Long-term safety of rituximab induced peripheral B-cell depletion in autoimmune neurological diseases.

Directory of Open Access Journals (Sweden)

Anza B Memon

Full Text Available B-cells play a pivotal role in several autoimmune diseases, including patients with immune-mediated neurological disorders (PIMND, such as neuromyelitis optica (NMO, multiple sclerosis (MS, and myasthenia gravis (MG. Targeting B-cells has been an effective approach in ameliorating both central and peripheral autoimmune diseases. However, there is a paucity of literature on the safety of continuous B-cell depletion over a long period of time.The aim of this study was to examine the long-term safety, incidence of infections, and malignancies in subjects receiving continuous therapy with a B-cell depleting agent rituximab over at least 3 years or longer.This was a retrospective study involving PIMND who received continuous cycles of rituximab infusions every 6 to 9 months for up to 7 years. The incidence of infection related adverse events (AE, serious adverse events (SAE, and malignancies were observed.There were a total of 32 AE and 4 SAE with rituximab treatment. The 3 SAE were noted after 9 cycles (48 months and 1 SAE was observed after 11 cycles (60 months of rituximab. There were no cases of Progressive multifocal leukoencephalopathy (PML and malignancies observed throughout the treatment period. Rituximab was well tolerated without any serious infusion reactions. Also, rituximab was found to be beneficial in treating PIMND over a 7-year period.This study demonstrates that long-term depletion of peripheral B-cells appears safe and efficacious in treating PIMND. Longer and larger prospective studies with rituximab are needed to carefully ascertain risks associated with chronic B-cell depletion, including malignancies. Recognizing that this is a small, retrospective study, such data nonetheless complement the growing literature documenting the safety and tolerability of B-cell depleting agents in neurological diseases.

Long-Lasting Sound-Evoked Afterdischarge in the Auditory Midbrain.

Science.gov (United States)

Ono, Munenori; Bishop, Deborah C; Oliver, Douglas L

2016-02-12

Different forms of plasticity are known to play a critical role in the processing of information about sound. Here, we report a novel neural plastic response in the inferior colliculus, an auditory center in the midbrain of the auditory pathway. A vigorous, long-lasting sound-evoked afterdischarge (LSA) is seen in a subpopulation of both glutamatergic and GABAergic neurons in the central nucleus of the inferior colliculus of normal hearing mice. These neurons were identified with single unit recordings and optogenetics in vivo. The LSA can continue for up to several minutes after the offset of the sound. LSA is induced by long-lasting, or repetitive short-duration, innocuous sounds. Neurons with LSA showed less adaptation than the neurons without LSA. The mechanisms that cause this neural behavior are unknown but may be a function of intrinsic mechanisms or the microcircuitry of the inferior colliculus. Since LSA produces long-lasting firing in the absence of sound, it may be relevant to temporary or chronic tinnitus or to some other aftereffect of long-duration sound.

Deuterium-depleted water

International Nuclear Information System (INIS)

Stefanescu, Ion; Steflea, Dumitru; Saros-Rogobete, Irina; Titescu, Gheorghe; Tamaian, Radu

2001-01-01

Deuterium-depleted water represents water that has an isotopic content smaller than 145 ppm D/(D+H) which is the natural isotopic content of water. Deuterium depleted water is produced by vacuum distillation in columns equipped with structured packing made from phosphor bronze or stainless steel. Deuterium-depleted water, the production technique and structured packing are patents of National Institute of Research - Development for Cryogenics and Isotopic Technologies at Rm. Valcea. Researches made in the last few years showed the deuterium-depleted water is a biological active product that could have many applications in medicine and agriculture. (authors)

Summary of the engineering analysis report for the long-term management of depleted uranium hexafluoride

International Nuclear Information System (INIS)

Dubrin, J.W.; Rahm-Crites, L.

1997-09-01

The Department of Energy (DOE) is reviewing ideas for the long-term management and use of its depleted uranium hexafluoride. DOE owns about 560,000 metric tons (over a billion pounds) of depleted uranium hexafluoride. This material is contained in steel cylinders located in storage yards near Paducah, Kentucky; Portsmouth, Ohio; and at the East Tennessee Technology Park (formerly the K-25 Site) in Oak Ridge, Tennessee. On November 10, 1994, DOE announced its new Depleted Uranium Hexafluoride Management Program by issuing a Request for Recommendations and an Advance Notice of Intent in the Federal Register (59 FR 56324 and 56325). The first part of this program consists of engineering, costs and environmental impact studies. Part one will conclude with the selection of a long-term management plan or strategy. Part two will carry out the selected strategy

Summary of the engineering analysis report for the long-term management of depleted uranium hexafluoride

Energy Technology Data Exchange (ETDEWEB)

Dubrin, J.W., Rahm-Crites, L.

1997-09-01

The Department of Energy (DOE) is reviewing ideas for the long-term management and use of its depleted uranium hexafluoride. DOE owns about 560,000 metric tons (over a billion pounds) of depleted uranium hexafluoride. This material is contained in steel cylinders located in storage yards near Paducah, Kentucky; Portsmouth, Ohio; and at the East Tennessee Technology Park (formerly the K-25 Site) in Oak Ridge, Tennessee. On November 10, 1994, DOE announced its new Depleted Uranium Hexafluoride Management Program by issuing a Request for Recommendations and an Advance Notice of Intent in the Federal Register (59 FR 56324 and 56325). The first part of this program consists of engineering, costs and environmental impact studies. Part one will conclude with the selection of a long-term management plan or strategy. Part two will carry out the selected strategy.

Quantum Stackelberg Duopoly Game in Depolarizing Channel

International Nuclear Information System (INIS)

Zhu Xia; Kuang Leman

2008-01-01

In this paper, we investigate the quantum Stackelberg duopoly (QSD) game in the noise environment with the depolarizing channel expressed by the Kraus-operator representation. It is found that the presence of the damping in the depolarizing channel always leads to the decrease of the quantities of the moves and payoffs of the two players in the QSD game. It is indicated that under certain conditions the first-mover advantage in the QSD game can be weakened due to the presence of the damping in the depolarizing channel.

Recovery of slow potentials in AC-coupled electrocorticography: application to spreading depolarizations in rat and human cerebral cortex

DEFF Research Database (Denmark)

Hartings, Jed A; Watanabe, Tomas; Dreier, Jens P

2009-01-01

Cortical spreading depolarizations (spreading depressions and peri-infarct depolarizations) are a pathology intrinsic to acute brain injury, generating large negative extracellular slow potential changes (SPCs) that, lasting on the order of minutes, are studied with DC-coupled recordings in animals...... of the inverse filter was validated by its ability to recover both simulated and real low-frequency input test signals. The inverse filter was then applied to AC-coupled ECoG recordings from five patients who underwent invasive monitoring after aneurysmal subarachnoid hemorrhage. For 117 SPCs, the inverse filter...

Repeated Transient Jets from a Warped Disk in the Symbiotic Prototype Z And: A Link to the Long-lasting Active Phase

Science.gov (United States)

Skopal, Augustin; Tarasova, Taya. N.; Wolf, Marek; Dubovský, Pavol A.; Kudzej, Igor

2018-05-01

Active phases of some symbiotic binaries survive for a long time, from years to decades. The accretion process onto a white dwarf (WD) sustaining long-lasting activity, and sometimes leading to collimated ejection, is not well understood. We present the repeated emergence of highly collimated outflows (jets) from the symbiotic prototype Z And during its 2008 and 2009–10 outbursts and suggest their link to the current long-lasting (from 2000) active phase. We monitored Z And with high-resolution spectroscopy, multicolor UBVR C—and high time resolution—photometry. The well-pronounced bipolar jets were ejected again during the 2009–10 outburst together with the simultaneous emergence of the rapid photometric variability (Δm ≈ 0.06 mag) on the timescale of hours, showing similar properties as those during the 2006 outburst. These phenomena and the measured disk–jets connection could be caused by the radiation-induced warping of the inner disk due to a significant increase of the burning WD luminosity. Ejection of transient jets by Z And around outburst maxima signals a transient accretion at rates above the upper limit of the stable hydrogen burning on the WD surface, and thus proves the nature of Z And-type outbursts. The enhanced accretion through the disk warping, supplemented by the accretion from the giant’s wind, can keep a high luminosity of the WD for a long time, until depletion of the disk. In this way, the jets provide a link to long-lasting active phases of Z And.

Spreading depolarizations and late secondary insults after traumatic brain injury

DEFF Research Database (Denmark)

Hartings, Jed A; Strong, Anthony J; Fabricius, Martin

2009-01-01

Here we investigated the incidence of cortical spreading depolarizations (spreading depression and peri-infarct depolarization) after traumatic brain injury (TBI) and their relationship to systemic physiologic values during neurointensive care. Subdural electrode strips were placed on peri......-contusional cortex in 32 patients who underwent surgical treatment for TBI. Prospective electrocorticography was performed during neurointensive care with retrospective analysis of hourly nursing chart data. Recordings were 84 hr (median) per patient and 2,503 hr in total. In 17 patients (53%), 280 spreading...... depolarizations (spreading depressions and peri-infarct depolarizations) were observed. Depolarizations occurred in a bimodal pattern with peak incidence on days 1 and 7. The probability of a depolarization occurring increased significantly as a function of declining mean arterial pressure (MAP; R(2) = 0.78; p...

Stitching Type Large Aperture Depolarizer for Gas Monitoring Imaging Spectrometer

Science.gov (United States)

Liu, X.; Li, M.; An, N.; Zhang, T.; Cao, G.; Cheng, S.

2018-04-01

To increase the accuracy of radiation measurement for gas monitoring imaging spectrometer, it is necessary to achieve high levels of depolarization of the incoming beam. The preferred method in space instrument is to introduce the depolarizer into the optical system. It is a combination device of birefringence crystal wedges. Limited to the actual diameter of the crystal, the traditional depolarizer cannot be used in the large aperture imaging spectrometer (greater than 100 mm). In this paper, a stitching type depolarizer is presented. The design theory and numerical calculation model for dual babinet depolarizer were built. As required radiometric accuracies of the imaging spectrometer with 250 mm × 46 mm aperture, a stitching type dual babinet depolarizer was design in detail. Based on designing the optimum structural parmeters the tolerance of wedge angle refractive index, and central thickness were given. The analysis results show that the maximum residual polarization degree of output light from depolarizer is less than 2 %. The design requirements of polarization sensitivity is satisfied.

Long-lasting desynchronization in rat hippocampal slice induced by coordinated reset stimulation

International Nuclear Information System (INIS)

Tass, P. A.; Barnikol, U. B.; Silchenko, A. N.; Hauptmann, C.; Speckmann, E.-J.

2009-01-01

In computational models it has been shown that appropriate stimulation protocols may reshape the connectivity pattern of neural or oscillator networks with synaptic plasticity in a way that the network learns or unlearns strong synchronization. The underlying mechanism is that a network is shifted from one attractor to another, so that long-lasting stimulation effects are caused which persist after the cessation of stimulation. Here we study long-lasting effects of multisite electrical stimulation in a rat hippocampal slice rendered epileptic by magnesium withdrawal. We show that desynchronizing coordinated reset stimulation causes a long-lasting desynchronization between hippocampal neuronal populations together with a widespread decrease in the amplitude of the epileptiform activity. In contrast, periodic stimulation induces a long-lasting increase in both synchronization and amplitude.

Parametric Analysis of PWR Spent Fuel Depletion Parameters for Long-Term-Disposal Criticality Safety

International Nuclear Information System (INIS)

DeHart, M.D.

1999-01-01

Utilization of burnup credit in criticality safety analysis for long-term disposal of spent nuclear fuel allows improved design efficiency and reduced cost due to the large mass of fissile material that will be present in the repository. Burnup-credit calculations are based on depletion calculations that provide a conservative estimate of spent fuel contents (in terms of criticality potential), followed by criticality calculations to assess the value of the effective neutron multiplication factor (k(sub)eff) for the a spent fuel cask or a fuel configuration under a variety of probabilistically derived events. In order to ensure that the depletion calculation is conservative, it is necessary to both qualify and quantify assumptions that can be made in depletion models

STITCHING TYPE LARGE APERTURE DEPOLARIZER FOR GAS MONITORING IMAGING SPECTROMETER

Directory of Open Access Journals (Sweden)

X. Liu

2018-04-01

Full Text Available To increase the accuracy of radiation measurement for gas monitoring imaging spectrometer, it is necessary to achieve high levels of depolarization of the incoming beam. The preferred method in space instrument is to introduce the depolarizer into the optical system. It is a combination device of birefringence crystal wedges. Limited to the actual diameter of the crystal, the traditional depolarizer cannot be used in the large aperture imaging spectrometer (greater than 100 mm. In this paper, a stitching type depolarizer is presented. The design theory and numerical calculation model for dual babinet depolarizer were built. As required radiometric accuracies of the imaging spectrometer with 250 mm × 46 mm aperture, a stitching type dual babinet depolarizer was design in detail. Based on designing the optimum structural parmeters，the tolerance of wedge angle，refractive index, and central thickness were given. The analysis results show that the maximum residual polarization degree of output light from depolarizer is less than 2 %. The design requirements of polarization sensitivity is satisfied.

Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.

Science.gov (United States)

Santini, Emanuela; Huynh, Thu N; Klann, Eric

2014-01-01

The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. © 2014 Elsevier Inc. All rights reserved.

First Observation of a Snake Depolarizing Resonance

International Nuclear Information System (INIS)

Phelps, R.; Anferov, V.; Blinov, B.; Crandell, D.; Koutin, S.; Krisch, A.; Liu, T.; Ratner, L.; Wong, V.; Chu, C.; Lee, S.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E.; von Przewoski, B.; Sato, H.

1997-01-01

Using a 104MeV stored polarized proton beam and a full Siberian snake, we recently found evidence for a so-called open-quotes snakeclose quotes depolarizing resonance. A full Siberian snake forces the spin tune ν s to be a half integer. Thus, if the vertical betatron tune ν y is set near a quarter integer, then the ν s =n±2ν y second-order snake resonance can depolarize the beam. Indeed, with a full Siberian snake, we found a deep depolarization dip when ν y was equal to 4.756; moreover, when ν y was changed to 4.781, the deep dip disappeared and the polarization was preserved. copyright 1997 The American Physical Society

Electrical characterization of polymer matrix — TiO2 filler composites through isothermal polarization / depolarization currents and I-V tests

Science.gov (United States)

Stavrakas, Ilias; Triantis, Dimos; Hloupis, George; Moutzouris, Konstantinos

2014-04-01

Specimens of polymer matrix — ceramic TiO2 filler composites were prepared. The contribution of the filler content on the electrical conductivity and energy storage properties of the samples was examined. I-V and Isothermal Polarization/Depolarization Current (IPC/IDC) measurements were conducted. Dc conductivity values directly calculated from the I-V curves exhibited excellent agreement with corresponding values derived from the IPC/IDC recordings. Standard models were employed for fitting the IPC/IDC data. In specific, the short and the very long depolarization times were fitted by use of power laws of different slopes, while the intermediate depolarization times were fitted as a sum of three exponential decays. The present study reveals a strong dependence of the depolarization and polarization processes, as well as of the dc conductivity, on the filler concentration.

Resonant depolarization in electron storage rings equipped with ''siberia snakes''

International Nuclear Information System (INIS)

Buon, J.

1984-11-01

Resonant depolarization induced by field errors and quantum emissions in an electron ring equipped with two ''siberian snakes'' is investigated with a first order perturbation calculation. It is shown that this depolarization is not reduced by the snakes when the operating energy is set out of the depolarization resonances [fr

Spreading Depression, Spreading Depolarizations, and the Cerebral Vasculature

DEFF Research Database (Denmark)

Ayata, Cenk; Lauritzen, Martin

2015-01-01

Spreading depression (SD) is a transient wave of near-complete neuronal and glial depolarization associated with massive transmembrane ionic and water shifts. It is evolutionarily conserved in the central nervous systems of a wide variety of species from locust to human. The depolarization spreads...

Compton effect thermally activated depolarization dosimeter

Science.gov (United States)

Moran, Paul R.

1978-01-01

A dosimetry technique for high-energy gamma radiation or X-radiation employs the Compton effect in conjunction with radiation-induced thermally activated depolarization phenomena. A dielectric material is disposed between two electrodes which are electrically short circuited to produce a dosimeter which is then exposed to the gamma or X radiation. The gamma or X-radiation impinging on the dosimeter interacts with the dielectric material directly or with the metal composing the electrode to produce Compton electrons which are emitted preferentially in the direction in which the radiation was traveling. A portion of these electrons becomes trapped in the dielectric material, consequently inducing a stable electrical polarization in the dielectric material. Subsequent heating of the exposed dosimeter to the point of onset of ionic conductivity with the electrodes still shorted through an ammeter causes the dielectric material to depolarize, and the depolarization signal so emitted can be measured and is proportional to the dose of radiation received by the dosimeter.

Is depleted uranium a threat to health and the environment?

International Nuclear Information System (INIS)

2002-01-01

This issue has come to the fore in recent years now that Norwegian military personnel have been sent to regions of the world where ammunition made of depleted uranium has been used. A number of surveys have been conducted in the Balkans, so far indicating no health hazards to people present in these areas. However, the latest international surveys show that contamination may be long-lasting. Tonje Sekse represented the Norwegian Radiation Protection Authority at the United Nations Environment Programme's (UNEP) inspection tour to Serbia and Montenegro in the autumn of 2001. The report, entitled ''Depleted uranium in Serbia and Montenegro - Post-Conflict Environmental Assessment in the Federal Republic of Yugoslavia'' was published by UNEP in March 2002.(author)

Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

CERN Document Server

Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

2011-01-01

We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

Neutron depolarization in compressed ferrite powders

International Nuclear Information System (INIS)

Rekveldt, M.Th.; Kraan, W.H.

1976-01-01

The polarization change of a polarized neutron beam after transmission through a partly magnetized ferromagnetic material can be described by a (3x3) depolarization matrix. This matrix can be expressed in terms of domain quantities such as the reduced mean magnetization M, the mean domain size delta and the mean square direction cosinus γsub(y) of the inner magnetization within the domain, and can be used for measuring magnetic properties of ferromagnetic materials. In the underlying depolarization theory it is assumed that no correlations exist between the direction of the spontaneous magnetization Bs in neighbouring domains, and between the direction of Bs and the individual domain sizes. In order to extend the measuring method for ferromagnetic materials, measurements have been made with different compressed ferrite powders assuming that the mean domain size is equal to the mean particle size. The neutron depolarization matrix is measured as a function of an alternative external magnetic field and interpreted in terms of m, γsub(y), and delta. The possibilities and limitations of the measuring method are discussed

Modulation of electromagnetic fields by a depolarizer of random polarizer array

DEFF Research Database (Denmark)

Ma, Ning; Hanson, Steen Grüner; Wang, Wei

2016-01-01

The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers with ran......The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers...... with randomly distributed polarization angles, where the incident fields experience a random polarization modulation after passing through the depolarizer. The propagation of the modulated electric fields through any quadratic optical system is examined within the framework of the complex ABCD matrix to show...

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

International Nuclear Information System (INIS)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-01-01

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, λ=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

Energy Technology Data Exchange (ETDEWEB)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-07-15

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, {lambda}=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc.

Long lasting protein synthesis- and activity-dependent spine shrinkage and elimination after synaptic depression.

Directory of Open Access Journals (Sweden)

Yazmín Ramiro-Cortés

Full Text Available Neuronal circuits modify their response to synaptic inputs in an experience-dependent fashion. Increases in synaptic weights are accompanied by structural modifications, and activity dependent, long lasting growth of dendritic spines requires new protein synthesis. When multiple spines are potentiated within a dendritic domain, they show dynamic structural plasticity changes, indicating that spines can undergo bidirectional physical modifications. However, it is unclear whether protein synthesis dependent synaptic depression leads to long lasting structural changes. Here, we investigate the structural correlates of protein synthesis dependent long-term depression (LTD mediated by metabotropic glutamate receptors (mGluRs through two-photon imaging of dendritic spines on hippocampal pyramidal neurons. We find that induction of mGluR-LTD leads to robust and long lasting spine shrinkage and elimination that lasts for up to 24 hours. These effects depend on signaling through group I mGluRs, require protein synthesis, and activity. These data reveal a mechanism for long lasting remodeling of synaptic inputs, and offer potential insights into mental retardation.

