical defocus rendering the focal plane of the eye in front of, behind, or at the level of the retinal photoreceptors respectively. Intravitreal injections of barium chloride, a non-specific inhibitor of potassium channels in the retina and RPE or bumetanide, a selective inhibitor of the sodium-potassium-chloride cotransporter were made, targeting fluid control mechanisms. Comparison of refractive compensation to 5 mM Ba(2+ and 10(-5 M bumetanide compared with control saline injected eyes shows significant change for both positive and negative lens defocus for Ba(2+ but significant change only for negative lens defocus with bumetanide (Rx(SAL(-10D = -8.6 +/- .9 D; Rx(Ba2+(-10D = -2.9 +/- .9 D; Rx(Bum(-10D = -2.9 +/- .9 D; Rx(SAL(+10D = +8.2 +/- .9 D; Rx(Ba2+(+10D = +2.8 +/- 1.3 D; Rx(Bum(+10D = +8.0 +/- .7 D. Vitreous chamber depths showed a main effect for drug conditions with less depth change in response to defocus shown for Ba(2+ relative to Saline, while bumetanide injected eyes showed a trend to increased depth without a significant interaction with applied defocus. The results indicate that both K channels and the NKCC cotransporter play a role in refractive compensation with NKCC blockade showing far more specificity for negative, compared with positive, lens defocus. Probable sites of action relevant to refractive control include the apical retinal pigment epithelium membrane and the photoreceptor/ON bipolar synapse. The similarities between the biometric effects of NKCC inhibition and biometric reports of the blockade of the retinal ON response, suggest a

Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels

Directory of Open Access Journals (Sweden)

Seung Min Hur

2009-06-01

Full Text Available We study the problem of how to alleviate the exposed terminal effect in multihop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that schedules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multihop wireless networks.

Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels.

Science.gov (United States)

Son, In Keun; Mao, Shiwen; Hur, Seung Min

2009-01-01

We study the problem of how to alleviate the exposed terminal effect in multi-hop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that sched-ules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multi-hop wireless networks.

P-waves imaging of the FRI and BK zones at the Grimsel Rock Laboratory

International Nuclear Information System (INIS)

Majer, E.L.; Peterson, J.E. Jr.; Blueming, P.; Sattel, G.

1990-08-01

This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geological repository for nuclear waste. Tomographic imaging studies using a high frequency (10 Khz.) piezoelectric source and a three component receiver were carried out in two different regions of the underground Nagra Grimsel test facility in Switzerland. Both sites were in fractured granite, one being in a strongly foliated granite (FRI site), and the other being in a relatively homogeneous granite (BK zone). The object of the work was to determine if the seismic techniques could be useful in imaging the fracture zones and provide information on the hydrologic conditions. Both amplitude and velocity tomograms were obtained from the Data. The results indicate that the fracture zones strongly influenced the seismic wave propagation, thus imaging the fracture zones that were hydrologically important. 11 refs., 24 figs

Development of a Loop-Mediated Isothermal Amplification Assay for Rapid Detection of BK Virus▿

Science.gov (United States)

Bista, Bipin Raj; Ishwad, Chandra; Wadowsky, Robert M.; Manna, Pradip; Randhawa, Parmjeet Singh; Gupta, Gaurav; Adhikari, Meena; Tyagi, Rakhi; Gasper, Gina; Vats, Abhay

2007-01-01

Loop-mediated isothermal amplification (LAMP) is a novel method for rapid amplification of DNA. Its advantages include rapidity and minimal equipment requirement. The LAMP assay was developed for BK virus (BKV), which is a leading cause of morbidity in renal transplant recipients. The characteristics of the assay, including its specificity and sensitivity, were evaluated. BKV LAMP was performed using various incubation times with a variety of specimens, including unprocessed urine and plasma samples. A ladder pattern on gel electrophoresis, typical of successful LAMP reactions, was observed specifically only for BKV and not for other viruses. The sensitivity of the assay with 1 h of incubation was 100 copies/tube of a cloned BKV fragment. Additionally, a positive reaction was visually ascertained by a simple color reaction using SYBR green dye. BKV LAMP was also successful for urine and plasma specimens without the need for DNA extraction. Due to its simplicity and specificity, the LAMP assay can potentially be developed for “point of care” screening of BKV. PMID:17314224

Long Channel Carbon Nanotube as an Alternative to Nanoscale Silicon Channels in Scaled MOSFETs

Directory of Open Access Journals (Sweden)

Michael Loong Peng Tan

2013-01-01

Full Text Available Long channel carbon nanotube transistor (CNT can be used to overcome the high electric field effects in nanoscale length silicon channel. When maximum electric field is reduced, the gate of a field-effect transistor (FET is able to gain control of the channel at varying drain bias. The device performance of a zigzag CNTFET with the same unit area as a nanoscale silicon metal-oxide semiconductor field-effect transistor (MOSFET channel is assessed qualitatively. The drain characteristic of CNTFET and MOSFET device models as well as fabricated CNTFET device are explored over a wide range of drain and gate biases. The results obtained show that long channel nanotubes can significantly reduce the drain-induced barrier lowering (DIBL effects in silicon MOSFET while sustaining the same unit area at higher current density.

Advanced Guidance Algorithms for Homing Missiles with Bearings-Only Measurements.

Science.gov (United States)

1987-11-01

poles are no longer determined by A - BK, and A - KfC . However, the following theorem shows that the coupling H,(s) :=I+PLN(sI -A +BK,) between the...jw) given in Section H-C deter- = N(sI -A + BK,(sI- A + BK, + KC) - ’ KfC )- IM mines the robustness of the FSRO control system. However, N(sl - A + BK...by (si-A+ KfC )-’M constructing a TITO system for the state-feedback regulator.) Therefore, Theorem 3 implies that a regulator with an asymptotic =N(sl-A

Five channel data acquisition system for tracer studies

International Nuclear Information System (INIS)

Narender Reddy, J.; Dhananjay Reddy, Y.; Dheeraj Reddy, J.

2001-01-01

Radioactive tracers are being used by many modern industries for trouble shooting, process control/quality control and optimization in the process plants. A five channel data acquisition system which has five independent scintillation detector based channels for data acquisition has been developed and made available. This system can be used for tracer studies involving Mean residence time, Resident time distribution and other similar parameters involving tracer movement. System developed can acquire data with dwell times ranging from 10 m sec to 100 sec into each channel and has a capacity to acquire data into 10K channels. Each channel electronics, has a 1x1 NaI Scintillation Detector probe, HV, AMP SCA, micro-controller based data acquisition card with independent dot matrix LCD display for visualization. Extensive use of serial bus (I 2 C, microwire) compatible devices has been incorporated in the design. Data acquisition is initiated simultaneously into all the channels. System design permits delayed/prompt data acquisition selectively. Dual counter switching technique has been employed to achieve faster dwell times for data acquisition. (author)

Stage- vs. Channel-strip Metaphor

DEFF Research Database (Denmark)

Gelineck, Steven; Korsgaard, Dannie Michael; Büchert, Morten

2015-01-01

This study compares the stage metaphor and the channel strip metaphor in terms of performance. Traditionally, music mixing consoles employ a channels strip control metaphor for adjusting parameters such as volume and panning of each track. An alternative control metaphor, the so-called stage meta...... is surprisingly similar and thus we are not able to detect any significant difference in performance between the two interfaces. Qualitative data however, suggests that the stage metaphor is largely favoured for its intuitive interaction - confirming earlier studies....

The secret life of ion channels: Kv1.3 potassium channels and proliferation.

Science.gov (United States)

Pérez-García, M Teresa; Cidad, Pilar; López-López, José R

2018-01-01

Kv1.3 channels are involved in the switch to proliferation of normally quiescent cells, being implicated in the control of cell cycle in many different cell types and in many different ways. They modulate membrane potential controlling K + fluxes, sense changes in potential, and interact with many signaling molecules through their intracellular domains. From a mechanistic point of view, we can describe the role of Kv1.3 channels in proliferation with at least three different models. In the "membrane potential model," membrane hyperpolarization resulting from Kv1.3 activation provides the driving force for Ca 2+ influx required to activate Ca 2+ -dependent transcription. This model explains most of the data obtained from several cells from the immune system. In the "voltage sensor model," Kv1.3 channels serve mainly as sensors that transduce electrical signals into biochemical cascades, independently of their effect on membrane potential. Kv1.3-dependent proliferation of vascular smooth muscle cells (VSMCs) could fit this model. Finally, in the "channelosome balance model," the master switch determining proliferation may be related to the control of the Kv1.3 to Kv1.5 ratio, as described in glial cells and also in VSMCs. Since the three mechanisms cannot function independently, these models are obviously not exclusive. Nevertheless, they could be exploited differentially in different cells and tissues. This large functional flexibility of Kv1.3 channels surely gives a new perspective on their functions beyond their elementary role as ion channels, although a conclusive picture of the mechanisms involved in Kv1.3 signaling to proliferation is yet to be reached.

