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Sample records for blms algirdas zukauskas

  1. Cyclic voltammetry of supported BLMs

    Science.gov (United States)

    Murgasova, Renata; Sabo, Jan; Ottova, Angelica L.; Tien, H. T.

    1996-06-01

    The transfer of an electron across a bilayer lipid membrane (BLM) is one of the BLMs most exciting processes. A number of well known electron mediators have been investigated using the method of cyclic voltammetry on a Teflon coated platinum wire, the tip of which has been modified by a self-assembled bilayer lipid membrane (s-BLM). The electrical capacitance of the s-BLM system was measured as a function of frequency. The results are discussed in terms of electron transfer and redox reactions.

  2. Leedus saadeti viimsele teekonnale ekspresident Algirdas Brazauskas

    Index Scriptorium Estoniae

    2010-01-01

    Vabariigi President Leedu endise riigipea Algirdas Brazauskase matustel Vilniuses 01.07.2010. Ilmunud ka: Õhtuleht 2. juuli 2010, lk. 9, pealk.: Leedu saatis viimsele teekonnale ekspresident Brazauskase

  3. Algirdas Brazauskas lubab Leedule uusi paremaid radareid / Algirdas Brazauskas ; interv. Toomas Sildam

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2005-01-01

    Leedu peaminister Algirdas Brazauskas vastab küsimustele, mis puudutavad Vene hävitaja allakukkumist Kaunase lähedal, õhujõudude juhataja kolonel Jonas Marcinkuse vabastamist ning Leedu õhuruumi turbe piisavust ja parandamise vajalikkust. Lisa: Vene hävitaja Leedus. Vt. samas: Balti riigid tahavad Schengeni leppega liituda 2007. aastal

  4. Algirdas Brazauskas lubab Leedule uusi paremaid radareid / Algirdas Brazauskas ; interv. Toomas Sildam

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2005-01-01

    Leedu peaminister Algirdas Brazauskas vastab küsimustele, mis puudutavad Vene hävitaja allakukkumist Kaunase lähedal, õhujõudude juhataja kolonel Jonas Marcinkuse vabastamist ning Leedu õhuruumi turbe piisavust ja parandamise vajalikkust. Lisa: Vene hävitaja Leedus. Vt. samas: Balti riigid tahavad Schengeni leppega liituda 2007. aastal

  5. Self-assembled and supported BLMs as a smart system for biosensors

    Science.gov (United States)

    Ottova, Angelica L.; Hianik, T.; Ziegler, W.; Tvarozek, Vladimir; Sabo, Jan; Passechnik, Victor I.; Ivanov, S. A.; Tien, H. Ti

    1997-06-01

    In the last few years there have been a number of research papers on self-assemblies of molecules as 'advanced materials' or 'smart sensors'. The inspiration for this exciting research, without question, comes from the biological world, where, for example, the lipid bilayer of the cell membrane is the most important self-assembling system. Although the first report on self-assembled bilayer lipid membranes (BLMs) in vitro was published in 1962, interface science including surface and colloid science has been dealing with these interfacial self-assemblies of amphophilic molecules since Robert Hooke's time. In this communication, we present results of extensive study of physical chemical properties of two new membrane systems: metal and hydrogel supported bilayer lipid membranes. Several methods have been sued to investigate the properties of these metal supported s-BLMs and hydrogel supported salt- bridge sb-BLMs. With the electrostriction method we observed different behavior of the planar lipid bilayer on metal substrate. The obtained results gave possibility to choose optical properties of the support for constructing s-BLM- based biosensors. The capacitance relaxation method was used to determine the changes of dielectric relaxation times and showed different dynamic proprieties of lipids on the metal substrate and in free standing BLMs. Analysis of membrane current noise allowed the examination of the dynamic properties of supported BLMs. Examples of a number of practical applications of s-BLMs for the construction of a glucose sensor for biomedical use as well as applications of agar supported BLMs for determining several toxins will be presented.

  6. Zur aktuellen Lage der semiotischen Forschung. : Algirdas Julien Greimas im Gespräch mit Peter Stockinger

    OpenAIRE

    1983-01-01

    International audience; Interview mit Algirdas Julien Greimas, realisiert im April 1983 in Paris. In diesem Interview werden folgende Themen diskutiert: 1) Präsentation der "Pariser Schule" der Semiotik durch Greimas. 2) Platz der Bedutungssemiotik innerhalb der verschiedenen semiotischen Forschungsrichtungen. 3) Die zentralen Modelle der Bedeutungssemiotik: narrative Syntax, modale Syntax, narratives Schema, Aussageweise (Enunziation) und Aussage; Diskurs. 4) Semiotik als transdisziplinäre M...

  7. ECG De-noising: A comparison between EEMD-BLMS and DWT-NN algorithms.

    Science.gov (United States)

    Kærgaard, Kevin; Jensen, Søren Hjøllund; Puthusserypady, Sadasivan

    2015-08-01

    Electrocardiogram (ECG) is a widely used non-invasive method to study the rhythmic activity of the heart and thereby to detect the abnormalities. However, these signals are often obscured by artifacts from various sources and minimization of these artifacts are of paramount important. This paper proposes two adaptive techniques, namely the EEMD-BLMS (Ensemble Empirical Mode Decomposition in conjunction with the Block Least Mean Square algorithm) and DWT-NN (Discrete Wavelet Transform followed by Neural Network) methods in minimizing the artifacts from recorded ECG signals, and compares their performance. These methods were first compared on two types of simulated noise corrupted ECG signals: Type-I (desired ECG+noise frequencies outside the ECG frequency band) and Type-II (ECG+noise frequencies both inside and outside the ECG frequency band). Subsequently, they were tested on real ECG recordings. Results clearly show that both the methods works equally well when used on Type-I signals. However, on Type-II signals the DWT-NN performed better. In the case of real ECG data, though both methods performed similar, the DWT-NN method was a slightly better in terms of minimizing the high frequency artifacts.

  8. Blm-s, a BH3-Only Protein Enriched in Postmitotic Immature Neurons, Is Transcriptionally Upregulated by p53 during DNA Damage

    Directory of Open Access Journals (Sweden)

    Wei-Wen Liu

    2014-10-01

    Full Text Available Programmed cell death is a pivotal process that regulates neuronal number during development. Key regulators of this process are members of the BCL-2 family. Using mRNA differential display, we identified a Bcl-2 family gene, Blm-s (Bcl-2-like molecule, short form, enriched in postmitotic neurons of the developing cerebral cortex. BLM-s functions as a BH3-only apoptosis sensitizer/derepressor and causes BAX-dependent mitochondria-mediated apoptosis by selectively binding to prosurvival BCL-2 or MCL-1. When challenged with γ-irradiation that produces DNA double-strand breaks (DSBs, Blm-s is transcriptionally upregulated in postmitotic immature neurons with concurrently increased apoptosis. RNAi-mediated depletion of Blm-s protects immature neurons from irradiation-induced apoptosis. Furthermore, Blm-s is a direct target gene of p53 and AP1 via the ataxia telangiectasia mutated (ATM- and c-Jun N-terminal kinase (JNK-signaling pathways activated by DSBs. Thus, BLM-s is likely an apoptosis sensor activated by DSBs accumulating in postmitotic immature neurons.

  9. Algirdas Brazauskas : Ma ei häbene rahvale oma liini näidata / Algirdas Brazauskas ; interv. Sirje Pärismaa

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2001-01-01

    Taasiseseisvunud Leedu esimene president oma ametiaja suurimatest saavutustest, oma edu saladusest, muutustest Leedu ühiskonnas, Balti riikide ühtsusest, Leedu-Vene suhetest, kokkupuudetest Eestiga jm. Eluloolisi andmeid

  10. Algirdas Brazauskas : Ma ei häbene rahvale oma liini näidata / Algirdas Brazauskas ; interv. Sirje Pärismaa

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2001-01-01

    Taasiseseisvunud Leedu esimene president oma ametiaja suurimatest saavutustest, oma edu saladusest, muutustest Leedu ühiskonnas, Balti riikide ühtsusest, Leedu-Vene suhetest, kokkupuudetest Eestiga jm. Eluloolisi andmeid

  11. Estimation of Threshold for the Signals of the BLMs around the LHC Final Focus Triplet Magnets

    CERN Document Server

    Cerutti, F; Ferrari, A; Hoa, C; Mauri, M; Mereghetti, A; Sapinski, M; Wildner, E; CERN. Geneva. ATS Department

    2012-01-01

    The Interaction Points of the Large Hadron Collider are the regions where the two circulating beams collide. Hence, the magnets the closest to any Interaction Point are exposed to an elevated radiation field due to the collision debris. In this study the signal in the Beam Loss Monitors due to the debris is estimated. In addition, for three different scenarios of beam losses, the energy density in the coils and the signal in the Beam Loss Monitors at quench are computed. It is shown that the Beam Loss Monitors, as presently installed on the vacuum vessel of the magnets, cannot disentangle the signal due to a localised loss from the constant signal due to the debris in case of steady-state losses.

  12. Tethered bilayer lipid membranes (tBLMs): interest and applications for biological membrane investigations.

    Science.gov (United States)

    Rebaud, Samuel; Maniti, Ofelia; Girard-Egrot, Agnès P

    2014-12-01

    Biological membranes play a central role in the biology of the cell. They are not only the hydrophobic barrier allowing separation between two water soluble compartments but also a supra-molecular entity that has vital structural functions. Notably, they are involved in many exchange processes between the outside and inside cellular spaces. Accounting for the complexity of cell membranes, reliable models are needed to acquire current knowledge of the molecular processes occurring in membranes. To simplify the investigation of lipid/protein interactions, the use of biomimetic membranes is an approach that allows manipulation of the lipid composition of specific domains and/or the protein composition, and the evaluation of the reciprocal effects. Since the middle of the 80's, lipid bilayer membranes have been constantly developed as models of biological membranes with the ultimate goal to reincorporate membrane proteins for their functional investigation. In this review, after a brief description of the planar lipid bilayers as biomimetic membrane models, we will focus on the construction of the tethered Bilayer Lipid Membranes, the most promising model for efficient membrane protein reconstitution and investigation of molecular processes occurring in cell membranes. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Towards simultaneous electrical and optical investigation of BLMS using a novel microfluidic device

    NARCIS (Netherlands)

    Uitert, van Iris; Cesa, Yanina; Boer, de Hans; Bomer, Johan; Bennink, Martin; Le Gac, Séverine; Berg, van den Albert; Locascio, L.E.; Gaitan, M.; Paegel, B.M.; Ross, D.J.; Vreeland, W.N.

    2008-01-01

    We firstly describe the influence of the phospholipid (PL) composition of bilayer lipid membrane on their electrical properties: (i) the more unsaturations in the tail, the earlier the BLM breakdown and (ii) the bulkier the head group, the less stable the membrane. Secondly, we design and fabricate

  14. Estimation of thresholds for the signals of the BLMs around the LHC final focus triplet magnets

    CERN Document Server

    Sapinski, M; Dehning, B; Ferrari, A; Hoa, C; Lechner, A; Mauri, M; Mereghetti, A

    2012-01-01

    The Interaction Points of the Large Hadron Collider are the regions where the two circulating beams collide. Hence, the magnets closest to any Interaction Point are exposed to an elevated radiation field due to the collision debris. In this study the signal in the Beam Loss Monitors due to the debris is estimated and compared with the measurements. In addition, the energy density in the coils and the signal in the Beam Loss Monitors at quench are estimated for a beam loss scenario. It is shown that the Beam Loss Monitors, as presently installed on the vacuum vessel of the magnets, cannot disentangle the signal due to a localized loss from the constant signal due to the debris in case of steady-state losses.

  15. Projektõ porta Klaipeda / Algirdas Kamarauskas, Lina Gudelionite-Giliene

    Index Scriptorium Estoniae

    Kamarauskas, Algirdas

    2000-01-01

    Klaipeda sadama sissesõidukanali rekonstrueerimine, stividorifirma Smelta asukoha nihutamine, kalasadama ehitamine jm. plaanid. Konkurentsis püsimise eelised, spetsialiseerumine, vabasadama staatuse saavutamine, muud investeeringud sadama arendamisse

  16. JeS - dengi k dengam / Algirdas Brazauskas ; interv. Ilja Nikiforov

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2005-01-01

    Leedu peaministri sõnul ei ole nüüd, kui EL-is hakati valmistuma uueks finantsperioodiks, tunda euroliidu humanitaarseid ideid aidata alliansi riike sõltuvalt nende arengutasemest, ei ole tunda eelkõige EL-i vanade riikide tähelepanu ega solidaarsusidee realiseerumist

  17. 76 FR 4940 - Algirdas J. Krisciunas, M.D.; Revocation of Registration

    Science.gov (United States)

    2011-01-27

    ... a pain clinic which was owned by his wife, Maria Bulich, and which did business under the name of... ``show the drugs the patient has been receiving''). Registrant stated that this was because state regulations required that a chronic pain patient first undergo a thirty-day regimen with non- controlled...

  18. JeS - dengi k dengam / Algirdas Brazauskas ; interv. Ilja Nikiforov

    Index Scriptorium Estoniae

    Brazauskas, Algirdas, 1932-2010

    2005-01-01

    Leedu peaministri sõnul ei ole nüüd, kui EL-is hakati valmistuma uueks finantsperioodiks, tunda euroliidu humanitaarseid ideid aidata alliansi riike sõltuvalt nende arengutasemest, ei ole tunda eelkõige EL-i vanade riikide tähelepanu ega solidaarsusidee realiseerumist

  19. A comprehensive performance analysis of EEMD-BLMS and DWT-NN hybrid algorithms for ECG denoising

    DEFF Research Database (Denmark)

    Kærgaard, Kevin; Jensen, Søren Hjøllund; Puthusserypady, Sadasivan

    2016-01-01

    Electrocardiogram (ECG) is a widely used non-invasive method to study the rhythmic activity of theheart. These signals, however, are often obscured by artifacts/noises from various sources and mini-mization of these artifacts is of paramount importance for detecting anomalies. This paper presents......), named the Wavelet NN (WNN)) for denoising the ECG signals. These methods arecompared to the conventional EMD (C-EMD), C-EEMD, EEMD-LMS as well as the DWT thresholding(DWT-Th) based methods through extensive simulation studies on real as well as noise corrupted ECGsignals. Results clearly show...

  20. Kurss na konteinernõje perevozki / Ainars Shlesers, Algirdas Butkevičius, Edgar Savisaar ; interv. Olga Pavuk

    Index Scriptorium Estoniae

    Shlesers, Ainars

    2007-01-01

    Baltimaade transpordiministrite 2006. aasta - millised ministeeriumi algatused on transpordile mõju avaldanud, olulisemad projektid. Hinnang Läti vabamajandustsoonide mõjule ning Venemaa ühinemisele WTOga

  1. Actant Pattern in Some of Masnavi's Theological Narratives (Based on Algirdas Greimas’ Theory of Actant Pattern

    Directory of Open Access Journals (Sweden)

    j Moshayedi

    2011-09-01

    Greimas believes his actant pattern is universal and compatible with any kind of narrative. On the other hand, the theme of narrative can somehow affect its structure. In this article, with respect to universality of Greimas’ pattern and its compatibility with any kind of narrative, some narratives of first and second book of Masnavi which have theological theme were selected to show what would happen during the confrontation of theological narratives and actant pattern as a part of structure, and through this confrontation a new window will be opened so that we can gain a novel and different view about some of theological narratives of Masnavi. What is emphasized as the result of this research are changes which take place due to the theological theme of narratives, especially in the action area of halter and helper. Proportional to their theological ideas, actants are sometimes aware of these changes and sometimes act unconsciously. Also, on the basis of Greimas’ theory and Actions Monotheism idea, the fundamental binary opposition in selected narratives of Man and God is considered as the real and unreal subjects whose objects can be in the same or opposite direction.

  2. Balti peaministrid unistavad kiirrongist / Toomas Sildam

    Index Scriptorium Estoniae

    Sildam, Toomas, 1961-

    2003-01-01

    Baltimaade peaministrite Algirdas Brazauskase, Einars Repshe ja Siim Kallase kohtumisest Kalvi mõisas. Arutlusest Helsingi-Berliini raudteeliini üle. Vt. samas lühiintervjuud Leedu peaministri Algirdas Brazauskasega: Brazauskas: Ignalina tulevik on kaalukausil

  3. A president's funeral / Rokas M. Tracevskis

    Index Scriptorium Estoniae

    Tracevskis, Rokas M.

    2010-01-01

    Leedu endise presidendi Algirdas Brazauskase matustest 1. juulil 2010 Vilniuses võttis osa ka president Toomas Hendrik Ilves. Konfliktist katoliku kiriku esindajatega, kes ei tahtnud lubada Algirdas Brazauskase kirstu toomist Vilniuse katedraali

  4. Balti peaministrid unistavad kiirrongist / Toomas Sildam

    Index Scriptorium Estoniae

    Sildam, Toomas, 1961-

    2003-01-01

    Baltimaade peaministrite Algirdas Brazauskase, Einars Repshe ja Siim Kallase kohtumisest Kalvi mõisas. Arutlusest Helsingi-Berliini raudteeliini üle. Vt. samas lühiintervjuud Leedu peaministri Algirdas Brazauskasega: Brazauskas: Ignalina tulevik on kaalukausil

  5. The development of logistics centres : important factor of increasing transport sector efficiency = Razvitije logistitsheskihh tsentrov : vazhnõi faktor uvelitshenija effektivnosti transportnogo sektora / Algirdas Sakalys

    Index Scriptorium Estoniae

    Sakalys, Algirdas

    2003-01-01

    Ettekanne 3.-4. detsembrini 2003 Tallinnas toimunud rahvusvahelisel konverents-näitusel "Logistics and transport in international trade" teeb ülevaate Leedu transpordisüsteemi olukorrast, arengustrateegiast ja reformidest, lähtudes Euroopa Liidu transpordipoliitika tegevuskavast. Kaardid. Diagramm. Tabel

  6. The development of logistics centres : important factor of increasing transport sector efficiency = Razvitije logistitsheskihh tsentrov : vazhnõi faktor uvelitshenija effektivnosti transportnogo sektora / Algirdas Sakalys

    Index Scriptorium Estoniae

    Sakalys, Algirdas

    2003-01-01

    Ettekanne 3.-4. detsembrini 2003 Tallinnas toimunud rahvusvahelisel konverents-näitusel "Logistics and transport in international trade" teeb ülevaate Leedu transpordisüsteemi olukorrast, arengustrateegiast ja reformidest, lähtudes Euroopa Liidu transpordipoliitika tegevuskavast. Kaardid. Diagramm. Tabel

  7. Lehti Kostabi - Carmeni flamenkotantsija / Lehti Kostabi ; interv. Kai Ilustrumm

    Index Scriptorium Estoniae

    Kostabi, Lehti

    2005-01-01

    Flamenkotantsu õpetajast ja Rahvusooperis Estonia 27. ja 30.apr.etenduvas G. Bizet' ooperis "Carmen" tantsivast Lehti Kostabist (ooperi peaosades Helen Lokuta Carmenina ja Algirdas Janutas Don Josena)

  8. Baseline Goblet Cell Mucin Secretion in the Airways Exceeds Stimulated Secretion over Extended Time Periods, and Is Sensitive to Shear Stress and Intracellular Mucin Stores.

    Directory of Open Access Journals (Sweden)

    Yunxiang Zhu

    Full Text Available Airway mucin secretion studies have focused on goblet cell responses to exogenous agonists almost to the exclusion of baseline mucin secretion (BLMS. In human bronchial epithelial cell cultures (HBECCs, maximal agonist-stimulated secretion exceeds baseline by ~3-fold as measured over hour-long periods, but mucin stores are discharged completely and require 24 h for full restoration. Hence, over 24 h, total baseline exceeds agonist-induced secretion by several-fold. Studies with HBECCs and mouse tracheas showed that BLMS is highly sensitive to mechanical stresses. Harvesting three consecutive 1 h baseline luminal incubations with HBECCs yielded equal rates of BLMS; however, lengthening the middle period to 72 h decreased the respective rate significantly, suggesting a stimulation of BLMS by the gentle washes of HBECC luminal surfaces. BLMS declined exponentially after washing HBECCs (t1/2 = 2.75 h, to rates approaching zero. HBECCs exposed to low perfusion rates exhibited spike-like increases in BLMS when flow was jumped 5-fold: BLMS increased >4 fold, then decreased within 5 min to a stable plateau at 1.5-2-fold over control. Higher flow jumps induced proportionally higher BLMS increases. Inducing mucous hyperplasia in HBECCs increased mucin production, BLMS and agonist-induced secretion. Mouse tracheal BLMS was ~6-fold higher during perfusion, than when flow was stopped. Munc13-2 null mouse tracheas, with their defect of accumulated cellular mucins, exhibited similar BLMS as WT, contrary to predictions of lower values. Graded mucous metaplasia induced in WT and Munc13-2 null tracheas with IL-13, caused proportional increases in BLMS, suggesting that naïve Munc13-2 mouse BLMS is elevated by increased mucin stores. We conclude that BLMS is, [i] a major component of mucin secretion in the lung, [ii] sustained by the mechanical activity of a dynamic lung, [iii] proportional to levels of mucin stores, and [iv] regulated differentially from agonist

  9. Happy anniversary to the Baltic Charter!

    Index Scriptorium Estoniae

    2014-01-01

    16. jaanuaril 1998 allkirjastasid Balti riikide presidendid ja USA president Washingtonis USA-Balti partnerlusharta. Foto: Läti president Guntis Ulmanis, USA president Clinton, Eesti president Lennart Meri ja Leedu president Algirdas Brazauskas Valges Majas. (AP foto)

  10. Brazauskas ja ärieliit tõusid Paksase vastu / Kaarel Kaas

    Index Scriptorium Estoniae

    Kaas, Kaarel, 1978-

    2003-01-01

    Leedu peaministri Algirdas Brazauskase raadiokõnest, milles ta soovitas president Rolandas Paksasel tagasi astuda. Vt. samas: Valik president Rolandas Paksase ümber puhkenud skandaali peategelasi; Skandaali kronoloogia

  11. Brazauskas : Let's wait and see on Yukos

    Index Scriptorium Estoniae

    2004-01-01

    Leedu peaminister Algirdas Brazauskas kutsus 5. juunil 2004 leedulasi üles säilitama rahu seoses Leedu suurima ettevõtte Mazheikiu Nafta omaniku Jukos majandusraskuste ja võimaliku pankrotistumisega

  12. Insurance bankruptcy creates political storm

    Index Scriptorium Estoniae

    2005-01-01

    Hoolimata peaminister Algirdas Brazauskase nõudmisest, keeldus Leedu kindlustusinspektsiooni juht Edvinas Vasilis-Vasiliauskas oma kohalt tagasi astumast, kuna soovib viia lõpule kindlustusseltsi Ingo Baltic pankrotiprotsessi

  13. Insurance bankruptcy creates political storm

    Index Scriptorium Estoniae

    2005-01-01

    Hoolimata peaminister Algirdas Brazauskase nõudmisest, keeldus Leedu kindlustusinspektsiooni juht Edvinas Vasilis-Vasiliauskas oma kohalt tagasi astumast, kuna soovib viia lõpule kindlustusseltsi Ingo Baltic pankrotiprotsessi

  14. MPs vote to investigate PM Brazauskas' family business / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu parlament hääletas uurimiskomisjoni loomise poolt, mis hakkab uurima peaminister Algirdas Brazauskase perekonna äritegevust. Peaminister on varem teatanud, et ei anna tunnistusi, kui selline komisjon luuakse ning võib isegi tagasi astuda

  15. Adamkus says security agencies should examine Brazauskas' family business / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu president Valdas Adamkus teatas oma kõnes, et peaminister Algirdas Barzauskase pereäri ümber tekkinud skandaali tagamaid ja süüdistusi peaksid uurima õiguskaitse institutsioonid, mitte poliitikud

  16. Letopis v ordenahh / Vladimir Fridljand

    Index Scriptorium Estoniae

    Fridljand, Vladimir

    2004-01-01

    Näitusest Leedu riiklikud teenetemärgid Vilius Kavaliauskase kollektsioonist, näituse avamisel Eesti Rahvusraamatukogus viibisid ka Leedu peaminister Algirdas Brazauskas ja EV president Arnold Rüütel

  17. Brazauskas address doesn't live up to expectations / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu peaminister Algirdas Brazauskas pidas oma televisiooniesinemises tema vastu esitatud süüdistusi õigustamatuteks. Nii koalitsioon kui opositsioon kritiseerisid peaministri kõnet, kuna ta ei vastanud varem esitatud küsimustele, vaid pidas monoloogi

  18. Adamkus says security agencies should examine Brazauskas' family business / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu president Valdas Adamkus teatas oma kõnes, et peaminister Algirdas Barzauskase pereäri ümber tekkinud skandaali tagamaid ja süüdistusi peaksid uurima õiguskaitse institutsioonid, mitte poliitikud

  19. MPs vote to investigate PM Brazauskas' family business / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu parlament hääletas uurimiskomisjoni loomise poolt, mis hakkab uurima peaminister Algirdas Brazauskase perekonna äritegevust. Peaminister on varem teatanud, et ei anna tunnistusi, kui selline komisjon luuakse ning võib isegi tagasi astuda

  20. Brazauskas address doesn't live up to expectations / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Leedu peaminister Algirdas Brazauskas pidas oma televisiooniesinemises tema vastu esitatud süüdistusi õigustamatuteks. Nii koalitsioon kui opositsioon kritiseerisid peaministri kõnet, kuna ta ei vastanud varem esitatud küsimustele, vaid pidas monoloogi

  1. A comparative study between the two biotic ligand models (BLMs) on predicting the acute Zn toxicity to Daphnia magna%两种生物配体模型(BLM)预测Zn对大型蚤急性毒性的比较

    Institute of Scientific and Technical Information of China (English)

    陈中智; 朱琳; 姚琨; 李燕; 刘硕

    2008-01-01

    通过天津地区一系列景观水体和配制的模拟溶液,评价应用于大型蚤(Daphnia magna)毒性预测的两种急性Zn-生物配体(BLM)模型(模型A和模型B)的预测能力.采用Visual MINTEQ 2.5.2进行BLM的相关计算和金属形态分析.对一定水化学参数的测定表明,根据Zn对大型蚤的急性毒性数据建立的模型B能够在Zn的生态风险评价中考虑其生物有效性,预测结果准确;以鱼类为对象开发并下调LA50后应用于水蚤毒性预测的模型A的预测值普遍高于实测值.可见,通过调整LA50拓展模型适用性的方法过于简单,还有待进一步研究.