Depolarization artifacts in dual rotating-compensator Mueller matrix ellipsometry

International Nuclear Information System (INIS)

Li, Weiqi; Zhang, Chuanwei; Jiang, Hao; Chen, Xiuguo; Liu, Shiyuan

2016-01-01

Noticeable depolarization effects are observed in the measurement of the air using an in-house developed dual rotating-compensator Mueller matrix ellipsometer. We demonstrate that these depolarization effects are essentially artifacts and mainly induced when the compensator with wavelength-dependent optical properties is integrated with the finite bandwidth detector. We define a general formula to represent the actual Mueller matrix of the compensator by taking into account the depolarization artifacts. After incorporating this formula into the system model, a correction method is further proposed, and consequently, improved accuracy can be achieved in the Mueller matrix measurement. (paper)

Spreading convulsions, spreading depolarization and epileptogenesis in human cerebral cortex

DEFF Research Database (Denmark)

Dreier, Jens P; Major, Sebastian; Pannek, Heinz-Wolfgang

2012-01-01

Spreading depolarization of cells in cerebral grey matter is characterized by massive ion translocation, neuronal swelling and large changes in direct current-coupled voltage recording. The near-complete sustained depolarization above the inactivation threshold for action potential generating...... stimulations. Eventually, epileptic field potentials were recorded during the period that had originally seen spreading depression of activity. Such spreading convulsions are characterized by epileptic field potentials on the final shoulder of the large slow potential change of spreading depolarization. We...

Influence of thermal reduced depolarization on a repetition-frequency laser amplifier and compensation

Institute of Scientific and Technical Information of China (English)

Xin-ying Jiang; Xiong-wei Yan; Zhen-guo Wang; Jian-gang Zheng; Ming-zhong Li; Jing-qin Su

2015-01-01

Thermal stress can induce birefringence in a laser medium, which can cause depolarization of the laser. The depolarization effect will be very severe in a high-average-power laser. Because the depolarization will make the frequency doubling efficiency decline, it should be compensated. In this paper, the thermal characteristics of two kinds of materials are analyzed in respect of temperature, thermal deformation and thermal stress. The depolarization result from thermal stress was simulated. Depolarization on non-uniform pumping was also simulated, and the compensation method is discussed.

Transmitter-controlled properties of α-motoneurones causing long-lasting motor discharge to brief excitatory inputs

DEFF Research Database (Denmark)

Hounsgaard, J.; Hultborn, H.; Kiehn, O.

1986-01-01

Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced ...... flipflops, which are set at one of two levels by short excitatory or inhibitory inputs. However, when the whole motoneuronal pool is considered, many different levels can be maintained by recruitment of new units.......Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced...

Recording, analysis, and interpretation of spreading depolarizations in neurointensive care

DEFF Research Database (Denmark)

Dreier, Jens P; Fabricius, Martin; Ayata, Cenk

2017-01-01

Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly r...

Effective utilization period of long-lasting insecticide treated nets ...

African Journals Online (AJOL)

The study was conducted to evaluate the bioefficacy of long-lasting insecticide treated nets (LLITNs) (PermaNet®2.0) over time and the species composition of Anopheles mosquitoes around Bahir Dar. The space spray collection method was used to determine the species composition of indoor resting Anopheles ...

Depolarizing Effects of Daikenchuto on Interstitial Cells of Cajal from Mouse Small Intestine.

Science.gov (United States)

Kim, Hyungwoo; Kim, Hyun Jung; Yang, Dongki; Jung, Myeong Ho; Kim, Byung Joo

2017-01-01

Daikenchuto (DKT; TJ-100, TU-100), a traditional herbal medicineis used in modern medicine to treat gastrointestinal (GI) functional disorders. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the GI tract and play important roles in the regulation of GI motility. The objective of this study was to investigate the effects of DKT on the pacemaker potentials (PPs) of cultured ICCs from murine small intestine. Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. All experiments on ICCs were performed after 12 h of culture. The whole-cell patch-clamp configuration was used to record ICC PPs (current clamp mode). All experiments were performed at 30-32°C. In current-clamp modeDKT depolarized and concentration-dependently decreased the amplitudes of PPs. Y25130 (a 5-HT 3 receptor antagonist) or SB269970 (a 5-HT 7 receptor antagonist) did not block DKT-induced PP depolarization, but RS39604 (a 5-HT 4 receptor antagonist) did. Methoctramine (a muscarinic M 2 receptor antagonist) failed to block DKT-induced PP depolarization, but pretreating 4-diphenylacetoxy-N-methylpiperidine methiodide (a muscarinic M 3 receptor antagonist) facilitated blockade of DKT-induced PP depolarization. Pretreatment with an external Ca 2+ -free solution or thapsigargin abolished PPsand under these conditions, DKT did not induce PP depolarization. Furthermore Ginseng radix and Zingiberis rhizomes depolarized PPs, whereas Zanthoxyli fructus fruit (the third component of DKT) hyperpolarized PPs. These results suggest that DKT depolarizes ICC PPs in an internal or external Ca 2+ -dependent manner by stimulating 5-HT 4 and M 3 receptors. Furthermore, the authors suspect that the component in DKT largely responsible for depolarization is probably also a component of Ginseng radix and Zingiberis rhizomes. Daikenchuto (DKT) depolarized and concentration-dependently decreased the amplitudes of pacemaker potentials (PPs)Y25130 (a 5-HT 3 receptor antagonist) or

Possible Depolarization Mechanism due to Low Beta Squeeze

International Nuclear Information System (INIS)

Ranjbar, V.; Luccio, A.; Bai, M.

2008-01-01

Simulations reveal a potential depolarization mechanism during low beta squeeze. This depolarization appears to be driven by a spin tune modulation caused by spin precession through the strong low beta quads due to the vertical fields. The modulation of the spin tune introduces an additional snake resonance condition at ν s0 ± nν x - ν z l = integer which while the same numerology as the well known sextupole resonance, can operate in the absence of sextupole elements

A scattering model for rain depolarization

Science.gov (United States)

Wiley, P. H.; Stutzman, W. L.; Bostian, C. W.

1973-01-01

A method is presented for calculating the amount of depolarization caused by precipitation for a propagation path. In the model the effects of each scatterer and their interactions are accounted for by using a series of simplifying steps. It is necessary only to know the forward scattering properties of a single scatterer. For the case of rain the results of this model for attenuation, differential phase shift, and cross polarization agree very well with the results of the only other model available, that of differential attenuation and differential phase shift. Calculations presented here show that horizontal polarization is more sensitive to depolarization than is vertical polarization for small rain drop canting angle changes. This effect increases with increasing path length.

Correction of Depolarizing Resonances in ELSA

Science.gov (United States)

Steier, C.; Husmann, D.

1997-05-01

The 3.5 GeV electron stretcherring ELSA (ELectron Stretcher Accelerator) at Bonn University is operational since 1987, both as a continuous beam facility for external fixed target experiments and as a partially dedicated synchrotron light source. For the external experiments an upgrade to polarized electrons is under way. One source of polarized electrons (GaAs crystal, photoeffect using circular polarized laser light) is operational. The studies of minimizing the losses in polarization degree due to crossing of depolarizing resonances that necessarily exist in circular accelerators (storagerings) just started recently. Calculations concerning different correction schemes for the depolarizing resonances in ELSA are presented, and first results of measurements are shown (done by means of a Møller polarimeter in one of the external beamlines).

Cortical stimulation evokes abnormal responses in the dopamine-depleted rat basal ganglia.

Science.gov (United States)

Kita, Hitoshi; Kita, Takako

2011-07-13

The motor cortex (MC) sends massive projections to the basal ganglia. Motor disabilities in patients and animal models of Parkinson's disease (PD) may be caused by dopamine (DA)-depleted basal ganglia that abnormally process the information originating from MC. To study how DA depletion alters signal transfer in the basal ganglia, MC stimulation-induced (MC-induced) unitary responses were recorded from the basal ganglia of control and 6-hydroxydopamine-treated hemi-parkinsonian rats anesthetized with isoflurane. This report describes new findings about how DA depletion alters MC-induced responses. MC stimulation evokes an excitation in normally quiescent striatal (Str) neurons projecting to the globus pallidus external segment (GPe). After DA-depletion, the spontaneous firing of Str-GPe neurons increases, and MC stimulation evokes a shorter latency excitation followed by a long-lasting inhibition that was invisible under normal conditions. The increased firing activity and the newly exposed long inhibition generate tonic inhibition and a disfacilitation in GPe. The disfacilitation in GPe is then amplified in basal ganglia circuitry and generates a powerful long inhibition in the basal ganglia output nucleus, the globus pallidus internal segment. Intra-Str injections of a behaviorally effective dose of DA precursor l-3,4-dihydroxyphenylalanine effectively reversed these changes. These newly observed mechanisms also support the generation of pauses and burst activity commonly observed in the basal ganglia of parkinsonian subjects. These results suggest that the generation of abnormal response sequences in the basal ganglia contributes to the development of motor disabilities in PD and that intra-Str DA supplements effectively suppress abnormal signal transfer.

Neuronal Depolarization Drives Increased Dopamine Synaptic Vesicle Loading via VGLUT.

Science.gov (United States)

Aguilar, Jenny I; Dunn, Matthew; Mingote, Susana; Karam, Caline S; Farino, Zachary J; Sonders, Mark S; Choi, Se Joon; Grygoruk, Anna; Zhang, Yuchao; Cela, Carolina; Choi, Ben Jiwon; Flores, Jorge; Freyberg, Robin J; McCabe, Brian D; Mosharov, Eugene V; Krantz, David E; Javitch, Jonathan A; Sulzer, David; Sames, Dalibor; Rayport, Stephen; Freyberg, Zachary

2017-08-30

The ability of presynaptic dopamine terminals to tune neurotransmitter release to meet the demands of neuronal activity is critical to neurotransmission. Although vesicle content has been assumed to be static, in vitro data increasingly suggest that cell activity modulates vesicle content. Here, we use a coordinated genetic, pharmacological, and imaging approach in Drosophila to study the presynaptic machinery responsible for these vesicular processes in vivo. We show that cell depolarization increases synaptic vesicle dopamine content prior to release via vesicular hyperacidification. This depolarization-induced hyperacidification is mediated by the vesicular glutamate transporter (VGLUT). Remarkably, both depolarization-induced dopamine vesicle hyperacidification and its dependence on VGLUT2 are seen in ventral midbrain dopamine neurons in the mouse. Together, these data suggest that in response to depolarization, dopamine vesicles utilize a cascade of vesicular transporters to dynamically increase the vesicular pH gradient, thereby increasing dopamine vesicle content. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term potentiation and olfactory memory formation in the carp (Cyprinus carpio L.) olfactory bulb.

Science.gov (United States)

Satou, M; Anzai, S; Huruno, M

2005-05-01

Long-term potentiation of synaptic transmission is considered to be an elementary process underlying the cellular mechanism of memory formation. In the present study we aimed to examine whether or not the dendrodendritic mitral-to-granule cell synapses in the carp olfactory bulb show plastic changes after their repeated activation. It was found that: (1) the dendrodendritic mitral-to-granule cell synapses showed three types of plasticity after tetanic electrical stimulation applied to the olfactory tract-long-term potentiation (potentiation lasting >1 h), short-term potentiation (potentiation lasting 1 h) of the odor-evoked bulbar response accompanied the electrically-induced LTP, and; (4) repeated olfactory stimulation enhanced dendrodendritic mitral-to-granule cell transmission. Based on these results, it was proposed that long-term potentiation (as well as olfactory memory) occurs at the dendrodendritic mitral-to-granule cell synapses after strong and long-lasting depolarization of granule cells, which follows repeated and simultaneous synaptic activation of both the peripheral and deep dendrites (or somata).

Risk of long-lasting negative cognitive consequences after electroconvulsive therapy

DEFF Research Database (Denmark)

Svendsen, Anne Marie; Miskowiak, Kamilla; Vinberg, Maj

2013-01-01

This case study describes a patient who had a unipolar depression and experienced long-lasting cognitive problems after electroconvulsive therapy (ECT). Neuropsychological testing revealed lower scores on measures of learning, memory and sustained attention. These results stress the importance...

Chlorovirus-mediated membrane depolarization of Chlorella alters secondary active transport of solutes.

Science.gov (United States)

Agarkova, Irina; Dunigan, David; Gurnon, James; Greiner, Timo; Barres, Julia; Thiel, Gerhard; Van Etten, James L

2008-12-01

Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of a family of large, double-stranded DNA, plaque-forming viruses that infect certain eukaryotic chlorella-like green algae from the genus Chlorovirus. PBCV-1 infection results in rapid host membrane depolarization and potassium ion release. One interesting feature of certain chloroviruses is that they code for functional potassium ion-selective channel proteins (Kcv) that are considered responsible for the host membrane depolarization and, as a consequence, the efflux of potassium ions. This report examines the relationship between cellular depolarization and solute uptake. Annotation of the virus host Chlorella strain NC64A genome revealed 482 putative transporter-encoding genes; 224 are secondary active transporters. Solute uptake experiments using seven radioactive compounds revealed that virus infection alters the transport of all the solutes. However, the degree of inhibition varied depending on the solute. Experiments with nystatin, a drug known to depolarize cell membranes, produced changes in solute uptake that are similar but not identical to those that occurred during virus infection. Therefore, these studies indicate that chlorovirus infection causes a rapid and sustained depolarization of the host plasma membrane and that this depolarization leads to the inhibition of secondary active transporters that changes solute uptake.

Properties of 13HMF steel welded joints after long-lasting service

International Nuclear Information System (INIS)

Zeman, M.

2002-01-01

Results are presented of research conducted on the 13HMF steel in the as-received condition after long-lasting service over 100000 hours. Simulation tests have been performed by means of modern research methods. The influence of thermal cycles on the microstructure (continuous cooling TTT diagrams), plastic properties (notch toughness and hardness) of simulated heat affected zones and reheat cracking resistance has been evaluated by using the thermal and strain cycle simulator. Susceptibility to thermal fatigue has been determined, the creep strength estimated and welding heat input was given, as well as the post weld heat treatment conditions of the 13HMF steel after service. properties of the welded joints made of 13HMF steel after long-lasting service are given. (author)

Maximizing percentage depletion in solid minerals

International Nuclear Information System (INIS)

Tripp, J.; Grove, H.D.; McGrath, M.

1982-01-01

This article develops a strategy for maximizing percentage depletion deductions when extracting uranium or other solid minerals. The goal is to avoid losing percentage depletion deductions by staying below the 50% limitation on taxable income from the property. The article is divided into two major sections. The first section is comprised of depletion calculations that illustrate the problem and corresponding solutions. The last section deals with the feasibility of applying the strategy and complying with the Internal Revenue Code and appropriate regulations. Three separate strategies or appropriate situations are developed and illustrated. 13 references, 3 figures, 7 tables

Neutron depolarization studies on magnetization process using pulsed polarized neutrons

International Nuclear Information System (INIS)

Mitsuda, Setsuo; Endoh, Yasuo

1985-01-01

Neutron depolarization experiments investigating the magnetization processes have been performed by using pulsed polarized neutrons for the first time. Results on both quenched and annealed ferromagnets of Fe 85 Cr 15 alloy indicate the significant difference in the wavelength dependence of depolarization between them. It also constitutes the experimental demonstration of the theoretical prediction of Halpern and Holstein. (author)

Depolarization of ultracold neutrons during their storage in material bottles

International Nuclear Information System (INIS)

Serebrov, A.P.; Lasakov, M.S.; Vassiljev, A.V.; Krasnoschekova, I.A.; Rudnev, Yu.P.; Fomin, A.K.; Varlamov, V.E.; Geltenbort, P.; Butterworth, J.; Young, A.R.; Pesavento, U.

2003-01-01

The depolarization of ultracold neutrons (UCN) during their storage in traps has been investigated. The neutron spin-flip probability for the materials studied amounts to ∼(1-2)x10 -5 per collision and does not depend on the temperature. The possible connection between the phenomenon of UCN depolarization and that of anomalous losses is discussed

Depolarization of ultracold neutrons during their storage in material bottles

Energy Technology Data Exchange (ETDEWEB)

Serebrov, A.P.; Lasakov, M.S.; Vassiljev, A.V.; Krasnoschekova, I.A.; Rudnev, Yu.P.; Fomin, A.K.; Varlamov, V.E.; Geltenbort, P.; Butterworth, J.; Young, A.R.; Pesavento, U

2003-07-14

The depolarization of ultracold neutrons (UCN) during their storage in traps has been investigated. The neutron spin-flip probability for the materials studied amounts to {approx}(1-2)x10{sup -5} per collision and does not depend on the temperature. The possible connection between the phenomenon of UCN depolarization and that of anomalous losses is discussed.

Special Issue: Planar Fully-Depleted SOI technology

Science.gov (United States)

Allibert, F.; Hiramoto, T.; Nguyen, B. Y.

2016-03-01

We are in the era of mobile computing with smart handheld devices and remote data storage "in the cloud," with devices that are almost always on and driven by needs of high data transmission rate, instant access/connection and long battery life. With all the ambitious requirements for better performance with lower power consumption, the SoC solution must also be cost-effective in order to capture the large, highly-competitive consumer mobile and wearable markets. The Fully-Depleted SOI device/circuit is a unique option that can satisfy all these requirements and has made tremendous progress in development for various applications and adoption by foundries, integrated device manufacturers (IDM), and fabless companies in the last 3 years.

Draft Programmatic Environmental Impact Statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 2: Appendices

International Nuclear Information System (INIS)

1997-12-01

This PEIS assesses the potential impacts of alternative management of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky; Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. The preferred alternative for the long-term management of depleted UF 6 is to use the entire inventory of material. This volume contains the appendices to volume I

miR-191 and miR-135 are required for long-lasting spine remodelling associated with synaptic long-term depression

Science.gov (United States)

Hu, Zhonghua; Yu, Danni; Gu, Qin-Hua; Yang, Yanqin; Tu, Kang; Zhu, Jun; Li, Zheng

2014-02-01

Activity-dependent modification of dendritic spines, subcellular compartments accommodating postsynaptic specializations in the brain, is an important cellular mechanism for brain development, cognition and synaptic pathology of brain disorders. NMDA receptor-dependent long-term depression (NMDAR-LTD), a prototypic form of synaptic plasticity, is accompanied by prolonged remodelling of spines. The mechanisms underlying long-lasting spine remodelling in NMDAR-LTD, however, are largely unclear. Here we show that LTD induction causes global changes in miRNA transcriptomes affecting many cellular activities. Specifically, we show that expression changes of miR-191 and miR-135 are required for maintenance but not induction of spine restructuring. Moreover, we find that actin depolymerization and AMPA receptor exocytosis are regulated for extended periods of time by miRNAs to support long-lasting spine plasticity. These findings reveal a miRNA-mediated mechanism and a role for AMPA receptor exocytosis in long-lasting spine plasticity, and identify a number of candidate miRNAs involved in LTD.

Entanglement degradation in depolarizing light scattering

International Nuclear Information System (INIS)

Aiello, A.; Woerdman, J.P.

2005-01-01

Full text: In the classical regime, when a beam of light is scattered by a medium, it may emerge partially or completely depolarized depending on the optical properties of the medium. Correspondingly, in the quantum regime, when an entangled two-photon pair is scattered, the classical depolarization may result in an entanglement degradation. Here, relations between photon scattering, entanglement and multi-mode detection are investigated. We establish a general framework in which one- and two-photon elastic scattering processes can be discussed, and we focus on the study of the intrinsic entanglement degradation caused by a multi-mode detection. We show that any multi-mode scattered state cannot maximally violate the Bell-CHSH inequality because of the momentum spread. The results presented here have general validity and can be applied to both deterministic and random scattering processes. (author)

Long-term management and use of depleted uranium

International Nuclear Information System (INIS)

Max, A.

2001-01-01

The products resulting from the process of enrichment of natural uranium, or reprocessed uranium, are enriched uranium products as the light fraction and depleted uranium (uranium tails) as the heavy fraction. If the source material is natural uranium, the mass ratios of uranium products and uranium tails can be derived relatively easily from the required enrichment level of the uranium product (product assay (% of U-235)) and the selected depletion level of the uranium tails (tails assay (% of U-235)). The paper discusses among other aspects the dependence of the tails mass on the required enrichment level of the relevant uranium product, for various tails assays. (orig./CB) [de

Thermal Stress-Induced Depolarization Loss in Conventional and Panda-Shaped Photonic Crystal Fiber Lasers

Science.gov (United States)

Mousavi, Seyedeh Laleh; Sabaeian, Mohammad

2016-10-01

We report on the modeling of the depolarization loss in the conventional and panda-shaped photonic crystal fiber lasers (PCFLs) due to the self-heating of the fiber, which we call it thermal stress-induced depolarization loss (TSIDL). We first calculated the temperature distribution over the fiber cross sections and then calculated the thermal stresses/strains as a function of heat load per meter. Thermal stress-induced birefringence (TSIB), which is defined as | n x - n y |, in the core and cladding regions was calculated. Finally, TSIDL was calculated for the conventional and panda-shaped PCFLs as a function of fiber length and, respectively, saturated values of 22 and 25 % were obtained which were independent of heat load per meter. For panda-shaped PCFLs, prior to being saturated, an oscillating and damping behavior against the fiber length was seen where in some lengths reached 35 %. The results are close to an experimental value of 30 % reported for a pulsed PCFL (Limpert et al., Opt Express 12:1313-1319, 2004) where the authors reported a degree of polarization of 70 % (i.e., a depolarization of 30 %). The most important result of this work is a saturation behavior of TSIDL at long-enough lengths of the fiber laser which is independent of heat load per meter. To our knowledge, this the first report of TSIBL for PCFLs.