Active Brownian motion in a narrow channel

Science.gov (United States)

Ao, X.; Ghosh, P. K.; Li, Y.; Schmid, G.; Hänggi, P.; Marchesoni, F.

2014-12-01

We review recent advances in rectification control of artificial microswimmers, also known as Janus particles, diffusing along narrow, periodically corrugated channels. The swimmer self-propulsion mechanism is modeled so as to incorporate a nonzero torque (propulsion chirality). We first summarize the effects of chirality on the autonomous current of microswimmers freely diffusing in channels of different geometries. In particular, left-right and upside-down asymmetric channels are shown to exhibit different transport properties. We then report new results on the dependence of the diffusivity of chiral microswimmers on the channel geometry and their own self-propulsion mechanism. The self-propulsion torque turns out to play a key role as a transport control parameter.

Four-channel delay generator model 5740

International Nuclear Information System (INIS)

Baumatz, D.; Milner, M.

1978-01-01

The 4-channel delay generator model 5740 generates 4-pulse groups in independent channels. The device offers the possibility of controlling both the time intervals between the pulses of a group and the rate of generation of groups

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

Science.gov (United States)

Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

2006-06-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

International Nuclear Information System (INIS)

Bechstein, S; Petsche, F; Scheiner, M; Drung, D; Thiel, F; Schnabel, A; Schurig, Th

2006-01-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-T c dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

Energy Technology Data Exchange (ETDEWEB)

Bechstein, S [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Petsche, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Scheiner, M [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Drung, D [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Thiel, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schnabel, A [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schurig, Th [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

2006-06-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/{radical}Hz was specially designed for a 304-channel low-T{sub c} dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

Influence of different structured channels of mesoporous silicate on the controlled ibuprofen delivery

Energy Technology Data Exchange (ETDEWEB)

Gao, Lin [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China); Sun, Jihong, E-mail: jhsun@bjut.edu.cn [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China); Zhang, Li; Wang, Jinpeng; Ren, Bo [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China)

2012-08-15

The bimodal mesoporous silicas with short random mesoporous channels and MCM-41 with long ordered mesopores were synthesised and modified with 3-(2-aminoethylamino) propyltrimethoxysilane as ibuprofen carriers to study the influence of mesoporous structure on drug delivery property. For further comparing the different mesoporous channels, modified SBA-15 with relative large and long ordered mesopores was also synthesized as drug carriers. The resultant samples were characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, N{sub 2} adsorption-desorption isotherms, thermogravimetric analyses, solid-state {sup 29}Si NMR spectra, elemental analysis, and UV-vis spectra. Meanwhile, the Korsmeyer-Peppas equation f{sub t} = kt{sup n} was employed to analyze the drug release profile and three release mediums including simulated fluid solution, distilled water and simulated gastric fluid were used. The results indicated that the modified BMMs with the bimodal mesopores leaded to the most drug loading amount of 25.0 mg/0.1 g, while the MCM-41 with the long and one-dimensional mesopores had the least loading amount around 20.3 mg/0.1 g. Meanwhile, the easier diffusion behavior of drug molecules in the bimodal mesopore channels of BMMs resulted in relatively faster drug release properties in comparison with MCM-41, while the release time maintained in SBF for about 12 h (release percent was about 90 wt%) and corresponding release constant k obtained from Korsmeyer-Peppas equation was around 4.10. Highlights: Black-Right-Pointing-Pointer BMMs, MCM-41 and SBA-15 with different mesostructure channels were modified with amino groups via post-treatment procedure. Black-Right-Pointing-Pointer Loading and release profiles of ibuprofen in modified BMMs, MCM-41 and SBA-15. Black-Right-Pointing-Pointer BMMs presents more drug loading amount than MCM-41 as well as better controlled release than SBA-15.

Influence of different structured channels of mesoporous silicate on the controlled ibuprofen delivery

International Nuclear Information System (INIS)

Gao, Lin; Sun, Jihong; Zhang, Li; Wang, Jinpeng; Ren, Bo

2012-01-01

The bimodal mesoporous silicas with short random mesoporous channels and MCM-41 with long ordered mesopores were synthesised and modified with 3-(2-aminoethylamino) propyltrimethoxysilane as ibuprofen carriers to study the influence of mesoporous structure on drug delivery property. For further comparing the different mesoporous channels, modified SBA-15 with relative large and long ordered mesopores was also synthesized as drug carriers. The resultant samples were characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, N 2 adsorption–desorption isotherms, thermogravimetric analyses, solid-state 29 Si NMR spectra, elemental analysis, and UV–vis spectra. Meanwhile, the Korsmeyer–Peppas equation f t = kt n was employed to analyze the drug release profile and three release mediums including simulated fluid solution, distilled water and simulated gastric fluid were used. The results indicated that the modified BMMs with the bimodal mesopores leaded to the most drug loading amount of 25.0 mg/0.1 g, while the MCM-41 with the long and one-dimensional mesopores had the least loading amount around 20.3 mg/0.1 g. Meanwhile, the easier diffusion behavior of drug molecules in the bimodal mesopore channels of BMMs resulted in relatively faster drug release properties in comparison with MCM-41, while the release time maintained in SBF for about 12 h (release percent was about 90 wt%) and corresponding release constant k obtained from Korsmeyer–Peppas equation was around 4.10. Highlights: ► BMMs, MCM-41 and SBA-15 with different mesostructure channels were modified with amino groups via post-treatment procedure. ► Loading and release profiles of ibuprofen in modified BMMs, MCM-41 and SBA-15. ► BMMs presents more drug loading amount than MCM-41 as well as better controlled release than SBA-15.

Intermolecular Interactions in the TMEM16A Dimer Controlling Channel Activity.

Science.gov (United States)

Scudieri, Paolo; Musante, Ilaria; Gianotti, Ambra; Moran, Oscar; Galietta, Luis J V

2016-12-08

TMEM16A and TMEM16B are plasma membrane proteins with Ca 2+ -dependent Cl - channel function. By replacing the carboxy-terminus of TMEM16A with the equivalent region of TMEM16B, we obtained channels with potentiation of channel activity. Progressive shortening of the chimeric region restricted the "activating domain" to a short sequence close to the last transmembrane domain and led to TMEM16A channels with high activity at very low intracellular Ca 2+ concentrations. To elucidate the molecular mechanism underlying this effect, we carried out experiments based on double chimeras, Forster resonance energy transfer, and intermolecular cross-linking. We also modeled TMEM16A structure using the Nectria haematococca TMEM16 protein as template. Our results indicate that the enhanced activity in chimeric channels is due to altered interaction between the carboxy-terminus and the first intracellular loop in the TMEM16A homo-dimer. Mimicking this perturbation with a small molecule could be the basis for a pharmacological stimulation of TMEM16A-dependent Cl - transport.

Cytoplasmic Domains and Voltage-Dependent Potassium Channel Gating

Science.gov (United States)

Barros, Francisco; Domínguez, Pedro; de la Peña, Pilar

2012-01-01

The basic architecture of the voltage-dependent K+ channels (Kv channels) corresponds to a transmembrane protein core in which the permeation pore, the voltage-sensing components and the gating machinery (cytoplasmic facing gate and sensor–gate coupler) reside. Usually, large protein tails are attached to this core, hanging toward the inside of the cell. These cytoplasmic regions are essential for normal channel function and, due to their accessibility to the cytoplasmic environment, constitute obvious targets for cell-physiological control of channel behavior. Here we review the present knowledge about the molecular organization of these intracellular channel regions and their role in both setting and controlling Kv voltage-dependent gating properties. This includes the influence that they exert on Kv rapid/N-type inactivation and on activation/deactivation gating of Shaker-like and eag-type Kv channels. Some illustrative examples about the relevance of these cytoplasmic domains determining the possibilities for modulation of Kv channel gating by cellular components are also considered. PMID:22470342

Urological management (medical and surgical of BK-virus associated haemorrhagic cystitis in children following haematopoietic stem cell transplantation

Directory of Open Access Journals (Sweden)

Nikhil Vasdev

2013-10-01

Full Text Available Aim: Haemorrhagic cystitis (HC is uncommon and in its severe form potentially life threatening complication of Haematopoietic stem cell transplantation (HSCT in children. We present our single centre experience in the urological management of this clinically challenging condition. Patients and Methods: Fourteen patients were diagnosed with BK-Virus HC in our centre. The mean age at diagnosis was 8.8 years (range, 3.2-18.4 years. The mean number of days post-BMT until onset of HC was 20.8 (range, 1 – 51. While all patients tested urine positive for BKV at the clinical onset of HC, only four patients had viral quantification, with viral loads ranging from 97,000 to >1 billion/ml. 8 patients had clinical HC. Ten patients experienced acute GVHD (grade I: 6 patients, grade II: 3 patients, grade 4: 1 patient.Results: Four patients received medical management for their HC. Treatments included hyperhydration, MESNA, blood and platelet transfusion, premarin and oxybutynin (Table 6.  Two patients received both medical and surgical management which included cystoscopy with clot evacuation, bladder irrigation and supra-pubic catheter insertion. One patient received exclusive surgical management. Seven patients were treated conservatively. Conclusion: There is limited available evidence for other potential therapeutic strategies highlighting the need for more research into the pathophysiology of HSCT-associated HC. Commonly used interventions with possible clinical benefit (e.g. cidofovir, ciprofloxacin still require to be evaluated in multi-centre, high-quality studies. Potential future preventative and therapeutic options, such as modulation of conditioning, immunosuppression and engraftment, new antiviral and anti-inflammatory and less nephrotoxic agents need to be assessed.---------------------------Cite this article as:Vasdev N, Davidson A, Harkensee C, Slatter M, Gennery A, Willetts I, Thorpe A.Urological management (medical and surgical of BK

ENEA-Frascati inertial confinement fusion: Multi-channel digitizer control, acquisition and analysis system

Energy Technology Data Exchange (ETDEWEB)

Caruso, A.; Strangio, C.; Elman, G.; Hugh, J. Mc; Rogers, G.; Pastina, E.; Raimondi, F.; Umbro, A.