  2. Facilitated catecholamine transport through bulk and polymer-supported liquid membranes

    NARCIS (Netherlands)

    Paugam, Marie-France; Bien, Jeffrey T.; Smith, Bradley D.; Chrisstoffels, L.A.J.; de Jong, Feike; Reinhoudt, David

    1996-01-01

    A series of crown boronic acids, 1-4, were synthesized and studied as carriers for catecholamine transport through bulk liquid membranes (BLMs) and supported liquid membranes (SLMs). Carrier 1 greatly facilitated the transport of primary catecholamines through BLMs; whereas, the more lipophilic anal

  3. The Baltic Presidents and prime Ministers to the UN Secretary General, H.E. Mr. Boutros Boutros Ghali

    Index Scriptorium Estoniae

    1993-01-01

    Balti presidentide ja peaministrite pöördumine ÜRO peasekretäri poole seoses Vene vägede väljaviimisega Balti riikidest. Meri, Lennart; Laar, Mart; Ulmanis, Guntis; Birkavs, Valdis; Brazauskas, Algirdas; Slezevicius, Adolfas

  4. Mazeikiu refinery goes on the defensive

    Index Scriptorium Estoniae

    2005-01-01

    20% Mazeikiu Nafta kasumist moodustab kütusemüügist teenitav tulu ja 80% teenib ettevõte äritegevusest Ameerika Ühendriikide, Lääne-Euroopa, Poola, Eesti ja Lätiga. Leedu peaminister Algirdas Brazauskas kritiseeris ettevõtet kõrgete hindade tõttu

  5. Mazeikiu refinery goes on the defensive

    Index Scriptorium Estoniae

    2005-01-01

    20% Mazeikiu Nafta kasumist moodustab kütusemüügist teenitav tulu ja 80% teenib ettevõte äritegevusest Ameerika Ühendriikide, Lääne-Euroopa, Poola, Eesti ja Lätiga. Leedu peaminister Algirdas Brazauskas kritiseeris ettevõtet kõrgete hindade tõttu

  6. Labor's charm wins over countryside / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Küsitluste järgi on Leedu Tööpartei toetus elanike seas tõusnud 25,3 protsendini. Juhul kui praegune peaminister Algirdas Brazauskas peaks skandaali tõttu ametist tagasi astuma, kavatseb sellele kohale kandideerida Tööpartei esimees Viktor Uspaskihh

  7. The Baltic Presidents and prime Ministers to the UN Secretary General, H.E. Mr. Boutros Boutros Ghali

    Index Scriptorium Estoniae

    1993-01-01

    Balti presidentide ja peaministrite pöördumine ÜRO peasekretäri poole seoses Vene vägede väljaviimisega Balti riikidest. Meri, Lennart; Laar, Mart; Ulmanis, Guntis; Birkavs, Valdis; Brazauskas, Algirdas; Slezevicius, Adolfas

  8. Labor's charm wins over countryside / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Küsitluste järgi on Leedu Tööpartei toetus elanike seas tõusnud 25,3 protsendini. Juhul kui praegune peaminister Algirdas Brazauskas peaks skandaali tõttu ametist tagasi astuma, kavatseb sellele kohale kandideerida Tööpartei esimees Viktor Uspaskihh

  9. PM Brazauskas strikes back - unsuccessfully / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Peaprokurör keeldus juhtumit uurimast, kui Leedu peaminister Algirdas Brazauskas pöördus prokuröri poole, et uuritaks tema perekonna süüdistamist ja laimamist. Konservatiivide partei kahtlustab, et Brazauskase abikaasa Kristina Brazauskiene on oma hotelliäri tõttu seotud Lukoil Baltija juhiga, kes on huvitatud Mazeikiu Nafta ostmisest

  10. PM Brazauskas strikes back - unsuccessfully / Milda Seputyte

    Index Scriptorium Estoniae

    Seputyte, Milda

    2005-01-01

    Peaprokurör keeldus juhtumit uurimast, kui Leedu peaminister Algirdas Brazauskas pöördus prokuröri poole, et uuritaks tema perekonna süüdistamist ja laimamist. Konservatiivide partei kahtlustab, et Brazauskase abikaasa Kristina Brazauskiene on oma hotelliäri tõttu seotud Lukoil Baltija juhiga, kes on huvitatud Mazeikiu Nafta ostmisest

  11. Fractional polymerization of a suspended planar bilayer creates a fluid, highly stable membrane for ion channel recordings.

    Science.gov (United States)

    Heitz, Benjamin A; Jones, Ian W; Hall, Henry K; Aspinwall, Craig A; Saavedra, S Scott

    2010-05-26

    Suspended planar lipid membranes (or black lipid membranes (BLMs)) are widely used for studying reconstituted ion channels, although they lack the chemical and mechanical stability needed for incorporation into high-throughput biosensors and biochips. Lipid polymerization enhances BLM stability but is incompatible with ion channel function when membrane fluidity is required. Here, we demonstrate the preparation of a highly stable BLM that retains significant fluidity by using a mixture of polymerizable and nonpolymerizable phospholipids. Alamethicin, a voltage-gated peptide channel for which membrane fluidity is required for activity, was reconstituted into mixed BLMs prepared using bis-dienoyl phosphatidylcholine (bis-DenPC) and diphytanoyl phosphatidylcholine (DPhPC). Polymerization yielded BLMs that retain the fluidity required for alamethicin activity yet are stable for several days as compared to a few hours prior to polymerization. Thus, these polymerized, binary composition BLMs feature both fluidity and long-term stability.

  12. A reusable device for electrochemical applications of hydrogel supported black lipid membranes

    DEFF Research Database (Denmark)

    Mech-Dorosz, Agnieszka; Heiskanen, Arto; Bäckström, Sania

    2015-01-01

    Black lipid membranes (BLMs) are significant in studies of membrane transport, incorporated proteins/ion transporters, and hence in construction of biosensor devices. Although BLMs provide an accepted mimic of cellular membranes, they are inherently fragile. Techniques are developed to stabilize...... of the gold electrode microchips and plasma modification of the ETFE aperture arrays facilitating covalent "sandwiching" of the hydrogel. Both fluorescence microscopy and EIS were used to demonstrate the induced spontaneous thinning of a deposited lipid solution, leading to formation of stabilized hs......BLMs on average in 10 min. The determined specific membrane capacitance and resistance were shown to vary in the range 0.31-0.49 mu F/cm2 and 45-65 k Omega cm2, respectively, corresponding to partially solvent containing BLMs with an average life time of 60-80 min. The characterized hsBLM formation and devised...

  13. Polymerized planar suspended lipid bilayers for single ion channel recordings: comparison of several dienoyl lipids.

    Science.gov (United States)

    Heitz, Benjamin A; Xu, Juhua; Jones, Ian W; Keogh, John P; Comi, Troy J; Hall, Henry K; Aspinwall, Craig A; Saavedra, S Scott

    2011-03-01

    The stabilization of suspended planar lipid membranes, or black lipid membranes (BLMs), through polymerization of mono- and bis-functionalized dienoyl lipids was investigated. Electrical properties, including capacitance, conductance, and dielectric breakdown voltage, were determined for BLMs composed of mono-DenPC, bis-DenPC, mono-SorbPC, and bis-SorbPC both prior to and following photopolymerization, with diphytanoyl phosphocholine (DPhPC) serving as a control. Poly(lipid) BLMs exhibited significantly longer lifetimes and increased the stability of air-water transfers. BLM stability followed the order bis-DenPC > mono-DenPC ≈ mono-SorbPC > bis-SorbPC. The conductance of bis-SorbPC BLMs was significantly higher than that of the other lipids, which is attributed to a high density of hydrophilic pores, resulting in relatively unstable membranes. The use of poly(lipid) BLMs as matrices for supporting the activity of an ion channel protein (IC) was explored using α-hemolysin (α-HL), a model IC. Characteristic i-V plots of α-HL were maintained following photopolymerization of bis-DenPC, mono-DenPC, and mono-SorbPC, demonstrating the utility of these materials for preparing more durable BLMs for single-channel recordings of reconstituted ICs.

  14. Mercury-Supported Biomimetic Membranes for the Investigation of Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Lucia Becucci

    2014-01-01

    Full Text Available Tethered bilayer lipid membranes (tBLMs consist of a lipid bilayer interposed between an aqueous solution and a hydrophilic “spacer” anchored to a gold or mercury electrode. There is great potential for application of these biomimetic membranes for the elucidation of structure-function relationships of membrane peptides and proteins. A drawback in the use of mercury-supported tBLMs with respect to gold-supported ones is represented by the difficulty in applying surface sensitive, spectroscopic and scanning probe microscopic techniques to gather information on the architecture of these biomimetic membranes. Nonetheless, mercury-supported tBLMs are definitely superior to gold-supported biomimetic membranes for the investigation of the function of membrane peptides and proteins, thanks to a fluidity and lipid lateral mobility comparable with those of bilayer lipid membranes interposed between two aqueous phases (BLMs, but with a much higher robustness and resistance to electric fields. The different features of mercury-supported tBLMs reconstituted with functionally active membrane proteins and peptides of bacteriological or pharmacological interest may be disclosed by a judicious choice of the most appropriate electrochemical techniques. We will describe the way in which electrochemical impedance spectroscopy, potential-step chronocoulometry, cyclic voltammetry and phase-sensitive AC voltammetry are conveniently employed to investigate the structure of mercury-supported tBLMs and the mode of interaction of antimicrobial peptides reconstituted into them.

  15. Structural, vibrational and electrical properties of ordered double perovskite oxide BaLaMnSbO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Bharti, Chandrahas, E-mail: bhartic@cgcri.res.in [Sensor and Actuator Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja SC Mullick Road, Kolkata 700032 (India); Sen, A. [Sensor and Actuator Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja SC Mullick Road, Kolkata 700032 (India); Chanda, Sadhan; Sinha, T.P. [Department of Physics, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700009 (India)

    2014-03-25

    Graphical abstract: Raman spectrum with group theoretical analysis -- Highlights: • BaLaMnSbO{sub 6} (BLMS) is synthesized in tetragonal phase (TP). • Rietveld refinement and Raman spectroscopy confirms the TP. • The presence of cation ordering is observed. • The electrical activation energy is ∼0.5 eV. • BLMS shows polaron hopping. -- Abstract: BaLaMnSbO{sub 6} (BLMS) has been successfully synthesized by solid-state reaction technique. In contrast to earlier reports, Rietveld refinement of powder X-ray diffraction (XRD) data of BLMS shows tetragonal structure having space group I4/m. The octahedral tilt about the direction of the c-axis is found to be 8.99° and the superlattice line (0 1 1) indicates the presence of cation ordering. FT-IR and Raman analysis as well as group theoretical investigation confirm the ordered tetragonal structure of BLMS with I4/m space group. The anti-phase distortions appear to be sufficiently large as detected by infrared and Raman spectroscopies, which give rise to the degeneracy and breaking of the symmetries of the normal modes. Impedance spectroscopy is used to investigate the dielectric relaxation and ac electrical conductivity in the temperature range of 303–403 K and in the frequency range of 0.1 kHz–1 MHz. Experimental electric modulus data are fitted to the Cole–Cole model in order to analyse the dielectric relaxation in BLMS. The frequency dependence ac electrical conductivity data are fitted to Jonscher’s universal power law at various temperatures. The dc conductivity follows Arrhenius law with activation energy (E{sub a}) 0.51 eV suggesting the polaron hopping. The complex impedance plane plots of BLMS indicate the presence of both grain and grain boundary effects and are analyzed by the electrical equivalent circuit consisting of a resistance and capacitance.

  16. Reconstitution of Human Ion Channels into Solvent-free Lipid Bilayers Enhanced by Centrifugal Forces.

    Science.gov (United States)

    Hirano-Iwata, Ayumi; Ishinari, Yutaka; Yoshida, Miyu; Araki, Shun; Tadaki, Daisuke; Miyata, Ryusuke; Ishibashi, Kenichi; Yamamoto, Hideaki; Kimura, Yasuo; Niwano, Michio

    2016-05-24

    Artificially formed bilayer lipid membranes (BLMs) provide well-defined systems for functional analyses of various membrane proteins, including ion channels. However, difficulties associated with the integration of membrane proteins into BLMs limit the experimental efficiency and usefulness of such BLM reconstitution systems. Here, we report on the use of centrifugation to more efficiently reconstitute human ion channels in solvent-free BLMs. The method improves the probability of membrane fusion. Membrane vesicles containing the human ether-a-go-go-related gene (hERG) channel, the human cardiac sodium channel (Nav1.5), and the human GABAA receptor (GABAAR) channel were formed, and the functional reconstitution of the channels into BLMs via vesicle fusion was investigated. Ion channel currents were recorded in 67% of the BLMs that were centrifuged with membrane vesicles under appropriate centrifugal conditions (14-55 × g). The characteristic channel properties were retained for hERG, Nav1.5, and GABAAR channels after centrifugal incorporation into the BLMs. A comparison of the centrifugal force with reported values for the fusion force revealed that a centrifugal enhancement in vesicle fusion was attained, not by accelerating the fusion process but by accelerating the delivery of membrane vesicles to the surface of the BLMs, which led to an increase in the number of membrane vesicles that were available for fusion. Our method for enhancing the probability of vesicle fusion promises to dramatically increase the experimental efficiency of BLM reconstitution systems, leading to the realization of a BLM-based, high-throughput platform for functional assays of various membrane proteins.

  17. Seismic vulnerability evaluation of axially loaded steel built-up laced members II: evaluations

    Science.gov (United States)

    Lee, Kangmin; Bruneau, Michel

    2008-06-01

    The test results described in Part 1 of this paper (Lee and Bruneau, 2008) on twelve steel built-up laced members (BLMs) subjected to quasi-static loading are analyzed to provide better knowledge on their seismic behavior. Strength capacity of the BLM specimens is correlated with the strength predicted by the AISC LRFD Specifications. Assessments of hysteretic properties such as ductility capacity, energy dissipation capacity, and strength degradation after buckling of the specimen are performed. The compressive strength of BLMs is found to be relatively well predicted by the AISC LRFD Specifications. BLMs with smaller kl/r were ductile but failed to reach the target ductility of 3.0 before starting to fracture, while those with larger kl/r could meet the ductility demand in most cases. The normalized energy dissipation ratio, E C/ E T and the normalized compressive strength degradation, C r″/ C r of BLMs typically decrease as normalized displacements δ/ δ b,exp increase, and the ratios for specimens with larger kl/r dropped more rapidly than for specimens with smaller kl/r; similar trends were observed for the monolithic braces. The BLMs with a smaller slenderness ratio, kl/r, and width-to-thickness ratio, b/t, experienced a larger number of inelastic cycles than those with larger ratios.

  18. Seismic vulnerability evaluation of axially loaded steel built-up laced members Ⅱ: evaluations

    Institute of Scientific and Technical Information of China (English)

    Kangmin Lee; Michel Bruneau

    2008-01-01

    The test results described in Part 1 of this paper (Lee and Bruneau, 2008) on twelve steel built-up laced members(BLMs) subjected to quasi-static loading are analyzed to provide better knowledge on their seismic behavior. Strengthcapacity of the BLM specimens is correlated with the strength predicted by the AISC LRFD Specifications. Assessmentsof hysteretic properties such as ductility capacity, energy dissipation capacity, and strength degradation after buckling of thespecimen are performed. The compressive strength of BLMs is found to be relatively well predicted by the AISC LRFDSpecifications. BLMs with smaller kl/r were ductile but failed to reach the target ductility of 3.0 before starting to fracture,while those with larger kl/r could meet the ductility demand in most cases. The normalized energy dissipation ratio, ECETand the normalized compressive strength degradation, Cr"/Cr of BLMs typically decrease as normalized displacements δ/δbexpincrease, and the ratios for specimens with larger kl/r dropped more rapidly than for specimens with smaller kl/r; similartrends were observed for the monolithic braces. The BLMs with a smaller slenderness ratio, kl/r, and width-to-thickness ratio,b/t, experienced a larger number of inelastic cycles than those with larger ratios.

  19. Una visión interdisciplinar de comunicación: semiótica y negociación

    Directory of Open Access Journals (Sweden)

    Lic. Clea Beatriz Macagnan Pretto

    1999-01-01

    Full Text Available * The present paper is the result of refletion about semiotic studies by Algirdas Julien Greimas, as a tool to identify the deep structure when analising the content of negotiation, in order to the negotiator make decisions in conflict situations. Firstly, it is going to approach Greimas’ theory and then, apply it in negotiation.* El objetivo de este artículo es aplicar la teoría semiótica desarrollada por Algirdas Julien Greimas como forma de identificación de la estructura profunda en el análisis del contenido de la negociación como arquitectura de situaciones de conflictos para la toma de decisión del negociador. Para esto, en primer lugar, se abordará aspectos de la teoría gremasiana para una posterior aplicación de la misma, en la teoría de negociación.

  20. Internacia Esperanto-Movado

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    UEA Post la estrar-kunsido de UEA, Lee Chong-Yeong flugis la 1-an de aprilo al Litovio kaj tie, helpate de estrarano Povilas Jegorovas, "vendis Esperanton" al tatprezidento Algirdas Brazauskas, al ministroj kaj aliaj litovaj eminentuloj. En la mateno de la dua tago la prezidento akceptis en sia laborambro lin kaj liajn kolegojn. En malstrea konversacio, Brazauskas agnoskis, ke Litovio spertas seriozajn lingvajn problemojn lige kun sia EU-

  1. La transformación de Víctor Frankenstein desde el modelo actancial de Greimas

    OpenAIRE

    2013-01-01

    El presente artículo analiza al personaje Víctor Frankenstein de la novela "Frankenstein o el moderno Prometeo" de la escritora inglesa Mary Shelley desde el Modelo o esquema actancial postulado por el lingüista francés Algirdas Julius Greimas, con el fin de demostrar la transformación que vive el personaje, antes y después de la creación de su empresa

  2. Lipid bilayer microarray for parallel recording of transmembrane ion currents.

    Science.gov (United States)

    Le Pioufle, Bruno; Suzuki, Hiroaki; Tabata, Kazuhito V; Noji, Hiroyuki; Takeuchi, Shoji

    2008-01-01

    This paper describes a multiwell biochip for simultaneous parallel recording of ion current through transmembrane pores reconstituted in planar lipid bilayer arrays. Use of a thin poly(p-xylylene) (parylene) film having micrometer-sized apertures (phi=15-50 microm, t=20 microm) led to formation of highly stable bilayer lipid membranes (BLMs) for incorporation of transmembrane pores; thus, a large number of BLMs could be arrayed without any skillful technique. We optically confirmed the simultaneous formation of BLMs in a 5x5 matrix, and in our durability test, the BLM lasted more than 15 h. Simultaneous parallel recording of alamethicin and gramicidin transmembrane pores in multiple contiguous recording sites demonstrated the feasibility of high-throughput screening of transmembrane ion currents in artificial lipid bilayers.

  3. A reusable device for electrochemical applications of hydrogel supported black lipid membranes.

    Science.gov (United States)

    Mech-Dorosz, Agnieszka; Heiskanen, Arto; Bäckström, Sania; Perry, Mark; Muhammad, Haseena B; Hélix-Nielsen, Claus; Emnéus, Jenny

    2015-02-01

    Black lipid membranes (BLMs) are significant in studies of membrane transport, incorporated proteins/ion transporters, and hence in construction of biosensor devices. Although BLMs provide an accepted mimic of cellular membranes, they are inherently fragile. Techniques are developed to stabilize them, such as hydrogel supports. In this paper, we present a reusable device for studies on hydrogel supported (hs) BLMs. These are formed across an ethylene tetrafluoroethylene (ETFE) aperture array supported by the hydrogel, which is during in situ polymerization covalently "sandwiched" between the ETFE substrate and a gold electrode microchip, thus allowing direct electrochemical studies with the integrated working electrodes. Using electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy and contact angle measurements, we demonstrate the optimized chemical modifications of the gold electrode microchips and plasma modification of the ETFE aperture arrays facilitating covalent "sandwiching" of the hydrogel. Both fluorescence microscopy and EIS were used to demonstrate the induced spontaneous thinning of a deposited lipid solution, leading to formation of stabilized hsBLMs on average in 10 min. The determined specific membrane capacitance and resistance were shown to vary in the range 0.31-0.49 μF/cm(2) and 45-65 kΩ cm(2), respectively, corresponding to partially solvent containing BLMs with an average life time of 60-80 min. The characterized hsBLM formation and devised equivalent circuit models lead to a schematic model to illustrate lipid molecule distribution in hydrogel-supported apertures. The functionality of stabilized hsBLMs and detection sensitivity of the platform were verified by monitoring the effect of the ion transporter valinomycin.

  4. An Adaptive Identification Algorithm of Nonlinear Output Frequency Response Functions and Its Application%非线性输出频域响应函数的自适应辨识算法及应用

    Institute of Scientific and Technical Information of China (English)

    韩海涛; 曹建福; 马红光; 张家良

    2011-01-01

    A nonlinear output frequency response functions (NOFRF) frequency adaptive identification algorithm (NOFRF-BLMS) is proposed to deal with the problems that the conventional identification method of NOFRF needs multiple stimulus and costs long time when the model of NOFRF is applied to fault diagnosis of analog circuit system. Input observation vectors and kernel vectors are constructed by means of NOFRF-BLMS, which makes the model of NOFRF become a pseudo-linear combination structure. Then, NOFRF adaptive identification recursive computational formula, which satisfies the norm of least mean square error, is deduced based on block least mean square (BLMS) and constraint optimization theory. Input power is used to estimate recursive learning factors, and output error is used to construct residual error vectors. NOFRF is identified via online learning and only one stimulus is needed in NOFRF-BLMS which simplifies the procedure of identifying dramatically and shortens the time of identifying. NOFRF-BLMS is robust to noise. Experimental results indicate that NOFRF-BLMS costs only 3 % of the identifying time of the conventional method, and the faults are correctly identified.%为解决非线性输出频域响应函数(NOFRF)模型用于模拟电路系统故障诊断时,传统辨识算法需多次激励计算过程耗时长的问题,提出了NOFRF的频域自适应辨识算法(NOFRF-BLMS).该算法构造了NOFRF的输入观测向量与核向量,从而可将NOFRF表示成一个伪线性结构.根据块最小均方(BLMS)原理及约束优化理论,推导出满足最小均方误差指标的NOFRF自适应辨识迭代计算公式,采用输入功率普迭代估算学习因子,由输出误差构造残差向量.NOFRF-BLMS通过在线学习方式,只需一次激励即可辨识出NOFRF,使辨识过程大幅度简化,缩短了辨识时间,具有更强的噪声抑制能力.实验结果表明,NOFRF-BLMS在相同的辨识精度下,耗时仅为传统算法的3%,且故障判断准确.