Management of depleted uranium

International Nuclear Information System (INIS)

2001-01-01

Large stocks of depleted uranium have arisen as a result of enrichment operations, especially in the United States and the Russian Federation. Countries with depleted uranium stocks are interested in assessing strategies for the use and management of depleted uranium. The choice of strategy depends on several factors, including government and business policy, alternative uses available, the economic value of the material, regulatory aspects and disposal options, and international market developments in the nuclear fuel cycle. This report presents the results of a depleted uranium study conducted by an expert group organised jointly by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It contains information on current inventories of depleted uranium, potential future arisings, long term management alternatives, peaceful use options and country programmes. In addition, it explores ideas for international collaboration and identifies key issues for governments and policy makers to consider. (authors)

Draft Programmatic Environmental Impact Statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 1: Main text

International Nuclear Information System (INIS)

1997-12-01

This PEIS assesses the potential impacts of alternative management of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky; Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. The preferred alternative for the long-term management of depleted UF 6 is to use the entire inventory of material

Time-resolved stimulated emission depletion and energy transfer dynamics in two-photon excited EGFP

Science.gov (United States)

Masters, T. A.; Robinson, N. A.; Marsh, R. J.; Blacker, T. S.; Armoogum, D. A.; Larijani, B.; Bain, A. J.

2018-04-01

Time and polarization-resolved stimulated emission depletion (STED) measurements are used to investigate excited state evolution following the two-photon excitation of enhanced green fluorescent protein (EGFP). We employ a new approach for the accurate STED measurement of the hitherto unmeasured degree of hexadecapolar transition dipole moment alignment ⟨α40 ⟩ present at a given excitation-depletion (pump-dump) pulse separation. Time-resolved polarized fluorescence measurements as a function of pump-dump delay reveal the time evolution of ⟨α40 ⟩ to be considerably more rapid than predicted for isotropic rotational diffusion in EGFP. Additional depolarization by homo-Förster resonance energy transfer is investigated for both ⟨α20 ⟩ (quadrupolar) and ⟨α40 ⟩ transition dipole alignments. These results point to the utility of higher order dipole correlation measurements in the investigation of resonance energy transfer processes.

Neutron Depolarization in Submicron Ferromagnetic Materials

NARCIS (Netherlands)

Rekveldt, M.Th.

1989-01-01

The neutron depolarization technique is based on the loss of polarization of a polarized neutron beam after transmission through ferromagnetic substances. This loss, caused by Larmor precession in individual domains, determines the mean domain size, the mean square direction cosines of the domains

Efficacy of topical mosquito repellent (picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of malaria : A cluster randomised controlled trial

NARCIS (Netherlands)

Sluydts, V.; Durnez, L.; Heng, S.; Gryseels, C.; Canier, L.; Kim, S.; Van Roey, K.; Kerkhof, K.; Khim, N.; Mao, S.; Menard, D.; Coosemans, M.

2016-01-01

Background Although effective topical repellents provide personal protection against malaria, whether mass use of topical repellents in addition to long-lasting insecticidal nets can contribute to a further decline of malaria is not known, particularly in areas where outdoor transmission occurs. We

Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Summary

International Nuclear Information System (INIS)

1999-04-01

This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

Electron beam depolarization in a damping ring

International Nuclear Information System (INIS)

Minty, M.

1993-04-01

Depolarization of a polarized electron beam injected into a damping ring is analyzed by extending calculations conventionally applied to proton synchrotrons. Synchrotron radiation in an electron ring gives rise to both polarizing and depolarizing effects. In a damping ring, the beam is stored for a time much less than the time for self polarization. Spin flip radiation may therefore be neglected. Synchrotron radiation without spin flips, however, must be considered as the resonance strength depends on the vertical betatron oscillation amplitude which changes as the electron beam is radiation damped. An expression for the beam polarization at extraction is derived which takes into account radiation damping. The results are applied to the electron ring at the Stanford Linear Collider and are compared with numerical matrix formalisms

Long-Term Maintenance Therapy Using Rituximab-Induced Continuous B-Cell Depletion in Patients with ANCA Vasculitis

Science.gov (United States)

Pendergraft, William F.; Cortazar, Frank B.; Wenger, Julia; Murphy, Andrew P.; Rhee, Eugene P.; Laliberte, Karen A.; Niles, John L.

2014-01-01

Background and objectives Remission in the majority of ANCA vasculitis patients is not sustained after a single course of rituximab, and risk of relapse warrants development of a successful strategy to ensure durable remission. Design, setting, participants, & measurements A retrospective analysis of ANCA vasculitis patients who underwent maintenance therapy using rituximab-induced continuous B-cell depletion for up to 7 years was performed. Maintenance therapy with rituximab was initiated after achieving remission or converting from other prior maintenance therapy. Continuous B-cell depletion was achieved in all patients by scheduled rituximab administration every 4 months. Disease activity, serologic parameters, adverse events, and survival were examined. Results In the study, 172 patients (mean age=60 years, 55% women, 57% myeloperoxidase–ANCA) treated from April of 2006 to March of 2013 underwent continuous B-cell depletion with rituximab. Median remission maintenance follow-up time was 2.1 years. Complete remission (Birmingham Vasculitis Activity Score [BVAS]=0) was achieved in all patients. Major relapse (BVAS≥3) occurred in 5% of patients and was associated with weaning of other immunosuppression drugs. Remission was reinduced in all patients. Survival mirrored survival of a general age-, sex-, and ethnicity-matched United States population. Conclusion This analysis provides evidence for long-term disease control using continuous B-cell depletion. This treatment strategy in ANCA vasculitis patients also seems to result in survival rates comparable with rates in a matched reference population. These findings suggest that prospective remission maintenance treatment trials using continuous B-cell depletion are warranted. PMID:24626432

Thermal-induced structural transition and depolarization behavior in (Bi0.5Na0.5)TiO3-BiAlO3 ceramics

Science.gov (United States)

Peng, Ping; Nie, Hengchang; Cheng, Guofeng; Liu, Zhen; Wang, Genshui; Dong, Xianlin

2018-03-01

The depolarization temperature Td determines the upper temperature limit for the application of piezoelectric materials. However, the origin of depolarization behavior for Bi-based materials still remains controversial and the mechanism is intricate for different (Bi0.5Na0.5)TiO3-based systems. In this work, the structure and depolarization behavior of (1-x)(Bi0.5Na0.5)TiO3-xBiAlO3 (BNT-BA, x = 0, 0.02, 0.04, 0.06, 0.07) ceramics were investigated using a combination of X-ray diffraction and electrical measurements. It was found that as temperature increased, the induced long-range ferroelectric phase irreversibly transformed to the relaxor phase as evidenced by the temperature-dependent ferroelectric and dielectric properties, which corresponded to a gradual structural change from the rhombohedral to the pseudocubic phase. Therefore, the thermal depolarization behavior of BNT-BA ceramics was proposed to be directly related to the rhombohedral-pseudocubic transition. Furthermore, Td (obtained from thermally stimulated depolarization currents curves) was higher than the induced ferroelectric-relaxor phase transition temperature TFR (measured from dielectric curves). The phenomenon was quite different from other reported BNT-based systems, which may suggest the formation of polar nanoregions (PNRs) within macrodomains prior to the detexturation of short-range ferroelectric domains with PNRs or nanodomains.

Spin Depolarization due to Beam-Beam Interaction in NLC

Energy Technology Data Exchange (ETDEWEB)

Thompson, Kathleen A

2001-01-04

Calculations of spin depolarization effects due to the beam-beam interaction are presented for several NLC designs. The depolarization comes from both classical (Bargmann-Michel-Telegdi precession) and quantum (Sokolov-Ternov spin-flip) effects. It is anticipated that some physics experiments at future colliders will require a knowledge of the polarization to better than 0.5% precision. We compare the results of CAIN simulations with the analytic estimates of Yokoya and Chen for head-on collisions. We also study the effects of transverse offsets and beamstrahlung-induced energy spread.

Mechanism of blue-light-induced plasma-membrane depolarization in etiolated cucumber hypocotyls

Science.gov (United States)

Spalding, E. P.; Cosgrove, D. J.

1992-01-01

A large, transient depolarization of the plasma membrane precedes the rapid blue-light (BL)-induced growth suppression in etiolated seedlings of Cucumis sativus L. The mechanism of this voltage transient was investigated by applying inhibitors of ion channels and the plasma-membrane H(+)-ATPase, by manipulating extracellular ion concentrations, and by measuring cell input resistance and ATP levels. The depolarizing phase was not affected by Ca(2+)-channel blockers (verapamil, La3+) or by reducing extracellular free Ca2+ by treatment with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). However, these treatments did reduce the rate of repolarization, indicating an inward movement of Ca2+ is involved. No effects of the K(+)-channel blocker tetraethylammonium (TEA+) were detected. Vanadate and KCN, used to inhibit the H(+)-ATPase, reduced or completely inhibited the BL-induced depolarization. Levels of ATP increased by 11-26% after 1-2 min of BL. Input resistance of trichrome cells, measured with double-barreled microelectrodes, remained constant during the onset of the depolarization but decreased as the membrane voltage became more positive than -90 mV. The results indicate that the depolarization mechanism initially involves inactivation of the H(+)-ATPase with subsequent transient activation of one or more types of ion channels.

Distributional learning has immediate and long-lasting effects.

Science.gov (United States)

Escudero, Paola; Williams, Daniel

2014-11-01

Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Dibucaine mitigates spreading depolarization in human neocortical slices and prevents acute dendritic injury in the ischemic rodent neocortex.

Directory of Open Access Journals (Sweden)

W Christopher Risher

Full Text Available Spreading depolarizations that occur in patients with malignant stroke, subarachnoid/intracranial hemorrhage, and traumatic brain injury are known to facilitate neuronal damage in metabolically compromised brain tissue. The dramatic failure of brain ion homeostasis caused by propagating spreading depolarizations results in neuronal and astroglial swelling. In essence, swelling is the initial response and a sign of the acute neuronal injury that follows if energy deprivation is maintained. Choosing spreading depolarizations as a target for therapeutic intervention, we have used human brain slices and in vivo real-time two-photon laser scanning microscopy in the mouse neocortex to study potentially useful therapeutics against spreading depolarization-induced injury.We have shown that anoxic or terminal depolarization, a spreading depolarization wave ignited in the ischemic core where neurons cannot repolarize, can be evoked in human slices from pediatric brains during simulated ischemia induced by oxygen/glucose deprivation or by exposure to ouabain. Changes in light transmittance (LT tracked terminal depolarization in time and space. Though spreading depolarizations are notoriously difficult to block, terminal depolarization onset was delayed by dibucaine, a local amide anesthetic and sodium channel blocker. Remarkably, the occurrence of ouabain-induced terminal depolarization was delayed at a concentration of 1 µM that preserves synaptic function. Moreover, in vivo two-photon imaging in the penumbra revealed that, though spreading depolarizations did still occur, spreading depolarization-induced dendritic injury was inhibited by dibucaine administered intravenously at 2.5 mg/kg in a mouse stroke model.Dibucaine mitigated the effects of spreading depolarization at a concentration that could be well-tolerated therapeutically. Hence, dibucaine is a promising candidate to protect the brain from ischemic injury with an approach that does not rely on

Depolarization due to the resonance tail during a fast resonance jump

International Nuclear Information System (INIS)

Ruth, R.D.

1980-01-01

The mechanism of depolarization due to a fast resonance jump is studied. The dominant effect for cases of interest is not dependent on the rate of passage through resonance, but rather on the size of the resonance jump as compared to the width, epsilon, of the resonance. The results are applied to a calculation of depolarization in the AGS at Brookhaven National Laboratory

Elastodynamic metasurface: Depolarization of mechanical waves and time effects

Energy Technology Data Exchange (ETDEWEB)

Boutin, Claude, E-mail: claude.boutin@entpe.fr [Ecole Nationale des Travaux Publics de l' Etat, Université de Lyon, LGCB, UMR CNRS 5513, Vaulx-en-Velin (France); Schwan, Logan [Acoustics Research Center, University of Salford, Newton Building, Salford M5 4WT (United Kingdom); Dietz, Matthew S. [Department of Civil Engineering, University of Bristol, Queen' s Building, Bristol BS8 1TR (United Kingdom)

2015-02-14

We report the concept of microstructured surfaces with inner resonance in the field of elastodynamics, so-called elastodynamic metasurfaces. Such metasurfaces allow for wavefield manipulation of mechanical waves by tuning the boundary conditions at specific frequencies. In particular, they can be used to depolarize elastic waves without introducing heterogeneities in the medium itself; the physical means to do so in homogeneous elastic media used to remain, surprisingly, an open question while depolarization is commonplace in electromagnetism. The principle relies on the anisotropic behaviour of a subwavelength array of resonators: Their subwavelength configuration confines the Bragg interferences scattered by resonators into a boundary layer. The effective behaviour of the resonating array is expressed with homogenization as an unconventional impedance, the frequency-dependence, and anisotropy of which lead to depolarization and time effects. The concept of the elastodynamic metasurface is tested experimentally and results bear testament to its efficacy and robustness. Elastodynamic metasurfaces are easily realized and analytically predictable, opening new possibilities in tomography techniques, ultrasonics, geophysics, vibration control, materials and structure design.

An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova.

Science.gov (United States)

Della Valle, M; Chincarini, G; Panagia, N; Tagliaferri, G; Malesani, D; Testa, V; Fugazza, D; Campana, S; Covino, S; Mangano, V; Antonelli, L A; D'Avanzo, P; Hurley, K; Mirabel, I F; Pellizza, L J; Piranomonte, S; Stella, L

2006-12-21

Gamma-ray bursts (GRBs) are short, intense flashes of soft gamma-rays coming from the distant Universe. Long-duration GRBs (those lasting more than approximately 2 s) are believed to originate from the deaths of massive stars, mainly on the basis of a handful of solid associations between GRBs and supernovae. GRB 060614, one of the closest GRBs discovered, consisted of a 5-s hard spike followed by softer, brighter emission that lasted for approximately 100 s (refs 8, 9). Here we report deep optical observations of GRB 060614 showing no emerging supernova with absolute visual magnitude brighter than M(V) = -13.7. Any supernova associated with GRB 060614 was therefore at least 100 times fainter, at optical wavelengths, than the other supernovae associated with GRBs. This demonstrates that some long-lasting GRBs can either be associated with a very faint supernova or produced by different phenomena.

Depleted uranium: A DOE management guide

International Nuclear Information System (INIS)

1995-10-01

The U.S. Department of Energy (DOE) has a management challenge and financial liability in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF 6 ) that are stored at the gaseous diffusion plants. The annual storage and maintenance cost is approximately $10 million. This report summarizes several studies undertaken by the DOE Office of Technology Development (OTD) to evaluate options for long-term depleted uranium management. Based on studies conducted to date, the most likely use of the depleted uranium is for shielding of spent nuclear fuel (SNF) or vitrified high-level waste (HLW) containers. The alternative to finding a use for the depleted uranium is disposal as a radioactive waste. Estimated disposal costs, utilizing existing technologies, range between $3.8 and $11.3 billion, depending on factors such as applicability of the Resource Conservation and Recovery Act (RCRA) and the location of the disposal site. The cost of recycling the depleted uranium in a concrete based shielding in SNF/HLW containers, although substantial, is comparable to or less than the cost of disposal. Consequently, the case can be made that if DOE invests in developing depleted uranium shielded containers instead of disposal, a long-term solution to the UF 6 problem is attained at comparable or lower cost than disposal as a waste. Two concepts for depleted uranium storage casks were considered in these studies. The first is based on standard fabrication concepts previously developed for depleted uranium metal. The second converts the UF 6 to an oxide aggregate that is used in concrete to make dry storage casks

Spreading depolarizations increase delayed brain injury in a rat model of subarachnoid hemorrhage

NARCIS (Netherlands)

Hamming, Arend M.; Wermer, Marieke J. H.; Rudrapatna, S. Umesh; Lanier, Christian; van Os, Hine J. A.; van den Bergh, Walter M.; Ferrari, Michel D.; van der Toorn, Annette; van den Maagdenberg, Arn M. J. M.; Stowe, Ann M.; Dijkhuizen, Rick M.

Spreading depolarizations may contribute to delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage, but the effect of spreading depolarizations on brain lesion progression after subarachnoid hemorrhage has not yet been assessed directly. Therefore, we tested the hypothesis that

Spreading depolarizations have prolonged direct current shifts and are associated with poor outcome in brain trauma

DEFF Research Database (Denmark)

Hartings, Jed A; Watanabe, Tomas; Bullock, M Ross

2011-01-01

, although prolonged events have not been observed in animal models. To determine whether detrimental penumbral-type depolarizations occur in human brain trauma, we analysed electrocorticographic recordings obtained by subdural electrode-strip monitoring during intensive care. Of 53 patients studied, 10......Cortical spreading depolarizations occur spontaneously after ischaemic, haemorrhagic and traumatic brain injury. Their effects vary spatially and temporally as graded phenomena, from infarction to complete recovery, and are reflected in the duration of depolarization measured by the negative direct...... current shift of electrocorticographic recordings. In the focal ischaemic penumbra, peri-infarct depolarizations have prolonged direct current shifts and cause progressive recruitment of the penumbra into the core infarct. In traumatic brain injury, the effects of spreading depolarizations are unknown...

Preventing long-lasting fear recovery using bilateral alternating sensory stimulation: A translational study.

Science.gov (United States)

Wurtz, H; El-Khoury-Malhame, M; Wilhelm, F H; Michael, T; Beetz, E M; Roques, J; Reynaud, E; Courtin, J; Khalfa, S; Herry, C

2016-05-03

Posttraumatic stress disorder (PTSD) is a highly debilitating and prevalent psychological disorder. It is characterized by highly distressing intrusive trauma memories that are partly explained by fear conditioning. Despite efficient therapeutic approaches, a subset of PTSD patients displays spontaneous recurrence of traumatic memories after successful treatment. The development of animal behavioral models mimicking the individual variability in treatment outcome for PTSD patients represent therefore an important challenge as it allows for the identification of predicting factors of resilience or susceptibility to relapse. However, to date, only few animal behavioral models of long-lasting fear recovery have been developed and their predictive validity has not been tested directly. The objectives of this study were twofold. First we aimed to develop a simple animal behavioral model of long-lasting fear recovery based on auditory cued fear conditioning and extinction learning, which recapitulates the heterogeneity of fear responses observed in PTSD patients after successful treatment. Second we aimed at testing the predictive validity of our behavioral model and used to this purpose a translational approach based (i) on the demonstration of the efficiency of Eye Movement Desensitization and Reprocessing (EMDR) therapy to reduce conditioned fear responses in PTSD patients and (ii) on the implementation in our behavioral model of an electrical bilateral alternating stimulation of the eyelid which mimics the core feature of EMDR. Our data indicate that electrical bilateral alternating stimulation of the eyelid during extinction learning alleviates long-lasting fear recovery of conditioned fear responses and dramatically reduces inter-individual variability. These results demonstrate the face and predictive validity of our animal behavioral model and provide an interesting tool to understand the neurobiological underpinnings of long-lasting fear recovery. Copyright �

Visual functions in phenylketonuria-evaluating the dopamine and long-chain polyunsaturated fatty acids depletion hypotheses.

Science.gov (United States)

Gramer, Gwendolyn; Förl, Birgit; Springer, Christina; Weimer, Petra; Haege, Gisela; Mackensen, Friederike; Müller, Edith; Völcker, Hans Eberhard; Hoffmann, Georg Friedrich; Lindner, Martin; Krastel, Hermann; Burgard, Peter

2013-01-01

In phenylketonuria presymptomatic treatment following newborn screening prevents severe mental and physical impairment. The reasons for subtle impairments of cerebral functions despite early treatment remain unclear. We assessed a broad spectrum of visual functions in early-treated patients with phenylketonuria and evaluated two hypotheses-the dopamine and the long-chain polyunsaturated fatty acids (LCPUFAs) depletion hypotheses. Contrast sensitivity, colour vision, electroretinography, frequency doubling technology campimetry (FDT), and their relation with blood phenylalanine and docosahexaenoic acid levels were assessed in 36 patients with phenylketonuria and 18 age-matched healthy controls. Contrast sensitivity was significantly lower and total error scores in colour vision significantly higher in patients than controls. Electroretinography results differed significantly between patients and controls. We found a trend for the effect of phenylalanine-levels on contrast sensitivity and a significant effect on colour vision/FDT results. Docosahexaenoic acid levels in erythrocytes were not associated with visual functions. This is the first evaluation of visual functions in phenylketonuria using a comprehensive ophthalmological test battery. We found no evidence supporting the long-chain polyunsaturated fatty acids depletion hypothesis. However, the effect of phenylalanine-levels on visual functions suggests that imbalance between phenylalanine and tyrosine may affect retinal dopamine levels in phenylketonuria. This is supported by the similar patterns of visual functions in patients with phenylketonuria observed in our study and patients with Parkinson's disease. Copyright © 2012 Elsevier Inc. All rights reserved.