1991-09-01

The ICF (Inertial Confinement Fusion) data acquisition and analysis system described in this paper incorporates digitizer channels, signal switching, an instrument controller, a graphic hardcopy unit, laser printer and software. The digitizers, signal switching and instrument controller are standard components appropriate to acquire the single fast shot signals (rise-time: from about 100 picoseconds to nanoseconds). The input signals are switched to the digitizers through the TSI-8150 test system interface by TSS40 switch controller cards and TSS46 18GHz microwave switches. Graphic hardcopy is accomplished using either a 4693PX colour hardcopy unit or a laser printer connected through a printer spooler/multiplexer. The software is based on an existing package from Ressler called RAI/DAC reviewed by Fus-Inerz and Tektronix-Italy to define the modifications needed for data acquisition and handling. The adopted software solution is based on an IBM PC compatible instrument controller running software developed by Ressler Associates.

Channel Power in Multi-Channel Environments

NARCIS (Netherlands)

M.G. Dekimpe (Marnik); B. Skiera (Bernd)

2004-01-01

textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

On the secrecy capacity of the wiretap channel with imperfect main channel estimation

KAUST Repository

Rezki, Zouheir

2014-10-01

We study the secrecy capacity of fast fading channels under imperfect main channel (between the transmitter and the legitimate receiver) estimation at the transmitter. Lower and upper bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate follows from a standard wiretap code in which a simple on-off power control is employed along with a Gaussian input. The upper bound is obtained using an appropriate correlation scheme of the main and eavesdropper channels and is the best known upper bound so far. The upper and lower bounds coincide with recently derived ones in case of perfect main CSI. Furthermore, the upper bound is tight in case of no main CSI, where the secrecy capacity is equal to zero. Asymptotic analysis at high and low signal-to-noise ratio (SNR) is also given. At high SNR, we show that the capacity is bounded by providing upper and lower bounds that depend on the channel estimation error. At low SNR, however, we prove that the secrecy capacity is asymptotically equal to the capacity of the main channel as if there were no secrecy constraint. Numerical results are provided for i.i.d. Rayleigh fading channels.

On the capacity of nakagami-m fading Channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log(1/SNR)}. In this paper, we investigate the Nakagami-m fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as m/ Omega SNR log(1/SNR), where m is the Nakagami-m fading parameter and where Ω is the channel mean-square. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by taking m=1. © 2012 IEEE.

Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

Directory of Open Access Journals (Sweden)

Yue Ma

2018-01-01

Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

Analysis of Traffic Parameter Estimation and Its Impacts on Wireless Channel

Institute of Scientific and Technical Information of China (English)

徐玉滨; 沙学军; 强蔚

2004-01-01

Wide band or broadband access was paid much attention with the development of radio transmission technique. The wireless access control procedure play an important role in this type of system and efficiency of control algorithm has a great impact on throughput of channel resource. Based on wide band network control model and the characteristics of radio channel, this paper proposed a channel traffic estimation method and then performed a dynamic parameter control procedure and give detail analysis on estimation error and its impact on channel throughput and delay performance. Computation and simulation of system performance show a positive solution on system design.

Channel uranium-graphite reactor mounting

International Nuclear Information System (INIS)

Polushkin, K.K.; Kuznetsov, A.G.; Zheleznyakov, B.N.

1981-01-01

According to theoretical principles of general engineering technology the engineering experience of construction-mounting works at the NPP with channel uranium-graphite reactors is systematized. Main parameters and structural features of the 1000 MW channel uranium-graphite reactors are considered. The succession of mounting operations, premounting equipment and pipelines preparation and mounting works technique are described. The most efficient methods of fitting, welding and machining of reactor elements are recommended. Main problems of technical control service are discussed. A typical netted diagram of main equipment of channel uranium-graphite reactors mounting is given

On-line gas mixing and multi-channel distribution system

International Nuclear Information System (INIS)

Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.; Joshi, Avinash

2009-01-01

In this presentation, we describe a mass-flow controller based on-line gas mixing unit with the multi-channel distribution system. We highlight different aspects such as requirement, design, calibration, control and operation of this system. This unit has the capability to mix up to four different input gases and distribute over 16 output channels. Output in individual channels is controlled accurately by using capillary-based system. At present, we are using this gas mixing unit for prototype of iron calorimeter (ICAL) detector of India-based Neutrino Observatory (INO).

Pricing Decision under Dual-Channel Structure considering Fairness and Free-Riding Behavior

Directory of Open Access Journals (Sweden)

Yongmei Liu

2014-01-01

Full Text Available Under dual-channel structure, the free-riding behavior based on different service levels between online channel and offline channel cannot be avoided, which would lead to channel unfairness. This study implies that the dual-channel supply chain is built up by online channel controlled by manufacturer and traditional channel controlled by retailer, respectively. Under this channel structure, we rebuild the linear demand function considering free-riding behavior and modify the pricing model based on channel fairness. Then the influences of fair factor and free-riding behavior on manufacturer and retailer pricing and performance are discussed. Finally, we propose some numerical analysis to provide some valuable recommendations for manufacturer and retailer improving channel management performance.

Flow separation on transversal ribs in an open channel

Czech Academy of Sciences Publication Activity Database

Příhoda, Jaromír; Šulc, J.; Sedlář, M.; Zubík, P.

2009-01-01

Roč. 13, - (2009), s. 218-220 ISSN 1335-2938. [Stretnutie katedier mechaniky tekutín a termomechaniky. Jasná, Demanovská dolina, 24.06.2009-26.06.2009] R&D Projects: GA ČR GA103/09/0977 Institutional research plan: CEZ:AV0Z20760514 Keywords : free-surface flow * supercritical flow over ribs * numerical and experimental modelling Subject RIV: BK - Fluid Dynamics

Use of navigation channels by Lake Sturgeon: Does channelization increase vulnerability of fish to ship strikes?

Directory of Open Access Journals (Sweden)

Darryl W Hondorp

Full Text Available Channelization for navigation and flood control has altered the hydrology and bathymetry of many large rivers with unknown consequences for fish species that undergo riverine migrations. In this study, we investigated whether altered flow distributions and bathymetry associated with channelization attracted migrating Lake Sturgeon (Acipenser fulvescens into commercial navigation channels, potentially increasing their exposure to ship strikes. To address this question, we quantified and compared Lake Sturgeon selection for navigation channels vs. alternative pathways in two multi-channel rivers differentially affected by channelization, but free of barriers to sturgeon movement. Acoustic telemetry was used to quantify Lake Sturgeon movements. Under the assumption that Lake Sturgeon navigate by following primary flow paths, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River were expected to choose navigation channels over alternative pathways and to exhibit greater selection for navigation channels than conspecifics in the less-channelized lower St. Clair River. Consistent with these predictions, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River selected the higher-flow and deeper navigation channels over alternative migration pathways, whereas in the less-channelized lower St. Clair River, individuals primarily used pathways alternative to navigation channels. Lake Sturgeon selection for navigation channels as migratory pathways also was significantly higher in the more-channelized lower Detroit River than in the less-channelized lower St. Clair River. We speculated that use of navigation channels over alternative pathways would increase the spatial overlap of commercial vessels and migrating Lake Sturgeon, potentially enhancing their vulnerability to ship strikes. Results of our study thus demonstrated an association between channelization and the path use of migrating Lake Sturgeon that could prove

Abiotic controls of emergent macrophyte density in a bedrock channel - The Cahaba River, AL (USA)

Science.gov (United States)

Vaughn, Ryan S.; Davis, Lisa

2015-10-01

Research examining bedrock channels is growing. Despite this, biotic-abiotic interactions remain a topic mostly addressed in alluvial systems. This research identified hydrogeomorphic factors operating at the patch-scale (100-102 m) in bedrock shoals of the Cahaba River (AL) that help determine the distribution of the emergent aquatic macrophyte, Justicia americana. Macrophyte patch density (number of stems/m2) and percent bedrock void surface area (rock surface area/m2 occupied by joints, fractures, and potholes) were measured (n = 24 within two bedrock shoals) using stem counts and underwater photography, respectively. One-dimensional hydrologic modeling (HEC-RAS 4.1.0) was completed for a section within a shoal to examine velocity and channel depth as controlling variables for macrophyte patch density. Results from binary logistic regression analysis identified depth and velocity as good predictors of the presence or absence of Justicia americana within shoal structures (depth p = 0.001, velocity p = 0.007), which is a similar finding to previous research conducted in alluvial systems. Correlation analysis between bedrock surface void area and stem density demonstrated a statistically significant positive correlation (r = 0.665, p = 0.01), elucidating a link between abiotic-biotic processes that may well be unique to bedrock channels. These results suggest that the amount of void space present in bedrock surfaces, in addition to localized depth and velocity, helps control macrophyte patch density in bedrock shoal complexes. The utility of geomorphology in explaining patch-scale habitat heterogeneity in this study highlights geomorphology's potential to help understand macrophyte habitat heterogeneity at the reach scale, while also demonstrating its promise for mapping and understanding habitat heterogeneity at the system scale.