  5. Dose evaluation of therapeutic radiolabeled bleomycin complexes based on biodistribution data in wild-type rats:Effect of radionuclides in absorbed dose of different organs

    Institute of Scientific and Technical Information of China (English)

    Hassan Yousefnia; Samaneh Zolghadri; Amir Reza Jalilian; Mohammad Ghannadi-Maragheh

    2015-01-01

    Bleomycins (BLMs), as tumor-seeking antibiotics, have been used for over 20 years in treatment of several types of cancers. Several radioisotopes are used in radiolabeling of BLMs for therapeutic and diagnostic purpos-es. An important points in developing new radiopharmaceuticals, especially therapeutic agents, is the absorbed dose delivered in critical organs. In this work, absorbed dose to organs after injection of 153Sm-, 177Lu-and 166Ho-labeled BLM was investigated by radiation dose assessment resource (RADAR) method based on biodis-tribution data in wild-type rats. The absorbed dose effect of the radionuclides was evaluated. The maximum absorbed dose for the complexes was observed in the kidneys, liver and lungs. For all the radiolabeled BLMs, bone and red marrow received considerable absorbed dose. Due to the high energy beta particles emitted by 166Ho, higher absorbed dose is observed for 166Ho-BLM in the most organs. The reported data can be useful for the determination of the maximum permissible injected activity of the radiolabeled BLMs in the treatment planning programs.

  6. Integrated microfluidic platform for bilayer studies and experimentation on single pore-forming species

    NARCIS (Netherlands)

    Stimberg, V.C.; Berg, van den A.; Le Gac, S.

    2011-01-01

    The combination of microfluidics with BLMs (bilayer lipid membranes) consists of a powerful tool for multiplexed and high-throughput studies on membrane properties and membrane proteins. Here, we report an integrated device for BLM ex-perimentation using both optical and electrical measurements. Thi

  7. Chk1 protects against chromatin bridges by constitutively phosphorylating BLM serine 502 to inhibit BLM degradation.

    Science.gov (United States)

    Petsalaki, Eleni; Dandoulaki, Maria; Morrice, Nick; Zachos, George

    2014-09-15

    Chromatin bridges represent incompletely segregated chromosomal DNA connecting the anaphase poles and can result in chromosome breakage. The Bloom's syndrome protein helicase (BLM, also known as BLMH) suppresses formation of chromatin bridges. Here, we show that cells deficient in checkpoint kinase 1 (Chk1, also known as CHEK1) exhibit higher frequency of chromatin bridges and reduced BLM protein levels compared to controls. Chk1 inhibition leads to BLM ubiquitylation and proteasomal degradation during interphase. Furthermore, Chk1 constitutively phosphorylates human BLM at serine 502 (S502) and phosphorylated BLM localises to chromatin bridges. Mutation of S502 to a non-phosphorylatable alanine residue (BLM-S502A) reduces the stability of BLM, whereas expression of a phospho-mimicking BLM-S502D, in which S502 is mutated to aspartic acid, stabilises BLM and prevents chromatin bridges in Chk1-deficient cells. In addition, wild-type but not BLM-S502D associates with cullin 3, and cullin 3 depletion rescues BLM accumulation and localisation to chromatin bridges after Chk1 inhibition. We propose that Chk1 phosphorylates BLM-S502 to inhibit cullin-3-mediated BLM degradation during interphase. These results suggest that Chk1 prevents deleterious anaphase bridges by stabilising BLM.

  8. BLM Experimentation and opto-electrical characterization in microchips, towards an integrated platform for drug screening on membrane proteins

    NARCIS (Netherlands)

    Stimberg, V.C.; Uitert, van I.; Le Gac, S.; Berg, van den A.; Verpoorte, S; Andersson-Svahn, S.M.H.; Emneus, J.; Pamme, N

    2010-01-01

    Experimentation on cell membranes and on membrane proteins commonly makes use of planar and simplified membrane models, or bilayer lipid membranes (BLMs). Although these models are extensively employed, the experimentation is tedious and time-consuming, and mostly limited to electrical measurements.

  9. CERN-RD39 collaboration activities aimed at cryogenic silicon detector application in high-luminosity Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng [National-Provincial Laboratory of Special Function Thin Film Materials, School of Material Sciences and Engineering, Xiangtan University, Xiangtan, Hunan 411105 (China); Eremin, Vladimir [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Verbitskaya, Elena, E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Dehning, Bernd; Sapinski, Mariusz; Bartosik, Marcin R.; Alexopoulos, Andreas [CERN, CH-1211, Geneva 23 (Switzerland); Kurfürst, Christoph [Technische Universität, Universitätsring 1, 1010 Wien (Austria); Härkönen, Jaakko [Helsinki Institute of Physics, Gustaf Hällströminkatu, 200014 Helsingin yliopisto (Finland)

    2016-07-11

    Beam Loss Monitors (BLM) made of silicon are new devices for monitoring of radiation environment in the vicinity of superconductive magnets of the Large Hadron Collider. The challenge of BLMs is extreme radiation hardness, up to 10{sup 16} protons/cm{sup 2} while placed in superfluid helium (temperature of 1.9 K). CERN BE-BI-BL group, together with CERN-RD39 collaboration, has developed prototypes of BLMs and investigated their device physics. An overview of this development—results of the in situ radiation tests of planar silicon detectors at 1.9 K, performed in 2012 and 2014—is presented. Our main finding is that silicon detectors survive under irradiation to 1×10{sup 16} p/cm{sup 2} at 1.9 K. In order to improve charge collection, current injection into the detector sensitive region (Current Injection Detector (CID)) was tested. The results indicate that the detector signal increases while operated in CID mode. - Highlights: • Activities aimed at upgrading of Beam Loss Monitors (BLM) at HL-LHC are described. • Overview of in situ radiation tests of silicon BLMs immersed in LHe is presented. • Silicon detectors with 300 and 100 μm thickness survived radiation at 1.9 K. • Current injection is still effective at 1.9 K for radiation hardness improvement. • Si detectors are currently installed on the magnets for their operation as BLMs.

  10. Efficient Nuclear DNA Cleavage in Human Cancer Cells by Synthetic Bleomycin Mimics

    NARCIS (Netherlands)

    Li, Qian; van der Wijst, Monique G. P.; Kazemier, Hinke G.; Rots, Marianne G.; Roelfes, Gerard

    2014-01-01

    Iron complexes of N,N-bis(2-Pyridylmethyl)-N-bis(2-pyridyl)-methylamine (N4Py) have proven to be excellent synthetic mimics of the Bleomycins (BLMs), which are a family of natural antibiotics used clinically in the treatment of certain cancers. However, most investigations of DNA cleavage activity o

  11. Bilayer lipid membrane (BLM) based ion selective electrodes at the meso-, micro-, and nano-scales.

    Science.gov (United States)

    Liu, Bingwen; Rieck, Daniel; Van Wie, Bernard J; Cheng, Gary J; Moffett, David F; Kidwell, David A

    2009-03-15

    This paper presents a novel method for making micron-sized apertures with tapered sidewalls and nano-sized apertures. Their use in bilayer lipid membrane-based ion selective electrode design is demonstrated and compared to mesoscale bilayers and traditional PVC ion selective electrodes. Micron-sized apertures are fabricated in SU-8 photoresist films and vary in diameter from 10 to 40 microm. The tapered edges in SU-8 films are desired to enhance bilayer lipid membrane (BLM) formation and are fabricated by UV-light overexposure. Nano-apertures are made in boron diffused silicon film. The membranes are used as septa to separate two potassium chloride solutions of different concentrations. Lecithin BLMs are assembled on the apertures by ejecting lipid solution. Potassium ionophore, dibenzo-18-crown-6, is incorporated into BLMs by dissolving it in the lipid solution before membrane assembly. Voltage changes with increasing potassium ion concentrations are recorded with an A/D converter. Various ionophore concentrations in BLMs are investigated. At least a 1% concentration is needed for consistent slopes. Electrode response curves are linear over the 10(-6) to 0.1M range with a sub-Nernstian slope of 20mV per Log concentration change. This system shows high selectivity to potassium ions over potential interfering sodium ions. BLMs on the three different aperture sizes at the meso-, micro-, and nano-scales all show similar linear ranges and limits of detection (LODs) as PVC ion selective membranes.

  12. Characterization of the effects of binary metal mixtures on short-term uptake of Ag, Cu, and Ni by rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Brix, Kevin V; Tellis, Margaret S; Crémazy, Anne; Wood, Chris M

    2016-11-01

    Single metal Biotic Ligand Models (BLMs) have been developed for a number of metals and model organisms. While these BLMs improve our ability to regulate metals in the aquatic environment, in reality, organisms are often simultaneously exposed to metal mixtures. Recently, several attempts have been made to develop mixture BLMs (mBLMs). Some of these models assume competitive interactions between all metals, while others assume only metals with a similar mode of action (e.g., Na(+) or Ca(2+) antagonists) will competitively interact. To begin testing these assumptions in the mBLM framework, standard 3-h gill metal binding assays with Ag, Cu, and Ni (primary metals), were performed in vivo on freshwater rainbow trout. Fish were exposed across a range of concentrations encompassing the 96-h LC50 for that metal to characterize uptake kinetics for each of these three primary metals (radiolabelled) in the presence and absence of a secondary metal (Ag, Cd, Cu, Ni, Pb, or Zn; not radiolabelled). We observed a complex series of interactions in binary mixtures that frequently contradicted theoretical expectations. Metals with similar modes of action did competitively interact in some instances, but not others, and when they did compete the competition was not necessarily reciprocal (e.g., Cu inhibited Ag uptake but Ag did not inhibit Cu uptake). We also observed examples of interactions between metals with dissimilar modes of action and several examples of metals stimulating the uptake of other metals. The underlying mechanisms for these unexpected interactions are unclear, but suggest that many of the current assumptions in mBLMs regarding the number and types of metal uptake sites and corresponding metal interactions are not correct. Careful characterization of metal mixture interactions is clearly needed before a reliable mBLM can be developed.

  13. A arte no processo educativo

    OpenAIRE

    Lucimar Bello Pereira Frange

    2006-01-01

    Os textos escritos por Noemia Varela pensam a educação e o ensino de arte como instâncias criadoras, apoiados em alguns educadores e filósofos. As análises destes textos, feitas por Lucimar Bello, baseadas principalmente na semiótica de Julian Algirdas Greimas, abrangem diversos campos de significações, abrindo espaços de pensamentos para um professor investigador na arte e sobre a arte e seu ensino. Palavras-chave: Arte e Ensino de Arte. Educação Criadora. Análise Semiótica. Professor-Pesqui...

  14. Uma leitura analítica da novela \\"A Metamorfose\\", de Franz Kafka

    OpenAIRE

    Francisco Elias Simão Merçon

    2006-01-01

    Este trabalho é uma análise da novela A Metamorfose, do escritor tcheco Franz Kafka, sob a perspectiva da teoria semiótica francesa, tal qual construída desde os estudos de Algirdas J. Greimas até estudos recentes, mais conhecidos como semiótica tensiva. A análise se dedica sobretudo a elementos decorrentes da metamorfose de Gregor, em especial às transformações que estão em torno do drama familiar vivido pelos Samsa, resultantes da metamorfose do personagem Gregor em um inseto, pois que pare...

  15. International Conference on Thermoelectrics(16th), Proceedings, ICT 󈨥 Held in Dresden, Germany on August 26-29, 1997

    Science.gov (United States)

    1998-05-08

    Lithuania Nature of Thermoelectric Anisotropy in Semiconductors 757 at the Lower Temperatures Eduard V. Osipov, and Algirdas Aulas , Semiconductor...9] and 0.19 + 0.01 eV for LaMn03 [22]. The plots for all the substituted samples except the Sb- substituted one gave small and virtually the same Ea...examined. In spite of the decrease in S2a, the Z values of (Zn0.9gM0.02)O (M = Ga, In) are virtually equal to that of the Al-doped one up to ca. 600°C

  16. Paradigma e progresso – uma questão sobre o desenvolvimento da teoria semiótica acerca das modalidades crer e saber

    Directory of Open Access Journals (Sweden)

    Eliane Domaneschi

    2014-12-01

    Full Text Available Based on “paradigm” and “progress” metatheoretical categories provided by Thomas Kuhn in The structure of scientific revolutions, 1962, this paper analyzes two Paris School Semiotics texts about the modalities believing and knowing: “Le savoir et le croire: un seul univers cognitif”, published in 1983 by Algirdas Julien Greimas; and “Reconnaissance de l’espace fiduciaire”, published by Claude Zilberberg in 1988. By means of a historiographical point of view, we propose a critical reading of these texts in order to analyze and discuss semiotics development and evolution about the aforementioned modalities.

  17. A arte no processo educativo

    Directory of Open Access Journals (Sweden)

    Lucimar Bello Pereira Frange

    2006-07-01

    Full Text Available Os textos escritos por Noemia Varela pensam a educação e o ensino de arte como instâncias criadoras, apoiados em alguns educadores e filósofos. As análises destes textos, feitas por Lucimar Bello, baseadas principalmente na semiótica de Julian Algirdas Greimas, abrangem diversos campos de significações, abrindo espaços de pensamentos para um professor investigador na arte e sobre a arte e seu ensino. Palavras-chave: Arte e Ensino de Arte. Educação Criadora. Análise Semiótica. Professor-Pesquisador.

  18. Olhar como os pssaros. Sobre a estrutura de enunciao de um tipo de mapa cartogrfico To look like the birds: about the enunciation structure present on a kind of cartographic map

    Directory of Open Access Journals (Sweden)

    Felix Thrlemann

    2012-01-01

    Full Text Available Alguns estudiosos das cincias humanas se interessaram por estudar textos visuais no valorizados pela grande arte. Esse recente interesse pelas imagens que no se enquadram na disciplina da histria da arte reflete o crescente papel que desempenha a visualidade atualmente. Seguindo os passos de Algirdas Julien Greimas, que sempre incentivou os estudos nos diferentes domnios da expresso visual independentemente da substncia da expresso implicada, escolhemos como objeto de anlise um gnero de texto visual extra-esttico - um mapa cartogrfico - com o intuito de estudar como se estrutura a enunciao de um tipo particular de mapa, o chamado vista voo de pssaro.Some human sciences researchers are interested on studying visual texts that are not valorized by the great art. This recent interest for images that are not framed by art history discipline reflect the upgrowing role that visuality plays nowadays. According to the steps of Algirdas Julien Greimas, that has always encouraged the studies on different domains of visual expression - regardless the implied expressions substance - we have chosen as an object of analysis a textual genre extra-aesthetical - a cartographic map - with the intention of studying how can be structured the enunciation of a particular type of map called view like a birds flight.

  19. Modeling and simulation of vibrational breathing-like modes in individual multiwalled carbon nanotubes

    Science.gov (United States)

    Sbai, K.; Rahmani, A.; Fakrach, B.; Chadli, H.; Benhamou, M.

    2014-02-01

    We study the collective vibrational breathing modes in the Raman spectrum of multiwalled carbon nanotubes (MCNTs). First, a bond polarization theory and the spectral moment's method (SMM) are used to calculate the non-resonant Raman frequencies of the breathing-like modes (BLMs) and the tangential-like ones (TLMs). Second, the Raman active modes of MCNTs are computed for different diameters and numbers of layers. The obtained low frequency modes in MCNTs can be identified to each single-walled carbon nanotubes. These modes that originate from the radial breathing ones of the individual walls are strongly coupled through the concentric tube-tube van der Waals interaction. The calculated BLMs in the low-frequency region are compared with the experimental Raman data obtained from other studies. Finally, special attention is given to the comparison with Raman data on MCNTs composed of six layers.

  20. Are Free Ion Activity Models Sufficient Alternatives to Biotic Ligand Models in Evaluating Metal Toxic Impacts in Terrestrial Environments?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred

    Metal partitioning between solid and aqueous phases and speciation in soil pore water control the bioavailability of toxic forms of metals, while protons and base cations can mitigate metal ecotoxicity by competitive interactions with biotic ligands. e employment of BLMs to evaluate toxicity...... potential of metals in soils results in site-specic toxicity scores due to large variability of soil properties and dierences in ionic composition. Unfortunately, terrestrial BMLs are available only for few metals and few organisms, thus their applicability to hazard ranking or toxic impact assessment...... is low and alternatives must be found. In this study, we compared published terrestrial BLMs and their potential alternatives such as free ion activity models (FIAM), for applicability in addressing metal toxic impacts in terrestrial environments. A set of 1300 soils representative for the whole world...

  1. CERN-RD39 collaboration activities aimed at cryogenic silicon detector application in high-luminosity Large Hadron Collider

    CERN Document Server

    Li, Zheng; Verbitskaya, Elena; Dehning, Bernd; Sapinski, Mariusz; Bartosik, Marcin R; Alexopoulos, Andreas; Kurfürst, Christoph; Härkönen, Jaakko

    2016-01-01

    Beam Loss Monitors (BLM) made of silicon are new devices for monitoring of radiation environment in the vicinity of superconductive magnets of the Large Hadron Collider. The challenge of BLMs is extreme radiation hardness, up to 10 16 protons/cm 2 while placed in superfluid helium (temperature of 1.9 K). CERN BE-BI-BL group, together with CERN-RD39 collaboration, has developed prototypes of BLMs and investigated their device physics. An overview of this development—results of the in situ radiation tests of planar silicon detectors at 1.9 K, performed in 2012 and 2014—is presented. Our main finding is that silicon detectors survive under irradiation to 1×10 16 p/cm 2 at 1.9 K. In order to improve charge collection, current injection into the detector sensitive region (Current Injection Detector (CID)) was tested. The results indicate that the detector signal increases while operated in CID mode.

  2. Reliability of Beam Loss Monitors System for the Large Hadron Collider

    CERN Document Server

    Guaglio, Gianluca; Santoni, C

    2004-01-01

    The employment of superconducting magnets, in the high energies colliders, opens challenging failure scenarios and brings new criticalities for the whole system protection. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses, while at medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standar...

  3. Hydrogels for in situ encapsulation of biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Ibragimova, Sania; Jensen, Karin Bagger Stibius; Szewczykowski, Piotr Przemyslaw

    2012-01-01

    . We investigated gels for in situ encapsulation of multiple BLMs formed across apertures in a hydrophobic ethylene tetrafluoroethylene (ETFE) support. The encapsulation gels consisted of networks of poly(ethylene glycol)-dimethacrylate or poly(ethylene glycol)-diacrylate polymerized using either...... to chemically initiated hydrogels; however, for all hydrogels the permeability was several-fold higher than the water permeability of conventional reverse osmosis (RO) membranes. Lifetimes of freestanding BLM arrays in gel precursor solutions were short compared to arrays formed in buffer. However, polymerizing......Hydrogels are hydrophilic, porous polymer networks that can absorb up to thousands of times their own weight in water. They have many potential applications, one of which is the encapsulation of freestanding black lipid membranes (BLMs) for novel separation technologies or biosensor applications...

  4. Development of an Automation Technique for the Establishment of Functional Lipid Bilayer Arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg;

    2009-01-01

    of the lipid membranes to the formation of bilayers. The results showed that multiple lipid bilayers could be reproducible formed across the airbrush-pretreated 8 x 8 rectangular arrays. The ionophoric peptide valinomycin was incorporated into established membrane arrays, resulting in ionic currents that could......In the present work, a technique for establishing multiple black lipid membranes (BLMs) in arrays of micro structured ethylene tetrafluoroethylene (ETFE) films, and supported by a micro porous material was developed. Rectangular 8 x 8 arrays with apertures having diameters of 301 +/- 5 mu m were...... fabricated in ETFE Teflon film by laser ablation using a carbon dioxide laser. Multiple lipid membranes could be formed across the micro structured 8 x 8 array ETFE partitions. Success rates for the establishment of cellulose-supported BLMs across the multiple aperture arrays were above 95%. However...

  5. CERN-RD39 collaboration activities aimed at cryogenic silicon detector application in high-luminosity Large Hadron Collider

    Science.gov (United States)

    Li, Zheng; Eremin, Vladimir; Verbitskaya, Elena; Dehning, Bernd; Sapinski, Mariusz; Bartosik, Marcin R.; Alexopoulos, Andreas; Kurfürst, Christoph; Härkönen, Jaakko

    2016-07-01

    Beam Loss Monitors (BLM) made of silicon are new devices for monitoring of radiation environment in the vicinity of superconductive magnets of the Large Hadron Collider. The challenge of BLMs is extreme radiation hardness, up to 1016 protons/cm2 while placed in superfluid helium (temperature of 1.9 K). CERN BE-BI-BL group, together with CERN-RD39 collaboration, has developed prototypes of BLMs and investigated their device physics. An overview of this development-results of the in situ radiation tests of planar silicon detectors at 1.9 K, performed in 2012 and 2014-is presented. Our main finding is that silicon detectors survive under irradiation to 1×1016 p/cm2 at 1.9 K. In order to improve charge collection, current injection into the detector sensitive region (Current Injection Detector (CID)) was tested. The results indicate that the detector signal increases while operated in CID mode.

  6. Charge-transfer processes and redox reactions in planar lipid monolayers and bilayers.

    Science.gov (United States)

    Krysiñki, P; Tien, H T; Ottova, A

    1999-01-01

    Supported bilayer lipid membranes (BLMs) and lipid monolayers have been known for quite sometime and are attracting sustained interest since they open new research vista and offer practical approaches in biosensor development and molecular device applications. Central to these areas of interest are electric processes and redox reactions where the movement of ions and electrons plays a pivotal role. In this paper an overview of the major findings in this field is presented. Further, we summarize the work on planar lipid bilayers and monolayers that have been done in the past few years in a number of laboratories. Supported planar BLMs and their closely related systems provide the foundation for a variety of lipid bilayer-based molecular sensors that are sensitive, versatile, as well as potentially inexpensive (i.e., disposable), and open to all sorts of experimentation.

  7. Beam loss detection system in the arcs of the LHC

    Science.gov (United States)

    Arauzo, A.; Bovet, C.

    2000-11-01

    Over the whole circumference of the LHC, Beam Loss Monitors (BLM) will be needed for a continuous surveillance of fast and slow beam losses. In this paper, the location of the BLMs set outside the magnet cryostats in the arcs is proposed. In order to know the number of protons lost on the beam screen, the sensitivity of each BLM has been computed using the program GEANT 3.21, which generates the shower inside the cryostat. The material and the magnetic fields have been described thoroughly in 3-D and the simulation results show the best locations for 6 BLMs needed around each quadrupole. The number of minimum ionizing particles received for each lost proton serves to define local thresholds to dump the beam when the losses are menacing to quench a magnet.

  8. Beam Loss Detection System in the Arcs of the LHC

    CERN Document Server

    Arauzo-Garcia, A

    2000-01-01

    Over the whole circumference of the LHC, Beam Loss Monitors (BLM) will be needed for a continuous surveillance of fast and slow beam losses. In this paper, the location of the BLMs set outside the magnet cryostats in the arcs is proposed. In order to know the number of protons lost on the beam screen, the sensitivity of each BLM has been computed using the program GEANT 3.21, which generates the shower inside the cryostat. The material and the magnetic fields have been described thoroughly in 3-D and the simulation results show the best locations for 6 BLMs needed around each quadrupole. The number of minimum ionizing particles received for each lost proton serves to define local thresholds to dump the beam when the losses are menacing to quench a magnet

  9. Environmental risk assessment of metals: tools for incorporating bioavailability.

    Science.gov (United States)

    Janssen, C R; Heijerick, D G; De Schamphelaere, K A C; Allen, H E

    2003-03-01

    In this paper, some of the main processes and parameters which affect metal bioavailability and toxicity in the aquatic environment and its implications for metal risk assessment procedures will be discussed. It has become clear that, besides chemical processes (speciation, complexation), attention should also be given to physiological aspects for predicting metal toxicity. The development of biotic ligand models (BLMs), which combine speciation models with more biologically oriented models (e.g. GSIM), has offered an answer to this need. The various BLMs which have been developed and/or refined for a number of metals (e.g. Cu, Ag, Zn) and species (algae, crustaceans, fish) are discussed here. Finally, the potential of the BLM approach is illustrated through a theoretical exercise in which chronic zinc toxicity to Daphnia magna is predicted in three regions, taking the physico-chemical characteristics of these areas into account.