Light depolarization induced by metallic tips in apertureless near-field optical microscopy and tip-enhanced Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Gucciardi, P G [CNR-Istituto per i Processi Chimico-Fisici, sezione Messina, Salita Sperone, Contrada Papardo, I-98158 Faro Superiore, Messina (Italy); Lopes, M; Deturche, R; Julien, C; Barchiesi, D; Chapelle, M Lamy de la [Institut Charles Delaunay-CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de Technologie de Troyes, 12 rue Marie Curie, BP2060, 10010 Troyes (France)

2008-05-28

We have investigated the depolarization effects of light scattered by sharp tips used for apertureless near-field optical microscopy. Dielectric and metal coated tips have been investigated and depolarization factors between 5 and 30% have been measured, changing as a function of the incident light polarization and of the tip shape. The experimental results are in good agreement with theoretical calculations performed by the finite element method, giving a near-field depolarization factor close to 10%. The effect of depolarization has been investigated in polarized tip-enhanced Raman spectroscopy (TERS) experiments; the depolarization gives rise to forbidden Raman modes in Si crystals.

How long do the short-term violent video game effects last?

Science.gov (United States)

Barlett, Christopher; Branch, Omar; Rodeheffer, Christopher; Harris, Richard

2009-01-01

How long do the effects of the initial short-term increase in aggression and physiological arousal last after violent video game play? Study 1 (N=91) had participants complete pre- and postvideo game measures of aggressive thoughts, aggressive feelings, and heart rate. Then, participants completed Time 3 measures after 4 min or 9 min of delay. Study 2 employed a similar procedure, but had participants (N=91) complete the hot sauce paradigm to assess aggressive behavior after a 0, 5, or 10 min delay. First, results indicated that aggressive feelings, aggressive thoughts, aggressive behavior, and heart rate initially increased after violent video game play. Second, results of the delay condition revealed that the increase in aggressive feelings and aggressive thoughts lasted less than 4 min, whereas heart rate and aggressive behavior lasted 4-9 min. Copyright 2009 Wiley-Liss, Inc.

Intermediate Leg SBLOCA - Long Lasting Pressure Transient

International Nuclear Information System (INIS)

Konjarek, D.; Bajs, T.; Vukovic, J.

2010-01-01

The basic phenomenology of Small Break Loss of Coolant Accident (SBLOCA) for PWR plant is described with focus on analysis of scenario in which reactor coolant pressure decreases below secondary system pressure. Best estimate light water reactor transient analysis code RELAP5/mod3.3 was used in calculation. Rather detailed model of the plant was used. The break occurs in intermediate leg on lowest elevation near pump suction. The size of the break is chosen to be small enough to cause cycling of safety valves (SVs) on steam generators (SGs) for some time, but, afterwards, it is large enough to remove decay heat through the break, causing cooling the secondary side. In this case of SBLOCA, when primary pressure decreases below secondary pressure, long lasting pressure transients with significant amplitude occur. Reasons for such behavior are explained.(author).

ANABOLIC STEROIDS HAVE LONG-LASTING EFFECTS ON MALE SOCIAL BEHAVIORS

Science.gov (United States)

Salas-Ramirez, Kaliris Y.; Montalto, Pamela R.; Sisk, Cheryl L.

2010-01-01

Anabolic androgenic steroids (AAS) use by adolescents is steadily increasing. Adolescence involves remodeling of steroid-sensitive neural circuits that mediate social behaviors, and previous studies using animal models document effects of AAS on male social behaviors. The present experiments tested whether AAS have persistent and more pronounced behavioral consequences when drug exposure occurs during adolescence as compared to exposure in adulthood. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or adulthood (63-77 days of age). As adults, subjects were tested two or four weeks after the last injection for either sexual behavior with a receptive female or male-male agonistic behavior in a resident-intruder test. Compared with vehicle-treated males, AAS-treated males, regardless of age of treatment, displayed fewer long intromissions and a significant increase in latency to the first long intromission, indicative of reduced potential to reach sexual satiety. Increased aggression was observed in males exposed to AAS compared with males treated with vehicle, independently of age of AAS treatment. However, unlike hamsters exposed to AAS in adulthood, hamsters exposed to AAS during adolescence did not display any submissive or risk-assessment behaviors up to 4 weeks after discontinuation of AAS treatment. Thus, AAS have long-lasting effects on male sexual and agonistic behaviors, with AAS exposure during adolescence resulting in a more pronounced reduction in submissive behavior compared to AAS exposure in adulthood. PMID:20036695

The continuum of spreading depolarizations in acute cortical lesion development

DEFF Research Database (Denmark)

Hartings, Jed A; Shuttleworth, C William; Kirov, Sergei A

2017-01-01

A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum....... The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion...

Simple non-Markovian microscopic models for the depolarizing channel of a single qubit

International Nuclear Information System (INIS)

Fonseca Romero, K M; Lo Franco, R

2012-01-01

The archetypal one-qubit noisy channels - depolarizing, phase-damping and amplitude-damping channels - describe both Markovian and non-Markovian evolution. Simple microscopic models for the depolarizing channel, both classical and quantum, are considered. Microscopic models that describe phase-damping and amplitude-damping channels are briefly reviewed.

Impaired reward learning and intact motivation after serotonin depletion in rats.

Science.gov (United States)

Izquierdo, Alicia; Carlos, Kathleen; Ostrander, Serena; Rodriguez, Danilo; McCall-Craddolph, Aaron; Yagnik, Gargey; Zhou, Feimeng

2012-08-01

Aside from the well-known influence of serotonin (5-hydroxytryptamine, 5-HT) on emotional regulation, more recent investigations have revealed the importance of this monoamine in modulating cognition. Parachlorophenylalanine (PCPA) depletes 5-HT by inhibiting tryptophan hydroxylase, the enzyme required for 5-HT synthesis and, if administered at sufficiently high doses, can result in a depletion of at least 90% of the brain's 5-HT levels. The present study assessed the long-lasting effects of widespread 5-HT depletions on two tasks of cognitive flexibility in Long Evans rats: effort discounting and reversal learning. We assessed performance on these tasks after administration of either 250 or 500 mg/kg PCPA or saline (SAL) on two consecutive days. Consistent with a previous report investigating the role of 5-HT on effort discounting, pretreatment with either dose of PCPA resulted in normal effortful choice: All rats continued to climb tall barriers to obtain large rewards and were not work-averse. Additionally, rats receiving the lower dose of PCPA displayed normal reversal learning. However, despite intact motivation to work for food rewards, rats receiving the largest dose of PCPA were unexpectedly impaired relative to SAL rats on the pretraining stages leading up to reversal learning, ultimately failing to approach and respond to the stimuli associated with reward. High performance liquid chromatography (HPLC) with electrochemical detection confirmed 5-HT, and not dopamine, levels in the ventromedial frontal cortex were correlated with this measure of associative reward learning. Copyright © 2012 Elsevier B.V. All rights reserved.

Two regulatory RNA elements affect TisB-dependent depolarization and persister formation.

Science.gov (United States)

Berghoff, Bork A; Hoekzema, Mirthe; Aulbach, Lena; Wagner, E Gerhart H

2017-03-01

Bacterial survival strategies involve phenotypic diversity which is generated by regulatory factors and noisy expression of effector proteins. The question of how bacteria exploit regulatory RNAs to make decisions between phenotypes is central to a general understanding of these universal regulators. We investigated the TisB/IstR-1 toxin-antitoxin system of Escherichia coli to appreciate the role of the RNA antitoxin IstR-1 in TisB-dependent depolarization of the inner membrane and persister formation. Persisters are phenotypic variants that have become transiently drug-tolerant by arresting growth. The RNA antitoxin IstR-1 sets a threshold for TisB-dependent depolarization under DNA-damaging conditions, resulting in two sub-populations: polarized and depolarized cells. Furthermore, our data indicate that an inhibitory 5' UTR structure in the tisB mRNA serves as a regulatory RNA element that delays TisB translation to avoid inappropriate depolarization when DNA damage is low. Investigation of the persister sub-population further revealed that both regulatory RNA elements affect persister levels as well as persistence time. This work provides an intriguing example of how bacteria exploit regulatory RNAs to control phenotypic heterogeneity. © 2016 John Wiley & Sons Ltd.

Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 2: Appendices

International Nuclear Information System (INIS)

1999-04-01

This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible. This volume contains Appendices A--O

Characteristics of long-lasting haze episodes observed in Seoul, South Korea, for 2009-2014

Science.gov (United States)

Lee, Hae-Jung; Kim, Jeong Eun; Cha, Joo Wan; Song, Seungjoo; Ryoo, Sang-Boom; Kim, Yong Pyo

2018-03-01

The meteorological, physical, chemical, and optical characteristics of long-lasting haze in Seoul were studied. Four episodes were observed between 2009 and 2014, all in winter. PM10 mass concentration (PM10), chemical species, and aerosol optical depth (AOD) were analyzed along with the synoptic meteorological conditions. During the episodes, the temporal variations of the PM10 generally proceeded from the west along the Yellow Sea. The ground-based AOD was also high in Seoul and other sites. High AOD (MODIS) distributions were observed to move from China to Korea. The high sulfate concentration, along with the high sulfur oxidation ratio value of the third and fourth episodes (Eps. 3 and 4), respectively, corroborated the possible long-range transport of air pollutants. Stagnant meteorological conditions were a reason for the occurrence of long-lasting hazes. An anticyclone system had a dominant influence on the Korean peninsula during all episodes. The air mass over China was able to rise, and that over Korea was more stagnant in terms of climatology except Ep. 2. In addition to transport from outside, locally emitted air pollutants contributed to the PM10 partly due to the stagnant conditions, during which diurnal variations in NO2 and nitrates showed similar peak times during Eps. 3 and 4. Analysis of the episodes consistently showed that the long-lasting haze episodes were influenced by both the long-range transport of air pollutants from outside Seoul, mostly from China, and the accumulation of air pollutants that were locally emitted and transformed.

Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 1: Main text

International Nuclear Information System (INIS)

1999-04-01

This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

Dearomatized white spirit inhalation exposure causes long-lasting neurophysiological changes in rats

DEFF Research Database (Denmark)

Lund, S. P.; Simonsen, L.; Hass, Ulla

1996-01-01

Dearomatized white spirit inhalation exposure causes long-lasting neurophysioloical changes in rats. NEUROTOXICOL TERATOL 18(1), 67-76, 1996. -Exposure for 6 h per day, 5 days per week, during a period of 6 months to the organic solvent dearomatized white spirit (0, 400, and 800 ppm) was studied ...

Homogenization via the strong-permittivity-fluctuation theory with nonzero depolarization volume

Science.gov (United States)

Mackay, Tom G.

2004-08-01

The depolarization dyadic provides the scattering response of a single inclusion particle embedded within a homogenous background medium. These dyadics play a central role in formalisms used to estimate the effective constitutive parameters of homogenized composite mediums (HCMs). Conventionally, the inclusion particle is taken to be vanishingly small; this allows the pointwise singularity of the dyadic Green function associated with the background medium to be employed as the depolarization dyadic. A more accurate approach is pursued in this communication by taking into account the nonzero spatial extent of inclusion particles. Depolarization dyadics corresponding to inclusion particles of nonzero volume are incorporated within the strong-permittivity-fluctuation theory (SPFT). The linear dimensions of inclusion particles are assumed to be small relative to the electromagnetic wavelength(s) and the SPFT correlation length. The influence of the size of inclusion particles upon SPFT estimates of the HCM constitutive parameters is investigated for anisotropic dielectric HCMs.In particular, the interplay between correlation length and inclusion size is explored.

Past and future contribution of global groundwater depletion to sea-level rise

NARCIS (Netherlands)

Wada, Y.; Beek, L.P.H. van; Sperna Weiland, F.C.; Chao, B.; Wu, Y.-H.; Bierkens, M.F.P.

2012-01-01

Recent studies suggest the increasing contribution of groundwater depletion to global sea-level rise. Groundwater depletion has more than doubled during the last decades, primarily due to increase in water demand, while the increase in water impoundments behind dams has been tapering off since

Dependence of negative muon depolarization on molecular weight and temperature in organic compounds

International Nuclear Information System (INIS)

Djuraev, A.A.; Evseev, V.S.; Obukhov, Yu.V.; Roganov, V.S.

2009-01-01

An atomic capture of negative muons in the aliphatic spirit series, the dependence of muon rest polarization on the molecular weight of spirit have been studied. The temperature dependence of depolarization in benzole and styrene has been obtained. The results on depolarization are being interpreted basing on notions about chemical interactions of mesic atoms in organic compounds. (author)

TACTILE STIMULATION EVOKES LONG-LASTING POTENTIATION OF PURKINJE CELL DISCHARGE IN VIVO

Directory of Open Access Journals (Sweden)

Ramakrishnan eKanchipuram

2016-02-01

Full Text Available In the cerebellar network, a precise relationship between plasticity and neuronal discharge has been predicted. However, the potential generation of persistent changes in PC spike discharge as a consequence of plasticity following natural stimulation patterns has not been clearly determined. Here we show that facial tactile stimuli organized in theta-patterns can induce stereotyped NMDA and GABA-A receptor-dependent changes in Purkinje cell (PCs and molecular layer interneuron (MLIs firing: invariably, all PCs showed a long-lasting increase (spike-related potentiation or SR-P and MLIs a long-lasting decrease (spike-related suppression or SR-S in baseline activity and spike response probability. These observations suggests that natural sensory stimulation engages multiple long-term plastic changes that are distributed along the mossy fiber – parallel fiber pathway and operate synergistically to potentiate spike generation in PCs. In contrast, theta-pattern electrical stimulation of PFs indistinctly induced SR-P and SR-S both in PCs and MLIs, suggesting that natural sensory stimulation preordinates plasticity upstream of the PF-PC synapse. All these effects occurred in the absence of complex spike changes, supporting the theoretical prediction that Purkinje cell activity is potentiated when the mossy fiber - parallel fiber system is activated in the absence of conjunctive climbing fiber activity.

μ+ depolarization in AlGd alloys

International Nuclear Information System (INIS)

Kohn, S.; Brown, J.A.; Heffner, R.H.; Huang, C.Y.; Kitchens, T.A. Jr.; Leon, M.; Olsen, C.E.; Schillaci, M.E.

1979-01-01

The μ + depolarization rate in dilute AlGd alloys containing 50 and 450 atomic ppm Gd was measured in a transverse field of 80 Oe over the temperature range 6-300 K. For both alloys, Λ increased dramatically above 200 K, reaching values of 0.69 and 0.93 μs -1 , respectively, near room temperature. The results are interpreted as providing evidence for a thermally-activated trapping mechanism. (Auth.)

Long lasting effects of chronic heavy cannabis abuse.

Science.gov (United States)

Nestoros, Joannis N; Vakonaki, Elena; Tzatzarakis, Manolis N; Alegakis, Athanasios; Skondras, Markos D; Tsatsakis, Aristidis M

2017-06-01

The purpose of this study was to evaluate the extent of short-term memory impairment and schizophrenia-like symptoms in heavy and systematic cannabis users and the association between the severity of abuse and the longevity of its persistent symptoms after refraining from such use. A complete psychiatric examination and a psychometric evaluation were performed in 48 solely cannabis users. Additionally, head hair samples were analyzed and the detected cannabinoids levels were correlated with the psychometric findings. A total of 33.3% (n = 16) of the total examined cannabis users were currently imprisoned. The years of abuse ranged from 1 to 35 years and the median daily dose was 5.84.4 gr and 4.84.0 gr for prisoners (n = 16) and non prisoners (n = 32), respectively. A total of 39.6% of the users experienced hallucinations (mostly auditory), 54.2% experienced delusions (mostly ideas of reference and persecution), 85.4% had organic brain dysfunction in a test addressing visual-motor functioning and visual perception skills, and all users (100%) were found to have organic brain dysfunction in a test of visual memory immediate recall. The cannabinoid metabolite levels in the hair samples were consistent with the reported history of substance abuse and total grams of consumption for the participants below 35 years old (p cannabis users seems to be associated with cannabinoid levels in hair. The continuation of persistent symptoms 3 months after the discontinuation of cannabis abuse, was a remarkable finding. We provide evidence that chronic and heavy cannabis abuse results in long-lasting brain dysfunction in all users and in long-lasting schizophrenia-like psychotic symptoms in more than half of all users. These findings suggest a reevaluation of the current classification of cannabis as a "soft narcotic" which erroneously, therefore, is typically considered harmless. (Am J Addict 2017;26:335-342). © 2017 American Academy of Addiction Psychiatry.

Molecular anisotropy effects in carbon K-edge scattering: depolarized diffuse scattering and optical anisotropy

Energy Technology Data Exchange (ETDEWEB)

Stone, Kevin H.

2014-07-14

Some polymer properties, such as conductivity, are very sensitive to short- and intermediate-range orientational and positional ordering of anisotropic molecular functional groups, and yet means to characterize orientational order in disordered systems are very limited. We demonstrate that resonant scattering at the carbon K-edge is uniquely sensitive to short-range orientation correlations in polymers through depolarized scattering at high momentum transfers, using atactic polystyrene as a well-characterized test system. Depolarized scattering is found to coexist with unpolarized fluorescence, and to exhibit pronounced anisotropy. We also quantify the spatially averaged optical anisotropy from low-angle reflectivity measurements, finding anisotropy consistent with prior visible, x-ray absorption, and theoretical studies. The average anisotropy is much smaller than that in the depolarized scattering and the two have different character. Both measurements exhibit clear spectral signatures from the phenyl rings and the polyethylene-like backbone. Discussion focuses on analysis considerations and prospects for using this depolarized scattering for studies of disorder in soft condensed matter.

Depolarization-induced release of amino acids from the vestibular nuclear complex.

Science.gov (United States)

Godfrey, Donald A; Sun, Yizhe; Frisch, Christopher; Godfrey, Matthew A; Rubin, Allan M

2012-04-01

There is evidence from immunohistochemistry, quantitative microchemistry, and pharmacology for several amino acids as neurotransmitters in the vestibular nuclear complex (VNC), including glutamate, γ-aminobutyrate (GABA), and glycine. However, evidence from measurements of release has been limited. The purpose of this study was to measure depolarization-stimulated calcium-dependent release of amino acids from the VNC in brain slices. Coronal slices containing predominantly the VNC were prepared from rats and perfused with artificial cerebrospinal fluid (ACSF) in an interface chamber. Fluid was collected from the chamber just downstream from the VNC using a microsiphon. Depolarization was induced by 50 mM potassium in either control calcium and magnesium concentrations or reduced calcium and elevated magnesium. Amino acid concentrations in effluent fluid were measured by high performance liquid chromatography. Glutamate release increased fivefold during depolarization in control calcium concentration and twofold in low calcium/high magnesium. These same ratios were 6 and 1.5 for GABA, 2 and 1.3 for glycine, and 2 and 1.5 for aspartate. Differences between release in control and low calcium/high magnesium ACSF were statistically significant for glutamate, GABA, and glycine. Glutamine release decreased during and after depolarization, and taurine release slowly increased. No evidence for calcium-dependent release was found for serine, glutamine, alanine, threonine, arginine, taurine, or tyrosine. Our results support glutamate and GABA as major neurotransmitters in the VNC. They also support glycine as a neurotransmitter and some function for taurine.

Risk of long-lasting negative cognitive consequences after electroconvulsive therapy

DEFF Research Database (Denmark)

Svendsen, Anne Marie; Miskowiak, Kamilla; Vinberg, Maj

2013-01-01

This case study describes a patient who had a unipolar depression and experienced long-lasting cognitive problems after electroconvulsive therapy (ECT). Neuropsychological testing revealed lower scores on measures of learning, memory and sustained attention. These results stress the importance...... of informing patients who have ECT of the potential cognitive consequences of this treatment as it may influence the patients' functional capabilities. Prospective studies are needed since we do not have sufficient knowledge regarding the 3-5% of these patients who experience sustained cognitive problems....

Depletion and capture: revisiting "the source of water derived from wells".

Science.gov (United States)

Konikow, L F; Leake, S A

2014-09-01

A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long-term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long-developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long-term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Neonatal oxytocin manipulations have long-lasting, sexually dimorphic effects on vasopressin receptors

OpenAIRE

Bales, KL; Plotsky, PM; Young, LJ; Lim, MM; Grotte, N; Ferrer, E; Carter, CS

2007-01-01

Developmental exposure to oxytocin (OT) or oxytocin antagonists (OTAs) has been shown to cause long-lasting and often sexually dimorphic effects on social behaviors in prairie voles (Microtus ochrogaster). Because regulation of social behavior in monogamous mammals involves central receptors for OT, arginine vasopressin (AVP), and dopamine, we examined the hypothesis that the lon...