Sub-cellular distribution and translocation of TRP channels.

Science.gov (United States)

Toro, Carlos A; Arias, Luis A; Brauchi, Sebastian

2011-01-01

Cellular electrical activity is the result of a highly complex processes that involve the activation of ion channel proteins. Ion channels make pores on cell membranes that rapidly transit between conductive and non-conductive states, allowing different ions to flow down their electrochemical gradients across cell membranes. In the case of neuronal cells, ion channel activity orchestrates action potentials traveling through axons, enabling electrical communication between cells in distant parts of the body. Somatic sensation -our ability to feel touch, temperature and noxious stimuli- require ion channels able to sense and respond to our peripheral environment. Sensory integration involves the summing of various environmental cues and their conversion into electrical signals. Members of the Transient Receptor Potential (TRP) family of ion channels have emerged as important mediators of both cellular sensing and sensory integration. The regulation of the spatial and temporal distribution of membrane receptors is recognized as an important mechanism for controlling the magnitude of the cellular response and the time scale on which cellular signaling occurs. Several studies have shown that this mechanism is also used by TRP channels to modulate cellular response and ultimately fulfill their physiological function as sensors. However, the inner-working of this mode of control for TRP channels remains poorly understood. The question of whether TRPs intrinsically regulate their own vesicular trafficking or weather the dynamic regulation of TRP channel residence on the cell surface is caused by extrinsic changes in the rates of vesicle insertion or retrieval remain open. This review will examine the evidence that sub-cellular redistribution of TRP channels plays an important role in regulating their activity and explore the mechanisms that control the trafficking of vesicles containing TRP channels.

Fault-tolerant controlled quantum secure direct communication over a collective quantum noise channel

International Nuclear Information System (INIS)

Yang, Chun-Wei; Hwang, Tzonelih; Tsai, Chia-Wei

2014-01-01

This work proposes controlled quantum secure direct communication (CQSDC) over an ideal channel. Based on the proposed CQSDC, two fault-tolerant CQSDC protocols that are robust under two kinds of collective noises, collective-dephasing noise and collective-rotation noise, respectively, are constructed. Due to the use of quantum entanglement of the Bell state (or logical Bell state) as well as dense coding, the proposed protocols provide easier implementation as well as better qubit efficiency than other CQSDC protocols. Furthermore, the proposed protocols are also free from correlation-elicitation attack and other well-known attacks. (paper)

Channel sialic acids limit hERG channel activity during the ventricular action potential.

Science.gov (United States)

Norring, Sarah A; Ednie, Andrew R; Schwetz, Tara A; Du, Dongping; Yang, Hui; Bennett, Eric S

2013-02-01

Activity of human ether-a-go-go-related gene (hERG) 1 voltage-gated K(+) channels is responsible for portions of phase 2 and phase 3 repolarization of the human ventricular action potential. Here, we questioned whether and how physiologically and pathophysiologically relevant changes in surface N-glycosylation modified hERG channel function. Voltage-dependent hERG channel gating and activity were evaluated as expressed in a set of Chinese hamster ovary (CHO) cell lines under conditions of full glycosylation, no sialylation, no complex N-glycans, and following enzymatic deglycosylation of surface N-glycans. For each condition of reduced glycosylation, hERG channel steady-state activation and inactivation relationships were shifted linearly by significant depolarizing ∼9 and ∼18 mV, respectively. The hERG window current increased significantly by 50-150%, and the peak shifted by a depolarizing ∼10 mV. There was no significant change in maximum hERG current density. Deglycosylated channels were significantly more active (20-80%) than glycosylated controls during phases 2 and 3 of action potential clamp protocols. Simulations of hERG current and ventricular action potentials corroborated experimental data and predicted reduced sialylation leads to a 50-70-ms decrease in action potential duration. The data describe a novel mechanism by which hERG channel gating is modulated through physiologically and pathophysiologically relevant changes in N-glycosylation; reduced channel sialylation increases hERG channel activity during the action potential, thereby increasing the rate of action potential repolarization.

Achievable Performance of Zero-Delay Variable-Rate Coding in Rate-Constrained Networked Control Systems with Channel Delay

DEFF Research Database (Denmark)

Barforooshan, Mohsen; Østergaard, Jan; Stavrou, Fotios

2017-01-01

This paper presents an upper bound on the minimum data rate required to achieve a prescribed closed-loop performance level in networked control systems (NCSs). The considered feedback loop includes a linear time-invariant (LTI) plant with single measurement output and single control input. Moreover......, in this NCS, a causal but otherwise unconstrained feedback system carries out zero-delay variable-rate coding, and control. Between the encoder and decoder, data is exchanged over a rate-limited noiseless digital channel with a known constant time delay. Here we propose a linear source-coding scheme...

Clofilium inhibits Slick and Slack potassium channels.

Science.gov (United States)

de Los Angeles Tejada, Maria; Stolpe, Kathleen; Meinild, Anne-Kristine; Klaerke, Dan A

2012-01-01

Slick and Slack high-conductance potassium channels have been recently discovered, and are found in the central nervous system and in the heart. Both channels are activated by Na(+) and Cl(-), and Slick channels are also inhibited by adenosine triphospate (ATP). An important role of setting the resting membrane potential and controlling the basal excitability of neurons has been suggested for these channels. In addition, no specific blockers for these channels are known up to the present. With the purpose of studying the pharmacological characteristics of Slick and Slack channels, the effects of exposure to the antiarrhythmic compound clofilium were evaluated. Clofilium was able to modulate the activity of Slick and Slack channels effectively, with a stronger effect on Slack than Slick channels. In order to evaluate the pharmacological behavior of Slick and Slack channels further, 38 commonly used potassium channel blockers were tested. Screening of these compounds did not reveal any modulators of Slick and Slack channels, except for clofilium. The present study provides a first approach towards elucidating the pharmacological characteristics of Slick and Slack channels and could be the basis for future studies aimed at developing potent and specific blockers and activators for these channels.

Spatial Modulation in the Underwater Acoustic Communication Channel

National Research Council Canada - National Science Library

Kilfoyle, Daniel

2000-01-01

.... The technique, termed spatial modulation, seeks to control the spatial distribution of signal energy such that multiple parallel communication channels are supported by the single, physical ocean channel...

Large scale replacement of fuel channels in the Pickering CANDU reactor using a man-in-the-loop remote control system

International Nuclear Information System (INIS)

Stratton, D.

1991-01-01

Spar Aerospace Limited of Toronto is presently under contract to Ontario Hydro to design a Remote Manipulation and Control System (RMCS) to be used during the large scale replacement of the fuel channels in the Pickering A Nuclear Generating Station. The system is designed to support the replacement of all 390 fuel channels in each of the four reactors at the Pickering A station in a safe manner that minimizes worker radiation exposure and unit outage time

A Gate Hinge Controls the Epithelial Calcium Channel TRPV5

OpenAIRE

van der Wijst, Jenny; Leunissen, Elizabeth H.; Blanchard, Maxime G.; Venselaar, Hanka; Verkaart, Sjoerd; Paulsen, Candice E.; Bindels, Ren? J.; Hoenderop, Joost G.

2017-01-01

TRPV5 is unique within the large TRP channel family for displaying a high Ca2+ selectivity together with Ca2+-dependent inactivation. Our study aims to uncover novel insights into channel gating through in-depth structure-function analysis. We identify an exceptional tryptophan (W583) at the terminus of the intracellular pore that is unique for TRPV5 (and TRPV6). A combination of site-directed mutagenesis, biochemical and electrophysiological analysis, together with homology modeling, demonst...

The elusive character of discontinuous deep-water channels: New insights from Lucia Chica channel system, offshore California

Science.gov (United States)

Maier, K.L.; Fildani, A.; Paull, C.K.; Graham, S.A.; McHargue, T.R.; Caress, D.W.; McGann, M.