  10. A tethered bilayer sensor containing alamethicin channels and its detection of amiloride based inhibitors.

    Science.gov (United States)

    Yin, Ping; Burns, Christopher J; Osman, Peter D J; Cornell, Bruce A

    2003-04-01

    Alamethicin, a small transmembrane peptide, inserts into a tethered bilayer membrane (tBLM) to form ion channels, which we have investigated using electrical impedance spectroscopy. The number of channels formed is dependent on the incubation time, concentration of the alamethicin and the application of DC voltage. The properties of the ion channels when formed in tethered bilayers are similar to those for such channels assembled into black lipid membranes (BLMs). Furthermore, amiloride and certain analogs can inhibit the channel pores, formed in the tBLMs. The potency and concentration of the inhibitors can be determined by measuring the change of impedance. Our work illustrates the possibility of using a synthetic tBLM for the study of small peptide voltage dependent ion channels. A potential application of such a device is as a screening tool in drug discovery processes.

  11. Reliability of the beam loss monitors system for the large hadron collider at CERN; Fiabilite du systeme des moniteurs de pertes du faisceau pour le Large Hadron Collider au CERN

    Energy Technology Data Exchange (ETDEWEB)

    Guaglio, G

    2005-12-15

    The energy stored in the Large Hadron Collider is unprecedented. The impact of the beam particles can cause severe damage on the superconductive magnets, resulting in significant downtime for repairing. The Beam Loss Monitors System (BLMS) detects the secondary particles shower of the lost beam particles and initiates the extraction of the beam before any serious damage to the equipment can occur. This thesis defines the BLMS specifications in term of reliability. The main goal is the design of a system minimizing both the probability to not detect a dangerous loss and the number of false alarms generated. The reliability theory and techniques utilized are described. The prediction of the hazard rates, the testing procedures, the Failure Modes Effects and Criticalities Analysis and the Fault Tree Analysis have been used to provide an estimation of the probability to damage a magnet, of the number of false alarms and of the number of generated warnings. The weakest components in the BLMS have been pointed out. The reliability figures of the BLMS have been calculated using a commercial software package (Isograph.). The effect of the variation of the parameters on the obtained results has been evaluated with a sensitivity analysis. The reliability model has been extended by the results of radiation tests. Design improvements, like redundant optical transmission, have been implemented in an iterative process. The proposed system is compliant with the reliability requirements. The model uncertainties are given by the limited knowledge of the thresholds levels of the superconductive magnets and of the locations of the losses along the ring. The implemented model allows modifications of the system, following the measuring of the hazard rates during the LHC life. It can also provide reference numbers to other accelerators which will implement similar technologies. (author)

  12. Tethered bilayer lipid membranes studied by simultaneous attenuated total reflectance infrared spectroscopy and electrochemical impedance spectroscopy

    Science.gov (United States)

    Erbe, Andreas; Bushby, Richard J.; Evans, Stephen D.; Jeuken, Lars J. C.

    2013-01-01

    The formation of tethered lipid bilayer membranes (tBLMs) from unilamelar vesicles of egg yolk phosphatidylcholine (EggPC) on mixed self–assembled monolayers (SAMs) from varying ratios of 6-mercaptohexanol and EO3Cholesteryl on gold has been monitored by simultaneous attenuated total reflectance fourier transform infrared (ATR–FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The influence of the lipid orientation (and hence the anisotropy) of lipids on a gold film on the dichroic ratio was studied by simulations of spectra with a matrix method for anisotropic layers. It is shown that for certain tilt angles of the dielectric tensor of the adsorbed anisotropic layer dispersive and negative absorption bands are possible. The experimental data indicates that the structure of the assemblies obtained varies with varying SAM composition. On SAMs with a high content of EO3Cholesteryl, tBLMs with reduced fluidity are formed. For SAMs with high content of 6-mercaptohexanol, the results are consistent with the adsorption of flattened vesicles, while spherical vesicles have been found in a small range of surface compositions. The kinetics of the adsorption process is consistent with the assumption of spherical vesicles as long–living intermediates for surfaces of high 6-mercaptohexanol content. No long–living spherical vesicles have been detected for surfaces with large fraction of EO3Cholesteryl tethers. The observed differences between the surfaces suggest that for the formation of tBLMs (unlike supported BLMs) no critical surface coverage of vesicles is needed prior to lipid bilayer formation. PMID:17388505

  13. Biosensor for dopamine based on stabilized lipid films with incorporated resorcin[4]arene receptor.

    Science.gov (United States)

    Nikolelis, Dimitrios P; Theoharis, George

    2003-04-01

    This work reports a technique for the stabilization after storage in air of a lipid film with incorporated resorcin[4]arene receptor based biosensor for dopamine. Microporous filters composed of glass fibers (nominal pore sizes, 0.7 and 1.0 microm) were used as supports for the formation and stabilization of these devices and the lipid film is formed on the filter by polymerization prior its use. Methacrylic acid was the functional monomer, ethylene glycol dimethacrylate was the crosslinker and 2,2'-azobis-(2-methylpropionitrile) was the initiator. The stability of the lipid films by incorporation of a receptor for the preparation of stabilized lipid film biosensor is studied throughout this work. The response towards dopamine of the present stabilized for repetitive uses lipid membrane biosensor composed of dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidic acid was compared with planar freely suspended bilayer lipid membranes (BLMs). The stabilized lipid membranes provided similar artificial ion gating events as BLMs in the form of transient signals and can function for repetitive uses after storage in air. However, the response of the stabilized lipid films was slower than that of the freely suspended BLMs. This will allow the practical use of the techniques for chemical sensing based on lipid films and commercialization of these devices, because it is now possible to prepare stabilized lipid film based biosensors and store them in the air.

  14. Using biotic ligand models to predict metal toxicity in mineralized systems

    Science.gov (United States)

    Smith, Kathleen S.; Balistrieri, Laurie S.; Todd, Andrew S.

    2015-01-01

    The biotic ligand model (BLM) is a numerical approach that couples chemical speciation calculations with toxicological information to predict the toxicity of aquatic metals. This approach was proposed as an alternative to expensive toxicological testing, and the U.S. Environmental Protection Agency incorporated the BLM into the 2007 revised aquatic life ambient freshwater quality criteria for Cu. Research BLMs for Ag, Ni, Pb, and Zn are also available, and many other BLMs are under development. Current BLMs are limited to ‘one metal, one organism’ considerations. Although the BLM generally is an improvement over previous approaches to determining water quality criteria, there are several challenges in implementing the BLM, particularly at mined and mineralized sites. These challenges include: (1) historically incomplete datasets for BLM input parameters, especially dissolved organic carbon (DOC), (2) several concerns about DOC, such as DOC fractionation in Fe- and Al-rich systems and differences in DOC quality that result in variations in metal-binding affinities, (3) water-quality parameters and resulting metal-toxicity predictions that are temporally and spatially dependent, (4) additional influences on metal bioavailability, such as multiple metal toxicity, dietary metal toxicity, and competition among organisms or metals, (5) potential importance of metal interactions with solid or gas phases and/or kinetically controlled reactions, and (6) tolerance to metal toxicity observed for aquatic organisms living in areas with elevated metal concentrations.

  15. Reliability of the Beam Loss Monitors System for the Large Hadron Collider at CERN

    CERN Document Server

    Guaglio, G; Santoni, C

    2005-01-01

    The energy stored in the Large Hadron Collider is unprecedented. The impact of the beam particles can cause severe damage on the superconductive magnets, resulting in significant downtime for repairing. The Beam Loss Monitors System (BLMS) detects the secondary particles shower of the lost beam particles and initiates the extraction of the beam before any serious damage to the equipment can occur. This thesis defines the BLMS specifications in term of reliability. The main goal is the design of a system minimizing both the probability to not detect a dangerous loss and the number of false alarms generated. The reliability theory and techniques utilized are described. The prediction of the hazard rates, the testing procedures, the Failure Modes Effects and Criticalities Analysis and the Fault Tree Analysis have been used to provide an estimation of the probability to damage a magnet, of the number of false alarms and of the number of generated warnings. The weakest components in the BLMS have been pointed out....

  16. SANMAI NO OFUDA DALAM PERSPEKTIF GREIMAS

    Directory of Open Access Journals (Sweden)

    Yuliani Rahmah

    2015-09-01

    Full Text Available This paper entitled  Sanmai no Ofuda in Greimas’s perspective. Sanmai no ofuda is the title of Japan’s folktale has similarities with localfolktales from several regions in Indonesia. In this paper, the writer tried to explain the narrative structure of Sanmai no Ofuda in Greimas’s perspective.Its mean to reveal the narrative structure of this folktale,the writer used structural naratology approaches with Algirdas Julien Greimas’s theory. The writer tried to understand about the intrinsic elements  in Sanmai no Ofuda by examining the actans schemes and functional structure. The findings show that the narrative structure can explain  the intrinsic elements more specificly.

  17. Euro-Integrations of Serbia: A Semiotic Analysis

    Directory of Open Access Journals (Sweden)

    Marija Krstić

    2016-02-01

    Full Text Available The paper focuses on the current process of euro-integrations of Serbia, from a semiotic perspective. Accordingly, based on data gathered from the media, euro-integrations are shaped into a narrative, which is subsequently analyzed from a semiotic point of view, primarily utilizing the methods of Algirdas Julien Greimas. Two levels of meaning will be analyzed in the paper: the semio-narrative (surface, syntagmatic, specific level will be explored using the transformational and actantial model, while the deep, abstract, paradigmatic and atemporal level will be analyzed using the semiotic square. The aim of the paper is to understand how knowledge and meaning are produced within the discourse of euro-integrations.

  18. O programa Café com o presidente à luz da semiótica

    OpenAIRE

    Ludovice, Camila de Araújo Beraldo

    2011-01-01

    Esta pesquisa propôs analisar as entrevistas dadas pelo ex-presidente Lula, ao programa de rádio “Café com o Presidente”, e verificar como o éthos do ator Lula foi construído nas suas respostas e que diferenças podem ser verificadas na construção de sua imagem com relação ao período eleitoral de propagandas, do ano de 2006, analisadas em nossa dissertação de mestrado. O trabalho fundamenta-se na teoria semiótica de origem francesa, desenvolvida por Algirdas Julien Greimas, que tem como objeto...

  19. Solid-Supported Lipid Membranes: Formation, Stability and Applications

    Science.gov (United States)

    Goh, Haw Zan

    This thesis presents a comprehensive investigation of the formation of supported lipid membranes with vesicle hemifusion, their stability under detergents and organic solvents and their applications in molecular biology. In Chapter 3, we describe how isolated patches of DOPC bilayers supported on glass surfaces are dissolved by various detergents (decyl maltoside, dodecyl maltoside, CHAPS, CTAB, SDS, TritonX-100 and Tween20) at their CMC, as investigated by fluorescence video microscopy. In general, detergents partition into distal leaflets of bilayers and lead to the expansion of the bilayers through a rolling motion of the distal over the proximal leaflets, in agreement with the first stage of the established 3-stage model of lipid vesicle solubilization by detergents. Subsequently, we study the partitioning of organic solvents (methanol, ethanol, isopropanol, propanol, acetone and chloroform) into isolated bilayer patches on glass in Chapter 4 with fluorescence microscopy. The area expansion of bilayers due to the partitioning of organic solvents is measured. From the titration of organic solvents, we measured the rate of area expansion as a function of the volume fraction of organic solvents, which is proposed to be a measure of strength of interactions between solvents and membranes. From the same experiments, we also measure the maximum expansion of bilayers (or the maximum binding stoichiometry between organic solvents and lipids) before structural breakdown, which depends on the depth of penetration of solvents to the membranes. In Chapter 5, we investigate the formation of sparsely-tethered bilayer lipid membranes (stBLMs) with vesicle hemifusion. In vesicle hemifusion, lipid vesicles in contact with a hydrophobic alkyl-terminated self-assembled monolayer (SAM) deposit a lipid monolayer to the SAM surface, thus completing the bilayer. Electrical Impedance Spectroscopy and Neutron Reflectivity are used to probe the integrity of stBLMs in terms of their

  20. Evaluation of agonist selectivity for the NMDA receptor ion channel in bilayer lipid membranes based on integrated single-channel currents.

    Science.gov (United States)

    Hirano, A; Sugawara, M; Umezawa, Y; Uchino, S; Nakajima-Iijima, S

    2000-06-01

    A new method for evaluating chemical selectivity of agonists to activate the N-methyl-D-aspartate (NMDA) receptor was presented by using typical agonists NMDA, L-glutamate and (2S, 3R, 4S)-2-(carboxycyclopropyl)glycine (L-CCG-IV) and the mouse epsilon1/zeta1 NMDA receptor incorporated in bilayer lipid membranes (BLMs) as an illustrative example. The method was based on the magnitude of an agonist-induced integrated single-channel current corresponding to the number of total ions passed through the open channel. The very magnitudes of the integrated single-channel currents were compared with the different BLMs as a new measure of agonist selectivity. The epsilon1/zeta1 NMDA receptor was partially purified from Chinese hamster ovary (CHO) cells expressing the epsilon1/zeta1 NMDA receptor and incorporated in BLMs formed by the tip-dip method. The agonist-induced integrated single-channel currents were obtained at 50 microM agonist concentration, where the integrated current for NMDA was shown to reach its saturated value. The obtained integrated currents were found to be (4.5 +/- 0.55) x 10(-13) C/s for NMDA, (5.8 +/- 0.72) x 10(-13) C/s for L-glutamate and (6.6 +/- 0.61) x 10(-13) C/s for L-CCG-IV, respectively. These results suggest that the agonist selectivity in terms of the total ion flux through the single epsilon1/zeta1 NMDA receptor is in the order of L-CCG-IV approximately = L-glutamate > NMDA.

  1. A single-channel method for evaluation of very magnitudes of Ca2+ ion fluxes through epsilon4/zeta1 N-methyl-D-aspartate receptor channels in bilayer lipid membranes.

    Science.gov (United States)

    Wakabayashi, M; Hirano, A; Sugawara, M; Uchino, S; Nakajima-Iijima, S

    2001-01-01

    A single-channel method for evaluating agonist selectivity in terms of the very number of Ca2+ ions passed through the epsilon4/zeta1 N-methyl-D-aspartate (NMDA) receptor ion channel in bilayer lipid membranes (BLMs) is described. The number of Ca2+ passed through the single-channel was obtained from single-channel recordings in a medium where the primary permeant ion is Ca2+. The recombinant epsilon4/zeta1 NMDA channel was partially purified from Chinese hamster ovary cells expressing the channel and incorporated in BLMs formed by the tip-dip method. It was found that the epsilon4/zeta1 channel in BLMs is permeable to Ca2+ and Na+, but the number of Ca2+ passed through the channel is much fewer than that of Na+. The integrated Ca2+ currents induced by three typical agonists NMDA, L-glutamate and L-CCG-IV were obtained at concentration of 50 microM, where the integrated currents for all the agonists reached their saturated values. The integrated Ca2+ currents obtained are (3.1+/-0.21) x 10(-13) C/s for NMDA, (4.6+/-0.31) x 10(-13) C/s for L-glutamate and (5.7+/-0.25) x 10(-13) C/s for L-CCG-IV, respectively, suggesting that the three kinds of agonists have different efficacies to induce permeation of Ca2+. The range of the agonist selectivity thus obtained is much narrower than that of binding affinities for the NMDA receptors from rat brain. The present method is able to detect Ca2+ permeation with a detection limit of approximately 10(5) Ca2+ ions/s.

  2. A designer bleomycin with significantly improved DNA cleavage activity.

    Science.gov (United States)

    Huang, Sheng-Xiong; Feng, Zhiyang; Wang, Liyan; Galm, Ute; Wendt-Pienkowski, Evelyn; Yang, Dong; Tao, Meifeng; Coughlin, Jane M; Duan, Yanwen; Shen, Ben

    2012-08-15

    The bleomycins (BLMs) are used clinically in combination with a number of other agents for the treatment of several types of tumors, and the BLM, etoposide, and cisplatin treatment regimen cures 90-95% of metastatic testicular cancer patients. BLM-induced pneumonitis is the most feared, dose-limiting side effect of BLM in chemotherapy, which can progress into lung fibrosis and affect up to 46% of the total patient population. There have been continued efforts to develop new BLM analogues in the search for anticancer drugs with better clinical efficacy and lower lung toxicity. We have previously cloned and characterized the biosynthetic gene clusters for BLMs from Streptomyces verticillus ATCC15003, tallysomycins from Streptoalloteichus hindustanus E465-94 ATCC31158, and zorbamycin (ZBM) from Streptomyces flavoviridis SB9001. Comparative analysis of the three biosynthetic machineries provided the molecular basis for the formulation of hypotheses to engineer novel analogues. We now report engineered production of three new analogues, 6'-hydroxy-ZBM, BLM Z, and 6'-deoxy-BLM Z and the evaluation of their DNA cleavage activities as a measurement for their potential anticancer activity. Our findings unveiled: (i) the disaccharide moiety plays an important role in the DNA cleavage activity of BLMs and ZBMs, (ii) the ZBM disaccharide significantly enhances the potency of BLM, and (iii) 6'-deoxy-BLM Z represents the most potent BLM analogue known to date. The fact that 6'-deoxy-BLM Z can be produced in reasonable quantities by microbial fermentation should greatly facilitate follow-up mechanistic and preclinical studies to potentially advance this analogue into a clinical drug.

  3. BlmB and TlmB provide resistance to the bleomycin family of antitumor antibiotics by N-acetylating metal-free bleomycin, tallysomycin, phleomycin, and zorbamycin.

    Science.gov (United States)

    Coughlin, Jane M; Rudolf, Jeffrey D; Wendt-Pienkowski, Evelyn; Wang, Liyan; Unsin, Claudia; Galm, Ute; Yang, Dong; Tao, Meifeng; Shen, Ben

    2014-11-11

    The bleomycin (BLM) family of glycopeptide-derived antitumor antibiotics consists of BLMs, tallysomycins (TLMs), phleomycins (PLMs), and zorbamycin (ZBM). The self-resistant elements BlmB and TlmB, discovered from the BLM- and TLM-producing organisms Streptomyces verticillus ATCC15003 and Streptoalloteichus hindustanus E465-94 ATCC31158, respectively, are N-acetyltransferases that provide resistance to the producers by disrupting the metal-binding domain of the antibiotics required for activity. Although each member of the BLM family of antibiotics possesses a conserved metal-binding domain, the structural differences between each member, namely, the bithiazole moiety and C-terminal amine of BLMs, have been suggested to instill substrate specificity within BlmB. Here we report that BlmB and TlmB readily accept and acetylate BLMs, TLMs, PLMs, and ZBM in vitro but only in the metal-free forms. Kinetic analysis of BlmB and TlmB reveals there is no strong preference or rate enhancement for specific substrates, indicating that the structural differences between each member of the BLM family play a negligible role in substrate recognition, binding, or catalysis. Intriguingly, the zbm gene cluster from Streptomyces flavoviridis ATCC21892 does not contain an N-acetyltransferase, yet ZBM is readily acetylated by BlmB and TlmB. We subsequently established that S. flavoviridis lacks the homologue of BlmB and TlmB, and ZbmA, the ZBM-binding protein, alone is sufficient to provide ZBM resistance. We further confirmed that BlmB can indeed confer resistance to ZBM in vivo in S. flavoviridis, introduction of which into wild-type S. flavoviridis further increases the level of resistance.

  4. Biochip for the Detection of Bacillus anthracis Lethal Factor and Therapeutic Agents against Anthrax Toxins

    Directory of Open Access Journals (Sweden)

    Vitalii Silin

    2016-06-01

    Full Text Available Tethered lipid bilayer membranes (tBLMs have been used in many applications, including biosensing and membrane protein structure studies. This report describes a biosensor for anthrax toxins that was fabricated through the self-assembly of a tBLM with B. anthracis protective antigen ion channels that are both the recognition element and electrochemical transducer. We characterize the sensor and its properties with electrochemical impedance spectroscopy and surface plasmon resonance. The sensor shows a sensitivity similar to ELISA and can also be used to rapidly screen for molecules that bind to the toxins and potentially inhibit their lethal effects.

  5. Recommended Locations of Beam Loss Monitors for the ATLAS Roman Pots

    CERN Document Server

    Hall-Wilton, R J; Talanov, V

    2007-01-01

    This note suggests suitable locations to position beam loss monitors to observe losses on the ATLAS Roman Pot station located close to 240m from IP1. This monitoring is envisaged to help to avoid quenches of the super- conducting magnets downstream of the roman pots and to avert damage to either the LHC machine elements or the roman pot detectors. The results presented in this note indicate the locations where the BLMs should be installed. The recommended locations are determined using previous simulation results on BLM response to losses; therefore these results should be considered in conjunction with the previous results. A more detailed note on the topic will follow later.

  6. Recommended locations of beam-loss monitors for the ATLAS Roman pots

    CERN Document Server

    Hall-Wilton, R J; Talanov, V

    2007-01-01

    This note suggests suitable locations to position beam loss monitors to observe losses on the ATLAS Roman Pot station located close to 240m from IP1. This monitoring is envisaged to help to avoid quenches of the super- conducting magnets downstream of the roman pots and to avert damage to either the LHC machine elements or the roman pot detectors. The results presented in this note indicate the locations where the BLMs should be installed. The recommended locations are determined using previous simulation results on BLM response to losses; therefore these results should be considered in conjunction with the previous results. A more detailed note on the topic will follow later.

  7. Radiation Levels around the LHC

    CERN Document Server

    Mala, P; Calviani, M; Nordt, A

    2013-01-01

    This work discuss on the radiation levels measured around the LHC machine during the 2012 operational year. The doses and particle fluences are measured primarily by RadMon detectors – about 300 RadMons are installed around the accelerator – and by thermoluminescent detectors. In addition, BLMs, IG5/PMI ionisation chambers as well as FGCs can be used for corresponding cumulated dose evaluations. The probability of SEE depends directly on the high-energy hadron (HEH) fluence, so this is the main parameter that is calculated based on RadMons counts.

  8. Critical halo loss locations in the LHC

    CERN Document Server

    Robert-Démolaize, Guillaume; Bracco, Chiara; Redaelli, Stefano; Weiler, Thomas

    2006-01-01

    Results of simulations with all movable elements of the LHC collimation system [1] are discussed for various operation modes. Compared to previous results, the placing of additional collimators reduced the beam losses by a factor 10 in the ideal machine case, i.e. nominal collimators settings for both 450 GeV and 7 TeV beam energies. First results for Beam 2 are also reviewed. The sensitivity of the system to free orbit oscillations is addressed. These results show that it is sufficient to use a limited number of beam loss monitors (BLMs) for the setup and optimization of the LHC Collimation System.

  9. Experimental Investigations of Direct and Converse Flexoelectric Effect in Bilayer Lipid Membranes.

    Science.gov (United States)

    Todorov, Angelio Todorov

    Flexoelectric coefficients (direct and converse), electric properties (capacitance and resistivity) and mechanical properties (thickness and elastic coefficients) have been determined for bilayer lipid membranes (BLMs) prepared from egg yolk lecithin (EYL), glycerol monoleate (GMO), phosphatidyl choline (PC) and phosphatidyl serine (PS) as a function of frequency, pH and surface charge modifiers. Direct flexoelectric effect manifested itself in the development of microvolt range a.c. potential (U_{f}) upon subjecting one side of a BLM to an oscillating hydrostatic pressure, in the 100-1000 Hz range. Operationally, the flexoelectric coefficient (f) is expressed by the ratio between U_{f} and the change of curvature (c) which accompanied the flexing of the membrane. Membrane curvature was determined by means of either the electric method (capacitance microphone effect) or by the newly developed method of stroboscopic interferometry. Real-time stroboscopic interferometry coupled with simultaneous electric measurements, provided a direct method for the determination of f. Two different frequency regimes of f were recognized. At low frequencies (free mobility of the surfactant, f-values of 24.1 times 10^{-19} and 0.87 times 10^ {-19} Coulombs were obtained for PC and GMO BLMs. At high frequencies (>300 Hz), associated with blocked mobility of the surfactant, f-values of 16.5 times 10^ {-19} and 0.30 times 10^{-19} Coulombs were obtained for PC and GMO BLMs. The theoretically calculated value for the GMO BLM oscillating at high frequency (0.12 times 10^{-19 } Coulombs) agreed well with that determined experimentally (0.3 times 10 ^{-19} Coulombs). For charged bovine brain PS BLM the observed flexocoefficient was f = 4.0 times 10^{ -18} Coulombs. Converse flexoelectric effect manifested itself in voltage-induced BLM curvature. Observations were carried out on uranyl acetate (UA) stabilized PS BLM under a.c. excitation. Frequency dependence of f was revealed by means of

  10. Injection quality measurements with diamond based particle detectors

    CERN Document Server

    Stein, Oliver; CERN. Geneva. ATS Department

    2016-01-01

    During the re-commissioning phase of the LHC after the long shutdown 1 very high beam losses were observed at the TDI during beam injection. The losses reached up to 90% of the dump threshold. To decrease the through beam losses induced stress on the accelerator components these loss levels need to be reduced. Measurements with diamond based particle detectors (dBLMs), which have nano-second time resolution, revealed that the majority of these losses come from recaptured SPS beam surrounding the nominal bunch train. In this MD the injection loss patterns and loss intensities were investigated in greater detail. Performed calibration shots on the TDI (internal beam absorber for injection) gave a conversion factor from impacting particles intensities to signal in the dBLMs (0.1Vs/109 protons). Using the SPS tune kicker for cleaning the recaptured beam in the SPS and changing the LHC injection kicker settings resulted in a reduction of the injection losses. For 144 bunch injections the loss levels were decreased...