Interaction between depolarization effects, interface layer, and fatigue behavior in PZT thin film capacitors

Science.gov (United States)

Böttger, U.; Waser, R.

2017-07-01

The existence of non-ferroelectric regions in ferroelectric thin films evokes depolarization effects leading to a tilt of the P(E) hysteresis loop. The analysis of measured hysteresis of lead zirconate titanate (PZT) thin films is used to determine a depolarization factor which contains quantitative information about interfacial layers as well as ferroelectrically passive zones in the bulk. The derived interfacial capacitance is smaller than that estimated from conventional extrapolation techniques. In addition, the concept of depolarization is used for the investigation of fatigue behavior of PZT thin films indicating that the mechanism of seed inhibition, which is responsible for the effect, occurs in the entire film.

Bacterial Urease and its Role in Long-Lasting Human Diseases

Science.gov (United States)

Konieczna, Iwona; Żarnowiec, Paulina; Kwinkowski, Marek; Kolesińska, Beata; Frączyk, Justyna; Kamiński, Zbigniew; Kaca, Wiesław

2012-01-01

Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by antibodies present in human sera. The presence of such antibodies is connected with progress of several long-lasting diseases, like rheumatoid arthritis, atherosclerosis or urinary tract infections. In bacterial ureases, motives with a sequence and/or structure similar to human proteins may occur. This phenomenon, known as molecular mimicry, leads to the appearance of autoantibodies, which take part in host molecules destruction. Detection of antibodies-binding motives (epitopes) in bacterial proteins is a complex process. However, organic chemistry tools, such as synthetic peptide libraries, are helpful in both, epitope mapping as well as in serologic investigations. In this review, we present a synthetic report on a molecular organization of bacterial ureases - genetic as well as structural. We characterize methods used in detecting urease and ureolytic activity, including techniques applied in disease diagnostic processes and in chemical synthesis of urease epitopes. The review also provides a summary of knowledge about a toxic effect of bacterial ureases on human body and about occurrence of anti-urease antibodies in long-lasting diseases. PMID:23305365

Neutron depolarization effects in a high-Tc superconductor (abstract)

Science.gov (United States)

Nunes, A. C.; Pickart, S. J.; Crow, L.; Goyette, R.; McGuire, T. R.; Shinde, S.; Shaw, T. M.

1988-11-01

Using the polarized beam small-angle neutron scattering spectrometer at the Rhode Island Nuclear Science Center Reactor, we have observed significant depolarization of a neutron beam by passage through polycrystalline high-Tc superconductors, specifically 123 Y-Ba-Cu-O prepared and characterized at the IBM Watson Research Center. We believe that this technique will prove useful in studying aspects of these materials, such as the penetration depth of shielding currents, the presence and structure of trapped flux vortices, and grain size effects on the supercurrent distribution in polycrystalline samples. The two samples showed sharp transitions at 87 and 89 K, and have been studied at temperatures of 77 K; the second sample has also been studied at 4 K. The transition to the superconducting state was monitored by the shift in resonant frequency of a coil surrounding the sample. No measurable depolarization was observed in either sample at 77 K in both the field-cooled and zero-field-cooled states, using applied fields of 0 (nominal), 54, and 1400 Oe. This negative result may be connected with the fact that the material is still in the reversible region as indicated by susceptibility measurements, but it allows an estimate of the upper bound of possible inhomogeneous internal fields, assuming a distance scale for the superconducting regions. For the 10-μm grain size suggested by photomicrographs, this upper bound for the field turns out to be 1.2 kOe, which seems reasonable. At 4 K a significant depolarization was observed when the sample was cooled in low fields and a field of 1400 Oe was subsequently applied. This result suggests that flux lines are penetrating the sample. Further investigations are being carried out to determine the field and temperature dependence of the depolarization, and attempts will be made to model it quantitatively in terms of possible internal field distributions. We are also searching for possible diffraction effects from ordered vortex

A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

NARCIS (Netherlands)

Bruining, J.; Fijnaut, H.M.

We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due

Long-lasting increase in axonal excitability after epidurally applied DC.

Science.gov (United States)

Jankowska, Elzbieta; Kaczmarek, Dominik; Bolzoni, Francesco; Hammar, Ingela

2017-08-01

Effects of direct current (DC) on nerve fibers have primarily been investigated during or just after DC application. However, locally applied cathodal DC was recently demonstrated to increase the excitability of intraspinal preterminal axonal branches for >1 h. The aim of this study was therefore to investigate whether DC evokes a similarly long-lasting increase in the excitability of myelinated axons within the dorsal columns. The excitability of dorsal column fibers stimulated epidurally was monitored by recording compound action potentials in peripheral nerves in acute experiments in deeply anesthetized rats. The results show that 1 ) cathodal polarization (0.8-1.0 µA) results in a severalfold increase in the number of epidurally activated fibers and 2 ) the increase in the excitability appears within seconds, 3 ) lasts for >1 h, and 4 ) is activity independent, as it does not require fiber stimulation during the polarization. These features demonstrate an unexplored form of plasticity of myelinated fibers and indicate the conditions under which it develops. They also suggest that therapeutic effects of epidural stimulation may be significantly enhanced if it is combined with DC polarization. In particular, by using DC to increase the number of fibers activated by low-intensity epidural stimuli, the low clinical tolerance to higher stimulus intensities might be overcome. The activity independence of long-lasting DC effects would also allow the use of only brief periods of DC polarization preceding epidural stimulation to increase the effect. NEW & NOTEWORTHY The study indicates a new form of plasticity of myelinated fibers. The differences in time course of DC-evoked increases in the excitability of myelinated nerve fibers in the dorsal columns and in preterminal axonal branches suggest that distinct mechanisms are involved in them. The results show that combining epidural stimulation and transspinal DC polarization may dramatically improve their outcome and

Depletion and capture: revisiting “The source of water derived from wells"

Science.gov (United States)

Konikow, Leonard F.; Leake, Stanley A.

2014-01-01

A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long-term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long-developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long-term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems.

Beam-beam depolarization in SPEAR and PEP

International Nuclear Information System (INIS)

Montague, B.W.

1977-01-01

In this note some approximate estimates are made of depolarization due to beam-beam forces in SPEAR and PEP, using the results of a calculation by Kondratenko. The model assumes head-on collisions between bunches of Gaussian distribution in the transverse directions; the force on the weak-beam particle is taken to be a δ-function at the interaction point. 1 ref

Global depletion of groundwater resources

NARCIS (Netherlands)

Wada, Y.; Beek, L.P.H. van; van Kempen, C.M.; Reckman, J.W.T.M.; Vasak, S.; Bierkens, M.F.P.

2010-01-01

In regions with frequent water stress and large aquifer systems groundwater is often used as an additional water source. If groundwater abstraction exceeds the natural groundwater recharge for extensive areas and long times, overexploitation or persistent groundwater depletion occurs. Here we

Tune space manipulations in jumping depolarizing resonances

International Nuclear Information System (INIS)

Ratner, L.G.; Ahrens, L.A.

1987-01-01

In February 1986, the AGS polarized beam reached a momentum of 22 GeV/c with a 45% polarization and an intensity of 1 to 2 x 10 10 polarized protons per pulse at a repetition rate of 2.1 seconds. In order to achieve this, one had to overcome the effect of some 40 depolarizing resonances. In our first commissioning run in 1984, we had reached 16.5 GeV/c using, with suitable modifications, the conventional techniques first used at the Argonne ZGS. This worked well, but we found that the fast tune shifts required to cross the intrinsic depolarizing resonances were causing an increase in beam emittance which led to the need for stronger corrections later in the cycle and to diminished extraction efficiency. For the 1986 run, we were prepared to minimize this emittance growth by the application of slow quadrupole pulses to change the region in tune space in which we operated the first tune quads. In this paper we give a brief description of the conventional corrections, but our main emphasis is on the descriptions of tune space manipulations

Characterization of ventricular depolarization and repolarization changes in a porcine model of myocardial infarction.

Science.gov (United States)

Romero, Daniel; Ringborn, Michael; Demidova, Marina; Koul, Sasha; Laguna, Pablo; Platonov, Pyotr G; Pueyo, Esther

2012-12-01

In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, [Formula: see text], evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by [Formula: see text], which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.

Depleted UF6 programmatic environmental impact statement

International Nuclear Information System (INIS)

1997-01-01

The US Department of Energy has developed a program for long-term management and use of depleted uranium hexafluoride, a product of the uranium enrichment process. As part of this effort, DOE is preparing a Programmatic Environmental Impact Statement (PEIS) for the depleted UF 6 management program. This report duplicates the information available at the web site (http://www.ead.anl.gov/web/newduf6) set up as a repository for the PEIS. Options for the web site include: reviewing recent additions or changes to the web site; learning more about depleted UF 6 and the PEIS; browsing the PEIS and related documents, or submitting official comments on the PEIS; downloading all or part of the PEIS documents; and adding or deleting one's name from the depleted UF 6 mailing list

A Beautician’s Dystonia: Long-Lasting Effect of Botulinum Toxin

Directory of Open Access Journals (Sweden)

Siria Di Martino

2014-01-01

Full Text Available Treatment options for dystonia are not curative but symptomatic; the treatment of choice for focal dystonias is repeated botulinum toxin injections. Here, we present the case of a 46-year-old beautician with focal dystonia in her left hand that affected her ability to work. Pharmacological treatment with clonazepam and gabapentin failed to resolve her symptoms and was discontinued due to side effects (sleepiness, gastrointestinal disorders. Intramuscular injection of botulinum toxin (incobotulinumtoxinA, Xeomin into the extensor digitorum communis (35 U, flexor carpi radialis (35 U, and flexor digitorum superficialis (30 U muscles resulted in complete resolution of symptoms at clinical assessments at 1, 3, 6, and 10 months after the injections, confirmed by the results of surface electromyography 10 months after treatment. The patient was able to work again 1 month after treatment. No reinjection has been necessary at the last evaluation (12 months after treatment. In conclusion, botulinum toxin is an effective treatment for focal dystonia that can have long-lasting effects and can improve patients’ ability to work and quality of life.

Ego Depletion Does Not Interfere With Working Memory Performance.

Science.gov (United States)

Singh, Ranjit K; Göritz, Anja S

2018-01-01

Ego depletion happens if exerting self-control reduces a person's capacity to subsequently control themselves. Previous research has suggested that ego depletion not only interferes with subsequent self-control but also with working memory. However, recent meta-analytical evidence casts doubt onto this. The present study tackles the question if ego depletion does interfere with working memory performance. We induced ego depletion in two ways: using an e-crossing task and using a Stroop task. We then measured working memory performance using the letter-number sequencing task. There was no evidence of ego depletion interfering with working memory performance. Several aspects of our study render this null finding highly robust. We had a large and heterogeneous sample of N = 1,385, which provided sufficient power. We deployed established depletion tasks from two task families (e-crossing task and Stroop), thus making it less likely that the null finding is due to a specific depletion paradigm. We derived several performance scores from the working memory task and ran different analyses to maximize the chances of finding an effect. Lastly, we controlled for two potential moderators, the implicit theories about willpower and dispositional self-control capacity, to ensure that a possible effect on working memory is not obscured by an interaction effect. In sum, this experiment strengthens the position that ego depletion works but does not affect working memory performance.

Long-lasting ovulation inhibition with a new injectable progestagen ORG-2154.

Science.gov (United States)

Coutinho, E M; De Souza, J C; Barbosa, I C; Dourado Silva, V

1982-06-01

A new long-acting injectable progestagen was tested in 15 women who volunteered for the study. The occurrence of ovulation was assumed by the elevation of progesterone levels above 2ng/ml following a pre-ovulatory estradiol peak. Following a 200mg injection, ovulation was inhibited in all 15 women for five to ten months. In four subjects the interval between the injection and the first progesterone peak was five months. For eight, the interval was six to eight months. In the other three women, ovulation occurred more than eight months following injection. Bleeding episodes, similar to menstruation, occurred in most patients. Bleeding intervals lasting longer than 45 days occurred in nine subjects but more prolonged amenorrhea lasting longer than 60 days was reported by only five subjects. Blood chemistry which included blood cell counts, cholesterol, glucose, alkaline phosphatase, transaminases, urea nitrogen and creatinine remained within normal limits throughout the treatment.

Depolarization temperature and piezoelectric properties of Na1/2 ...

Indian Academy of Sciences (India)

1/2Bi1/2(Zn1/3Nb2/3)O3, was synthesized using the two-stage calcination method and depolarization temperatures and piezoelectric properties were also investigated. The XRD analysis showed that the ceramics system had a morphotropic ...

The Chemistry and Toxicology of Depleted Uranium

Directory of Open Access Journals (Sweden)

Sidney A. Katz

2014-03-01

Full Text Available Natural uranium is comprised of three radioactive isotopes: 238U, 235U, and 234U. Depleted uranium (DU is a byproduct of the processes for the enrichment of the naturally occurring 235U isotope. The world wide stock pile contains some 1½ million tons of depleted uranium. Some of it has been used to dilute weapons grade uranium (~90% 235U down to reactor grade uranium (~5% 235U, and some of it has been used for heavy tank armor and for the fabrication of armor-piercing bullets and missiles. Such weapons were used by the military in the Persian Gulf, the Balkans and elsewhere. The testing of depleted uranium weapons and their use in combat has resulted in environmental contamination and human exposure. Although the chemical and the toxicological behaviors of depleted uranium are essentially the same as those of natural uranium, the respective chemical forms and isotopic compositions in which they usually occur are different. The chemical and radiological toxicity of depleted uranium can injure biological systems. Normal functioning of the kidney, liver, lung, and heart can be adversely affected by depleted uranium intoxication. The focus of this review is on the chemical and toxicological properties of depleted and natural uranium and some of the possible consequences from long term, low dose exposure to depleted uranium in the environment.

Atrioventricular depolarization differences identify coronary artery anomalies in Kawasaki disease.

Science.gov (United States)

Cortez, Daniel; Sharma, Nandita; Jone, Pei-Ni

2017-03-01

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. Signal average electrocardiogram changes in patients during the acute phase of KD with coronary artery anomalies (CAA) include depolarization changes. We set out to determine if 12-lead-derived atrioventricular depolarization differences can identify CAA in patients with KD. A blinded, retrospective case-control study of patients with KD was performed. Deep Q waves, corrected QT-intervals (QTc), spatial QRS-T angles, T-wave vector magnitudes (RMS-T), and a novel parameter for assessment of atrioventricular depolarization difference (the spatial PR angle) and a two dimensional PR angle were assessed. Comparisons between groups were performed to test for significant differences. One hundred one patients with KD were evaluated, with 68 having CAA (67.3%, mean age 3.6 ± 3.0 years, 82.6% male), and 32 without CAA (31.7%, mean age 2.7 ± 3.2 years, 70.4% male). The spatial PR angle significantly discriminated KD patients with CAA from those without, 59.7° ± 31.1° versus 41.6° ± 11.5° (p differences, measured by the spatial or two dimensional PR angle differentiate KD patients with CAA versus those without. © 2016 Wiley Periodicals, Inc.

Plasmonic Nanoprobes for Stimulated Emission Depletion Nanoscopy.

Science.gov (United States)

Cortés, Emiliano; Huidobro, Paloma A; Sinclair, Hugo G; Guldbrand, Stina; Peveler, William J; Davies, Timothy; Parrinello, Simona; Görlitz, Frederik; Dunsby, Chris; Neil, Mark A A; Sivan, Yonatan; Parkin, Ivan P; French, Paul M W; Maier, Stefan A

2016-11-22

Plasmonic nanoparticles influence the absorption and emission processes of nearby emitters due to local enhancements of the illuminating radiation and the photonic density of states. Here, we use the plasmon resonance of metal nanoparticles in order to enhance the stimulated depletion of excited molecules for super-resolved nanoscopy. We demonstrate stimulated emission depletion (STED) nanoscopy with gold nanorods with a long axis of only 26 nm and a width of 8 nm. These particles provide an enhancement of up to 50% of the resolution compared to fluorescent-only probes without plasmonic components irradiated with the same depletion power. The nanoparticle-assisted STED probes reported here represent a ∼2 × 10 3 reduction in probe volume compared to previously used nanoparticles. Finally, we demonstrate their application toward plasmon-assisted STED cellular imaging at low-depletion powers, and we also discuss their current limitations.

The anomalous depolarization anisotropy in the central backscattering area for turbid medium with Mie scatterers

Science.gov (United States)

Wang, Xuezhen; Lai, Jiancheng; Song, Yang; Li, Zhenhua

2018-05-01

It is generally recognized that circularly polarized light is preferentially maintained over linearly polarized light in turbid medium with Mie scatterers. However, in this work, the anomalous depolarization anisotropy is reported in the backscattering area near the point of illumination. Both experimental and Monte Carlo simulations show preferential retention of linear polarization states compared to circular polarization states in a specific backscattering area. Further analysis indicates that the anomalous depolarization behavior in the specific area is induced by lateral scattering events, which own low circular polarization memory. In addition, it is also found that the size of the anomalous depolarization area is related to the transport mean free path of the turbid medium.

Spreading depolarizations occur in human ischemic stroke with high incidence

DEFF Research Database (Denmark)

Dohmen, C.; Sakowitz, O.W.; Fabricius, M.

2008-01-01

Objective: Cortical spreading depression (CSD) and periinfarct depolarization (PID) have been shown in various experimental models of stroke to cause secondary neuronal damage and infarct expansion. For decades it has been questioned whether CSD or PID occur in human ischemic stroke. Here, we...... potential change spreading between adjacent channels was accompanied by transient depression of ECoG activity. In PID, a slow potential change spread between neighboring channels despite already established suppression of ECoG activity. Most CSDs and PIDs appeared repetitively in clusters. CSD or PID...... was observed in all but two patients. In these two patients, the electrode strip had been placed over infarcted tissue, and accordingly, no local ECoG or recurrent transient depolarization activity occurred throughout the observation period. Interpretation: CSD and PID occurred spontaneously with high...

Linear theory of beam depolarization due to vertical betatron motion

International Nuclear Information System (INIS)

Chao, A.W.; Schwitters, R.F.

1976-06-01

It is well known that vertical betatron motion in the presence of quantum fluctuations leads to some degree of depolarization of a transversely polarized beam in electron-positron storage rings even for energies away from spin resonances. Analytic formulations of this problem, which require the use of simplifying assumptions, generally have shown that there exist operating energies where typical storage rings should exhibit significant beam polarization. Due to the importance of beam polarization in many experiments, we present here a complete calculation of the depolarization rate to lowest order in the perturbing fields, which are taken to be linear functions of the betatron motion about the equilibrium orbit. The results are applicable to most high energy storage rings. Explicit calculations are given for SPEAR and PEP. 7 refs., 8 figs

Fluorescence/depolarization lidar for mid-range stand-off detection of biological agents

Science.gov (United States)

Mierczyk, Z.; Kopczyński, K.; Zygmunt, M.; Wojtanowski, J.; Młynczak, J.; Gawlikowski, A.; Młodzianko, A.; Piotrowski, W.; Gietka, A.; Knysak, P.; Drozd, T.; Muzal, M.; Kaszczuk, M.; Ostrowski, R.; Jakubaszek, M.

2011-06-01

LIDAR system for real-time standoff detection of bio-agents is presented and preliminary experimental results are discussed. The detection approach is based on two independent physical phenomena: (1) laser induced fluorescence (LIF), (2) depolarization resulting from elastic scattering on non-spherical particles. The device includes three laser sources, two receiving telescopes, depolarization component and spectral signature analyzing spectrograph. It was designed to provide the stand-off detection capability at ranges from 200 m up to several kilometers. The system as a whole forms a mobile platform for vehicle or building installation. Additionally, it's combined with a scanning mechanics and advanced software, which enable to conduct the semi-automatic monitoring of a specified space sector. For fluorescence excitation, 3-rd (355 nm) and 4-th (266 nm) harmonics of Nd:YAG pulsed lasers are used. They emit short (~6 ns) pulses with the repetition rate of 20 Hz. Collecting optics for fluorescence echo detection and spectral content analysis includes 25 mm diameter f/4 Newton telescope, Czerny Turner spectrograph and 32-channel PMT. Depending on the grating applied, the spectral resolution from 20 nm up to 3 nm per channel can be achieved. The system is also equipped with an eye-safe (1.5 μm) Nd:YAG OPO laser for elastic backscattering/depolarization detection. The optical echo signal is collected by Cassegrain telescope with aperture diameter of 12.5 mm. Depolarization detection component based on polarizing beam-splitter serves as the stand-off particle-shape analyzer, which is very valuable in case of non-spherical bio-aerosols sensing.