2011-01-01

New high-resolution autonomous underwater vehicle (AUV) seafloor images, with 1 m lateral resolution and 0.3 m vertical resolution, reveal unexpected seafloor rugosity and low-relief (thalwegs were interpreted originally from lower-resolution images, but newly acquired AUV data indicate that a single sinuous channel fed a series of discontinuous lower-relief channels. These discontinuous channels were created by at least four avulsion events. Channel relief, defined as the height from the thalweg to the levee crest, controls avulsions and overall stratigraphic architecture of the depositional area. Flowstripped turbidity currents separated into and reactivated multiple channels to create a distributary pattern and developed discontinuous trains of cyclic scours and megaflutes, which may be erosional precursors to continuous channels. The diverse features now imaged in the Lucia Chica channel system (offshore California) are likely common in modern and ancient systems with similar overall morphologies, but have not been previously mapped with lower-resolution detection methods in any of these systems. ?? 2011 Geological Society of America.

Nonlocal multi-target controlled–controlled gate using Greenberger–Horne–Zeilinger channel and qutrit catalysis

International Nuclear Information System (INIS)

Chen Li-Bing; Lu Hong

2015-01-01

We present a scheme for implementing locally a nonlocal N-target controlled–controlled gate with unit probability of success by harnessing two (N+1)-qubit Greenberger–Horne–Zeilinger (GHZ) states as quantum channel and N qutrits as catalyser. The quantum network that implements this nonlocal (N+2)-body gate is built entirely of local single-body and two-body gates, and has only (3N+2) two-body gates. This result suggests that both the computational depth of quantum network and the quantum resources required to perform this nonlocal gate might be significantly reduced. This scheme can be generalized straightforwardly to implement a nonlocal N-target and M-control qubits gate. (paper)

Edge plasma control: Particle channeling in Tore Supra pump limiter and ergodic divertor

International Nuclear Information System (INIS)

Ghendrih, P.; Samain, A.; Grosman, A.; Capes, H.; Morera, J.P.

1989-01-01

Improved pumping efficiency can be achieved on Tore Supra by channeling process for particles, i.e. channeling of neutrals in the throat of pump limiters and channeling of plasma towards neutralizer plates in the ergodic divertor. The plugging length for the pump limiter throat is computed and numerical evidence of plasma flux channeling between the conductor bars of the ergodic divertor is presented. The effect of the Tore Supra ergodic divertor on edge plasma state and edge plasma transport is discussed. (orig.)

Channel Bow in Boiling Water Reactors - Hot Cell Examination Results and Correlation to Measured Bow

International Nuclear Information System (INIS)

Mahmood, S.T.; Lin, Y.P.; Dubecky, M.A.; Edsinger, K.; Mader, E.V.

2007-01-01

An increase in frequency of fuel channel-control blade interference has been observed in Boiling Water Reactors (BWR) in recent years. Many of the channels leading to interference were found to bow towards the control blade in a manner that was inconsistent with the expected bow due to other effects. The pattern of bow appeared to indicate a new channel bow mechanism that differed from the predominant bow mechanism caused by differential growth due to fast-fluence gradients. In order to investigate this new type of channel bow, coupons from several channels with varying degrees of bow were returned to the GE Vallecitos Nuclear Center (VNC) for Post-Irradiation Examination (PIE). This paper describes the characteristics of channel corrosion and hydrogen pickup observed, and relates the observations to the channel exposure level, control history, and measured channel bow. The channels selected for PIE had exposures in the range of 36-48 GWd/MTU and covered a wide range of measured bow. The coupons were obtained at 4 elevations from opposing channel sides adjacent and away from the control blade. The PIE performed on these coupons included visual examination, metallography, and hydrogen concentration measurements. A new mechanism of control-blade shadow corrosion-induced channel bow was found to correlate with differences in the extent of corrosion and corresponding differences in the hydrogen concentration between opposite sides of the channels. The increased corrosion on the control blade sides was found to be dependent on the level of control early in the life of the channel. The contributions of other potential factors leading to increased channel bow and channel-control blade interference are also discussed in this paper. (authors)

CONDUCTIVE CHANNEL FOR ENERGY TRANSMISSION

Directory of Open Access Journals (Sweden)

V. V. Apollonov

2014-01-01

Full Text Available Laser spark obtained by using a conical optics is much more appropriate to form conducting channels in atmosphere. Only two types of lasers are actively considered to be used in forming high-conductivity channels in atmosphere, controlled by laser spark: pulsed sub-microsecond gas and chemical lasers (CO2, DF and short pulse solid-state and UV lasers. Main advantage of short pulse lasers is their ability in forming of super long ionized channels with a characteristic diameter of ~100  µ  in atmosphere along the  beam propagation direction. At estimated electron densities below  10 ⋅ 16 cm–3 in these filaments and laser wavelengths in the range of 0,5–1,0 mm, the plasma barely absorbs laser radiation.  In this case, the length of the track composed of many filaments is determined by the laser intensity and may reach many kilometers at a femtosecond pulse energy of ~100 mJ. However, these lasers could not be used to form high-conductivity long channels in atmosphere. The ohmic resistance of this type a conducting channels turned out to be very high, and the gas in the channels could not be strongly heated (< 1 J. An electric breakdown controlled by radiation of femtosecond solid-state laser was implemented in only at a length of 3 m with a voltage of 2 MV across the discharge gap (670 kV/m.Not so long ago scientific group from P. N. Lebedev has improved that result, the discharge gap – 1 m had been broken under KrF laser irradiation when switching high-voltage (up to 390 kV/m electric discharge by 100-ns UV pulses. Our previous result  –  16 m long conducting channel controlled by a  laser spark at the voltage  –  3 MV  – was obtained more than 20 years ago in Russia and Japan by using pulsed CO2  laser with energy  –  0,5 kJ. An average electric field strength  was < 190 kV/m. It is still too much for efficient applications.

A Fast Channel Switching Method in EPON System for IPTV Service

Science.gov (United States)

Nie, Yaling; Yoshiuchi, Hideya

This paper presents a fast channel switching method in Ethernet Passive Optical Network (EPON) system for IPTV service. Fast channel switching is one of the important features of successful IPTV systems. Users surely prefer IPTV systems with small channel switching time rather than a longer one. Thus a channel switching control module and a channel/permission list in EPON system’s ONU or OLT is designed. When EPON system receives channel switching message from IPTV end user, the channel switching control module will catch the message and search the channel list and permission list maintained in EPON system, then got the matching parameter of EPON for the new channel. The new channel’s data transmission will be enabled by directly updating the optical filter of the ONU that end user connected. By using this method in EPON system, it provides a solution for dealing with channel switching delays in IPTV service.

ECIL guidelines for the prevention, diagnosis and treatment of BK polyomavirus-associated haemorrhagic cystitis in haematopoietic stem cell transplant recipients.

Science.gov (United States)

Cesaro, Simone; Dalianis, Tina; Hanssen Rinaldo, Christine; Koskenvuo, Minna; Pegoraro, Anna; Einsele, Hermann; Cordonnier, Catherine; Hirsch, Hans H

2018-01-01

To define guidelines for BK polyomavirus (BKPyV)-associated haemorrhagic cystitis (BKPyV-HC) after paediatric and adult HSCT. Review of English literature and evidence-based recommendations by expert consensus. BKPyV-HC occurs in 8%-25% of paediatric and 7%-54% of adult recipients undergoing allogeneic HSCT. Diagnosis requires the triad of cystitis, macro-haematuria and high urine BKPyV loads >7 log10 copies/mL, and exclusion of other relevant aetiologies. BKPyV viraemia is frequent and may serve as a more specific semiquantitative follow-up marker. No randomized controlled trials are available to inform antiviral prophylaxis or treatment. However, hyper-hydration and/or bladder irrigation showed limited prophylactic value. Fluoroquinolones are not effective for prophylaxis or treatment, but rather increase antibiotic resistance. Hyperbaric oxygen or fibrin glue is marginally effective based on small case series from correspondingly equipped centres. Although cidofovir has been reported to improve and/or reduce BKPyV viraemia or viruria, the current data do not support its regular use. BKPyV-HC remains a disabling unmet clinical need in HSCT that requires novel approaches supported by proper clinical trials. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Octanol reduces end-plate channel lifetime

Science.gov (United States)

Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk

1978-01-01

1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that

Quaternary tectonic control on channel morphology over sedimentary low land: A case study in the Ajay-Damodar interfluve of Eastern India

Directory of Open Access Journals (Sweden)

Suvendu Roy

2015-11-01

Full Text Available The style of active tectonic on the deformation and characterization of fluvial landscape has been investigated on three typical skrike-slip fault zones of the Ajay-Damodar Interfluve (ADI in Eastern India through field mapping, structural analysis and examination of digital topography (ASTER-30 m, multi-spectral imageries, and Google Earth images. Channel morphology in Quaternary sediment is more deformed than Cenozoic lateritic tract and igneous rock system by the neotectonic activities. The structural and lithological controls on the river system in ADI region are reflected by distinct drainage patterns, abrupt change in flow direction, offset river channels, straight river lines, ponded river channel, marshy lands, sag ponds, palaeo-channels, alluvial fans, meander cutoffs, multi-terrace river valley, incised compressed meander, convexity of channel bed slope and knick points in longitudinal profile. Seven morphotectonic indices have been used to infer the role of neotectonic on the modification of channel morphology. A tectonic index map for the ADI region has been prepared by the integration of used morphotectonic indices, which is also calibrated by Bouguer gravity anomaly data and field investigation.