  11. Pingyangmycin and Bleomycin Share the Same Cytotoxicity Pathway

    Directory of Open Access Journals (Sweden)

    Yanli He

    2016-06-01

    Full Text Available Pingyangmycin is an anticancer drug known as bleomycin A5 (A5, discovered in the Pingyang County of Zhejiang Province of China. Bleomycin (BLM is a mixture of mainly two compounds (A2 and B2, which is on the World Health Organization’s list of essential medicines. Both BLM and A5 are hydrophilic molecules that depend on transporters or endocytosis receptors to get inside of cells. Once inside, the anticancer activities rely on their abilities to produce DNA breaks, thus leading to cell death. Interestingly, the half maximal inhibitory concentration (IC50 of BLMs in different cancer cell lines varies from nM to μM ranges. Different cellular uptake, DNA repair rate, and/or increased drug detoxification might be some of the reasons; however, the molecules and signaling pathways responsible for these processes are largely unknown. In the current study, we purified the A2 and B2 from the BLM and tested the cytotoxicities and the molecular mechanisms of each individual compound or in combination with six different cell lines, including a Chinese hamster ovary (CHO cell line defective in glycosaminoglycan biosynthesis. Our data suggested that glycosaminoglycans might be involved in the cellular uptake of BLMs. Moreover, both BLM and A5 shared similar signaling pathways and are involved in cell cycle and apoptosis in different cancer cell lines.

  12. Detergent interaction with tethered bilayer lipid membranes for protein reconstitution

    Science.gov (United States)

    Broccio, Matteo; Zan Goh, Haw; Loesche, Mathias

    2009-03-01

    Tethered bilayer lipid membranes (tBLMs) are self-assembled biomimetic structures in which the membrane is separated from a solid substrate by a nm-thick hydrated submembrane space. These model systems are being used in binding studies of peripheral proteins and exotoxins. Here we aim at their application for the reconstitution of water-insoluble integral membrane proteins. As an alternative to fusion of preformed proteoliposomes we study the direct reconstitution of such proteins for applications in biosensing and pharmaceutical screening. For reconstitution, highly insulating tBLMs (R˜10^5-10^6 φ) were temporarily incubated with a detergent to screen for conditions that keep the detergent-saturated membranestable and ready to incorporate detergent-solubilized proteins. We assess the electrical characteristics, i.e. specific resistance and capacitance, by means of electrochemical impedance spectroscopy (EIS) under timed incubation with decylmaltoside and dodecylmaltoside detergents in a regime around their critical micelle concentration, 1.8 mM and 0.17 mM respectively and demonstrate the restoration of the tBLM upon detergent removal. Thereby a range of concentration and incubation times was identified, that represents optimal conditions for the subsequent membrane protein reconstitution.

  13. The Effect of Tethers on Artificial Cell Membranes: A Coarse-Grained Molecular Dynamics Study

    Science.gov (United States)

    Hoiles, William; Gupta, Rini; Cornell, Bruce; Krishnamurthy, Vikram

    2016-01-01

    Tethered bilayer lipid membranes (tBLMs) provide a stable platform for modeling the dynamics and order of biological membranes where the tethers mimic the cytoskeletal supports present in biological cell membranes. In this paper coarse-grained molecular dynamics (CGMD) is applied to study the effects of tethers on lipid membrane properties. Using results from the CGMD model and the overdamped Fokker-Planck equation, we show that the diffusion tensor and particle density of water in the tBLM is spatially dependent. Further, it is shown that the membrane thickness, lipid diffusion, defect density, free energy of lipid flip-flop, and membrane dielectric permittivity are all dependent on the tether density. The numerically computed results from the CGMD model are in agreement with the experimentally measured results from tBLMs containing different tether densities and lipids derived from Archaebacteria. Additionally, using experimental measurements from Escherichia coli bacteria and Saccharomyces Cerevisiae yeast tethered membranes, we illustrate how previous molecular dynamics results can be combined with the proposed model to estimate the dielectric permittivity and defect density of these membranes as a function of tether density. PMID:27736860

  14. Reliability of Beam Loss Monitor Systems for the Large Hadron Collider

    CERN Document Server

    Guaglio, Gianluca; Santoni, C

    2005-01-01

    The increase of beam energy and beam intensity, together with the use of super conducting magnets, opens new failure scenarios and brings new criticalities for the whole accelerator protection system. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system, and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses at 7 TeV and assisted by the Fast Beam Current Decay Monitors at 450 GeV. At medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data...

  15. End-of-Fill Diffusion and Halo Population Measurements with Physics Beams at 6.5 TeV

    CERN Document Server

    Valentino, Gianluca; Gorzawski, Arkadiusz; Redaelli, Stefano; Trad, Georges; Wagner, Joschka; Xu, Chen; CERN. Geneva. ATS Department

    2017-01-01

    Beam halo measurements at 6.5 TeV in the LHC were conducted with a full physics beam via collimator scrapings in end-of-fill MDs carried out in May and July 2016. From the time evolution of the beam losses in a collimator scan, it is possible to extract information on the halo diffusion and population. In the first MD, six scans were performed with two collimators in the vertical and horizontal planes in B1 and B2 respectively. The scans were done with squeezed colliding beams, with and without a gentle continuous transverse blow-up with the ADT (transverse damper) on a non-colliding bunch train. In the second MD, four scans were performed with the same collimators with squeezed colliding beams. The beam losses observed with the standard ionization chamber BLMs are compared to the diamond BLMs, and parametric fits of the diffusion model are applied to temporal loss patterns from colliding and non-colliding bunch trains. The results presented in this note also include the particle escape times and frequency an...

  16. Effect of temperature on the formation and inactivation of syringomycin E pores in human red blood cells and bimolecular lipid membranes.

    Science.gov (United States)

    Agner, G; Kaulin, Y A; Schagina, L V; Takemoto, J Y; Blasko, K

    2000-06-01

    The effects of temperature on the formation and inactivation of syringomycin E (SRE) pores were investigated with human red blood cells (RBCs) and lipid bilayer membranes (BLMs). SRE enhanced the RBC membrane permeability of 86Rb and monomeric hemoglobin in a temperature dependent manner. The kinetics of 86Rb and hemoglobin effluxes were measured at different temperatures and pore formation was found to be only slightly affected, while inactivation was strongly influenced by temperature. At 37 degrees C, SRE pore inactivation began 15 min after and at 20 degrees C, 40 min after SRE addition. At 6 degrees C, below the phase transition temperature of the major lipid components of the RBC membrane, no inactivation occurred for as long as 90 min. With BLMs, SRE induced a large current that remained stable at 14 degrees C, but at 23 degrees C it decreased over time while the single channel conductance and dwell time did not change. The results show that the temperature dependent inactivation of SRE pores is due to a decrease in the number of open pores.

  17. Integrating a Machine Protection System for High-Current Free Electron Lasers and Energy Recovery Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Trent Allison; James Coleman; Richard Evans; Al Grippo; Kevin Jordan

    2002-09-01

    A fully integrated Machine Protection System (MPS) is critical to efficient commissioning and safe operation of all high-current accelerators. The MPS needs to monitor the status of all devices that could enter the beam path, the beam loss monitors (BLMs), magnet settings, beam dump status, etc. This information is then presented to the electron source controller, which must limit the beam power or shut down the beam completely. The MPS for the energy recovery linac (ERL) at the Jefferson Lab Free Electron Laser [1] generates eight different power limits, or beam modes, which are passed to the drive laser pulse controller (DLPC) (photocathode source controller). These range from no beam to nearly 2 megawatts of electron beam power. Automatic masking is used for the BLMs during low-power modes when one might be using beam viewers. The system also reviews the setup for the two different beamlines, the IR path or the UV path, and will allow or disallow operations based on magnet settings and valve positions. This paper will describe the approach taken for the JLab 10-kW FEL. Additional details can be found on our website http://laser.jlab.org [2].

  18. Na+/D-glucose cotransporter based bilayer lipid membrane sensor for D-glucose.

    Science.gov (United States)

    Sugao, N; Sugawara, M; Minami, H; Uto, M; Umezawa, Y

    1993-02-15

    A new type of amperometric blosensor for glucose was fabricated using a Na+/D-glucose cotransporter as the signal-transducing sensory element that exploits the D-glucose-triggered Na+ ion current through bilayer lipid membranes (BLMs). The planar BLM was formed by the folding method across a small aperture of a thin Teflon film. The Na+/D-glucose cotransporter, isolated and purified from small intestinal brush border membrane of guinea pigs, was embedded into BLMs through proteoliposomes. The number of the protein molecules thus incorporated in the present sensing membrane was estimated to be ca. 10(7). The sensor response was measured as an ionic current through the BLM arising from cotransported Na+ ion flux under a constant applied potential and was only induced by D-glucose above 10(-9) M, but not by the other monosaccharides except for D-galactose. The effect of applied potentials, Na+ and K+ ion concentrations, and the addition of a competitive inhibitor, phlorizin, were scrutinized to characterize the sensor output. The results were briefly discussed in terms of the potential use of the Na+/D-glucose cotransporter as a sensory element for D-glucose.

  19. Modulation of the conductance of a 2,2'-bipyridine-functionalized peptidic ion channel by Ni2+.

    Science.gov (United States)

    Pilz, Claudia S; Steinem, Claudia

    2008-07-01

    An alpha-helical amphipathic peptide with the sequence H2N-(LSSLLSL)3-CONH2 was obtained by solid phase synthesis and a 2,2'-bipyridine was coupled to its N-terminus, which allows complexation of Ni2+. Complexation of the 2,2'-bipyridine residues was proven by UV/Vis spectroscopy. The peptide helices were inserted into lipid bilayers (nano black lipid membranes, nano-BLMs) that suspend the pores of porous alumina substrates with a pore diameter of 60 nm by applying a potential difference. From single channel recordings, we were able to distinguish four distinct conductance states, which we attribute to an increasing number of peptide helices participating in the conducting helix bundle. Addition of Ni2+ in micromolar concentrations altered the conductance behaviour of the formed ion channels in nano-BLMs considerably. The first two conductance states appear much more prominent demonstrating that the complexation of bipyridine by Ni2+ results in a considerable confinement of the observed multiple conductance states. However, the conductance levels were independent of the presence of Ni2+. Moreover, from a detailed analysis of the open lifetimes of the channels, we conclude that the complexation of Ni2+ diminishes the frequency of channel events with larger open times.

  20. A Versatile Beam Loss Monitoring System for CLIC

    CERN Document Server

    Kastriotou, Maria; Farabolini, Wilfrid; Holzer, Eva Barbara; Nebot Del Busto, Eduardo; Tecker, Frank; Welsch, Carsten

    2016-01-01

    The design of a potential CLIC beam loss monitoring (BLM) system presents multiple challenges. To successfully cover the 48 km of beamline, ionisation chambers and optical fibre BLMs are under investigation. The former fulfils all CLIC requirements but would need more than 40000 monitors to protect the whole facility. For the latter, the capability of reconstructing the original loss position with a multi-bunch beam pulse and multiple loss locations still needs to be quantified. Two main sources of background for beam loss measurements are identified for CLIC. The two-beam accelerator scheme introduces so-called crosstalk, i.e. detection of losses originating in one beam line by the monitors protecting the other. Moreover, electrons emitted from the inner surface of RF cavities and boosted by the high RF gradients may produce signals in neighbouring BLMs, limiting their ability to detect real beam losses. This contribution presents the results of dedicated experiments performed in the CLIC Test Facility to qu...

  1. Effect of synthetic aβ peptide oligomers and fluorinated solvents on Kv1.3 channel properties and membrane conductance.

    Directory of Open Access Journals (Sweden)

    Maria I Lioudyno

    Full Text Available The impact of synthetic amyloid β (1-42 (Aβ(1-42 oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs was quantified for protocols using hexafluoroisopropanol (HFIP or sodium hydroxide (NaOH as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ(1-42 samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ(1-42 oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ(1-42 solutions had no effect on Kv 1.3 channel properties. Aβ(1-42 oligomers had no effect on the steady-state current (at -80 mV recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ(1-42 peptide, and trifluoroacetic acid (TFA (used during Aβ(1-42 synthesis, we determined concentrations of these fluorinated compounds in the stock Aβ(1-42 solutions by (19F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ(1-42 solutions was ∼1.7 μM. The concentration of residual TFA in the 70× stock Aβ(1-42 solutions was ∼20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ(1-42 oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ(1-42 aggregation and potentially enhance ability

  2. Effect of synthetic aβ peptide oligomers and fluorinated solvents on Kv1.3 channel properties and membrane conductance.

    Science.gov (United States)

    Lioudyno, Maria I; Broccio, Matteo; Sokolov, Yuri; Rasool, Suhail; Wu, Jessica; Alkire, Michael T; Liu, Virginia; Kozak, J Ashot; Dennison, Philip R; Glabe, Charles G; Lösche, Mathias; Hall, James E

    2012-01-01

    The impact of synthetic amyloid β (1-42) (Aβ(1-42)) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ(1-42) samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ(1-42) oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ(1-42) solutions had no effect on Kv 1.3 channel properties. Aβ(1-42) oligomers had no effect on the steady-state current (at -80 mV) recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ(1-42) peptide), and trifluoroacetic acid (TFA) (used during Aβ(1-42) synthesis), we determined concentrations of these fluorinated compounds in the stock Aβ(1-42) solutions by (19)F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ(1-42) solutions was ∼1.7 μM. The concentration of residual TFA in the 70× stock Aβ(1-42) solutions was ∼20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ(1-42) oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ(1-42) aggregation and potentially enhance

  3. A extinção que não se acaba - "Nenhum, nenhuma"

    Directory of Open Access Journals (Sweden)

    Luiz Tatit

    2009-12-01

    Full Text Available

    Este artigo coteja duas visões de construção do sentido, uma formulada de maneira científi ca pela semiótica de Algirdas Julien Greimas e outra elaborada em termos literários pela pena de João Guimarães Rosa. A partir de uma análise do conto “Nenhum, nenhuma”, do escritor brasileiro, o autor desvenda as oscilações tensivas (de intensidade e extensidade que regulam a trama narrativa da história, mostrando que os diferentes graus de tonicidade e/ou velocidade dos afetos revelados pelas personagens confi guram com maior precisão as causas de seus encontros ou separações. O próprio enunciador manifesta sua fi delidade a uma das personagens do conto por meio de ajustes tensivos (ambos cultivam a duração, a longevidade que asseguram entre eles uma identidade profunda. Esse plano de interação difi cilmente seria reconhecido por um enfoque exclusivamente narrativo e discursivo.

  4. The Narrativization of an Unusual Event at the Belgrade Zoo: A Semiotic Analysis of The Story of Gabi the Dog and the Jaguar

    Directory of Open Access Journals (Sweden)

    Sonja Žakula

    2016-02-01

    Full Text Available The paper offers a semiotic analysis of the narrative of Gabi the dog and the jaguar in the form in which the story appears on the website of the Belgrade zoo. I believe that it is valid to assume that an analysis of this narrative can provide a window into the ways in which meanings of concepts such as ‘wildness’, ‘domesticity’, ‘freedom’, ‘captivity’ and ultimately, ‘nature’ and ‘culture’ are articulated within the context of this institution. On the one hand, I will base the paper on ideas articulated in the field of human-animal relations, and on the other on the methodological postulates of semiotic analysis introduced by Algirdas Julien Greimas and further developed by Dragana Antonijević. The aim of the paper is to, by applying semiotic analysis to the way in which an unusual event at the zoo was narrativized, uncover the deeper structure of thought which underlies the story and reflects and shapes not just the discourse of the Belgrade zoo, but the implicit understanding of the role and function of zoos in Serbia up until the present day.

  5. Romaria- uma análise semiótica

    Directory of Open Access Journals (Sweden)

    Ana Raquel Mota

    2007-06-01

    Full Text Available O presente artigo é uma análise semiótica de uma canção popular brasileira, Romaria, de Renato Teixeira. Como base teórica e metodológica, utiliza-se a Semiótica estabelecida por Algirdas Greimas, presente, por exemplo, na exploração de conceitos como os de  isotopia e debreagem no nível discursivo e os de funções actanciais no nível narrativo. Aliada a esses níveis, propõe-se uma análise de algumas categorias tensivas de Romaria, nos termos estabelecidos por Claude Zilberberg e que vêm sendo desenvolvidos no Brasil por Luiz Tatit. Em sua primeira parte, o artigo traz uma análise englobante dos três níveis da letra; já em sua segunda parte, é feita a relação com a melodia. Por fim, o artigo traz uma breve contextualização histórica de Romaria em 1977, momento de sua mais célebre gravação, por Elis Regina e o Grupo Água.

  6. Estruturalismo e semiótica: aproximações entre Saussure e Greimas

    Directory of Open Access Journals (Sweden)

    José Petrúcio Farias Júnior

    2010-06-01

    Full Text Available

    Propor-nos-emos, no transcorrer desse artigo, discorrer sobre dois lingüistas preocupados com a questão do signo lingüístico, a saber: Ferdinand de Saussure (1857-1913 e Algirdas Julien Greimas (1917-1992, os quais se debruçaram sobre a teoria da verificação do significado e colaboraram, guardadas as devidas proporções, para a organização, fortalecimento e dinamicidade do estruturalismo, como corrente do pensamento científico. Objetivamos, mais precisamente, delinear as contribuições de Saussure ao estruturalismo e verificar em que medida Greimas promoveu a revisão do pensamento de Saussure e produziu inovações, no campo das pesquisas sobre a manifestação do significado.

  7. Korupsi dalam Film Indonesia

    Directory of Open Access Journals (Sweden)

    Rhafidilla Vebrynda

    2015-01-01

    Full Text Available Abstract: Corruption has been rooted and institutionalized in our smallest environment. The campaign to fight corruption comes from various organizations through numerous varieties of means. This study looks at the Komisi Pemberantasan Korupsi (KPK campaign through a film entitled “Kita Versus Korupsi”. This study uses narrative analysis by looking at the elements of narrative, narrative structure, the analysis model of aktan and the Greimas’ semiotic square. It is found that the film narrates corruption as trouble and resistor. The various forms of corruption are narrated using the combination of techniques scene, dialogue and flashback. Abstrak: Korupsi sudah mengakar dan melembaga hingga lingkungan terkecil kita. Kampanye untuk melawannya datang dari berbagai pihak melalui beragam sarana. Penelitian ini melihat kampanye Komisi Pemberantasan Korupsi (KPK melalui film “Kita Versus Korupsi”. Menggunakan metode analisis naratif dengan melihat unsur naratif, struktur naratif, analisis model aktan dan oposisi segi empat Algirdas Greimas, penelitian ini menemukan bahwa korupsi dinarasikan sebagai gangguan dan penghambat. Film tersebut selalu menghadapkan pelaku korupsi dengan pihak yang tidak korupsi secara langsung. Latar belakang pengetahuan tokoh utama tentang korupsi berpengaruh dalam pengambilan keputusannya. Berbagai bentuk korupsi dinarasikan dengan teknik penggabungan scene, dialog dan flashback.

  8. Scans of the Physics Debris Absorbers (TCL) at the 4TeV LHC

    CERN Document Server

    Marsili, A; Quaranta, E; Redaelli, S; Salvachua, B; Valentino, G; CERN. Geneva. ATS Department

    2014-01-01

    At the Large Hadron Collider (LHC), dedicated physics debris collimators (TCL) protect the machine from the collision products at the high-luminosity experiments. These collimators reduce the risk of quenches of superconducting magnets by cleaning physics debris losses. One TCL is installed per beam in IR1 and IR5. Several measurements have been performed in 2012 at 4TeV, with peak luminosity values up to 6:3 1033 cm2 s1 to address the need of these devices and optimize their settings. They consist in opening the collimator from its nominal setting to an \\open" setting, and observing the evolution of the losses measured by the Beam Loss Monitors (BLMs) downstream. All the 2012 measurements are analysed here, including asymmetric measurement with only one jaw. The evolution of the losses as a function of the collimator setting are presented, as well as the loss proles and the ratio of the losses with TCL in over TCL out.

  9. Cryogenic Semiconductor Detectors: Simulation of Signal Formation & Irradiation Beam Test

    CERN Document Server

    AUTHOR|(CDS)2091318; Stamoulis, G; Vavougios, D

    The Beam Loss Monitoring system of the Large Hadron Collider is responsible for the pro- tection of the machine from damage and for the prevention of a magnet quench. Near the interaction points of the LHC, in the triplet magnets area, the BLMs are sensitive to the collision debris, limiting their ability to distinguish beam loss signal from signal caused due to the collision products. Placing silicon & diamond detectors inside the cold mass of the mag- nets, in liquid helium temperatures, would provide significant improvement to the precision of the measurement of the energy deposition in the superconducting coil of the magnet. To further study the signal formation and the shape of the transient current pulses of the aforementioned detectors in cryogenic temperatures, a simulation application has been developed. The application provides a fast way of determining the electric field components inside the detectors bulk and then introduces an initial charge distribution based on the properties of the radiat...

  10. A Parallel Sensing Technique for Automatic Bilayer Lipid Membrane Arrays Monitoring

    Directory of Open Access Journals (Sweden)

    Michele ROSSI

    2012-03-01

    Full Text Available Ion channels are transmembrane proteins responsible of cell signaling and a large part of pharmaceutical compounds are interacting with them. In-vitro testing of ion channels is a promising technique for high throughput screening (HTS in drug discovery and personalized medicine. Automated tests of single ion channels embedded in artificial bilayer lipid membranes (BLM is gaining attention over patch clamp technique due to its characteristic of performing parallel tests on selected sets of channels or multiple pharmaceutical targets. However, BLM arrays formation is a critical process based on manual and time-consuming techniques. In this paper, an automatic liquid dispensing system for BLM formation monitored in real-time by using low-noise current amplifiers is presented. As proof of this approach, concurrent formation of BLMs is shown. Additionally, single ion channel recordings on an automatically formed BLM is presented and discussed.

  11. Development of solid supports for electrochemical study of biomimetic membrane systems

    DEFF Research Database (Denmark)

    Mech-Dorosz, Agnieszka

    recording of a steady-state photocurrent while only a transient photocurrent peak was recorded on the polyelectrolyte cushion without a PES membrane. This PhD thesis also comprises the design and fabrication process of a modular microfluidic system with automated fluid delivery (micropumps and valves...... with reconstituted membrane spanning proteins, are attractive tools. However, BLMs suffer from intrinsic fragility, therefore, requiring techniques to increase their robustness and stability. This PhD thesis presents strategies to construct solid supports for electrochemical studies of two biomimetic membrane...... transporter valinomycin. The presented work also includes a comprehensive EIS analysis and cryological scanning electron microscopic (cryo-SEM) imaging of hydrogels formulated in various molar ratios (1:100; 1:200; 1:400) of the cross-linker poly(ethylene glycol)dimethacrylate (PEGDMA) and 2-hydroxyethylene...

  12. Preservation of beam loss induced quenches, beam lifetime and beam loss measurements with the HERAp beam-loss-monitor system

    Science.gov (United States)

    Wittenburg, Kay

    1994-06-01

    The beam-loss-monitors (BLMs) in the HERA-proton-ring (HERAp) must fulfill the following requirements: They have to measure losses sensitive and fast enough to prevent the superconducting magnets from beam loss induced quenching; the dynamic range of the monitors must exceed several decades in order to measure losses during beam lifetimes of hundreds of hours as well as the much stronger losses that may quench superconducting magnets; they have to be insensitive to the synchrotron radiation of the adjacent electron-ring (HERAe); and their radiation hardness must allow a monitor-lifetime of a few years of HERA operation. These requirements are well satisfied by the HERAp-BLM-System.

  13. Simulator for beam-based LHC collimator alignment

    Science.gov (United States)

    Valentino, Gianluca; Aßmann, Ralph; Redaelli, Stefano; Sammut, Nicholas

    2014-02-01

    In the CERN Large Hadron Collider, collimators need to be set up to form a multistage hierarchy to ensure efficient multiturn cleaning of halo particles. Automatic algorithms were introduced during the first run to reduce the beam time required for beam-based setup, improve the alignment accuracy, and reduce the risk of human errors. Simulating the alignment procedure would allow for off-line tests of alignment policies and algorithms. A simulator was developed based on a diffusion beam model to generate the characteristic beam loss signal spike and decay produced when a collimator jaw touches the beam, which is observed in a beam loss monitor (BLM). Empirical models derived from the available measurement data are used to simulate the steady-state beam loss and crosstalk between multiple BLMs. The simulator design is presented, together with simulation results and comparison to measurement data.