Depolarization temperature and piezoelectric properties of TiO3 ...

Indian Academy of Sciences (India)

WINTEC

2TiO3–Na1/2Bi1/2(Zn1/3Nb2/3)O3, was synthesized using the two-stage calcination method and depolarization temperatures and piezoelectric properties were also investigated. The XRD analysis showed that the ceramics system had a ...

Measurement of the depolarization rate of positive muons in copper and aluminium

International Nuclear Information System (INIS)

Gauster, W.B.; Heffner, R.H.; Huang, C.Y.; Hutson, R.L.; Leon, M.; Parkin, D.M.; Schillaci, M.E.; Triftshaeuser, W.; Wampler, W.R.

1977-01-01

Positive muon spin rotation experiments for polycrystalline Cu and Al from 19 K to temperatures near the melting points are reported. At low temperatures, the depolarization associated with localization of the muons at octahedral interstitial sites is seen in Cu, while in Al only slight depolarization is observed below 250 K. At high temperatures, no evidence for trapping of positive muons at vacancies in thermal equilibrium is found for either metal. It is concluded that the muons either diffuse too slowly to find vacancies or, if they do find vacancies, are bound too weakly to remain trapped. (author)

Calibration procedure and wavelength correction for neutron depolarization experiments

International Nuclear Information System (INIS)

Roest, W.; Rekveldt, M.T.

1992-01-01

The neutron polarimeter, for which an extended calibration procedure is described here, enables one to investigate magnetic properties of materials. Such an investigation is carried out by offering a polarized neutron beam in the x-, y- and z-direction successively and, after transmission through the sample, by analysing the polarization in all three directions. The result is a 3x3 depolarization matrix. After the polarizer, the neutron beam has a polarization along the z-direction. Two coil systems creating a magnetic field in the yz-plane perpendicular to the beam direction provide the possibility to direct the polarization in the x-, y- and z-direction by means of Larmor precession of the polarization in these fields. New research areas, where small depolarization effects together with considerable polarization rotation are measured, have caused a need for more accuracy in, and better knowledge of the calibration of the polarimeter. The calibration procedure use up to now and the improvements made on it are described. (orig.)

Involvement of TrkB- and p75NTR-signaling pathways in two contrasting forms of long-lasting synaptic plasticity

Science.gov (United States)

Sakuragi, Shigeo; Tominaga-Yoshino, Keiko; Ogura, Akihiko

2013-11-01

The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75NTR pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75NTR pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75NTR-masking conditions, thus supporting the aforementioned hypothesis.

Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

DEFF Research Database (Denmark)

Shaffer, G.; Olsen, S.M.; Pedersen, Jens Olaf Pepke

2009-01-01

Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion and assoc......Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion...... solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean. We conclude that substantial reductions in fossil-fuel use over the next...

Tennessee and Florida: Continuity and Change in Long-Lasting State Performance Funding Systems for Higher Education. CCRC Brief. Number 43

Science.gov (United States)

Dougherty, Kevin J.; Natow, Rebecca S.

2010-01-01

This study analyzes changes over time in long-lasting state performance funding systems for higher education. It addresses two research questions: First, in what ways have long-lasting systems changed over time in funding levels, indicators used to allocate funds, and measures used for those indicators? Second, what political actors, actions, and…

Threshold stoichiometry for beam induced nitrogen depletion of SiN

International Nuclear Information System (INIS)

Timmers, H.; Weijers, T.D.M.; Elliman, R.G.; Uribasterra, J.; Whitlow, H.J.; Sarwe, E.-L.

2002-01-01

Measurements of the stoichiometry of silicon nitride films as a function of the number of incident ions using heavy ion elastic recoil detection (ERD) show that beam-induced nitrogen depletion depends on the projectile species, the beam energy, and the initial stoichiometry. A threshold stoichiometry exists in the range 1.3>N/Si≥1, below which the films are stable against nitrogen depletion. Above this threshold, depletion is essentially linear with incident fluence. The depletion rate correlates non-linearly with the electronic energy loss of the projectile ion in the film. Sufficiently long exposure of nitrogen-rich films renders the mechanism, which prevents depletion of nitrogen-poor films, ineffective. Compromising depth-resolution, nitrogen depletion from SiN films during ERD analysis can be reduced significantly by using projectile beams with low atomic numbers

Norepinephrine induces pathway-specific long-lasting potentiation and depression in the hippocampal dentate gyrus.

Science.gov (United States)

Dahl, D; Sarvey, J M

1989-01-01

The study presented here indicates that norepinephrine (NE) selectively induces long-lasting modifications of synaptically mediated responses in the dentate gyrus of the rat hippocampal slice. A low concentration of NE (1.0 microM; in the presence of 50 microM phentolamine, an alpha-adrenergic antagonist) or a 1.0 microM concentration of the specific beta-adrenergic agonist isoproterenol induced long-lasting pathway-specific alterations of granule cell electrophysiological responses. Excitatory postsynaptic potentials and population spikes evoked by stimulation of the medial perforant pathway (PP) were potentiated for more than 45 min. In contrast, responses to lateral PP stimulation were depressed for the same period. Both potentiation and depression were blocked by the beta-adrenergic antagonist propranolol (1.0 microM). These results indicate that NE can act differentially on projections to the dentate gyrus arising in the entorhinal cortex. Such selective persistent modifications of cortical circuits may be involved in processes in the mammalian brain underlying attention, learning, and memory. PMID:2734319

Treg depletion inhibits efficacy of cancer immunotherapy: implications for clinical trials.

Directory of Open Access Journals (Sweden)

James F Curtin

2008-04-01

Full Text Available Regulatory T lymphocytes (Treg infiltrate human glioblastoma (GBM; are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61 has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients.Using a syngeneic intracrabial glioblastoma (GBM mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs present in tumors, draining lymph nodes and spleen and improved long-term survival (50% of mice survived >150 days. No improvement in survival was observed when Tregs were depleted 24 days after tumor implantation, suggesting that tumor burden is an important factor for determining efficacy of Treg depletion in clinical trials. In a T cell dependent model of brain tumor regression elicited by intratumoral delivery of adenoviral vectors (Ad expressing Fms-like Tyrosine Kinase 3 ligand (Flt3L and Herpes Simplex Type 1-Thymidine Kinase (TK with ganciclovir (GCV, we demonstrate that administration of PC61 24 days after tumor implantation (7 days after treatment inhibited T cell dependent tumor regression and long term survival. Further, depletion with PC61 completely inhibited clonal expansion of tumor antigen-specific T lymphocytes in response to the treatment.Our data demonstrate for the first time, that although Treg depletion inhibits the progression/eliminates GBM tumors, its efficacy is dependent on tumor burden. We conclude that this approach will be useful in a setting of minimal residual disease. Further, we also demonstrate that Treg depletion, using PC61 in combination with immunotherapy, inhibits clonal expansion of tumor antigen-specific T cells, suggesting that new, more

Long-lasting injection of solar energetic electrons into the heliosphere

Science.gov (United States)

Dresing, N.; Gómez-Herrero, R.; Heber, B.; Klassen, A.; Temmer, M.; Veronig, A.

2018-05-01

Context. The main sources of solar energetic particle (SEP) events are solar flares and shocks driven by coronal mass ejections (CMEs). While it is generally accepted that energetic protons can be accelerated by shocks, whether or not these shocks can also efficiently accelerate solar energetic electrons is still debated. In this study we present observations of the extremely widespread SEP event of 26 Dec 2013 To the knowledge of the authors, this is the widest longitudinal SEP distribution ever observed together with unusually long-lasting energetic electron anisotropies at all observer positions. Further striking features of the event are long-lasting SEP intensity increases, two distinct SEP components with the second component mainly consisting of high-energy particles, a complex associated coronal activity including a pronounced signature of a shock in radio type-II observations, and the interaction of two CMEs early in the event. Aims: The observations require a prolonged injection scenario not only for protons but also for electrons. We therefore analyze the data comprehensively to characterize the possible role of the shock for the electron event. Methods: Remote-sensing observations of the complex solar activity are combined with in situ measurements of the particle event. We also apply a graduated cylindrical shell (GCS) model to the coronagraph observations of the two associated CMEs to analyze their interaction. Results: We find that the shock alone is likely not responsible for this extremely wide SEP event. Therefore we propose a scenario of trapped energetic particles inside the CME-CME interaction region which undergo further acceleration due to the shock propagating through this region, stochastic acceleration, or ongoing reconnection processes inside the interaction region. The origin of the second component of the SEP event is likely caused by a sudden opening of the particle trap.

Long lasting behavior of Gd2O2S:Eu3+ phosphor synthesized by hydrothermal routine

International Nuclear Information System (INIS)

Hang Tao; Liu Qun; Mao Dali; Chang Chengkang

2008-01-01

This paper reports the detailed preparation process and afterglow properties of Eu 3+ activated long lasting Gd 2 O 2 S phosphor by hydrothermal routine. Rod-like Gd(OH) 3 were firstly synthesized by hydrothermal method to serve as the precursor. Long lasting Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor was obtained by calcinating the precursor with co-activators and S powder. It was found from the results that the hydrothermally prepared Gd(OH) 3 revealed a rod-like morphology, while the calcinated Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor showed a round granular shape. The morphological change can be explained by the etching effect of the melt that was formed by the carbonate and S powder during the high temperature calcination. The obtained Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor produced a red emission upon 243 nm UV excitation, which is a typical emission of Eu 3+ from 5 D j to 7 F j states. Long lasting behavior was observed after the UV source was switched off, due to the formation of electron traps with suitable trap depth within the matrix by the codoped Ti 4+ and Mg 2+ ions

Simulation of Halocarbon Production and Emissions and Effects on Ozone Depletion

Science.gov (United States)

Holmes; Ellis

1997-09-01

/ This paper describes an integrated model that simulates future halocarbon production/emissions and potential ozone depletion. Applications and historical production levels for various halocarbons are discussed first. A framework is then presented for modeling future halocarbon impacts incorporating differences in underlying demands, applications, regulatory mandates, and environmental characteristics. The model is used to simulate the potential impacts of several prominent issues relating to halocarbon production, regulation, and environmental interactions, notably: changes in agricultural methyl bromide use, increases in effectiveness of bromine for ozone depletion, modifications to the elimination schedule for HCFCs, short-term expansion of CFC demand in low use compliance countries, and delays in Russian Federation compliance. Individually, each issue does not unequivocally represent a significant likely increase in long-term atmospheric halogen loading and stratospheric ozone depletion. In combination, however, these impacts could increase peak halogen concentrations and long-term integral halogen loading, resulting in higher levels of stratospheric ozone depletion and longer exposure to increased levels of UV radiation.KEY WORDS: Halocarbons; Ozone depletion; Montreal Protocol; Integrated assessment

The problem of radiative depolarization in the 'Siberian Snake'

International Nuclear Information System (INIS)

Schwitters, R.

1979-01-01

As pointed out by Derbenev and Kondratenko and by the LEP Study Group, a 'Siberian Snake' may be a convenient method for providing longitudinally polarized beams at LEP. The author shows that at the highest LEP energies (approximately>60 GeV) synchrotron radiation with spin-flip may depolarize the beams. (Auth.)

Depleted uranium hexafluoride: Waste or resource?

International Nuclear Information System (INIS)

Schwertz, N.; Zoller, J.; Rosen, R.; Patton, S.; Bradley, C.; Murray, A.

1995-07-01

The US Department of Energy is evaluating technologies for the storage, disposal, or re-use of depleted uranium hexafluoride (UF 6 ). This paper discusses the following options, and provides a technology assessment for each one: (1) conversion to UO 2 for use as mixed oxide duel, (2) conversion to UO 2 to make DUCRETE for a multi-purpose storage container, (3) conversion to depleted uranium metal for use as shielding, (4) conversion to uranium carbide for use as high-temperature gas-cooled reactor (HTGR) fuel. In addition, conversion to U 3 O 8 as an option for long-term storage is discussed

Storage ring lattice calibration using resonant spin depolarization

Directory of Open Access Journals (Sweden)

K. P. Wootton

2013-07-01

Full Text Available This paper presents measurements of the GeV-scale electron beam energy for the storage rings at the synchrotron light source facilities Australian Synchrotron (AS and SPEAR3 at SLAC. Resonant spin depolarization was employed in the beam energy measurement, since it is presently the highest precision technique and an uncertainty of order 10^{-6} was achieved at SPEAR3 and AS. Using the resonant depolarization technique, the beam energy was measured at various rf frequencies to measure the linear momentum compaction factor. This measured linear momentum compaction factor was used to evaluate models of the beam trajectory through combined-function bending magnets. The main bending magnets of both lattices are rectangular, horizontally defocusing gradient bending magnets. Four modeling approaches are compared for the beam trajectory through the bending magnet: a circular trajectory, linear and nonlinear hyperbolic cosine trajectories, and numerical evaluation of the trajectory through the measured magnetic field map. Within the uncertainty of the measurement the momentum compaction factor is shown to agree with the numerical model of the trajectory within the bending magnet, and disagree with the hyperbolic cosine approximation.

A review of depolarization modeling for earth-space radio paths at frequencies above 10 GHz

Science.gov (United States)

Bostian, C. W.; Stutzman, W. L.; Gaines, J. M.

1982-01-01

A review is presented of models for the depolarization, caused by scattering from raindrops and ice crystals, that limits the performance of dual-polarized satellite communication systems at frequencies above 10 GHz. The physical mechanisms of depolarization as well as theoretical formulations and empirical data are examined. Three theoretical models, the transmission, attenuation-derived, and scaling models, are described and their relative merits are considered.

Detection of spreading depolarization with intraparenchymal electrodes in the injured human brain

DEFF Research Database (Denmark)

Jeffcote, Toby; Hinzman, Jason M; Jewell, Sharon L

2014-01-01

be detected using intra-cortical electrodes, opening the way for electrode insertion via burr hole. METHODS: Animal work was carried out on adult Sprague-Dawley rats in a laboratory setting to investigate the feasibility of recording depolarization events. Subsequently, 8 human patients requiring craniotomy...... for craniotomy. The method provides a new investigative tool for the evaluation of the contribution of these events to secondary brain injury in human patients.......BACKGROUND: Spreading depolarization events following ischemic and traumatic brain injury are associated with poor patient outcome. Currently, monitoring these events is limited to patients in whom subdural electrodes can be placed at open craniotomy. This study examined whether these events can...

Histamine H3 receptor activation selectively inhibits dopamine D1 receptor-dependent [3H]GABA release from depolarization-stimulated slices of rat substantia nigra pars reticulata

International Nuclear Information System (INIS)

Aceves, J.; Young, J.M.; Arias-Montano, J.A.; Floran, B.; Garcia, M.

1997-01-01

The release of [ 3 H]GABA from slices of rat substantia nigra pars reticulata induced by increasing extracellular K + from 6 to 15 mM in the presence of 10 μM sulpiride was inhibited by 73±3% by 1 μM SCH 23390, consistent with a large component of release dependent upon D 1 receptor activation. The histamine H 3 receptor-selective agonist immepip (1 μM) and the non-selective agonist histamine (100 μM) inhibited [ 3 H]GABA release by 78±2 and 80±2%, respectively. The inhibition by both agonists was reversed by the H 3 receptor antagonist thioperamide (1 μM). However, in the presence of 1 μM SCH 23390 depolarization-induced release of [ 3 H]GABA was not significantly decreased by 1 μM immepip. In rats depleted of dopamine by pretreatment with reserpine, immepip no longer inhibited control release of [ 3 H]GABA, but in the presence of 1 μM SKF 38393, which produced a 7±1-fold stimulation of release, immepip reduced the release to a level not statistically different from that in the presence of immepip alone. Immepip (1 μM) also inhibited the depolarization-induced release of [ 3 H]dopamine from substantia nigra pars reticulata slices, by 38±3%.The evidence is consistent with the proposition that activation of histamine H 3 receptors leads to the selective inhibition of the component of depolarization-induced [ 3 H]GABA release in substantia nigra pars reticulata slices which is dependent upon D 1 receptor activation. This appears to be largely an action at the terminals of the striatonigral GABA projection neurons, which may be enhanced by a partial inhibition of dendritic [ 3 H]dopamine release. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Gz mediates the long-lasting desensitization of brain CB1 receptors and is essential for cross-tolerance with morphine

Directory of Open Access Journals (Sweden)

Rodríguez-Muñoz María

2009-03-01

Full Text Available Abstract Background Although the systemic administration of cannabinoids produces antinociception, their chronic use leads to analgesic tolerance as well as cross-tolerance to morphine. These effects are mediated by cannabinoids binding to peripheral, spinal and supraspinal CB1 and CB2 receptors, making it difficult to determine the relevance of each receptor type to these phenomena. However, in the brain, the CB1 receptors (CB1Rs are expressed at high levels in neurons, whereas the expression of CB2Rs is marginal. Thus, CB1Rs mediate the effects of smoked cannabis and are also implicated in emotional behaviors. We have analyzed the production of supraspinal analgesia and the development of tolerance at CB1Rs by the direct injection of a series of cannabinoids into the brain. The influence of the activation of CB1Rs on supraspinal analgesia evoked by morphine was also evaluated. Results Intracerebroventricular (icv administration of cannabinoid receptor agonists, WIN55,212-2, ACEA or methanandamide, generated a dose-dependent analgesia. Notably, a single administration of these compounds brought about profound analgesic tolerance that lasted for more than 14 days. This decrease in the effect of cannabinoid receptor agonists was not mediated by depletion of CB1Rs or the loss of regulated G proteins, but, nevertheless, it was accompanied by reduced morphine analgesia. On the other hand, acute morphine administration produced tolerance that lasted only 3 days and did not affect the CB1R. We found that both neural mu-opioid receptors (MORs and CB1Rs interact with the HINT1-RGSZ module, thereby regulating pertussis toxin-insensitive Gz proteins. In mice with reduced levels of these Gz proteins, the CB1R agonists produced no such desensitization or morphine cross-tolerance. On the other hand, experimental enhancement of Gz signaling enabled an acute icv administration of morphine to produce a long-lasting tolerance at MORs that persisted for more than

Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumber

Science.gov (United States)

Spalding, E. P.; Cosgrove, D. J.

1989-01-01

Blue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.

Anti-Hebbian long-term potentiation in the hippocampal feedback inhibitory circuit.

Science.gov (United States)

Lamsa, Karri P; Heeroma, Joost H; Somogyi, Peter; Rusakov, Dmitri A; Kullmann, Dimitri M

2007-03-02

Long-term potentiation (LTP), which approximates Hebb's postulate of associative learning, typically requires depolarization-dependent glutamate receptors of the NMDA (N-methyl-D-aspartate) subtype. However, in some neurons, LTP depends instead on calcium-permeable AMPA-type receptors. This is paradoxical because intracellular polyamines block such receptors during depolarization. We report that LTP at synapses on hippocampal interneurons mediating feedback inhibition is "anti-Hebbian":Itis induced by presynaptic activity but prevented by postsynaptic depolarization. Anti-Hebbian LTP may occur in interneurons that are silent during periods of intense pyramidal cell firing, such as sharp waves, and lead to their altered activation during theta activity.

Depolarization Ratio Profiles Calibration and Observations of Aerosol and Cloud in the Tibetan Plateau Based on Polarization Raman Lidar

Directory of Open Access Journals (Sweden)

Guangyao Dai

2018-03-01

Full Text Available A brief description of the Water vapor, Cloud and Aerosol Lidar (WACAL system is provided. To calibrate the volume linear depolarization ratio, the concept of “ Δ 90 ° -calibration” is applied in this study. This effective and accurate calibration method is adjusted according to the design of WACAL. Error calculations and analysis of the gain ratio, calibrated volume linear depolarization ratio and particle linear depolarization ratio are provided as well. In this method, the influences of the gain ratio, the rotation angle of the plane of polarization and the polarizing beam splitter are discussed in depth. Two groups of measurements with half wave plate (HWP at angles of (0 ° , 45 ° and (22.5 ° , −22.5 ° are operated to calibrate the volume linear depolarization ratio. Then, the particle linear depolarization ratios measured by WACAL and CALIOP (the Cloud-Aerosol Lidar with Orthogonal Polarization during the simultaneous observations were compared. Good agreements are found. The calibration method was applied in the third Tibetan Plateau Experiment of Atmospheric Sciences (TIPEX III in 2013 and 2014 in China. Vertical profiles of the particle depolarization ratio of clouds and aerosol in the Tibetan Plateau were measured with WACAL in Litang (30.03° N, 100.28° E, 3949 m above sea level (a.s.l. in 2013 and Naqu (31.48° N, 92.06° E, 4508 m a.s.l. in 2014. Then an analysis on the polarizing properties of the aerosol, clouds and cirrus over the Tibetan Plateau is provided. The particle depolarization ratio of cirrus clouds varies from 0.36 to 0.52, with a mean value of 0.44 ± 0.04. Cirrus clouds occurred between 5.2 and 12 km above ground level (a.g.l.. The cloud thickness ranges from 0.12 to 2.55 km with a mean thickness of 1.22 ± 0.70 km. It is found that the particle depolarization ratio of cirrus clouds become larger as the height increases. However, the increase rate of the particle depolarization ratio becomes smaller as

Monitoring long-lasting insecticidal net (LLIN) durability to validate net serviceable life assumptions, in Rwanda

NARCIS (Netherlands)

Hakizimana, E.; Cyubahiro, B.; Rukundo, A.; Kabayiza, A.; Mutabazi, A.; Beach, R.; Patel, R.; Tongren, J.E.; Karema, C.