Export channel pricing management for integrated solutions

OpenAIRE

Roine, Henna; Sainio, Liisa-Maija; Saarenketo, Sami

2012-01-01

This article studies systems integrators' export channel pricing management for integrated solutions. We find support from our empirical case study for the notion that a systems integrator's export channel pricing strategy is multidimensional and dependent on international pricing environment and partner characteristics and that export partnerships have unique implications on a systems integrator's pricing process. The results show that giving up pricing control in export channel context may ...

Generating multiplex gradients of biomolecules for controlling cellular adhesion in parallel microfluidic channels.

Science.gov (United States)

Didar, Tohid Fatanat; Tabrizian, Maryam

2012-11-07

Here we present a microfluidic platform to generate multiplex gradients of biomolecules within parallel microfluidic channels, in which a range of multiplex concentration gradients with different profile shapes are simultaneously produced. Nonlinear polynomial gradients were also generated using this device. The gradient generation principle is based on implementing parrallel channels with each providing a different hydrodynamic resistance. The generated biomolecule gradients were then covalently functionalized onto the microchannel surfaces. Surface gradients along the channel width were a result of covalent attachments of biomolecules to the surface, which remained functional under high shear stresses (50 dyn/cm(2)). An IgG antibody conjugated to three different fluorescence dyes (FITC, Cy5 and Cy3) was used to demonstrate the resulting multiplex concentration gradients of biomolecules. The device enabled generation of gradients with up to three different biomolecules in each channel with varying concentration profiles. We were also able to produce 2-dimensional gradients in which biomolecules were distributed along the length and width of the channel. To demonstrate the applicability of the developed design, three different multiplex concentration gradients of REDV and KRSR peptides were patterned along the width of three parallel channels and adhesion of primary human umbilical vein endothelial cell (HUVEC) in each channel was subsequently investigated using a single chip.

5,6-EET potently inhibits T-type calcium channels

DEFF Research Database (Denmark)

Cazade, M.; Bidaud, I.; Hansen, Pernille B. Lærkegaard

2014-01-01

T-type calcium channels (T-channels) are important actors in neuronal pacemaking, in heart rhythm, and in the control of the vascular tone. T-channels are regulated by several endogenous lipids including the primary eicosanoid arachidonic acid (AA), which display an important role in vasodilation...

Multi-channel control circuit for real-time control of events in Aditya tokamak

Energy Technology Data Exchange (ETDEWEB)

Edappala, Praveenlal, E-mail: praveen@ipr.res.in; Shah, Minsha; Rajpal, Rachana; Tanna, R.L.; Ghosh, Joydeep; Chattopadhyay, P.K.; Jha, R.

2016-11-15

Highlights: • Low cost microcontroller based control circuit. • The control hardware can be programmed/configured very easily for different applications. • Microcontroller programming is done in assembly language so that precise timing can be achieved with micro seconds resolution. • Successful implementation of this circuit in noisy tokamak environment. • Efficient noise and burst elimination. • Can be integrated in to the other subsystems. • Low cost solution for implementing feedback control in small and medium size tokamaks and other experiments requiring feedback control. - Abstract: Tokamak plasma is prone to many random events having potential for causing severe damages to the machine, such as disruptions, production and elimination of high-energy runaway electrons etc. These events can be mitigated by obtaining pre-cursor signal leading to these events and then taking proper measures just before their onset to avoid their happenings, like disruptions can be mitigated by massive gas injection or putting a bias voltage on an electrode placed inside the plasma, the runaways can be mitigated by gas injection and by applying specific magnetic fields. Hence for real time control of these events, the pre-cursors should be electronically recorded and the mitigation techniques should be initiated by sending triggers to their individual operational systems. To implement these methodologies of real-time controlling of events in Aditya Tokamak, a low cost multi-channel Micro-Controller based timing circuit is designed and developed in-house. This circuit first compares the precursor signals fed into it with the pre-set values and gives a trigger output whenever the signals overshoot the pre-set values. The circuit readies itself for operation along with start of the tokamak discharge and waits up to an initial pre-determined delay and then initiates a trigger at the time of overshooting of precursor signal. The circuit is fully integrated and assembled in

On the capacity of Rician fading channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log (1/SNR). In this paper, we investigate the Rician fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as 1/1+K SNR log (1 /SNR), where K is the Rician factor. This characterization includes perfect CSI at both the transmitter and the receiver or noisy CSI at the transmitter and perfect CSI at the receiver. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by letting K goes to zero. © 2012 IEEE.

Frequency Control: Proceedings of the 40th Annual Symposium on held in Philadelphia, Pennsylvania on 28-30 May 1986

Science.gov (United States)

1986-05-30

lower grades (ŕst" to Řth") is in correlation with the crack patterns of 2.62 lascas, which become more and more intense, es __________, pecially...problem. Introduction 1 iemical etching of quartz plates is a techni- bk-o\\ /O-bk b-o\\ /0- bk-o /0- que by means of which the construction of Si Si...tumble test data least of the parabola is the same as that predicted, i.e. squares line fit. The line is a least squares concave downward, straight

Dividing Streamline Formation Channel Confluences by Physical Modeling

Directory of Open Access Journals (Sweden)

Minarni Nur Trilita

2010-02-01

Full Text Available Confluence channels are often found in open channel network system and is the most important element. The incoming flow from the branch channel to the main cause various forms and cause vortex flow. Phenomenon can cause erosion of the side wall of the channel, the bed channel scour and sedimentation in the downstream confluence channel. To control these problems needed research into the current width of the branch channel. The incoming flow from the branch channel to the main channel flow bounded by a line distributors (dividing streamline. In this paper, the wide dividing streamline observed in the laboratory using a physical model of two open channels, a square that formed an angle of 30º. Observations were made with a variety of flow coming from each channel. The results obtained in the laboratory observation that the width of dividing streamline flow is influenced by the discharge ratio between the channel branch with the main channel. While the results of a comparison with previous studies showing that the observation in the laboratory is smaller than the results of previous research.

Reliability Improved Design for a Safety System Channel

Energy Technology Data Exchange (ETDEWEB)

Oh, Eung Se; Kim, Yun Goo [KHNP, Daejeon (Korea, Republic of)

2016-05-15

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced.

Reliability Improved Design for a Safety System Channel

International Nuclear Information System (INIS)

Oh, Eung Se; Kim, Yun Goo

2016-01-01

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced

Effectiveness Using Circular Fibre Steel Flap Gate As a Control Structure Towards the Hydraulic Characteristics in Open Channel

Science.gov (United States)

Adib, M. R. M.; Amirza, A. R. M.; Wardah, T.; Junaidah, A.

2016-07-01

Hydraulic control gate structure plays an important role in regulating the flow of water in river, canal or water reservoir. One of the most appropriate structures in term of resolving the problem of flood occured is the construction of circular fibre steel flap gate. Therefore, an experiment has been conducted by using an open channel model at laboratory. In this case, hydraulic jump and backwater were the method to determined the hydraulic characteristics of circular fibre steel flap gate in an open channel model. From the experiment, the opening angle of flap gate can receive discharges with the highest flow rate of 0.035 m3/s with opening angle was 47°. The type of jump that occurs at the slope of 1/200 for a distance of 5.0 m is a standing jump or undulating wave. The height of the backwater can be identified based on the differences of specific force which is specific force before jump, F1 and specific force after jump, F2 from the formation of backwater. Based on the research conducted, the tendency of incident backwater wave occurred was high in every distance of water control location from water inlet is flap slope and the slope of 1/300 which is 0.84 m/s and 0.75 m/s of celerity in open channel model.

Calcium channel modulation as a target in chronic pain control.