  14. RF Cavity Induced Sensitivity Limitations on Beam Loss Monitors

    Science.gov (United States)

    Kastriotou, M.; Degiovanni, A.; Sousa, F. S. Domingues; Effinger, E.; Holzer, E. B.; Quirante, J. L. Navarro; del Busto, E. N.; Tecker, F.; Viganò, W.; Welsch, C. P.; Woolley, B. J.

    Due to the secondary showers generated when a particle hits the vacuum chamber, beam losses at an accelerator may be detected via radiation detectors located near the beam line. Several sources of background can limit the sensitivity and reduce the dynamic range of a Beam Loss Monitor (BLM). This document concentrates on potential sources of background generated near high gradient RF cavities due to dark current and voltage breakdowns. An optical fibre has been installed at an experiment of the Compact Linear Collider (CLIC) Test Facility (CTF3), where a dedicated study of the performance of a loaded and unloaded CLIC accelerating structure is undergoing. An analysis of the collected data and a benchmarking simulation are presented to estimate BLM sensitivity limitations. Moreover, the feasibility for the use of BLMs optimised for the diagnostics of RF cavities is discussed.

  15. Raman Spectra Of Double-Walled Carbon Nanotubes

    Science.gov (United States)

    Vuković, T.; Dmitrović, S.; Dobardžić, E.

    2007-04-01

    Using nonresonant bond-polarization theory, Raman spectra of periodic double-walled carbon nanotubes (DWCNTs) are calculated. Due to the lower symmetry of DWCNT, the number of Raman active modes is much larger compared to those of its layers. Complete frequency range of the tubes spectra has been analyzed for large number of tubes. We found that only modes whose frequencies are below 800 cm-1 have noticeable up shifts compared to those of isolated layers. Special attention is given to radial breathing modes (RBMs) and G-band region since these modes are used for the identification of singe-walled carbon nanotubes. In case of breathing like modes (BLMs), frequency of the out of phase mode is found to be chirality dependent, while the in phase one remains only diameter dependent as in the case of individual layers.

  16. Electro-optical BLM chips enabling dynamic imaging of ordered lipid domains.

    Science.gov (United States)

    Shao, Chenren; Kendall, Eric L; DeVoe, Don L

    2012-09-01

    Studies of lipid rafts, ordered microdomains of sphingolipids and cholesterol within cell membranes, are essential in probing the relationships between membrane organization and cellular function. While in vitro studies of lipid phase separation are commonly performed using spherical vesicles as model membranes, the utility of these models is limited by a number of factors. Here we present a microfluidic device that supports simultaneous electrical measurements and confocal imaging of on-chip bilayer lipid membranes (BLMs), enabling real-time multi-domain imaging of membrane organization. The chips further support closed microfluidic access to both sides of the membrane, allowing the membrane boundary conditions to be rapidly changed and providing a mechanism for dynamically adjusting membrane curvature through application of a transmembrane pressure gradient. Here we demonstrate the platform through the study of dynamic generation and dissolution of ordered lipid domains as membrane components are transported to and from the supporting annulus containing solvated lipids and cholesterol.

  17. Halo Scraping, Diffusion and Repopulation MD

    CERN Document Server

    Valentino, G; Bruce, R; Burkart, F; Redaelli, F; Salvachua, B; Previtali, V; Stancari, G; Valishev, A

    2012-01-01

    Beam halo measurements in the LHC were conducted through collimator scrapings in an MD carried out on the 22nd June 2012 for the first time at 4 TeV. The time evolution of losses during a collimator scan provides information on halo diffusion and population. Four scans were performed with two collimators in the vertical and horizontal plane in B1 and B2 respectively, before and after bringing the beams into collisions. During an inward step, the beam losses measured at the BLMs for the first 3 seconds are believed to be dominated by multi-turn halo removal by the collimator jaw. However, a good comparison was found between fits of the diffusion model and the subsequent loss decay. In addition, the fitted diffusion coefficients compare well to the coefficients estimated from the core emittance growth rates as a function of action.

  18. Environmental management and monitoring of coal bed methane development and production, northern San Juan Basin, Colorado, USA

    Energy Technology Data Exchange (ETDEWEB)

    Witherbee, K.G.; Salwerowicz, F.A.; Hoffmann, K.L.; Swanson, D.M.; Lovato, J.A. [Colorado State Office, Lakewood, CO (United States). Bureau of Land Management

    1994-12-31

    Potential contamination of groundwater supplies from methane produced from coal has become a critical environmental concern in the northern San Juan basin, Colorado. BLM`s San Juan Resources Area (SJRA) office was instrumental and proactive in building citizens` confidence in our regulatory responsibilities, establishing an environmental baseline, identifying potential sources of contamination, and instituting annual monitoring (Bradenhead testing) of all jurisdictional wells. Outreach programs by the SJRA have continued to maintain lines of communication among the various regulatory agencies, special interest groups, and concerned citizens. These programs emphasized the regulatory requirements necessary to protect valid existing rights to develop the gas resources, as well as protecting the resource values of the surface. Future activity includes continued coordination with other governmental agencies, state and local governments, and citizens groups and remains among our highest priority in managing resource development. This coordination is necessary to maintain the starting of information, identificating and mitigating of problems, and for developing reasonable alternatives. 4 refs.

  19. ECG De-noising

    DEFF Research Database (Denmark)

    Kærgaard, Kevin; Jensen, Søren Hjøllund; Puthusserypady, Sadasivan

    2015-01-01

    Electrocardiogram (ECG) is a widely used noninvasive method to study the rhythmic activity of the heart and thereby to detect the abnormalities. However, these signals are often obscured by artifacts from various sources and minimization of these artifacts are of paramount important. This paper...... proposes two adaptive techniques, namely the EEMD-BLMS (Ensemble Empirical Mode Decomposition in conjunction with the Block Least Mean Square algorithm) and DWT-NN (Discrete Wavelet Transform followed by Neural Network) methods in minimizing the artifacts from recorded ECG signals, and compares...... their performance. These methods were first compared on two types of simulated noise corrupted ECG signals: Type-I (desired ECG+noise frequencies outside the ECG frequency band) and Type-II (ECG+noise frequencies both inside and outside the ECG frequency band). Subsequently, they were tested on real ECG recordings...

  20. Undulation instability in a bilayer lipid membrane due to electric field interaction with lipid dipoles

    CERN Document Server

    Bingham, Richard J; Smye, Stephen W

    2010-01-01

    Bilayer lipid membranes [BLMs] are an essential component of all biological systems, forming a functional barrier for cells and organelles from the surrounding environment. The lipid molecules that form membranes contain both permanent and induced dipoles, and an electric field can induce the formation of pores when the transverse field is sufficiently strong (electroporation). Here, a phenomenological free energy is constructed to model the response of a BLM to a transverse static electric field. The model contains a continuum description of the membrane dipoles and a coupling between the headgroup dipoles and the membrane tilt. The membrane is found to become unstable through buckling modes, which are weakly coupled to thickness fluctuations in the membrane. The thickness fluctuations, along with the increase in interfacial area produced by membrane buckling, increase the probability of localized membrane breakdown, which may lead to pore formation. The instability is found to depend strongly on the strengt...

  1. Is there a limitation to the stored beam energy for 2011 and beyond?

    CERN Document Server

    Schmidt, R

    2011-01-01

    The machine protection systems have been designed to ultimately operate with beams of a stored energy of 360MJ. This presentation will address if there is an intermediate limit and what upgrades are required to permit operation with 360MJ. A failure in one of the protection systems (BLM, BIC, LBDS, ...) could have catastrophic consequences for LHC. Considering the operational experience, the most critical failure modes are reviewed, their probability is estimated and methods for mitigation are discussed. Ideas for reducing the risk include additional interlocks (DIDT interlock, abort gap cleaning/monitoring, fast BLMs, additional BPMs as HW interlock, aperture measurements,...), operational procedures and upgrades of hardware systems. There are also examples when the beams should NOT be dumped immediately.

  2. MD456: Monitoring of abort gap population with diamond particle detectors at the BGI in IP 4

    CERN Document Server

    Stein, Oliver

    2016-01-01

    In this MD, diamond based particle detectors (dBLM) were used for measuring showers of the beam interactions with the in the BGI induced neon gas. This setup was proposed in a feasibility study for using dBLMs at the BGI to measure the abort gap population by detecting the beam gas interactions. During the MD neon gas was induced in the BGI vacuum chamber to increase the interaction rate. Two nominal bunches were injected and accelerated up to 6.5 TeV. The measurements lasted for 140 minutes. The bunches could be clearly identified. But the resulting count rate of the beam gas interactions was a factor 70 lower than predicted by the feasibility study. In addition, a problem with the timing information lead to a widening of the histogram peaks.

  3. Ecological risk assessment of boreal sediments affected by metal mining: Metal geochemistry, seasonality, and comparison of several risk assessment methods.

    Science.gov (United States)

    Väänänen, Kristiina; Kauppila, Tommi; Mäkinen, Jari; Leppänen, Matti T; Lyytikäinen, Merja; Akkanen, Jarkko

    2016-10-01

    The mining industry is a common source of environmental metal emissions, which cause long-lasting effects in aquatic ecosystems. Metal risk assessment is challenging due to variations in metal distribution, speciation, and bioavailability. Therefore, seasonal effects must be better understood, especially in boreal regions in which seasonal changes are large. We sampled 4 Finnish lakes and sediments affected by mining for metals and geochemical characteristics in autumn and late winter, to evaluate seasonal changes in metal behavior, the importance of seasonality in risk assessment, and the sensitivity and suitability of different risk assessment methods. We compared metal concentrations in sediment, overlying water, and porewater against environmental quality guidelines (EQGs). We also evaluated the toxicity of metal mixtures using simultaneously extracted metals and an acid volatile sulfides (SEM-AVS) approach together with water quality criteria (US Environmental Protection Agency equilibrium partitioning benchmarks). Finally, site-specific risks for 3 metals (Cu, Ni, Zn) were assessed using 2 biotic ligand models (BLMs). The metal concentrations in the impacted lakes were elevated. During winter stratification, the hypolimnetic O2 saturation levels were low (89%) and neutral pH (6.1-7.5) were found after the autumnal water overturn. Guidelines were the most conservative benchmark for showing an increased risk of toxicity in the all of the lakes. The situation remained stable between seasons. On the other hand, SEM-AVS, equilibrium partition sediment benchmarks (ESBs), and BLMs provided a clearer distinction between lakes and revealed a seasonal variation in risk among some of the lakes, which evidenced a higher risk during late winter. If a sediment risk assessment is based on the situation in the autumn, the overall risk may be underestimated. It is advisable to carry out sampling and risk assessment during periods in which metals are assumed to be the most

  4. Value of counting positive PHH3 cells in the diagnosis of uterine smooth muscle tumors.

    Science.gov (United States)

    Pang, Shu-Jie; Li, Cheng-Cheng; Shen, Yan; Liu, Yian-Zhu; Shi, Yi-Quan; Liu, Yi-Xin

    2015-01-01

    The diagnosis of uterine smooth muscle tumors including leiomyosarcomas (LMS), smooth muscle tumors of uncertain malignant potential (STUMP), bizarre (atypical) leiomyoma (BLM), mitotically active leiomyoma (MAL) and leiomyoma (LM) depends on a combination of microscopic features, such as mitoses, cytologic atypia, and coagulative tumor cell necrosis. However, a small number of these tumors still pose difficult diagnostic challenges. The assessment of accurate mitotic figures (MF) is one of the major parameters in the proper classification of uterine smooth muscle tumors. This assessment can be hampered by the presence of increased number of apoptotic bodies or pyknotic nuclei, which frequently mimic mitoses. Phospho-histone H3 (PHH3) is a recently described immunomarker specific for cells undergoing mitoses. In our study, we collected 132 cases of uterine smooth muscle tumors, including 26 LMSs, 16 STUMPs, 30 BLMs, 30 MALs and 30 LMs. We used mitosis specific marker PHH3 to count mitotic indexes (MI) of uterine smooth muscle tumors and compared with the mitotic indexes of hematoxylin and eosin (H&E). There is a positive correlation with the number of mitotic figures in H&E-stained sections and PHH3-stained sections (r=0.944, P0.05). The counting value of PHH3 in LMSs have significantly higher than STUMPs, BLMs, MALs and LMs (Pnumber of mitotic indexes in H&E. To conclude, our results show that counting PHH3 is a useful index in the diagnosis of uterine smooth muscle tumors and it can provide a more accurate index instead of the time-honored mitotic figure counts at a certain ratio.

  5. Electrochemical evaluation of chemical selectivity of glutamate receptor ion channel proteins with a multi-channel sensor.

    Science.gov (United States)

    Sugawara, M; Hirano, A; Rehák, M; Nakanishi, J; Kawai, K; Sato, H; Umezawa, Y

    1997-01-01

    A new method for evaluating chemical selectivity of agonists towards receptor ion channel proteins is proposed by using glutamate receptor (GluR) ion channel proteins and their agonists N-methyl-D-aspartic acid (NMDA), L-glutamate, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (L-CCG-IV). Integrated multi-channel currents, corresponding to the sum of total amount of ions passed through the multiple open channels, were used as a measure of agonists' selectivity to recognize ion channel proteins and induce channel currents. GluRs isolated from rat synaptic plasma membranes were incorporated into planar bilayer lipid membranes (BLMs) formed by the folding method. The empirical factors that affect the selectivity were demonstrated: (i) the number of GluRs incorporated into BLMs varied from one membrane to another; (ii) each BLM contained different subtypes of GluRs (NMDA and/or non-NMDA subtypes); and (iii) the magnitude of multi-channel responses induced by L-glutamate at negative applied potentials was larger than at positive potentials, while those by NMDA and L-CCG-IV were linearly related to applied potentials. The chemical selectivity among NMDA, L-glutamate and L-CCG-IV for NMDA subtype of GluRs was determined with each single BLM in which only NMDA subtype of GluRs was designed to be active by inhibiting the non-NMDA subtypes using a specific antagonist DNQX. The order of selectivity among the relevant agonists for the NMDA receptor subtype was found to be L-CCG-IV > L-glutamate > NMDA, which is consistent with the order of binding affinity of these agonists towards the same NMDA subtypes. The potential use of this approach for evaluating chemical selectivity towards non-NMDA receptor subtypes of GluRs and other receptor ion channel proteins is discussed.

  6. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    comprehensive review of the different localization mechanisms and their implication for internal quantum efficiency (IQE) is proposed by Oliver and co-workers from Cambridge University. When discussing IQE in InGaN-based LEDs, the efficiency droop at high-current injection always emerges, which is a major concern for the future of SSL technology. Here, a collaborative work between Samsung and the Gwangju Institute of Science and Technology (Korea) proves that a specific design of the active region can limit this detrimental effect. Once the issue of the IQE is solved, one still has to let the photons out of the chip. Matioli and Weisbuch from the University of California at Santa Barbara introduce the use of photonic crystals (PhCs) to improve light extraction efficiency. They describe different approaches to overcoming the main limitation of LEDs when implementing surface PhCs. The technology of SSL, and in particular of colour rendering, is tackled by Zukauskas et al who studied in detail different white light sources. They show that extreme colour-fidelity indices need to cover the entire spectrum, with a broad-band at 530-610 nm and a component beyond 610 nm. Then, the reliability of GaN-based LEDs is discussed in the paper of Meneghesso and co-workers. The authors consider the most important physical mechanisms that are (i) the degradation of the active layer of LEDs, (ii) the degradation of the package/phosphor system, (iii) the failure of GaN-based LEDs against electrostatic discharge. Finally, GaN LEDs on silicon developed in the group of Egawa at the Nagoya Institute of Technology are presented. This technology could allow a significant decrease in the fabrication cost of white LEDs.

  7. Delineating Two Exclusive Views on Power of Choosing & Modal Dynamics of Double Performances

    Directory of Open Access Journals (Sweden)

    Mahshad Jalalpourroodsari

    2012-11-01

    Full Text Available This article endeavors to make use of the theories presented by French semiotician Algirdas Julien Greimas, in order to demonstrate the main structural exchanges inherent within some of the critical choices and acute performances at the heart of Ibsen’s A Doll’s House. In this study, the syntagmatic exchange structures and the paradigmatic structures of gift and test which are at work within the narrative line of the play are discussed and exteriorized so that there can be a better apprehension and appreciation for the internal path of signification concerning the relation of the main couple actants (Note 1 in this discourse. It will be seen how the power to choose of the protagonists of exchange or loci of exchange structures might be exercised or overlooked and how one may devalorise and negate an offer of exchange based on the way it is modally interpreted. This study will contemplate on the manner in which one’s voluntary renunciation of rights may metamorphose into a manipulative and deceptive dispossession of that right, when actants get involved in parallel programmes which are complementary and at the same time contradictory to one another. Thus, through adopting such a perspective towards the choices made and the dilemmas faced by the main actants of Ibsen’s discourse, one gets the chance to have a more tangible canvas on which to draw Nora and Torvald’s change of hearts and malfunctioning transactions.  Keywords: Exchange Structure, Double Performance, Power of Choosing, Dilemma, Free Choice, Veridictory  Modality, Overmodality, Valence, Attribution, Renunciation, Dispossession, Appropriation.

  8. Exploring the State of Unbalance within the Topical and Heterotopical Spaces at the Core of Story

    Directory of Open Access Journals (Sweden)

    Mahshad Jalalpourroodsari

    2013-01-01

    Full Text Available This paper examines one of the ways in which narrativity as a complex concept is rooted in almost simple notions which support it at its basic levels. The discussion here would be devoted to the concept of the minimal story (récit minimal which is defined as being part of the surface narrative syntax of every discourse in general and Ibsen’s            A Doll’s House in particular. It will be seen how the play’s content signs are converted via the minimal story and how the supporting pillars of this discourse are grounded in elementary types of narrative programmes which cement the trajectory (Note 1 of meaning at its surface stratum. The basis of this research is the semiotic theory proposed by the French structuralist semiotician Algirdas Julien Greimas as the founder of Paris School of semiotics. It will be seen how the story can arrange itself from its end and how the whole narrative process may possess a temporal and syntactic orientation which forms the bare structure around which the whole story is weaved. This paper attempts to shed some light on the inner fluctuations at the heart of Ibsen’s play accommodating an orientational schema which the semioticians would call the nucleus of all narrative systems. Therefore, in this article, an introduction of the basic concepts will be followed by an analysis of the turbulences affecting the main figures/actants (Note 2 inhabiting the minimal story of Ibsen’s discourse.      Keywords: Minimal Story, Permanence, Change, Correlated Contents, Temporal/Thematic Axis,    Inversed/posited Content, Topical/Heterotopical Space

  9. Tethered bimolecular lipid membranes - A novel model membrane platform

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, Wolfgang; Koeper, Ingo; Naumann, Renate; Sinner, Eva-Kathrin [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)

    2008-10-01

    This contribution summarizes some of our efforts in designing, synthesizing, assembling, and characterizing functional tethered bimolecular lipid membranes (tBLMs) as a novel platform for biophysical studies of and with artificial membranes or for sensor development employing, e.g., membrane integral receptor proteins. Chemical coupling schemes based on thiol groups for Au substrates or silanes used in the case of oxide surfaces allow for the covalent and, hence, chemically and mechanically robust attachment of anchor lipids to the solid support, stabilizing the proximal layer of a tethered membrane on the transducer surface. Surface plasmon optics, the quartz crystal microbalance, fluorescence- and IR spectroscopies, and electrochemical techniques are used to characterize the build-up of these complex supramolecular interfacial architectures. We demonstrate, in particular, that bilayers with a specific electrical resistance of better than 10 M{omega} cm{sup 2} can be achieved routinely with this approach. The functionalization of the lipid membranes by the incorporation of peptides is demonstrated for the carrier valinomycin which shows in our tBLMs the expected discrimination by four orders of magnitude between the translocation of K{sup +}- and Na{sup +}-ions across the hydrophobic barrier. For the synthetic channel-forming peptide M2 the high electrical resistance of the bilayer with the correspondingly low background current allows for the recording of even single channel current fluctuations. From the many membrane proteins that we reconstituted so far we describe results obtained with the redox-protein cytochrome c oxidase. Here, we also use a genetically modified mutant with a His-tag at either the C- or the N-terminus for the oriented attachment of the protein via the NTA/Ni{sup 2+} approach. With this strategy, we not only can control the density of the immobilized functional units, we introduce a completely new and alternative concept for the

  10. Study of supported bilayer lipid membranes for use in chemo-electric energy conversion via active proton transport

    Science.gov (United States)

    Sarles, Stephen A.; Sundaresan, Vishnu B.; Leo, Donald J.

    2007-09-01

    Bilayer lipid membranes (BLMs) have been studied extensively due to functional and structural similarities to cell membranes, fostering research to understand ion-channel protein functions, measure bilayer mechanical properties, and identify self-assembly mechanisms. BLMs have traditionally been formed across single pores in substrates such as PTFE (Teflon). The incorporation of ion-channel proteins into the lipid bilayer enables the selective transfer of ions and fluid through the BLM. Processes of this nature have led to the measurement of ion current flowing across the lipid membrane and have been used to develop sensors that signal the presence of a particular reactant (glucose, urea, penicillin), improve drug recognition in cells, and develop materials capable of creating chemical energy from light. Recent research at Virginia Tech has shown that the incorporation of proton transporters in a supported BLM formed across an array of pores can convert chemical energy available in the adenosine triphosphate (ATP) into electricity. Experimental results from this work show that the system-named Biocell-is capable of developing 2µW/cm2 of membrane area with 15μl of ATPase. Efforts to increase the power output and conversion efficiency of this process while moving toward a packaged device present a unique engineering problem. The bilayer, as host to the active proton transporters, must therefore be formed evenly across a porous substrate, remain stable and yet fluid-like for protein interaction, and exhibit a large seal resistance. This article presents the ongoing work to characterize the Biocell using impedance analysis. Electrical impedance spectroscopy (EIS) is used to study the effect of adding ATPase proteins to POPS:POPE bilayer lipid membranes and correlate structural changes evident in the impedance data to the energy-conversion capability of various partial and whole Biocell assemblies. The specific membrane resistance of a pure BLM drops from 40-120k

  11. Monte Carlo Studies of the Radiation Fields in the Linac Coherent Light Source Undulators and of the Corresponding Signals in the Cerenkov Beam Loss Monitors

    Energy Technology Data Exchange (ETDEWEB)

    Santana Leitner, Mario; Fasso, Alberto; Fisher, Alan S.; Nuhn, Heinz D.; /SLAC; Dooling, Jeffrey C.; Berg, William; Yang, Bin X.; /Argonne

    2010-09-14

    In 2009 the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Center started free electron laser (FEL) operation. In order to continue to produce the bright and short-pulsed x-ray laser demanded by FEL scientists, this pioneer hard x-ray FEL requires a perfectly tailored magnetic field at the undulators, so that the photons generated at the electron wiggling path interact at the right phase with the electron beam. In such a precise system, small (>0.01%) radiation-induced alterations of the magnetic field in the permanent magnets could affect FEL performance. This paper describes the simulation studies of radiation fields in permanent magnets and the expected signal in the detectors. The transport of particles from the radiation sources (i.e. diagnostic insert) to the undulator magnets and to the beam loss monitors (BLM) was simulated with the intra nuclear cascade codes FLUKA and MARS15. In order to accurately reproduce the optics of LCLS, lattice capabilities and magnetic fields were enabled in FLUKA and betatron oscillations were validated against reference data. All electron events entering the BLMs were printed in data files. The paper also introduces the Radioactive Ion Beam Optimizer (RIBO) Monte Carlo 3-D code, which was used to read from the event files, to compute Cerenkov production and then to simulate the optical coupling of the BLM detectors, accounting for the transmission of light through the quartz.