2014-01-01

Background To validate assumptions about the length of the distribution–replacement cycle for long-lasting insecticidal nets (LLINs) in Rwanda, the Malaria and other Parasitic Diseases Division, Rwanda Ministry of Health, used World Health Organization methods to independently confirm the three-year

Activation of cathepsin L contributes to the irreversible depolarization induced by oxygen and glucose deprivation in rat hippocampal CA1 neurons.

Science.gov (United States)

Kikuta, Shogo; Murai, Yoshinaka; Tanaka, Eiichiro

2017-01-01

Oxygen and glucose deprivation (OGD) elicits a rapid and irreversible depolarization with a latency of ∼5min in intracellular recordings of hippocampal CA1 neurons in rat slice preparations. In the present study, we examined the role of cathepsin L in the OGD-induced depolarization. OGD-induced depolarizations were irreversible as no recovery of membrane potential was observed. The membrane potential reached 0mV when oxygen and glucose were reintroduced immediately after the onset of the OGD-induced rapid depolarization. The OGD-induced depolarizations became reversible when the slice preparations were pre-incubated with cathepsin L inhibitors (types I and IV at 0.3-2nM and 0.3-30nM, respectively). Moreover, pre-incubation with these cathepsin inhibitors prevented the morphological changes, including swelling of the cell soma and fragmentation of dendrites, observed in control neurons after OGD. These findings suggest that the activation of cathepsin L contributes to the irreversible depolarization produced by OGD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Twomey effect in subtropical stratocumulus clouds from UV depolarization lidar

NARCIS (Netherlands)

de Graaf, M.; Brown, Jessica; Donovan, D.P.; Nicolae, D.; Makoto, A.; Vassilis, A.; Balis, D.; Behrendt, A.; Comeron, A.; Gibert, F.; Landulfo, E.; McCormick, M.P.; Senff, C.; Veselovskii, I.; Wandinger, U.

2018-01-01

Marine stratocumulus clouds are important climate regulators, reflecting sunlight over a dark ocean background. A UV-depolarization lidar on Ascension, a small remote island in the south Atlantic, measured cloud droplet sizes and number concentration using an inversion method based on Monte Carlo

Piezoelectric effect in polarized and electrically depolarized ferrotextures

International Nuclear Information System (INIS)

Luchaninov, A.G.; Shil'nikov, A.V.; Shuvalov, L.A.

1999-01-01

Piezoelectric moduli were calculated for ferroelectric textures in the states with the greatest possible (in terms of symmetry) polarization and the zero polarization (obtained from the former by electrical depolarization). The calculations were performed for the textures of crystals of the classes 2, 3, 4, 6, mm2, 3m, 4mm,and 6mm. The experimental results for lead zirconate-titanate- and barium-titanate-based piezoelectric ceramic are reported

On the nature of the fast depolarization of muons in condensed nitrogen

International Nuclear Information System (INIS)

Duginov, V.N.; Grebinnik, V.G.; Kirillov, B.F.

1990-01-01

Temperature dependences of the depolarization rate, the muon precession initial amplitude and phase in liquid and crystalline nitrogen with the oxygen content of 10 -6 have been measured. It has been shown that muon spin relaxation parameters in nitrogen do not change at the reduction of the oxygen impurity content from 0.7x10 -4 to 10 -6 . The fast depolarization of muons in condensed nitrogen is apparently due to the formation of muonium atoms. The muon precession initial phase has been measured as a function of the perpendicular magnetic field to determine the state of short-lived muonium in nitrogen. It has been determined that muonium in nitrogen is in an excited state. 14 refs.; 3 figs

The Physical Origin of Long Gas Depletion Times in Galaxies

Science.gov (United States)

Semenov, Vadim A.; Kravtsov, Andrey V.; Gnedin, Nickolay Y.

2017-08-01

We present a model that explains why galaxies form stars on a timescale significantly longer than the timescales of processes governing the evolution of interstellar gas. We show that gas evolves from a non-star-forming to a star-forming state on a relatively short timescale, and thus the rate of this evolution does not limit the star formation rate (SFR). Instead, the SFR is limited because only a small fraction of star-forming gas is converted into stars before star-forming regions are dispersed by feedback and dynamical processes. Thus, gas cycles into and out of a star-forming state multiple times, which results in a long timescale on which galaxies convert gas into stars. Our model does not rely on the assumption of equilibrium and can be used to interpret trends of depletion times with the properties of observed galaxies and the parameters of star formation and feedback recipes in simulations. In particular, the model explains how feedback self-regulates the SFR in simulations and makes it insensitive to the local star formation efficiency. We illustrate our model using the results of an isolated L *-sized galaxy simulation that reproduces the observed Kennicutt-Schmidt relation for both molecular and atomic gas. Interestingly, the relation for molecular gas is almost linear on kiloparsec scales, although a nonlinear relation is adopted in simulation cells. We discuss how a linear relation emerges from non-self-similar scaling of the gas density PDF with the average gas surface density.

The Physical Origin of Long Gas Depletion Times in Galaxies

International Nuclear Information System (INIS)

Semenov, Vadim A.; Kravtsov, Andrey V.; Gnedin, Nickolay Y.

2017-01-01

We present a model that explains why galaxies form stars on a timescale significantly longer than the timescales of processes governing the evolution of interstellar gas. We show that gas evolves from a non-star-forming to a star-forming state on a relatively short timescale, and thus the rate of this evolution does not limit the star formation rate (SFR). Instead, the SFR is limited because only a small fraction of star-forming gas is converted into stars before star-forming regions are dispersed by feedback and dynamical processes. Thus, gas cycles into and out of a star-forming state multiple times, which results in a long timescale on which galaxies convert gas into stars. Our model does not rely on the assumption of equilibrium and can be used to interpret trends of depletion times with the properties of observed galaxies and the parameters of star formation and feedback recipes in simulations. In particular, the model explains how feedback self-regulates the SFR in simulations and makes it insensitive to the local star formation efficiency. We illustrate our model using the results of an isolated L * -sized galaxy simulation that reproduces the observed Kennicutt–Schmidt relation for both molecular and atomic gas. Interestingly, the relation for molecular gas is almost linear on kiloparsec scales, although a nonlinear relation is adopted in simulation cells. We discuss how a linear relation emerges from non-self-similar scaling of the gas density PDF with the average gas surface density.

Depleted uranium hexafluoride: Waste or resource?

Energy Technology Data Exchange (ETDEWEB)

Schwertz, N.; Zoller, J.; Rosen, R.; Patton, S. [Lawrence Livermore National Lab., CA (United States); Bradley, C. [USDOE Office of Nuclear Energy, Science, Technology, Washington, DC (United States); Murray, A. [SAIC (United States)

1995-07-01

the US Department of Energy is evaluating technologies for the storage, disposal, or re-use of depleted uranium hexafluoride (UF{sub 6}). This paper discusses the following options, and provides a technology assessment for each one: (1) conversion to UO{sub 2} for use as mixed oxide duel, (2) conversion to UO{sub 2} to make DUCRETE for a multi-purpose storage container, (3) conversion to depleted uranium metal for use as shielding, (4) conversion to uranium carbide for use as high-temperature gas-cooled reactor (HTGR) fuel. In addition, conversion to U{sub 3}O{sub 8} as an option for long-term storage is discussed.

Depleted uranium

International Nuclear Information System (INIS)

Huffer, E.; Nifenecker, H.

2001-02-01

This document deals with the physical, chemical and radiological properties of the depleted uranium. What is the depleted uranium? Why do the military use depleted uranium and what are the risk for the health? (A.L.B.)

The benefits of cholinergic enhancement during perceptual learning are long-lasting

Directory of Open Access Journals (Sweden)

Ariel eRokem

2013-05-01

Full Text Available The neurotransmitter acetylcholine (ACh regulates many aspects of cognition, including attention and memory. Previous research in animal models has shown that plasticity in sensory systems often depends on the behavioral relevance of a stimulus and/or task. However, experimentally increasing ACh release in the cortex can result in experience-dependent plasticity, even in the absence of behavioral relevance. In humans, the pharmacological enhancement of ACh transmission by administration of the cholinesterase inhibitor donepezil during performance of a perceptual task increases the magnitude of perceptual learning (PL and its specificity to physical parameters of the stimuli used for training. Behavioral effects of PL have previously been shown to persist for many months. In the present study, we tested whether enhancement of PL by donepezil is also long-lasting. Healthy human subjects were trained on a motion direction discrimination task during cholinergic enhancement, and follow-up testing was performed 5-15 months after the end of training and without additional drug administration. Increases in performance associated with training under donepezil were evident in follow-up retesting, indicating that cholinergic enhancement has beneficial long-term effects on PL. These findings suggest that cholinergic enhancement of training procedures used to treat clinical disorders should improve long-term outcomes of these procedures.

First observation of the depolarization of Thomson scattering radiation by a fusion plasma

Science.gov (United States)

Giudicotti, L.; Kempenaars, M.; McCormack, O.; Flanagan, J.; Pasqualotto, R.; contributors, JET

2018-04-01

We report the first experimental observation of the depolarization of the Thomson scattering (TS) radiation, a relativistic effect expected to occur in very high {{T}e} plasmas and never observed so far in a fusion machine. A set of unused optical fibers in the collection optics of the high resolution Thomson scattering system of JET has been used to detect the depolarized TS radiation during a JET campaign with {{T}e}≤slant 8 keV . A linear polarizer with the axis perpendicular to the direction of the incident E-field was placed in front of a fiber optic pair observing a region close to the plasma core, while another fiber pair with no polariser simultaneously observed an adjacent plasma region. The measured intensity ratio was found to be consistent with the theory, taking into account sensitivity coefficients of the two measurement channels determined with post-experiment calibrations and Raman scattering. This depolarization effect is at the basis of polarimetric TS, a different and complementary method for the analysis of TS spectra that can provide significant advantages for {{T}e} measurements in very hot plasmas such as in ITER ≤ft({{T}e}≤slant 40 keV \\right) .

Ipilimumab in advanced melanoma: reports of long-lasting responses.

Science.gov (United States)

Farolfi, Alberto; Ridolfi, Laura; Guidoboni, Massimo; Nicoletti, Stefania Vittoria Luisa; Piciucchi, Sara; Valmorri, Linda; Costantini, Matteo; Scarpi, Emanuela; Amadori, Dino; Ridolfi, Ruggero

2012-06-01

Patients with metastatic melanoma have a poor prognosis; the results of chemotherapy remain unsatisfactory. Ipilimumab, an anticytotoxic T lymphocyte-associated antigen-4 antibody, has shown promising results in several clinical trials. In this report, advanced melanoma patients receiving ipilimumab were scored according to novel immune-related response criteria (irRC) in an attempt to capture additional response patterns and to avoid premature treatment cessation. Thirty-six heavily pretreated metastatic melanoma patients recieved ipilimumab within five international clinical trials at our Institution from May 2006 to August 2008. Disease progression was defined as an increase in tumor burden by at least 25% compared with the nadir, irrespective of any initial increase in baseline lesions or the appearance of new lesions. We report unusually long-lasting responses in patients treated with ipilimumab 10 mg/kg. An overall response was observed in six out of 30 patients (20%), a complete response in three (10%), and disease control in 11 (37%), which seemed to be of a long duration (median of 16 months; complete response 36+, 34+, and 41+ months). All irRC patterns seemed to be strongly associated with an improvement in overall survival. Interestingly, we found a correlation between the presence of a grade 3/4 immune-related adverse event and responses, time to progression, and overall survival. Ipilimumab therapy resulted in clinically meaningful responses in advanced melanoma patients, supporting the need for further irRC validation.

Currents of thermally stimulated depolarization in CaIn2S4 single crystals

International Nuclear Information System (INIS)

Tagiev, B.G.; Tagiev, O.B.; Dzhabbarov, R.B.; Musaeva, N.N.

1996-01-01

The results of investigation into currents of thermally stimulated depolarization in CaIn 2 S 4 monocrystals are presented for the first time. Spectra of thermally stimulated depolarization for In-CaIn S4 -In structures are measured under T=99 K at various rates of heat, times of polarization and times of expectation following switching off of electrical field up to beginning of measurements of shorting. The main parameters of capture cross section, partial factor, concentration of traps, are determined. It is determined that one may observed a biomolecular mechanism with a strong secondary capture in CaIn 2 S 4 monocrystals. 9 refs.; 4 figs

Effect of the depolarization field on coherent optical properties in semiconductor quantum dots

Science.gov (United States)

Mitsumori, Yasuyoshi; Watanabe, Shunta; Asakura, Kenta; Seki, Keisuke; Edamatsu, Keiichi; Akahane, Kouichi; Yamamoto, Naokatsu

2018-06-01

We study the photon echo spectrum of self-assembled semiconductor quantum dots using femtosecond light pulses. The spectrum shape changes from a single-peaked to a double-peaked structure as the time delay between the two excitation pulses is increased. The spectrum change is reproduced by numerical calculations, which include the depolarization field induced by the biexciton-exciton transition as well as the conventional local-field effect for the exciton-ground-state transition in a quantum dot. Our findings suggest that various optical transitions in tightly localized systems generate a depolarization field, which renormalizes the resonant frequency with a change in the polarization itself, leading to unique optical properties.

Generation of vector beams using a double-wedge depolarizer: Non-quantum entanglement

Science.gov (United States)

Samlan, C. T.; Viswanathan, Nirmal K.

2016-07-01

Propagation of horizontally polarized Gaussian beam through a double-wedge depolarizer generates vector beams with spatially varying state of polarization. Jones calculus is used to show that such beams are maximally nonseparable on the basis of even (Gaussian)-odd (Hermite-Gaussian) mode parity and horizontal-vertical polarization state. The maximum nonseparability in the two degrees of freedom of the vector beam at the double wedge depolarizer output is verified experimentally using a modified Sagnac interferometer and linear analyser projected interferograms to measure the concurrence 0.94±0.002 and violation of Clauser-Horne-Shimony-Holt form of Bell-like inequality 2.704±0.024. The investigation is carried out in the context of the use of vector beams for metrological applications.

Long lasting clinical response to chemotherapy for advanced uterine leiomyosarcoma: a case report.

Science.gov (United States)

Ridolfi, Claudio; Pasini, Giuseppe; Drudi, Fabrizio; Barzotti, Eleonora; Santelmo, Carlotta; Polselli, Antonio; Ravaioli, Alberto

2013-01-24

Uterine leiomyosarcoma is one of the most frequent uterine sarcomas. In the metastatic setting it is sensitive to doxorubicin, ifosfamide, gemcitabine, docetaxel and a few other drugs, but time to progression is generally short. For this reason prognosis is often poor and there are few reports in the literature of long responders. We report a case of a 40-year-old Caucasian woman with metastatic uterine leiomyosarcoma who began treatment six years before the presentation of this case report and for the following six years underwent ten lines of chemotherapy, achieving excellent results and a good quality of life. Among the treatments administered we observed a long response to temolozomide, an unconventional drug for this kind of disease. Although there are few chemotherapeutic options for the management of metastatic uterine leiomyosarcoma, a small number of patients have an unexpected long lasting response to treatment. For this reason further research is needed to identify new therapeutic agents and the predictive factors for the achievement of response.

Long-lasting pathological consequences of overexpression-induced α-synuclein spreading in the rat brain.

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Rusconi, Raffaella; Ulusoy, Ayse; Aboutalebi, Helia; Di Monte, Donato A

2018-04-01

Increased expression of α-synuclein can initiate its long-distance brain transfer, representing a potential mechanism for pathology spreading in age-related synucleinopathies, such as Parkinson's disease. In this study, the effects of overexpression-induced α-synuclein transfer were assessed over a 1-year period after injection of viral vectors carrying human α-synuclein DNA into the rat vagus nerve. This treatment causes targeted overexpression within neurons in the dorsal medulla oblongata and subsequent diffusion of the exogenous protein toward more rostral brain regions. Protein advancement and accumulation in pontine, midbrain, and forebrain areas were contingent upon continuous overexpression, because death of transduced medullary neurons resulted in cessation of spreading. Lack of sustained spreading did not prevent the development of long-lasting pathological changes. Particularly remarkable were findings in the locus coeruleus, a pontine nucleus with direct connections to the dorsal medulla oblongata and greatly affected by overexpression-induced transfer in this model. Data revealed progressive degeneration of catecholaminergic neurons that proceeded long beyond the time of spreading cessation. Neuronal pathology in the locus coeruleus was accompanied by pronounced microglial activation and, at later times, astrocytosis. Interestingly, microglial activation was also featured in another region reached by α-synuclein transfer, the central amygdala, even in the absence of frank neurodegeneration. Thus, overexpression-induced spreading, even if temporary, causes long-lasting pathological consequences in brain regions distant from the site of overexpression but anatomically connected to it. Neurodegeneration may be a consequence of severe protein burden, whereas even a milder α-synuclein accumulation in tissues affected by protein transfer could induce sustained microglial activation. © 2018 The Authors. Aging Cell published by the Anatomical Society and

Ferroelectric behavior of a lead titanate nanosphere due to depolarization fields and mechanical stresses

Energy Technology Data Exchange (ETDEWEB)

Andrade Landeta, J.; Lascano, I.

2017-07-01

A theorical model has been developed based on the theory of Ginzburg-Landau-Devonshire to study and predict the effects the decreasing of size particle in a nanosphere of PbTiO3 subjected to the action of depolarization fields and mechanical stress. It was considered that the nanosphere is surrounded by a layer of space charges on its surface, and containing 180° domains generated by minimizing free energy of depolarization. Energy density of depolarization, wall domain and electro-elastic energy have been incorporated into the free energy of the theory Ginzburg-Landau-Devonshire. Free energy minimization was performed to determine the spontaneous polarization and transition temperature system. These results show that the transition temperature for nanosphere is substantially smaller than the corresponding bulk material. Also, it has been obtained that the stability of the ferroelectric phase of nanosphere is favored for configurations with a large number of 180° domains, with the decreasing of thickness space charge layer, and the application of tensile stress and decreases with compressive stress. (Author)

Selection of a management strategy for depleted uranium

International Nuclear Information System (INIS)

Patton, S.; Hanrahan, E.; Bradley, C. Jnr.

1995-01-01

A consequence of the uranium enrichment process is the accumulation of a significant amount of depleted uranium hexafluoride (UF 6 ). Currently, in the United States approximately 560 000 tonnes of the material are stored at three different sites. The US Department of Energy (DOE) has recently initiated a programme to consider alternative strategies for the cost-effective and environmentally safe long-term management of this inventory of depleted UF 6 . The programme involves a technology and engineering assessment of proposed management options (which are: use/reuse, conversion, storage, or disposal) and an analysis of the potential environmental impacts and life-cycle costs of alternative management strategies. The information obtained from the studies will be used by the DOE to select a preferred long-term management strategy. Because of its provisions for considering a wide range of relevant issues and involving the public, this programme has become a model for future DOE materials disposition programmes. This paper presents an overview of the Depleted Uranium Hexafluoride Management Programme. Technical findings of the programme to date are presented, and major issues involved in selecting and implementing a management strategy are discussed. (author)

Short-Term, Intermittent Fasting Induces Long-Lasting Gut Health and TOR-Independent Lifespan Extension.