Science.gov (United States)

Patel, Ryan; Montagut-Bordas, Carlota; Dickenson, Anthony H

2018-06-01

Neuropathic pain remains poorly treated for large numbers of patients, and little progress has been made in developing novel classes of analgesics. To redress this issue, ziconotide (Prialt™) was developed and approved as a first-in-class synthetic version of ω-conotoxin MVIIA, a peptide blocker of Ca v 2.2 channels. Unfortunately, the impracticalities of intrathecal delivery, low therapeutic index and severe neurological side effects associated with ziconotide have restricted its use to exceptional circumstances. Ziconotide exhibits no state or use-dependent block of Ca v 2.2 channels; activation state-dependent blockers were hypothesized to circumvent the side effects of state-independent blockers by selectively targeting high-frequency firing of nociceptive neurones in chronic pain states, thus alleviating aberrant pain but not affecting normal sensory transduction. Unfortunately, numerous drugs, including state-dependent calcium channel blockers, have displayed efficacy in preclinical models but have subsequently been disappointing in clinical trials. In recent years, it has become more widely acknowledged that trans-aetiological sensory profiles exist amongst chronic pain patients and may indicate similar underlying mechanisms and drug sensitivities. Heterogeneity amongst patients, a reliance on stimulus-evoked endpoints in preclinical studies and a failure to utilize translatable endpoints, all are likely to have contributed to negative clinical trial results. We provide an overview of how electrophysiological and operant-based assays provide insight into sensory and affective aspects of pain in animal models and how these may relate to chronic pain patients in order to improve the bench-to-bedside translation of calcium channel modulators. This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175

Axial Couette-Poiseuille flow of power-law viscoplastic fluids in concentric annuli

Czech Academy of Sciences Publication Activity Database

Filip, Petr; David, Jiří

2003-01-01

Roč. 40, 3/4 (2003), s. 111-119 ISSN 0920-4105 R&D Projects: GA AV ČR IAA2060004 Institutional research plan: CEZ:AV0Z2060917 Keywords : boreholes * channel geometry * viscoplastic materials Subject RIV: BK - Fluid Dynamics Impact factor: 0.570, year: 2003

Interface Engineering for Precise Threshold Voltage Control in Multilayer-Channel Thin Film Transistors

KAUST Repository

Park, Jihoon

2016-11-29

Multilayer channel structure is used to effectively manipulate the threshold voltage of zinc oxide transistors without degrading its field-effect mobility. Transistors operating in enhancement mode with good mobility are fabricated by optimizing the structure of the multilayer channel. The optimization is attributed to the formation of additional channel and suppression of the diffusion of absorbed water molecules and oxygen vacancies.

Interface Engineering for Precise Threshold Voltage Control in Multilayer-Channel Thin Film Transistors

KAUST Repository

Park, Jihoon; Alshammari, Fwzah Hamud; Wang, Zhenwei; Alshareef, Husam N.

2016-01-01

Multilayer channel structure is used to effectively manipulate the threshold voltage of zinc oxide transistors without degrading its field-effect mobility. Transistors operating in enhancement mode with good mobility are fabricated by optimizing the structure of the multilayer channel. The optimization is attributed to the formation of additional channel and suppression of the diffusion of absorbed water molecules and oxygen vacancies.

Extended plasma channels created by UV laser in air and their application to control electric discharges

International Nuclear Information System (INIS)

Zvorykin, V. D.; Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Sinitsyn, D. V.; Smetanin, I. V.; Ustinovskii, N. N.; Shutov, A. V.

2015-01-01

Results are presented from a series of experimental and theoretical studies on creating weakly ionized extended plasma channels in atmospheric air by 248-nm UV laser radiation and their application to control long high-voltage discharges. The main mechanisms of air ionization by UV laser pulses with durations from 100 fs to 25 ns and intensities in the ranges of 3×10 11 –1.5×10 13 and 3×10 6 –3×10 11 W/cm 2 , respectively, which are below the threshold for optical gas breakdown, as well as the main relaxation processes in plasma with a density of 10 9 –10 17 cm −3 , are considered. It is shown that plasma channels in air can be efficiently created by amplitude-modulated UV pulses consisting of a train of subpicosecond pulses producing primary photoelectrons and a long UV pulse suppressing electron attachment and sustaining the density of free electrons in plasma. Different modes of the generation and amplification of trains of subterawatt subpicosecond pulses and amplitude-modulated UV pulses with an energy of several tens of joules were implemented on the GARPUN-MTW hybrid Ti:sapphire-KrF laser facility. The filamentation of such UV laser beams during their propagation in air over distances of up to 100 m and the parameters of the corresponding plasma channels were studied experimentally and theoretically. Laser initiation of high-voltage electric discharges and control of their trajectories by means of amplitude-modulated UV pulses, as well as the spatiotemporal structure of breakdowns in air gaps with length of up to 80 cm, were studied

Control of the ZnO nanowires nucleation site using microfluidic channels.

Science.gov (United States)

Lee, Sang Hyun; Lee, Hyun Jung; Oh, Dongcheol; Lee, Seog Woo; Goto, Hiroki; Buckmaster, Ryan; Yasukawa, Tomoyuki; Matsue, Tomokazu; Hong, Soon-Ku; Ko, HyunChul; Cho, Meoung-Whan; Yao, Takafumi

2006-03-09

We report on the growth of uniquely shaped ZnO nanowires with high surface area and patterned over large areas by using a poly(dimethylsiloxane) (PDMS) microfluidic channel technique. The synthesis uses first a patterned seed template fabricated by zinc acetate solution flowing though a microfluidic channel and then growth of ZnO nanowire at the seed using thermal chemical vapor deposition on a silicon substrate. Variations the ZnO nanowire by seed pattern formed within the microfluidic channel were also observed for different substrates and concentrations of the zinc acetate solution. The photocurrent properties of the patterned ZnO nanowires with high surface area, due to their unique shape, were also investigated. These specialized shapes and patterning technique increase the possibility of realizing one-dimensional nanostructure devices such as sensors and optoelectric devices.

Capacity of a quantum memory channel correlated by matrix product states

Science.gov (United States)

Mulherkar, Jaideep; Sunitha, V.

2018-04-01

We study the capacity of a quantum channel where channel acts like controlled phase gate with the control being provided by a one-dimensional quantum spin chain environment. Due to the correlations in the spin chain, we get a quantum channel with memory. We derive formulas for the quantum capacity of this channel when the spin state is a matrix product state. Particularly, we derive exact formulas for the capacity of the quantum memory channel when the environment state is the ground state of the AKLT model and the Majumdar-Ghosh model. We find that the behavior of the capacity for the range of the parameters is analytic.

Eleven new heaviest isotopes of elements Z=105 to Z=117 identified among the products of 249Bk+48Ca reactions

International Nuclear Information System (INIS)

Oganessian, Yu. Ts.; Abdullin, F. Sh.; Dmitriev, S. N.; Itkis, M. G.; Lobanov, Yu. V.; Mezentsev, A. N.; Polyakov, A. N.; Sagaidak, R. N.; Shirokovsky, I. V.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.; Bailey, P. D.; Benker, D. E.; Ezold, J. G.; Porter, C. E.; Riley, F. D.

2011-01-01

The heaviest isotopes of elements Z=117 to Z=105, 294 117, 293 117, 290 115, 289 115, 286 113, 285 113, 282 Rg, 281 Rg, 278 Mt, 274 Bh, and 270 Db, were identified by means of the Dubna gas-filled recoil separator among the products of the 249 Bk + 48 Ca reaction. The details of the observed six decay chains, indicating the production and decay of isotopes 293 117 and 294 117, are presented and discussed. The decay energies and resulting half-lives of these new nuclei show a strong rise of stability with increasing neutron number, validating the concept of the island of enhanced stability for superheavy nuclei [Oganessian et al., Phys. Rev. Lett. 104, 142502 (2010)].

Quantum finite-depth memory channels: Case study

International Nuclear Information System (INIS)

Rybar, Tomas; Ziman, Mario

2009-01-01

We analyze the depth of the memory of quantum memory channels generated by a fixed unitary transformation describing the interaction between the principal system and internal degrees of freedom of the process device. We investigate the simplest case of a qubit memory channel with a two-level memory system. In particular, we explicitly characterize all interactions for which the memory depth is finite. We show that the memory effects are either infinite, or they disappear after at most two uses of the channel. Memory channels of finite depth can be to some extent controlled and manipulated by so-called reset sequences. We show that actions separated by the sequences of inputs of the length of the memory depth are independent and constitute memoryless channels.

FPGA based, DSP integrated, 8-channel SIMCON, ver. 3.0. Initial results for 8-channel algorithm

Energy Technology Data Exchange (ETDEWEB)

Giergusiewicz, W.; Koprek, W.; Jalmuzna, W.; Pozniak, K.T.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland). Inst. of Electronic Systems

2005-07-01

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the VUV-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layer, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0. encouraged us to enter the design of SIMCON 3.1. possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0. is a modular solution, while SIMCON 3.1. will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one, after branching off in this version of the Simcon, will be continued. (orig.)

Disposal of waste channels and control rods and radioactive waste; Gestion de canales usados y barras de control como residuos radiactivos

Energy Technology Data Exchange (ETDEWEB)

Lopez Alvarez, L.

2015-07-01

Iberdrola and ENRESA are jointly developing a project for the characterization and conditioning of around 200 control rods and 70 used channel from Cofrentes Nuclear Power Plant. This treatment line for high level waste with a radiologic inventory that avoids using the El Cabril low level waste repository is new in Spain and incorporates specific features like the option to carry on with the conditioning stage prior to having a licensed package and available storage facility for this type of waste. (Author)

Clearance gap flow: Simulations by discontinuous Galerkin method and experiments

Czech Academy of Sciences Publication Activity Database

Hála, Jindřich; Luxa, Martin; Bublík, O.; Prausová, H.; Vimmr, J.