  12. LHC BFPP Quench Test with Ions (2015)

    CERN Document Server

    Schaumann, Michaela; Bahamonde Castro, Cristina; Auchmann, Bernhard; Chetvertkova, Vera; Giachino, Rossano; Jowett, John; Kalliokoski, Matti; Lechner, Anton; Mertens, Tom; Ponce, Laurette; CERN. Geneva. ATS Department

    2016-01-01

    The 2015 Pb-Pb collision run of the LHC operated at a beam energy of 6.37Z TeV. The power of the secondary beams emitted from the interaction point by the bound-free pair production (BFPP) process reached new levels while the propensity of the bending magnets to quench is higher at the new magnetic field levels. This beam power is about 70 times greater than that contained in the luminosity debris and is focussed on a specific location. As long foreseen, orbit bumps were introduced in the dispersion suppressors around the highest luminosity experiments to mitigate the risk of quenches by displacing and spreading out these losses. Because the impact position and intensity of these secondary beams is well known and can be tracked easily with the Beam Loss Monitors (BLMs), the BFPP1 beam (208Pb81+ ions), which is the most intense, provides a tool to accurately measure the steady state quench limit of the LHC main dipoles. At the moment the exact quench limit is not known, but this knowledge is important to asses...

  13. Detailed IR aperture measurements

    CERN Document Server

    Bruce, Roderik; Garcia Morales, Hector; Giovannozzi, Massimo; Hermes, Pascal Dominik; Mirarchi, Daniele; Quaranta, Elena; Redaelli, Stefano; Rossi, Carlo; Skowronski, Piotr Krzysztof; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2016-01-01

    MD 1673 was carried out on October 5 2016, in order to investigate in more detail the available aperture in the LHC high-luminosity insertions at 6.5 TeV and β∗=40 cm. Previous aperture measurements in 2016 during commissioning had shown that the available aperture is at the edge of protection, and that the aperture bottleneck at β∗=40 cm in certain cases is found in the separation plane instead of in the crossing plane. Furthermore, the bottlenecks were consistently found in close to the upstream end of Q3 on the side of the incoming beam, and not in Q2 on the outgoing beam as expected from calculations. Therefore, this MD aimed at measuring IR1 and IR5 separately (at 6.5 TeV and β∗=40 cm, for 185 µrad half crossing angle), to further localize the bottlenecks longitudinally using newly installed BLMs, investigate the difference in aperture between Q2 and Q3, and to see if any aperture can be gained using special orbit bumps.

  14. The LCLS Undulator Beam Loss Monitor Readout System

    Energy Technology Data Exchange (ETDEWEB)

    Dusatko, John; Browne, M.; Fisher, A.S.; Kotturi, D.; Norum, S.; Olsen, J.; /SLAC

    2012-07-23

    The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.

  15. OPERATIONAL EXPERIENCE WITH FAST FIBER-OPTIC BEAM LOSS MONITORS FOR THE ADVANCED PHOTON SOURCE STORAGE RING SUPERCONDUCTING UNDULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Dooling, J.; Harkay, K.; Sajaev, V.; Shang, H.

    2017-06-25

    Fast fiber-optic (FFO) beam loss monitors (BLMs) installed with the first two superconducting undulators (SCUs) in the Advanced Photon Source storage ring have proven to be a useful diagnostic for measuring deposited charge (energy) during rapid beam loss events. The first set of FFOBLMs were installed outside the cryostat of the short SCU, a 0.33-m long device, above and below the beam centerline. The second set are mounted with the first 1.1-mlong SCU within the cryostat, on the outboard and inboard sides of the vacuum chamber. The next 1.1-m-long SCU is scheduled to replace the short SCU later in 2016 and will be fitted with FFOBLMs in a manner similar to original 1.1-m device. The FFOBLMs were employed to set timing and voltage for the abort kicker (AK) system. The AK helps to prevent quenching of the SCUs during beam dumps [1] by directing the beam away from the SC magnet windings. The AK is triggered by the Machine Protection System (MPS). In cases when the AK fails to prevent quenching, the FFOBLMs show that losses often begin before detection by the MPS.

  16. Crystal Structure of the Zorbamycin-Binding Protein ZbmA, the Primary Self-Resistance Element in Streptomyces flavoviridis ATCC21892

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf, Jeffrey D. [Scripps Research Inst., Jupiter, FL (United States); Bigelow, Lance [Argonne National Lab. (ANL), Argonne, IL (United States); Chang, Changsoo [Argonne National Lab. (ANL), Argonne, IL (United States); Cuff, Marianne E. [Argonne National Lab. (ANL), Argonne, IL (United States); Lohman, Jeremy R. [Scripps Research Inst., Jupiter, FL (United States); Chang, Chin-Yuan [Scripps Research Inst., Jupiter, FL (United States); Ma, Ming [Scripps Research Inst., Jupiter, FL (United States); Yang, Dong [Scripps Research Inst., Jupiter, FL (United States); Clancy, Shonda [Argonne National Lab. (ANL), Argonne, IL (United States); Babnigg, Gyorgy [Argonne National Lab. (ANL), Argonne, IL (United States); Joachimiak, Andrzej [Argonne National Lab. (ANL), Argonne, IL (United States); Phillips, George N. [Rice Univ., Houston, TX (United States); Shen, Ben [Scripps Research Inst., Jupiter, FL (United States)

    2015-11-17

    The bleomycins (BLMs), tallysomycins (TLMs), phleomycin, and zorbamycin (ZBM) are members of the BLM family of glycopeptide-derived antitumor antibiotics. The BLM-producing Streptomyces verticillus ATCC15003 and the TLM-producing Streptoalloteichus hindustanus E465-94 ATCC31158 both possess at least two self-resistance elements, an N-acetyltransferase and a binding protein. The N-acetyltransferase provides resistance by disrupting the metal-binding domain of the antibiotic that is required for activity, while the binding protein confers resistance by sequestering the metal-bound antibiotic and preventing drug activation via molecular oxygen. We recently established that the ZBM producer, Streptomyces flavoviridis ATCC21892, lacks the N-acetyltransferase resistance gene and that the ZBM-binding protein, ZbmA, is sufficient to confer resistance in the producing strain. To investigate the resistance mechanism attributed to ZbmA, we determined the crystal structures of apo and Cu(II)-ZBM-bound ZbmA at high resolutions of 1.90 and 1.65 angstrom, respectively. A comparison and contrast with other structurally characterized members of the BLM-binding protein family revealed key differences in the protein ligand binding environment that fine-tunes the ability of ZbmA to sequester metal-bound ZBM and supports drug sequestration as the primary resistance mechanism in the producing organisms of the BLM family of antitumor antibiotics.

  17. Development of silicon detectors for Beam Loss Monitoring at HL-LHC

    Science.gov (United States)

    Verbitskaya, E.; Eremin, V.; Zabrodskii, A.; Bogdanov, A.; Shepelev, A.; Dehning, B.; Bartosik, M. R.; Alexopoulos, A.; Glaser, M.; Ravotti, F.; Sapinski, M.; Härkönen, J.; Egorov, N.; Galkin, A.

    2017-03-01

    Silicon detectors were proposed as novel Beam Loss Monitors (BLM) for the control of the radiation environment in the vicinity of the superconductive magnets of the High-Luminosity Large Hadron Collider. The present work is aimed at enhancing the BLM sensitivity and therefore the capability of triggering the beam abort system before a critical radiation load hits the superconductive coils. We report here the results of three in situ irradiation tests of Si detectors carried out at the CERN PS at 1.9-4.2 K. The main experimental result is that all silicon detectors survived irradiation up to 1.22× 1016 p/cm2. The third test, focused on the detailed characterization of the detectors with standard (300 μm) and reduced (100 μm) thicknesses, showed only a marginal difference in the sensitivity of thinned detectors in the entire fluence range and a smaller rate of signal degradation that promotes their use as BLMs. The irradiation campaigns produced new information on radiation damage and carrier transport in Si detectors irradiated at the temperatures of 1.9-4.2 K. The results were encouraging and permitted to initiate the production of the first BLM prototype modules which were installed at the end of the vessel containing the superconductive coil of a LHC magnet immersed in superfluid helium to be able to test the silicon detectors in real operational conditions.

  18. Monitoring the Transmembrane Proton Gradient Generated by Cytochrome bo3 in Tethered Bilayer Lipid Membranes Using SEIRA Spectroscopy.

    Science.gov (United States)

    Wiebalck, Swantje; Kozuch, Jacek; Forbrig, Enrico; Tzschucke, C Christoph; Jeuken, Lars J C; Hildebrandt, Peter

    2016-03-10

    Membrane proteins act as biocatalysts or ion/proton pumps to convert and store energy from ubiquitous environmental sources. Interfacing these proteins to electrodes allows utilizing the energy for enzymatic biofuel cells or other auspicious biotechnological applications. To optimize the efficiency of these devices, appropriate membrane models are required that ensure structural and functional integrity of the embedded enzymes and provide structural insight. We present a spectroelectrochemical surface-enhanced infrared absorption (SEIRA) and electrical impedance spectroscopy (EIS) study of the bacterial respiratory ubiquinol/cytochrome bo3 (cyt bo3) couple incorporated into a tethered bilayer lipid membrane (tBLM). Here, we employed a new lipid tether (WK3SH, dihydrocholesteryl (2-(2-(2-ethoxy)ethoxy)ethanethiol), which was synthesized using a three-step procedure with very good yield and allowed measuring IR spectra without significant spectral interference of the tBLM. The functional integrity of the incorporated cyt bo3 was demonstrated by monitoring the enzymatic O2 reduction current and the formation of the transmembrane proton gradient. Based on a SEIRA-spectroscopic redox titration, a shift of the pH-dependent redox potential of the ubiquinones under turnover conditions was correlated with an alkalinization of the submembrane reservoir by +0.8 pH units. This study demonstrates the high potential of tBLMs and the SEIRA spectroscopic approach to study bioenergetic processes.

  19. Analysis of fast losses in the LHC with the BLM system

    CERN Document Server

    Nebot, E; Holzer, E; Dehning, B; Nordt, A; Sapinski, M; Emery, J; Zamantzas, C; Effinger, E; Marsili, A; Wenninger, J; Baer, T; Schmidt, R; Yang, Z; Zimmerman, F; Fuster, N

    2011-01-01

    About 3600 Ionization Chambers are located around the LHC ring to detect beam losses that could damage the equipment or quench superconducting magnets. The Beam Loss Monitors (BLMs) integrate the losses in 12 different time intervals (from 40 us to 83.8 s) allowing for different abort thresholds depending on the duration of the loss and the beam energy. The signals are also recorded in a database at 1 Hz for offline analysis. During the 2010 run, a limiting factor in the machine availability were sudden losses appearing around the ring on the ms time scale and detected exclusively by the BLM system. It is believed that such losses originate from dust particles falling into the beam, or being attracted by its strong electromagnetic field. This document describes some of the properties of these ”Unidentified Falling Objects” (UFOs) putting special emphasis on their dependence on beam parameters (energy, intensity, etc). The subsequent modification of the BLM beam abort thresholds for the 2011 run that were ...

  20. In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

    Science.gov (United States)

    Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M. R.; Eisel, T.; Fabjan, C.; Rementeria, C. A.; Griesmayer, E.; Eremin, V.; Verbitskaya, E.; Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I.; Egorov, N.; Härkönen, J.; Luukka, P.; Tuominen, E.

    2015-05-01

    As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×1016 proton/cm2, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×1016 p/cm2 irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage.

  1. Development and application of a multimetal multibiotic ligand model for assessing aquatic toxicity of metal mixtures.

    Science.gov (United States)

    Santore, Robert C; Ryan, Adam C

    2015-04-01

    A multimetal, multiple binding site version of the biotic ligand model (mBLM) has been developed for predicting and explaining the bioavailability and toxicity of mixtures of metals to aquatic organisms. The mBLM was constructed by combining information from single-metal BLMs to preserve compatibility between the single-metal and multiple-metal approaches. The toxicities from individual metals were predicted by assuming additivity of the individual responses. Mixture toxicity was predicted based on both dissolved metal and mBLM-normalized bioavailable metal. Comparison of the 2 prediction methods indicates that metal mixtures frequently appear to have greater toxicity than an additive estimation of individual effects on a dissolved metal basis. However, on an mBLM-normalized basis, mixtures of metals appear to be additive or less than additive. This difference results from interactions between metals and ligands in solutions including natural organic matter, processes that are accounted for in the mBLM. As part of the mBLM approach, a technique for considering variability was developed to calculate confidence bounds (called response envelopes) around the central concentration-response relationship. Predictions using the mBLM and response envelope were compared with observed toxicity for a number of invertebrate and fish species. The results show that the mBLM is a useful tool for considering bioavailability when assessing the toxicity of metal mixtures.

  2. Syringotoxin pore formation and inactivation in human red blood cell and model bilayer lipid membranes.

    Science.gov (United States)

    Szabó, Zsófia; Gróf, Pál; Schagina, Ludmila V; Gurnev, Philip A; Takemoto, Jon Y; Mátyus, Edit; Blaskó, Katalin

    2002-12-23

    The effect of syringotoxin (ST), a member of the cyclic lipodepsipeptides family (CLPs) produced by Pseudomonas syringae pv. syringae on the membrane permeability of human red blood cells (RBCs) and model bilayer lipid membranes (BLMs) was studied and compared to that of two recently investigated CLPs, syringomycin E (SRE) and syringopeptin 22A (SP22A) [Biochim. Biophys. Acta 1466 (2000) 79 and Bioelectrochemistry 52 (2000) 161]. The permeability-increasing effect of ST on RBCs was the least among the three CLPs. A time-dependent ST pore inactivation was observed on RBCs at 20 and 37 degrees C but not at 8 degrees C. From the kinetic model worked out parameters as permeability coefficient of RBC membrane for 86Rb(+) and pores mean lifetime were calculated. A shorter pores mean lifetime was calculated at 37 degrees C then at 20 degrees C, which gave us an explanation for the unusual slower rate of tracer efflux measured at 37 degrees C then that at 20 degrees C. The results obtained on BLM showed that the pore inactivation was due to a decrease in the number of pores but not to a change of their dwell time or conductance.

  3. Formation of individual protein channels in lipid bilayers suspended in nanopores.

    Science.gov (United States)

    Studer, André; Han, Xiaojun; Winkler, Fritz K; Tiefenauer, Louis X

    2009-10-15

    Free-standing lipid bilayers are formed in regularly arranged nanopores of 200, 400 and 800 nm in a 300 nm thin hydrophobic silicon nitride membrane separating two fluid compartments. The extraordinary stability of the lipid bilayers allows us to monitor channel formation of the model peptide melittin and alpha-hemolysin from Staphylococcus aureus using electrochemical impedance spectroscopy and chronoamperometry. We observed that melittin channel formation is voltage-dependent and transient, whereas transmembrane heptameric alpha-hemolysin channels in nano-BLMs persist for hours. The onset of alpha-hemolysin-mediated conduction depends on the applied protein concentration and strongly on the diameter of the nanopores. Heptameric channel formation from adsorbed alpha-hemolysin monomers needs more time in bilayers suspended in 200 nm pores compared to bilayers in pores of 400 and 800 nm diameters. Diffusion of sodium ions across alpha-hemolysin channels present in a sufficiently high number in the bilayers was quantitatively and specifically determined using ion selective electrodes. The results demonstrate that relatively small variations of nano-dimensions have a tremendous effect on observable dynamic biomolecular processes. Such nanopore chips are potentially useful as supports for stable lipid bilayers to establish functional assays of membrane proteins needed in basic research and drug discovery.

  4. MACHINE PROTECTION FOR HIGH AVERAGE CURRENT LINACS

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Kevin; Allison, Trent; Evans, Richard; Coleman, James; Grippo, Albert

    2003-05-01

    A fully integrated Machine Protection System (MPS) is critical to efficient commissioning and safe operation of all high current accelerators. The Jefferson Lab FEL [1,2] has multiple electron beam paths and many different types of diagnostic insertion devices. The MPS [3] needs to monitor both the status of these devices and the magnet settings which define the beam path. The matrix of these devices and beam paths are programmed into gate arrays, the output of the matrix is an allowable maximum average power limit. This power limit is enforced by the drive laser for the photocathode gun. The Beam Loss Monitors (BLMs), RF status, and laser safety system status are also inputs to the control matrix. There are 8 Machine Modes (electron path) and 8 Beam Modes (average power limits) that define the safe operating limits for the FEL. Combinations outside of this matrix are unsafe and the beam is inhibited. The power limits range from no beam to 2 megawatts of electron beam power.

  5. Cholesterol favors the emergence of a long-range autocorrelated fluctuation pattern in voltage-induced ionic currents through lipid bilayers.

    Science.gov (United States)

    Corvalán, Natalia A; Kembro, Jackelyn M; Clop, Pedro D; Perillo, María A

    2013-08-01

    The present paper was aimed at evaluating the effect of cholesterol (CHO) on the voltage-induced lipid pore formation in bilayer membranes through a global characterization of the temporal dynamics of the fluctuation pattern of ion currents. The bilayer model used was black lipid membranes (BLMs) of palmitoyloleoylphosphatidylethanolamine and palmitoyloleoylphosphatidylcholine (POPE:POPC) at a 7:3 molar ratio in the absence (BLM0) or in the presence of 30 (BLM30), 40 (BLM40) or 50(BLM50)mol% of cholesterol with respect to total phospholipids. Electrical current intensities (I) were measured in voltage (ΔV) clamped conditions at ΔV ranging between 0 and ±200mV. The autocorrelation parameter α derived from detrended fluctuation analysis (DFA) on temporal fluctuation patterns of electrical currents allowed discriminating between non-correlated (α=0.5, white noise) and long-range correlated (0.5number of conductance states, the magnitude of conductance level, the capacitance of the bilayers and increased the tendency towards the development of long-range autocorrelated (fractal) processes (0.5<α<1) in lipid channel generation. Experiments were performed above the phase transition temperature of the lipid mixtures, but compositions used predicted a superlattice-like organization. This leads to the conclusion that structural defects other than phase coexistence may promote lipid channel formation under voltage clamped conditions. Furthermore, cholesterol controls the voltage threshold that allows the percolation of channel behavior where isolated channels become an interconnected network.

  6. Commissioning and Operation of the H4IRRAD Mixed-Field Test Area

    CERN Document Server

    Biskup, B; Calviani, M; Efthymiopoulos, I; Kwee, R; Mekki, J; La Torre, F; Lebbos, E; Mala, P; Manessi, G; Nordt, A; Pozzi, F; Roeed, K; Severino, C; Silari, M; Thornton, A

    2011-01-01

    This note reports on the commissioning and operation period of the H4IRRAD Test Area in which well characterised mixed-fields are provided for LHC equipment users. In benchmark simulations the mixed-field components were estimated and measured with the H4IRRAD beam and radiation monitoring systems. The radiation monitors, the “RadMons” and beam-loss monitors (BLMs) are the same detector types used for monitoring radiation fluences in the underground areas of the LHC. In the first two irradiation periods various equipment was exposed to irradiation produced by a secondary proton beam of 280 GeV impacting on the H4IRRAD copper target. Measurements compared to simulations are presented that quantify the high energy hadron, thermal neutron and Si 1 MeV neutron equivalent fluences at the given test locations. A crucial part was to calibrate the beam monitoring systems to measure the number of protons, p.o.t., which is outlined using different techniques. In addition, cross-checks of p.o.t. measurements are pre...

  7. Biochemical evaluation of a 108-member deglycobleomycin library: viability of a selection strategy for identifying bleomycin analogues with altered properties.

    Science.gov (United States)

    Ma, Qian; Xu, Zhidong; Schroeder, Benjamin R; Sun, Wenyue; Wei, Fang; Hashimoto, Shigeki; Konishi, Kazuhide; Leitheiser, Christopher J; Hecht, Sidney M

    2007-10-17

    The bleomycins (BLMs) are clinically used glycopeptide antitumor antibiotics that have been shown to mediate the sequence-selective oxidative damage of both DNA and RNA. Previously, we described the solid-phase synthesis of a library of 108 unique analogues of deglycoBLM A6, a congener that cleaves DNA analogously to BLM itself. Each member of the library was assayed for its ability to effect single- and double-strand nicking of duplex DNA, sequence-selective DNA cleavage, and RNA cleavage in the presence and absence of a metal ion cofactor. All of the analogues tested were found to mediate concentration-dependent plasmid DNA relaxation to some extent, and a number exhibited double-strand cleavage with an efficiency comparable to or greater than deglycoBLM A6. Further, some analogues having altered linker and metal-binding domains mediated altered sequence-selective cleavage, and a few were found to cleave a tRNA3Lys transcript both in the presence and in the absence of a metal cofactor. The results provide insights into structural elements within BLM that control DNA and RNA cleavage. The present study also permits inferences to be drawn regarding the practicality of a selection strategy for the solid-phase construction and evaluation of large libraries of BLM analogues having altered properties.

  8. Review of BLM thresholds at tertiary LHC collimators

    CERN Document Server

    D'Andrea, Marco; Zanetti, Marco

    The Large Hadron Collider is designed to accelerate protons at the unprecedented energy of 7 TeV. With a total stored energy of 360 MJ, even tiny losses can cause machine downtime or induce damage to sensitive accelerator components. The Beam Loss Monitors (BLMs) are an important component of the complex LHC protection system. They consist of a series of ionisation chambers located all around the ring to detect secondary particle showers induced by beam losses. The monitors are assigned thresholds such that if the radiation generated by the loss is too high, the BLM triggers a beam dump, preventing the loss to grow excessively. BLM signals are recorded for different integration windows, in order to detect losses on very different time scales, ranging from the extremely short ones (taking place over half a turn) to those very close to steady state (i.e. lasting for more than a minute). The LHC is equipped with a complex collimation system, to provide the machine with passive protection in case of transient los...

  9. Biotic ligand modeling approach: Synthesis of the effect of major cations on the toxicity of metals to soil and aquatic organisms.

    Science.gov (United States)

    Ardestani, Masoud M; van Straalen, Nico M; van Gestel, Cornelis A M

    2015-10-01

    The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca(2+) , Mg(2+) , and protons. Other important characteristics of the exposure medium, such as levels of dissolved organic carbon and concentrations of other cations, should also be considered to obtain a proper assessment of metal toxicity to soil and aquatic organisms.

  10. Pressure effects on the equilibrium configurations of bilayer lipid membranes

    Science.gov (United States)

    DeVita, Raffaella; Stewart, Iain W.; Leo, Donald J.

    2007-10-01

    Planar bilayer lipid membranes (BLMs) are currently employed to construct many bio-inspired material systems and structures. In order to characterize the pressure effects on the equilibrium configurations of these biological membranes, a novel continuum model is proposed. The BLM is assumed to be a two-layer smectic A liquid crystal. The mean orientation of the amphiphilic molecules comprising the membrane is postulated to be perpendicular to the layers and each layer is idealized as a two-dimensional liquid. Moreover, the BLM is modeled as a simply supported plate undergoing small deformations. It is subjected to a pressure load that acts perpendicularly to the layers. The equilibrium equations and boundary conditions are derived from the bulk elastic energy for smectic A liquid crystals as described by de Gennes and Prost (1993 The Physics of Liquid Crystals 2nd edn (Oxford Science Publications)) by using variational methods. The resulting fourth-order linear partial differential equation is solved by employing cylindrical functions and the series solution is proved to be convergent. The solution is numerically computed for values of the model parameters that are reported in the literature. This paper is dedicated to the memory of our colleagues, Professors Kevin P Granata and Liviu Librescv, who lost their lives during the sensless tragedy on 16 April, 2007 at Virginia Tech.

  11. Influences of water chemistry on the acute toxicity of lead to Pimephales promelas and Ceriodaphnia dubia.

    Science.gov (United States)

    Mager, Edward M; Esbaugh, Andrew J; Brix, Kevin V; Ryan, Adam C; Grosell, Martin

    2011-01-01

    The acute toxicity of lead (Pb) was examined for fathead minnows (Pimephales promelas; 96-h) and daphnids (Ceriodaphnia dubia; 48-h) in waters modified for hardness (as CaSO₄), dissolved organic carbon (DOC; as Aldrich humic acid) and alkalinity (as NaHCO₃) for parameterization of an acute freshwater biotic ligand model (BLM). Additionally, acute (96-h) and chronic (30-d) bioassays were performed for P. promelas to more clearly define the influence of pH (5.5-8.3) on Pb toxicity as modified by addition of HCl or NaOH using an automated titration system. Results indicate that Ca(2+) is protective against acute Pb toxicity to P. promelas but not C. dubia. Strong protection was afforded by DOC and NaHCO(3) against acute Pb toxicity to P. promelas, whereas milder protection was observed for C. dubia with both parameters. Dissolved Pb LC50s from the P. promelas pH bioassays revealed a complex effect of pH on Pb toxicity, likely explained in part by Pb speciation and the competitive interaction of H(+) with ionic Pb(2+). Chronic pH bioassays also demonstrated that 30-d growth is not impaired in fathead minnows at relevant Pb concentrations. The findings reported herein suggest that development of separate BLMs for P. promelas and C. dubia should be considered.

  12. Speech and language development after cochlear implantation in children with bony labyrinth malformations: long-term results.