2016-01-01

Roč. 92, May (2016), 02073-02073 ISSN 2100-014X. [EFM14 – Experimental Fluid Mechanics 2014. Český Krumlov, 18.11.2014-21.11.2014] Institutional support: RVO:61388998 Keywords : compressible fluid flow * narrow channel flow * discontinuous Galerkin finite element method Subject RIV: BK - Fluid Dynamics

The PSI web interface to the EPICS channel archiver

International Nuclear Information System (INIS)

Gaudenz Jud; Luedeke, A.; Portmann, W.

2012-01-01

the EPICS (Experimental Physics and Industrial Control System) channel archiver is used at different facilities at PSI (Paul Scherrer Institute) like the Swiss Light Source or the medical cyclotron. The EPICS channel archiver is a powerful tool to collect control system data of thousands of EPICS process variables with rates of many Hertz each to an archive for later retrieval. Within the package of the channel archiver version 2 you get a Java application for graphical data retrieval and a command line tool for data extraction into different file formats. For the Paul Scherrer Institute (PSI) we wanted a possibility to retrieve the archived data from a web interface. It was desired to have flexible retrieval functions and to allow interchanging data references by e-mail. This web interface has been implemented by the PSI controls group and has now been in operation for several years. This paper will highlight the special features of the PSI web interface to the EPICS channel archiver

cAMP control of HCN2 channel Mg2+ block reveals loose coupling between the cyclic nucleotide-gating ring and the pore.

Directory of Open Access Journals (Sweden)

Alex K Lyashchenko

Full Text Available Hyperpolarization-activated cyclic nucleotide-regulated HCN channels underlie the Na+-K+ permeable IH pacemaker current. As with other voltage-gated members of the 6-transmembrane KV channel superfamily, opening of HCN channels involves dilation of a helical bundle formed by the intracellular ends of S6 albeit this is promoted by inward, not outward, displacement of S4. Direct agonist binding to a ring of cyclic nucleotide-binding sites, one of which lies immediately distal to each S6 helix, imparts cAMP sensitivity to HCN channel opening. At depolarized potentials, HCN channels are further modulated by intracellular Mg2+ which blocks the open channel pore and blunts the inhibitory effect of outward K+ flux. Here, we show that cAMP binding to the gating ring enhances not only channel opening but also the kinetics of Mg2+ block. A combination of experimental and simulation studies demonstrates that agonist acceleration of block is mediated via acceleration of the blocking reaction itself rather than as a secondary consequence of the cAMP enhancement of channel opening. These results suggest that the activation status of the gating ring and the open state of the pore are not coupled in an obligate manner (as required by the often invoked Monod-Wyman-Changeux allosteric model but couple more loosely (as envisioned in a modular model of protein activation. Importantly, the emergence of second messenger sensitivity of open channel rectification suggests that loose coupling may have an unexpected consequence: it may endow these erstwhile "slow" channels with an ability to exert voltage and ligand-modulated control over cellular excitability on the fastest of physiologically relevant time scales.

SH Oxidation Stimulates Calcium Release Channels (Ryanodine Receptors From Excitable Cells

Directory of Open Access Journals (Sweden)

CECILIA HIDALGO

2000-01-01

Full Text Available The effects of redox reagents on the activity of the intracellular calcium release channels (ryanodine receptors of skeletal and cardiac muscle, or brain cortex neurons, was examined. In lipid bilayer experiments, oxidizing agents (2,2'-dithiodipyridine or thimerosal modified the calcium dependence of all single channels studied. After controlled oxidation channels became active at sub µM calcium concentrations and were not inhibited by increasing the calcium concentration to 0.5 mM. Subsequent reduction reversed these effects. Channels purified from amphibian skeletal muscle exhibited the same behavior, indicating that the SH groups responsible for modifying the calcium dependence belong to the channel protein. Parallel experiments that measured calcium release through these channels in sarcoplasmic reticulum vesicles showed that following oxidation, the channels were no longer inhibited by sub mM concentrations of Mg2+. It is proposed that channel redox state controls the high affinity sites responsible for calcium activation as well as the low affinity sites involved in Mg2+ inhibition of channel activity. The possible physiological and pathological implications of these results are discussed

Timing and control requirements for a 32-channel AMU-ADC ASIC for the PHENIX detector

International Nuclear Information System (INIS)

Emery, M.S.; Ericson, M.N.; Britton, C.L. Jr.

1998-01-01

A custom CMOS Application Specific Integrated Circuit (ASIC) has been developed consisting of an analog memory unit (AMU) has been developed consisting of an analog memory unit (AMU) and analog to digital converter (ADC), both of which have been designed for applications in the PHENIX experiment. This IC consists of 32 pipes of analog memory with 64 cells per pipe. Each pipe also has its own ADC channel. Timing and control signal requirements for optimum performance are discussed in this paper

Finite element analysis of BWR fuel channel buckling during a seismic event

International Nuclear Information System (INIS)

Kinoshita, Mika; Iwamoto, Yuji; Ledford, Kevin; Cantonwine, Paul

2014-01-01

This paper documents the predicted response of three BWR fuel channel designs in bending using a typical moment profile for GNF fuel designs. The bending performance of the fuel channel is predicted using ANSYS, a finite element modeling tool. Specifically, linear and non-linear buckling analyses were performed to determine the onset of elastic buckling, which causes a wavy structure on the compression face in bending that might also increase channel – control blade friction, and to determine to onset of channel collapse, which causes permanent deformation and would inhibit control rod insertion. The three channel designs considered in this paper are the 0.080 inch uniform channel, the 0.100 inch uniform channel and the 0.120 inch uniform channel at the beginning of fuel life (BOL) and at the end of fuel life (EOL). (author)

Boundary Layer Transition, Separation and Flow Control on Airfoils, Wings and Bodies in CFD, Wind-Tunnel and In-Flight Studies

Czech Academy of Sciences Publication Activity Database

Popelka, Lukáš; Matějka, M.; Šimurda, David; Součková, Natálie

2011-01-01

Roč. 35, č. 4 (2011), s. 97-104 ISSN 0744-8996 R&D Projects: GA MŠk(CZ) 1M06031; GA AV ČR IAA2076403; GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : airfoil * wing-fuselage interaction * flow control Subject RIV: BK - Fluid Dynamics

De Novo collapsing glomerulopathy in renal allograft in association with BK virus nephropathy in a child and stabilization of renal function by elimination of viremia

Directory of Open Access Journals (Sweden)

D N Gera

2017-01-01

Full Text Available Well-recognized association between HIV 1 infection and collapsing glomerulopathy (CG raises the possibility that intrarenal infection by other viruses may also contribute to the development of this lesion in native or post-transplant kidneys. There is evidence in literature about association of these lesions with cytomegalovirus, Epstein–Barr virus, hepatitis C virus, and parvovirus B19 infections. Here, we present a case report of post-transplant BK virus nephropathy in a male child who was found to have CG in subsequent biopsy 2 months later. His renal function and proteinuria were stabilized on elimination of viremia.

DETAILS OF OPERATIONS PERFORMED BY THE REMOTE CONTROL ROBOT (CONCEPT TO THE HORIZONTAL FUEL CHANNEL DURING DECOMMISSIONING PHASE OF NUCLEAR REACTOR CALANDRIA STRUCTURE. PART II: INSIDE OPERATIONS

Directory of Open Access Journals (Sweden)

Constantin POPESCU

2017-05-01

Full Text Available The authors contribution to this paper is to present a concept solution of a remote control robot (RCR used for decommissioning of the horizontal fuel channels pressure tube in the CANDU nuclear reactor. In this paper the authors highlight few details of geometry, operations, constraints by kinematics and dynamics of the robot movement inside of the reactor fuel channel. Inside operations performed has as the main steps of dismantling process the followings: unblock and extract the channel closure plug (from End Fitting - EF, unblock and extract the channel shield plug (from Lattice Tube - LT, cut the ends of the pressure tube, extract the pressure tube and cut it in small parts, sorting and storage extracted items in the safe robot container. All steps are performed in automatic mode. The remote control robot (RCR represents a safety system controlled by sensors and has the capability to analyze any error registered and decide next activities or abort the inside decommissioning procedure in case of any risk rise in order to ensure the environmental and workers protection.

Inactivation as a new regulatory mechanism for neuronal Kv7 channels

DEFF Research Database (Denmark)

Jensen, Henrik Sindal; Grunnet, Morten; Olesen, Søren-Peter

2007-01-01

neuronal channels and are important for controlling excitability. Kv7.1 channels have been considered the only Kv7 channels to undergo inactivation upon depolarization. However, here we demonstrate that inactivation is also an intrinsic property of Kv7.4 and Kv7.5 channels, which inactivate to a larger...