    Science.gov (United States)

    Catli, Tolgahan; Uckan, Burcu; Olgun, Levent

    2015-11-01

    The aim of this study was to investigate speech and language development after long-term cochlear implantation in children with bony labyrinth malformations (BLMs) and to present the surgical findings in this group of patients. The auditory and linguistic skills of 21 children who had BLM were assessed in this study. They were implanted between 1998 and 2009. Twenty-two sex-matched and age-matched implantees without BLM were evaluated as the control group. To compare speech perception and speech intelligibility between the groups, the categories of auditory performance (CAP) test and speech intelligibility rating (SIR) test, respectively, were administered. The Turkish version of the Test of Early Language Development (TELD-3-T) was administered to evaluate and compare the linguistic skills of the groups. Surgical findings and complications were also analyzed. Implanted anomalies were common cavity in five patients, incomplete partition type 1 in 5 patients, and incomplete partition type 2 in 11 patients. The CAP and SIR scores were significantly higher in the control group (p 0.05). Based on the specific type of malformation, the CAP and SIR scores were comparable between the subgroups (p > 0.05). No perioperative complications occurred in the control group. However, various perioperative complications (gusher, etc.) and surgical difficulty occurred in the anomaly group. The malformation group had unsatisfactory results with regard to speech perception skills; however, this group and the non-anomalous group exhibited comparable long-term results on linguistic development.

  13. Channel-forming activity of syringopeptin 25A in mercury-supported phospholipid monolayers and negatively charged bilayers.

    Science.gov (United States)

    Becucci, Lucia; Toppi, Arianna; Fiore, Alberto; Scaloni, Andrea; Guidelli, Rolando

    2016-10-01

    Interactions of the cationic lipodepsipeptide syringopeptin 25A (SP25A) with mercury-supported dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylserine (DOPS) and dioeleoylphosphatidic acid (DOPA) self-assembled monolayers (SAMs) were investigated by AC voltammetry in 0.1M KCl at pH3, 5.4 and 6.8. SP25A targets and penetrates the DOPS SAM much more effectively than the other SAMs not only at pH6.8, where the DOPS SAM is negatively charged, but also at pH3, where it is positively charged just as SP25A. Similar investigations at tethered bilayer lipid membranes (tBLMs) consisting of a thiolipid called DPTL anchored to mercury, with a DOPS, DOPA or DOPC distal monolayer on top of it, showed that, at physiological transmembrane potentials, SP25A forms ion channels spanning the tBLM only if DOPS is the distal monolayer. The distinguishing chemical feature of the DOPS SAM is the ionic interaction between the protonated amino group of a DOPS molecule and the carboxylate group of an adjacent phospholipid molecule. Under the reasonable assumption that SP25A preferentially interacts with this ion pair, the selective lipodepsipeptide antimicrobial activity against Gram-positive bacteria may be tentatively explained by its affinity for similar protonated amino-carboxylate pairs, which are expected to be present in the peptide moieties of peptidoglycan strands.

  14. Update on beam loss monitoring at CTF3 for CLIC

    CERN Document Server

    Devlin, L J; Effinger, E; Holzer, E B; del Busto, E N; Mallows, S; Branger, E

    2013-01-01

    The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beam line is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fibre BLM system is currently under investigation which can cover large sections of beam line at a time. A multimode fibre has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fibre resulting from beam loss and their subsequent transport along the fibre where they are then detected at the fibre ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comp...

  15. Multi-linear regression analysis, preliminary biotic ligand modeling, and cross species comparison of the effects of water chemistry on chronic lead toxicity in invertebrates.

    Science.gov (United States)

    Esbaugh, A J; Brix, K V; Mager, E M; De Schamphelaere, K; Grosell, M

    2012-03-01

    The current study examined the chronic toxicity of lead (Pb) to three invertebrate species: the cladoceran Ceriodaphnia dubia, the snail Lymnaea stagnalis and the rotifer Philodina rapida. The test media consisted of natural waters from across North America, varying in pertinent water chemistry parameters including dissolved organic carbon (DOC), calcium, pH and total CO(2). Chronic toxicity was assessed using reproductive endpoints for C. dubia and P. rapida while growth was assessed for L. stagnalis, with chronic toxicity varying markedly according to water chemistry. A multi-linear regression (MLR) approach was used to identify the relative importance of individual water chemistry components in predicting chronic Pb toxicity for each species. DOC was an integral component of MLR models for C. dubia and L. stagnalis, but surprisingly had no predictive impact on chronic Pb toxicity for P. rapida. Furthermore, sodium and total CO(2) were also identified as important factors affecting C. dubia toxicity; no other factors were predictive for L. stagnalis. The Pb toxicity of P. rapida was predicted by calcium and pH. The predictive power of the C. dubia and L. stagnalis MLR models was generally similar to that of the current C. dubia BLM, with R(2) values of 0.55 and 0.82 for the respective MLR models, compared to 0.45 and 0.79 for the respective BLMs. In contrast the BLM poorly predicted P. rapida toxicity (R(2)=0.19), as compared to the MLR (R(2)=0.92). The cross species variability in the effects of water chemistry, especially with respect to rotifers, suggests that cross species modeling of invertebrate chronic Pb toxicity using a C. dubia model may not always be appropriate.

  16. Fractionation of fulvic acid by iron and aluminum oxides: influence on copper toxicity to Ceriodaphnia dubia

    Science.gov (United States)

    Smith, Kathleen S.; James F. Ranville,; Emily K. Lesher,; Daniel J. Diedrich,; Diane M. McKnight,; Ruth M. Sofield,

    2014-01-01

    This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on ,i>Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.6 μg Cu/L) than were the unfractionated dissolved FAs (EC50 39 ± 0.4 and 41 ± 1.2 μg Cu/L). The fractionation is a consequence of preferential sorption of molecules having strong metal-binding (more aromatic) moieties to precipitating Fe- and Al-rich oxyhydroxides, causing the remaining dissolved FA to be depleted in these functional groups. As a result, there is more bioavailable dissolved Cu in the water and hence greater potential for Cu toxicity to aquatic organisms. In predicting Cu toxicity, biotic ligand models (BLMs) take into account dissolved organic carbon (DOC) concentration; however, unless DOC characteristics are accounted for, model predictions can underestimate acute Cu toxicity for water containing fractionated dissolved FA. This may have implications for water-quality criteria in systems containing Fe- and Al-rich sediment, and in mined and mineralized areas in particular. Optical measurements, such as specific ultraviolet absorbance at 254 nm (SUVA254), show promise for use as spectral indicators of DOC chemical fractionation and inferred increased Cu toxicity.

  17. Fractionation of fulvic acid by iron and aluminum oxides--influence on copper toxicity to Ceriodaphnia dubia.

    Science.gov (United States)

    Smith, Kathleen S; Ranville, James F; Lesher, Emily K; Diedrich, Daniel J; McKnight, Diane M; Sofield, Ruth M

    2014-10-21

    This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.6 μg Cu/L) than were the unfractionated dissolved FAs (EC50 39 ± 0.4 and 41 ± 1.2 μg Cu/L). The fractionation is a consequence of preferential sorption of molecules having strong metal-binding (more aromatic) moieties to precipitating Fe- and Al-rich oxyhydroxides, causing the remaining dissolved FA to be depleted in these functional groups. As a result, there is more bioavailable dissolved Cu in the water and hence greater potential for Cu toxicity to aquatic organisms. In predicting Cu toxicity, biotic ligand models (BLMs) take into account dissolved organic carbon (DOC) concentration; however, unless DOC characteristics are accounted for, model predictions can underestimate acute Cu toxicity for water containing fractionated dissolved FA. This may have implications for water-quality criteria in systems containing Fe- and Al-rich sediment, and in mined and mineralized areas in particular. Optical measurements, such as specific ultraviolet absorbance at 254 nm (SUVA254), show promise for use as spectral indicators of DOC chemical fractionation and inferred increased Cu toxicity.

  18. Bilayer lipid membranes supported on Teflon filters: a functional environment for ion channels.

    Science.gov (United States)

    Phung, Thai; Zhang, Yanli; Dunlop, James; Dalziel, Julie

    2011-03-15

    Many ion channel proteins have binding sites for toxins and pharmaceutical drugs and therefore have much promise as the sensing entity in high throughput technologies and biosensor devices. Measurement of ionic conductance changes through ion channels requires a robust biological membrane with sufficient longevity for practical applications. The conventional planar BLM is 100-300 μm in diameter and typically contains fewer than a dozen channels whereas pharmaceutical screening methods in cells use current recordings for many ion channels. We present a new, simple method for the fabrication of a disposable porous-supported bilayer lipid membrane (BLM) ion channel biosensor using hydrated Teflon (polytetrafluoroethylene, PTFE) filter material (pore size 5 μm, filter diameter=1 mm). The lipid layer was monitored for its thickness and mechanical stability by electrical impedance spectroscopy. The results showed membrane capacitances of 1.8±0.2 nF and membrane resistances of 25.9±4.1 GΩ, indicating the formation of lipid bilayers. The current level increased upon addition of the pore-forming peptide gramicidin. Following addition of liposomes containing voltage-gated sodium channels, small macroscopic sodium currents (1-80 pA) could be recorded. By preloading the porous Teflon with sodium channel proteoliposomes, prior to BLM formation, currents of 1-10 nA could be recorded in the presence of the activator veratridine that increased with time, and were inhibited by tetrodotoxin. A lack of rectification suggests that the channels incorporated in both orientations. This work demonstrates that PTFE filters can support BLMs that provide an environment in which ion channels can maintain their functional activity relevant for applications in drug discovery, toxin detection, and odour sensing.

  19. Loss of Bloom syndrome protein destabilizes human gene cluster architecture.

    Science.gov (United States)

    Killen, Michael W; Stults, Dawn M; Adachi, Noritaka; Hanakahi, Les; Pierce, Andrew J

    2009-09-15

    Bloom syndrome confers strong predisposition to malignancy in multiple tissue types. The Bloom syndrome patient (BLM) protein defective in the disease biochemically functions as a Holliday junction dissolvase and human cells lacking functional BLM show 10-fold elevated rates of sister chromatid exchange. Collectively, these phenomena suggest that dysregulated mitotic recombination drives the genomic instability underpinning the development of cancer in these individuals. Here we use physical analysis of the highly repeated, highly self-similar human ribosomal RNA gene clusters as sentinel biomarkers for dysregulated homologous recombination to demonstrate that loss of BLM protein function causes a striking increase in spontaneous molecular level genomic restructuring. Analysis of single-cell derived sub-clonal populations from wild-type human cell lines shows that gene cluster architecture is ordinarily very faithfully preserved under mitosis, but is so unstable in cell lines derived from BLMs as to make gene cluster architecture in different sub-clonal populations essentially unrecognizable one from another. Human cells defective in a different RecQ helicase, the WRN protein involved in the premature aging Werner syndrome, do not exhibit the gene cluster instability (GCI) phenotype, indicating that the BLM protein specifically, rather than RecQ helicases generally, holds back this recombination-mediated genomic instability. An ataxia-telangiectasia defective cell line also shows elevated rDNA GCI, although not to the extent of BLM defective cells. Genomic restructuring mediated by dysregulated recombination between the abundant low-copy repeats in the human genome may prove to be an important additional mechanism of genomic instability driving the initiation and progression of human cancer.

  20. Impacts of major cations (K(+), Na (+), Ca (2+), Mg (2+)) and protons on toxicity predictions of nickel and cadmium to lettuce (Lactuca sativa L.) using exposure models.

    Science.gov (United States)

    Liu, Yang; Vijver, Martina G; Peijnenburg, Willie J G M

    2014-04-01

    Biotic ligand models (BLM) explicitly accounting for hypothetical interactions with biotic ligands and bioavailability as dictated by water chemistry have been developed for various metals and different organisms. It is only recently that BLMs for plants have received increasing attention. Lettuce is one of the most important vegetable crops in the world. This study investigated the impacts of Ca(2+), Mg(2+), K(+), Na(+) and pH, on acute toxicity of Ni and Cd to butter-head lettuce seedlings (Lactuca sativa L.). 4-day assays with the root elongation inhibition (REI) as the endpoint were performed in hydroponic solutions. Magnesium was found to be the sole cation significantly enhancing the median inhibition concentration (IC50) of Ni(2+) with increasing concentration. By incorporating the competitive effects of Mg(2+), the Ni-toxicity prediction was improved significantly as compared to the total metal model (TMM) and the free ion activity model (FIAM). The conditional stability constants derived from the Ni-BLM were log K MgBL = 2.86, log K NiBL = 5.1, and f NiBL (50%)  = 0.57. A slight downtrend was observed in the 4-d IC50 of Cd(2+) at increasing H(+) concentrations, but this tendency was not consistent and statistically significant (p = 0.07) over the whole range. The overall variations of Cd-toxicity within the tested Na(+), K(+), Ca(2+) and Mg(2+) concentration ranges were relatively small and not statistically significant. 80 % of lettuce REI by Cd could be explained using both TMM and FIAM instead of BLM in the present study. Thus, the mechanistically underpinned models for soil quality guidelines should be developed on a metal-specific basis across different exposure conditions.

  1. Enhanced Temporal Resolution with Ion Channel-Functionalized Sensors Using a Conductance-Based Measurement Protocol.

    Science.gov (United States)

    Agasid, Mark T; Comi, Troy J; Saavedra, S Scott; Aspinwall, Craig A

    2017-01-17

    The binding of a target analyte to an ion channel (IC), which is readily detected electrochemically in a label-free manner with single-molecule selectivity and specificity, has generated widespread interest in using natural and engineered ICs as transducers in biosensing platforms. To date, the majority of developments in IC-functionalized sensing have focused on IC selectivity or sensitivity or development of suitable membrane environments and aperture geometries. Comparatively little work has addressed analytical performance criteria, particularly criteria required for temporal measurements of dynamic processes. We report a measurement protocol suitable for rapid, time-resolved monitoring (≤30 ms) of IC-modulated membrane conductance. Key features of this protocol include the reduction of membrane area and the use of small voltage steps (10 mV) and short duration voltage pulses (10 ms), which have the net effect of reducing the capacitive charging and decreasing the time required to achieve steady state currents. Application of a conductance protocol employing three sequential, 10 ms voltage steps (-10 mV, -20 mV, -30 mV) in an alternating, pyramid-like arrangement enabled sampling of membrane conductance every 30 ms. Using this protocol, dynamic IC measurements on black lipid membranes (BLMs) functionalized with gramicidin A were conducted using a fast perfusion system. BLM conductance decreased by 76 ± 7.5% within 30 ms of switching from solutions containing 0 to 1 M Ca(2+), which demonstrates the feasibility of using this approach to monitor rapid, dynamic chemical processes. Rapid conductance measurements will be broadly applicable to IC-based sensors that undergo analyte-specific gating.

  2. The mechanisms of nickel toxicity in aquatic environments: an adverse outcome pathway analysis.

    Science.gov (United States)

    Brix, Kevin V; Schlekat, Christian E; Garman, Emily R

    2016-12-09

    Current ecological risk assessment and water quality regulations for nickel (Ni) use mechanistically based, predictive tools such as biotic ligand models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concern over the use of tools like the BLM in some regulatory settings. To address this knowledge gap, the authors used an adverse outcome pathway (AOP) analysis, the first AOP for a metal, to identify multiple potential mechanisms of Ni toxicity and their interactions with freshwater aquatic organisms. The analysis considered potential mechanisms of action based on data from a wide range of organisms in aquatic and terrestrial environments on the premise that molecular initiating events for an essential metal would potentially be conserved across taxa. Through this analysis the authors identified 5 potential molecular initiating events by which Ni may exert toxicity on aquatic organisms: disruption of Ca(2+) homeostasis, disruption of Mg(2+) homeostasis, disruption of Fe(2+/3+) homeostasis, reactive oxygen species-induced oxidative damage, and an allergic-type response of respiratory epithelia. At the organ level of biological organization, these 5 potential molecular initiating events collapse into 3 potential pathways: reduced Ca(2+) availability to support formation of exoskeleton, shell, and bone for growth; impaired respiration; and cytotoxicity and tumor formation. At the level of the whole organism, the organ-level responses contribute to potential reductions in growth and reproduction and/or alterations in energy metabolism, with several potential feedback loops between each of the pathways. Overall, the present AOP analysis provides a robust framework for future directed studies on the mechanisms of Ni toxicity and for developing AOPs for other metals. Environ Toxicol Chem 2017;9999:1-10. © 2016 SETAC.

  3. Dėl kankorėžių pavadinimų kilmės

    Directory of Open Access Journals (Sweden)

    Saulius Ambrazas

    2011-12-01

    Full Text Available On the origin of cone termsSummaryAlgirdas Sabaliauskas (1972 on the basis of the rough copy of the maps of the Atlas of the Lithuanian language (cf. Lietuvių kalbos atlasas 1, Map 93 established, that čiū̃tė ‘cone’ (used in the Western part of North Low Lithuanian dialect not far from the area where kiaũlė, kiaulẽlė, kiaulìkė have the meaning of cone is formed not from čečka, čyčka, the varriants of Slavic borrowing šyškà (characteristic of some West High Lithuanian dialects, as Ernst Fraenkel (1955–1965, 72, 77 thought, but from onomatopoeic names of pig, cf. Lith. čiúotė, čiúotis; čiūkà, čiū̃kas, Latv. čūčis. During preparation of Atlas of the Baltic Languages the revision has been made of other cone terms in Lithuanian dialects. The greatest part of them is also formed from onomatopoeic words, cf.  kukùtis (: kùkti ‘give a scream, utter’, kaũkti ‘howl, wail, hoot’, gurgùtis (: gur̃gti ‘rumble, grumble’, burkùtis (: bur̃kti ‘purr, mutter; gramble’, burkúoti ‘coo, purr’, baubùkas (: baũbti ‘moo, bellow, roar’, bū̃kas, bùkas (: baũkti ‘moo, bellow, roar; bleat, baa; shout, shriek’, bū̃kti ‘bleat, baa, moo’ a. o.In the similar way the origin of the older cone terms has been explained: Lith. kìrkužė, Latv. cirkuzis ‘cone’  (cf. Lith. kir̃kti ‘cluck; weep; croak; squeak, creak’, Latv. cir̃kstêt ‘chirp, chirr; squeak, creak’, Lith. kankórėžis ‘cone’ (cf. kañkalas ‘clapper’ and rė́žti ‘cut, curve’, Lith. skujà ‘needle; cone’, Latv. skuja ‘needle’ (cf. Lith. skuĩstas ‘bush; pine forest’, skuĩstis ‘thick-set fir-grove’; kuĩstas ‘bush’, kuĩtas, kuĩtis ‘thick-set coniferous forest’; skuĩsti ‘play pranks, be naughty, romp, rage, rave’, kuĩsti ‘rummage, ransack; dig up the ground; rush’, Latv. skuit, skuju ‘shave, scrape, peel; cut, clip; clean’.

  4. Apresentação

    Directory of Open Access Journals (Sweden)

    Os Editores

    2004-12-01

    Full Text Available Este número da Significação segue os parâmetros já definidos pela revista, isto é, integra um conjunto de trabalhos de pesquisadores de diferentes Programas de Pós-Graduação do País e ensaios de investigadores estrangeiros que se publicam pela primeira vez, dois deles na língua original e um terceiro traduzido para o português. Quanto à temática, os textos aqui reunidos lidam com assuntos que nos parecem de interesse considerando as tendências atuais dos estudos da comunicação e, ainda, a relevância da epistemologia para a análise e interpretação das metáforas visuais, assim como das mudanças porque vem passando o conceito de sujeito nas ciências humanas. Isso fica claro se, por exemplo, nos adentramos na leitura e discussão dos fundamentos narratológicos, no equacionamento da metodologia posta em prática nas abordagens de discursos fílmicos ou da apropriação caricatural e grotesca da crise do sujeito que se manifesta no espetáculo midiático. Somem-se a isso os esforços destinados a nos dar, de um lado, um panorama diacrônico dos aspectos fundamentais do cinema mexicano moderno e, de outro, uma visão predominantemente sincrônica de um tema que funciona como entremeio no cinema espanhol contemporâneo. Em seu conjunto, a diversidade de tópicos abordados define, como não poderia deixar de ser, eixos comuns em torno dos quais giram pontos de vista cujas diferenças não impedem o diálogo, traço característico que orienta as particularidades deste periódico. É de se ressaltar, também, a preocupação com o estudo da imagem a partir das peculiaridades das etimologias iconográficas, pressuposto que, a nosso ver, abre novas perspectivas para a crítica das mensagens visuais. Mas este número, levando em conta a já longa trajetória da revista, se toma, sobretudo, singular pelo fato de publicar, pela primeira vez e em português, um texto pouco conhecido de Algirdas Julien Greimas, traduzido diretamente do

  5. Recent developments in sequence selective minor groove DNA effectors.

    Science.gov (United States)

    Reddy, B S; Sharma, S K; Lown, J W

    2001-04-01

    class of PBD-lexitropsin conjugates is also discussed. Certain functional models of the bleomycins (BLMs) show outstanding DNA cleavage activity comparable with that of and positionally distinct from natural BLM.

  6. In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M.R.; Eisel, T.; Fabjan, C.; Rementeria, C.A. [CERN, Geneva (Switzerland); Griesmayer, E. [CIVIDEC Instrumentation, GmbH, Vienna (Austria); Eremin, V. [Ioffe Institute, St. Petersburg (Russian Federation); Verbitskaya, E., E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, St. Petersburg (Russian Federation); Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I. [Ioffe Institute, St. Petersburg (Russian Federation); Egorov, N. [Research Institute of Material Science and Technology, Zelenograd, Moscow (Russian Federation); Härkönen, J.; Luukka, P.; Tuominen, E. [Helsinki Institute of Physics, Helsinki (Finland)

    2015-05-11

    As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×10{sup 16} proton/cm{sup 2}, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×10{sup 16} p/cm{sup 2} irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage. - Highlights: • Silicon and diamond detectors are proposed for beam loss monitoring at LHC. • The first in situ radiation test of Si and diamond detectors at 1.9 K is described. • Both diamond and silicon detectors survived after 1×10{sup 16} p/cm{sup 2} irradiation at 1.9 K. • The rate of Si detectors degradation depends on bias polarity and is larger at V{sub forw}. • Sensitivity of Si detectors irradiated to 1×10{sup 16} p/cm{sup 2} is independent on resistivity.

  7. Basolateral Na+/HCO3– cotransport activity is regulated by the dissociable Na+/H+ exchanger regulatory factor

    Science.gov (United States)

    Bernardo, Angelito A.; Kear, Felicidad T.; Santos, Anna V.P.; Ma, Jianfei; Steplock, Debra; Robey, R. Brooks; Weinman, Edward J.

    1999-01-01

    In the renal proximal tubule, the activities of the basolateral Na+/HCO3– cotransporter (NBC) and the apical Na+/H+ exchanger (NHE3) uniformly vary in parallel, suggesting that they are coordinately regulated. PKA-mediated inhibition of NHE3 is mediated by a PDZ motif–containing protein, the Na+/H+ exchanger regulatory factor (NHE-RF). Given the common inhibition of these transporters after protein kinase A (PKA) activation, we sought to determine whether NHE-RF also plays a role in PKA-regulated NBC activity. Renal cortex immunoblot analysis using anti-peptide antibodies directed against rabbit NHE-RF demonstrated the presence of this regulatory factor in both brush-border membranes (BBMs) and basolateral membranes (BLMs). Using a reconstitution assay, we found that limited trypsin digestion of detergent solubilized rabbit renal BLM preparations resulted in NBC activity that was unaffected by PKA activation. Co-reconstitution of these trypsinized preparations with a recombinant protein corresponding to wild-type rabbit NHE-RF restored the inhibitory effect of PKA on NBC activity in a concentration-dependent manner. NBC activity was inhibited 60% by 10–8M NHE-RF; this effect was not observed in the absence of PKA. Reconstitution with heat-denatured NHE-RF also failed to attenuate NBC activity. To establish further a physiologic role for NHE-RF in NBC regulation, the renal epithelial cell line B-SC-1, which lacks detectable endogenous NHE-RF expression, was engineered to express stably an NHE-RF transgene. NHE-RF–expressing B-SC-1 cells (B-SC-RF) exhibited markedly lower basal levels of NBC activity than did wild-type controls. Inhibition of NBC activity in B-SC-RF cells was enhanced after 10 μM of forskolin treatment, consistent with a postulated role for NHE-RF in mediating the inhibition of NBC activity by PKA. These findings not only suggest NHE-RF involvement in PKA-regulated NBC activity, but also provide a unique molecular mechanism whereby

  8. Application of diamond based beam loss monitors at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria

    2013-04-15

    The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in