Science.gov (United States)

Catterson, James H; Khericha, Mobina; Dyson, Miranda C; Vincent, Alec J; Callard, Rebecca; Haveron, Steven M; Rajasingam, Arjunan; Ahmad, Mumtaz; Partridge, Linda

2018-06-04

Intermittent fasting (IF) can improve function and health during aging in laboratory model organisms, but the mechanisms at work await elucidation. We subjected fruit flies (Drosophila melanogaster) to varying degrees of IF and found that just one month of a 2-day fed:5-day fasted IF regime at the beginning of adulthood was sufficient to extend lifespan. This long-lasting, beneficial effect of early IF was not due to reduced fecundity. Starvation resistance and resistance to oxidative and xenobiotic stress were increased after IF. Early-life IF also led to higher lipid content in 60-day-old flies, a potential explanation for increased longevity. Guts of flies 40 days post-IF showed a significant reduction in age-related pathologies and improved gut barrier function. Improved gut health was also associated with reduced relative bacterial abundance. Early IF thus induced profound long-term changes. Pharmacological and genetic epistasis analysis showed that IF acted independently of the TOR pathway because rapamycin and IF acted additively to extend lifespan, and global expression of a constitutively active S6K did not attenuate the IF-induced lifespan extension. We conclude that short-term IF during early life can induce long-lasting beneficial effects, with robust increase in lifespan in a TOR-independent manner, probably at least in part by preserving gut health. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Physical Origin of Long Gas Depletion Times in Galaxies

Energy Technology Data Exchange (ETDEWEB)

Semenov, Vadim A.; Kravtsov, Andrey V.; Gnedin, Nickolay Y., E-mail: semenov@uchicago.edu [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States)

2017-08-20

We present a model that explains why galaxies form stars on a timescale significantly longer than the timescales of processes governing the evolution of interstellar gas. We show that gas evolves from a non-star-forming to a star-forming state on a relatively short timescale, and thus the rate of this evolution does not limit the star formation rate (SFR). Instead, the SFR is limited because only a small fraction of star-forming gas is converted into stars before star-forming regions are dispersed by feedback and dynamical processes. Thus, gas cycles into and out of a star-forming state multiple times, which results in a long timescale on which galaxies convert gas into stars. Our model does not rely on the assumption of equilibrium and can be used to interpret trends of depletion times with the properties of observed galaxies and the parameters of star formation and feedback recipes in simulations. In particular, the model explains how feedback self-regulates the SFR in simulations and makes it insensitive to the local star formation efficiency. We illustrate our model using the results of an isolated L {sub *}-sized galaxy simulation that reproduces the observed Kennicutt–Schmidt relation for both molecular and atomic gas. Interestingly, the relation for molecular gas is almost linear on kiloparsec scales, although a nonlinear relation is adopted in simulation cells. We discuss how a linear relation emerges from non-self-similar scaling of the gas density PDF with the average gas surface density.

Depolarization of the conductance-voltage relationship in the NaV1.5 mutant, E1784K, is due to altered fast inactivation

Science.gov (United States)

Yu, Alec; Zhu, Wandi; Silva, Jonathan R.; Ruben, Peter C.

2017-01-01

E1784K is the most common mixed long QT syndrome/Brugada syndrome mutant in the cardiac voltage-gated sodium channel NaV1.5. E1784K shifts the midpoint of the channel conductance-voltage relationship to more depolarized membrane potentials and accelerates the rate of channel fast inactivation. The depolarizing shift in the midpoint of the conductance curve in E1784K is exacerbated by low extracellular pH. We tested whether the E1784K mutant shifts the channel conductance curve to more depolarized membrane potentials by affecting the channel voltage-sensors. We measured ionic currents and gating currents at pH 7.4 and pH 6.0 in Xenopus laevis oocytes. Contrary to our expectation, the movement of gating charges is shifted to more hyperpolarized membrane potentials by E1784K. Voltage-clamp fluorimetry experiments show that this gating charge shift is due to the movement of the DIVS4 voltage-sensor being shifted to more hyperpolarized membrane potentials. Using a model and experiments on fast inactivation-deficient channels, we show that changes to the rate and voltage-dependence of fast inactivation are sufficient to shift the conductance curve in E1784K. Our results localize the effects of E1784K to DIVS4, and provide novel insight into the role of the DIV-VSD in regulating the voltage-dependencies of activation and fast inactivation. PMID:28898267

Depolarization of the conductance-voltage relationship in the NaV1.5 mutant, E1784K, is due to altered fast inactivation.

Directory of Open Access Journals (Sweden)

Colin H Peters

Full Text Available E1784K is the most common mixed long QT syndrome/Brugada syndrome mutant in the cardiac voltage-gated sodium channel NaV1.5. E1784K shifts the midpoint of the channel conductance-voltage relationship to more depolarized membrane potentials and accelerates the rate of channel fast inactivation. The depolarizing shift in the midpoint of the conductance curve in E1784K is exacerbated by low extracellular pH. We tested whether the E1784K mutant shifts the channel conductance curve to more depolarized membrane potentials by affecting the channel voltage-sensors. We measured ionic currents and gating currents at pH 7.4 and pH 6.0 in Xenopus laevis oocytes. Contrary to our expectation, the movement of gating charges is shifted to more hyperpolarized membrane potentials by E1784K. Voltage-clamp fluorimetry experiments show that this gating charge shift is due to the movement of the DIVS4 voltage-sensor being shifted to more hyperpolarized membrane potentials. Using a model and experiments on fast inactivation-deficient channels, we show that changes to the rate and voltage-dependence of fast inactivation are sufficient to shift the conductance curve in E1784K. Our results localize the effects of E1784K to DIVS4, and provide novel insight into the role of the DIV-VSD in regulating the voltage-dependencies of activation and fast inactivation.

Neonatal oxytocin manipulations have long-lasting, sexually dimorphic effects on vasopressin receptors.

Science.gov (United States)

Bales, K L; Plotsky, P M; Young, L J; Lim, M M; Grotte, N; Ferrer, E; Carter, C S

2007-01-05

Developmental exposure to oxytocin (OT) or oxytocin antagonists (OTAs) has been shown to cause long-lasting and often sexually dimorphic effects on social behaviors in prairie voles (Microtus ochrogaster). Because regulation of social behavior in monogamous mammals involves central receptors for OT, arginine vasopressin (AVP), and dopamine, we examined the hypothesis that the long-lasting, developmental effects of exposure to neonatal OT or OTA might reflect changes in the expression of receptors for these peptides. On postnatal day 1, prairie voles were injected intraperitoneally with either OT (1 mg/kg), an OTA (0.1 mg/kg), saline vehicle, or were handled only. At approximately 60 days of age, vasopressin V1a receptors, OT receptors (OTR) and dopamine D2 receptor binding were quantified using receptor autoradiography in brain tissue taken from males and females. Significant treatment effects on V1a binding were found in the bed nucleus of the stria terminalis (BNST), cingulate cortex (CgCtx), mediodorsal thalamus (MdThal), medial preoptic area of the hypothalamus (MPOA), and lateral septum (LS). The CgCtx, MPOA, ventral pallidum, and LS also showed significant sex by treatment interactions on V1a binding. No significant treatment or sex differences were observed for D2 receptor binding. No significant treatment difference was observed for OTR receptor binding, and only a marginal sex difference. Changes in the neuropeptide receptor expression, especially the V1a receptor, may help to explain sexually dimorphic changes in behavior that follow comparable neonatal manipulations.

Beam depolarization and gain saturation in neodymium rods with a diameter of 85 mm

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, V N; Ugodenko, A A

1990-04-01

Depolarization and gain saturation were investigated in rod amplifiers using phosphate and silicate Nd glasses 85 mm in diameter and 300 mm in length at a pulse duration of 35 ns. Total depolarization losses over the rod cross section were measured for various radial distributions of the small-signal gain. For the phosphate glass the losses amounted to 3-6 percent; for the silicate glass, they amounted to 4-7 percent. Saturation energy densities of 4.5 + or - 0.4 and 8.0 + or - 0.7 J/sq cm were obtained for the phosphate and silicate glass, respectively. 8 refs.

Depleted uranium hexafluoride management program : data compilation for the Paducah site

International Nuclear Information System (INIS)

Hartmann, H.

2001-01-01

This report is a compilation of data and analyses for the Paducah site, near Paducah, Kentucky. The data were collected and the analyses were done in support of the U.S. Department of Energy (DOE) 1999 Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted Uranium Hexafluoride (DOE/EIS-0269). The report describes the affected environment at the Paducah site and summarizes potential environmental impacts that could result from conducting the following depleted uranium hexafluoride (UF 6 ) activities at the site: continued cylinder storage, preparation of cylinders for shipment, conversion, and long-term storage. DOE's preferred alternative is to begin converting the depleted UF 6 inventory as soon as possible to either uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

Depleted uranium hexafluoride management program : data compilation for the Portsmouth site

International Nuclear Information System (INIS)

Hartmann, H. M.

2001-01-01

This report is a compilation of data and analyses for the Portsmouth site, near Portsmouth, Ohio. The data were collected and the analyses were done in support of the U.S. Department of Energy (DOE) 1999 Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted Uranium Hexafluoride (DOE/EIS-0269). The report describes the affected environment at the Portsmouth site and summarizes potential environmental impacts that could result from conducting the following depleted uranium hexafluoride (UF 6 ) management activities at the site: continued cylinder storage, preparation of cylinders for shipment, conversion, and long-term storage. DOE's preferred alternative is to begin converting the depleted UF 6 inventory as soon as possible to either uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster.

Science.gov (United States)

Trannoy, Séverine; Penn, Jill; Lucey, Kenia; Popovic, David; Kravitz, Edward A

2016-04-26

In many animal species, learning and memory have been found to play important roles in regulating intra- and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short- and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.

Quantum key distribution with several intercept-resend attacks via a depolarizing channel

International Nuclear Information System (INIS)

Dehmani, Mustapha; Errahmani, Mohamed; Ez-Zahraouy, Hamid; Benyoussef, Abdelilah

2012-01-01

The disturbance effect of a depolarizing channel on the security of the quantum key distribution of the four-state BB84 protocol, with multiple sequential intercept-resend attacks of many eavesdroppers, has been studied. The quantum bit error rate and the mutual information are computed for an arbitrary number N of eavesdroppers. It is found that the quantum error rate decreases with increasing the depolarizing parameter p characterizing the noise of the channel. For p tr of p below which the information is secure and otherwise the information is not secure. The value of p tr decreases with increasing the number of attacks. In contrast, for p ⩾ 0.165, the information is not secure independently of the number of eavesdroppers. Phase diagrams corresponding to the secure—unsecure information are also established. (paper)

Thermally stimulated depolarization currents in the natural fluorite

International Nuclear Information System (INIS)

Valerio, Mario Ernesto Giroldo

1986-01-01

The present work deals with natural calcium fluoride from Criciuma, Santa Catarina. Thermally Stimulated Depolarization Currents (TSDC) can be used to determine the properties of dipole defects present in this crystal. The TSDC spectrum of this material shows three bands in the temperature range of 80 to 450 K. The first one, at 130 K, is due the dipoles formed by a trivalent impurity and an interstitial fluorine ion in the next nearest position of an impurity ion (nn R s 3+ -F i - ). The second one, at 102 k, is due to the presence of small aggregates of dipoles (like a dimer). The last band, at 360 k is due to the formation of Large Clusters. The continuous distribution model gave the best fit for these bands with mean activation energies of 0.41 eV, 0.595 eV and 1.02 eV for the first, second and third band respectively. Thermal treatments can modify the number of dipoles, dimers and clusters present in the crystal. The variation in the areas under each band can be used to measure this effect. In this work we used thermal treatments between 15 minutes and 10 hours and temperatures between 200 deg C and 500 deg C. For thermal treatments at 300 deg C, the dipoles and dimers are created and the clusters are destroyed as the time of thermal treatment increases. At 400 deg C the clusters are created and the dipoles and dimers and 350 deg C for the clusters. (author)

Long-lasting antifog plasma modification of transparent plastics.

Science.gov (United States)

Di Mundo, Rosa; d'Agostino, Riccardo; Palumbo, Fabio

2014-10-08

Antifog surfaces are necessary for any application requiring optical efficiency of transparent materials. Surface modification methods aimed toward increasing solid surface energy, even when supposed to be permanent, in fact result in a nondurable effect due to the instability in air of highly hydrophilic surfaces. We propose the strategy of combining a hydrophilic chemistry with a nanotextured topography, to tailor a long-lasting antifog modification on commercial transparent plastics. In particular, we investigated a two-step process consisting of self-masked plasma etching followed by plasma deposition of a silicon-based film. We show that the deposition of the silicon-based coatings on the flat (pristine) substrates allows a continuous variation of wettability from hydrophobic to superhydrophilic, due to a continuous reduction of carbon-containing groups, as assessed by Fourier transform infrared and X-ray photoelectron spectroscopies. By depositing these different coatings on previously nanotextured substrates, the surface wettability behavior is changed consistently, as well as the condensation phenomenon in terms of microdroplets/liquid film appearance. This variation is correlated with advancing and receding water contact angle features of the surfaces. More importantly, in the case of the superhydrophilic coating, though its surface energy decreases with time, when a nanotextured surface underlies it, the wetting behavior is maintained durably superhydrophilic, thus durably antifog.

Scattering and depolarization of polarized neutrons in ferrofluids

International Nuclear Information System (INIS)

Balasoiu, M.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Y.V.

1999-01-01

On the SPN - 1 polarized neutron spectrometer at IBR -2 high - flux pulsed rector there were carried out preliminary measurements on transmission and polarization of a neutron beam passing through a magnetic colloidal system of Fe 3 O 4 particles in transformer oil and dodecane carriers. It was found that in the ferrofluids with magnetite particles exist, dependent on the particle volume concentration and the magnitude of the external magnetic field, effects of depolarization and nuclear - magnetic small angle scattering. (author)

Short term memory may be the depletion of the readily releasable pool of presynaptic neurotransmitter vesicles of a metastable long term memory trace pattern.

Science.gov (United States)

Tarnow, Eugen

2009-09-01

The Tagging/Retagging model of short term memory was introduced earlier (Tarnow in Cogn Neurodyn 2(4):347-353, 2008) to explain the linear relationship between response time and correct response probability for word recall and recognition: At the initial stimulus presentation the words displayed tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 s and to 20% after 220 s. If a probe word is reintroduced the tagging level has to return to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss. The tagging level is directly related to the probability of correct word recall and recognition. Evidence presented suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis). The pattern of depleted presynaptic terminals corresponds to the long term memory trace.

Blue photoluminescence and long lasting phosphorescence properties of a novel chloride phosphate phosphor: Sr5(PO4)3Cl:Eu2+

International Nuclear Information System (INIS)

Wu, Chuanqiang; Zhang, Jiachi; Feng, Pengfei; Duan, Yiming; Zhang, Zhiya; Wang, Yuhua

2014-01-01

A novel blue emitting long lasting phosphorescence phosphor Sr 5 (PO 4 ) 3 Cl:Eu 2+ is synthesized by solid state method at 1223 K in reducing atmosphere. The afterglow emission spectrum shows one broad band centered at 441 nm due to the 5d–4f transition of Eu 2+ at six coordinated Sr(II) sites and the color coordinates are calculated to be (0.149, 0.095) which is close to the light blue region. The excitation band is in 240–430 nm and partly overlaps the solar irradiation on Earth's surface. The long lasting phosphorescence of the optimal sample doping by 0.1 mol%Eu 2+ can be recorded for about 1040 s (0.32 mcd/m 2 ). Thermoluminescence shows that there are at least three types of traps corresponding to peaks at 340 K, 382 K, 500 K, respectively. The filling and fading experiments reveal that the traps in Sr 5 (PO 4 ) 3 Cl:Eu 2+ are independent. The shallow traps (340 K) essentially contribute to the visible long lasting phosphorescence, while the deep traps (382 K and 500 K) are proved to be very stable. Thus, the Sr 5 (PO 4 ) 3 Cl:Eu 2+ material shows potential applications as not only a long lasting phosphorescence phosphor, but also an optical storage material. -- Highlights: • The blue long lasting phosphorescence of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is first reported. • Filling and fading experiments are carried out for revealing natures of traps. • The afterglow mechanism for independent traps of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is proposed

Low-frequency stimulation cancels the high-frequency-induced long-lasting effects in the rat medial vestibular nuclei.

Science.gov (United States)

Grassi, S; Pettorossi, V E; Zampolini, M

1996-05-15

In rat brainstem slices, we investigated the effects of low-frequency stimulation (LFS) of the primary vestibular afferents on the amplitude of the field potentials evoked in the medial vestibular nuclei (MVN). LFS induced long-term effects, the sign of which depended on whether the vestibular neurons were previously conditioned by HFS. In unconditioned slices, LFS evoked modifications of the responses that were similar to those observed after HFS but had a smaller extension. In fact, LFS caused long-lasting potentiation of the N1 wave in the MVN ventral portion (Vp) and long-lasting depression of the N2 wave in the MVN dorsal portion (Dp), whereas it provoked small and variable effects on the N1 wave. By contrast, when the synaptic transmission was already conditioned, LFS influenced the synaptic responses oppositely, reducing or annulling the HFS long-term effects. This phenomenon was specifically induced by LFS, because HFS was not able to cause it. The involvement of NMDA receptors in mediating the LFS long-term effects was supported by the fact that AP-5 prevented their induction. In addition, the annulment of HFS long-term effects by LFS was also demonstrated by the shift in the latency of the evoked unitary potentials after LFS. In conclusion, we suggest that the reduction of the previously induced conditioning could represent a cancellation mechanism, useful to quickly adapt the vestibular system to continuous different needs and to avoid saturation.

A stochastic model of depolarization enhancement due to large energy spread in electron storage rings

International Nuclear Information System (INIS)

Buon, J.

1988-10-01

A new semiclassical and stochastic model of spin diffusion is used to obtain numerical predictions for depolarization enhancement due to beam energy spread. It confirms the results of previous models for the synchrotron sidebands of isolated spin resonances. A satisfactory agreement is obtained with the width of a synchrotron satellite observed at SPEAR. For HERA and LEP, at Z 0 energy, the depolarization enhancement is of the order of a few units and increases very rapidly with the energy spread. Large reduction of polarization degree is expected in these rings

Analytic calculation of depolarization due to large energy spread in high-energy electron storage rings

International Nuclear Information System (INIS)

Buon, J.

1989-08-01

A new semiclassical and stochastic model of spin diffusion is used to obtain numerical predictions for depolarization enhancement due to beam energy spread. It confirms the results of previous models for the synchrotron sidebands of spin resonances. A satisfactory agreement is obtained with the width of a synchrotron satellite observed at SPEAR. For HERA, TRISTAN, and LEP at Z 0 energy, the depolarization enhancement is of the order of a few units and increases very rapidly with the energy spread. Large reduction of polarization degree is expected in these rings

On the polarization and depolarization of the electromagnetic waves

International Nuclear Information System (INIS)

Borghese, Ferdinando; Denti, Paolo; Saija, Rosalba; Cecchi-Pestellini, Cesare

2005-01-01

We discuss a general description of the polarization of monochromatic electromagnetic waves that proves useful when the customary description in terms of Stokes parameters does not apply. We also show how this description can be exploited to study the depolarization of linearly polarized waves in the interior of porous model cosmic dust grains. The results that we discuss may affect our understanding of several problems that are relevant for astrobiology

Depolarization-dependent 45Ca uptake by synaptosomes of rat cerebral cortex is enhanced by L-triiodothyronine

International Nuclear Information System (INIS)

Mason, G.A.; Walker, C.H.; Prange, A.J. Jr.

1990-01-01

Depolarization-induced release of neurotransmitters and other secretions from nerve endings is triggered by the rapid entry of Ca++ through voltage-sensitive channels. Calcium entry is thought to occur in two distinct phases or processes: a fast-phase response to an action potential, which initiates release; and a slow phase associated with extended stimulation of the neuron. Thyroid hormones are sequestered by nerve terminals and can produce changes in behaviour and mood. They may therefore be involved in modulating central synaptic transmission. We studied the effects of L-triiodothyronine (T3), L-thyroxine (T4), reverse T3 (rT3) and D-T3 on depolarization-induced uptake of 45Ca by synaptosomes from euthyroid and hypothyroid rats. T3, but not T4, rT3, or D-T3 significantly enhanced depolarization-induced 45Ca uptake at physiologically relevant (1 to 10 nmol/L) concentrations. The stimulatory effect of 10 nmol/L T3 on depolarization-induced uptake after 2 seconds (21%) was greater than after 5 (10%) or 30 (8%) seconds, indicating that T3 enhanced primarily the fast-phase process. There was no effect of T3 or other hormones tested on nondepolarization-induced 45Ca uptake. Preincubation of synaptosomes with T3 prior to depolarization did not enhance the effect of T3; in fact, preincubations of 30 seconds or more resulted in diminished T3 effects. Preincubation of synaptosomes for 15 seconds with D-T3 or the addition of D-T3 and T3 together reduced the effect of T3. We found no difference in the effect of T3 on 45Ca uptake by synaptosomes from euthyroid and hypothyroid rats. These results suggest a novel mechanism of action of thyroid hormones in the brain

Long lasting clinical response to chemotherapy for advanced uterine leiomyosarcoma: a case report

Directory of Open Access Journals (Sweden)

Ridolfi Claudio

2013-01-01

Full Text Available Abstract Introduction Uterine leiomyosarcoma is one of the most frequent uterine sarcomas. In the metastatic setting it is sensitive to doxorubicin, ifosfamide, gemcitabine, docetaxel and a few other drugs, but time to progression is generally short. For this reason prognosis is often poor and there are few reports in the literature of long responders. Case presentation We report a case of a 40-year-old Caucasian woman with metastatic uterine leiomyosarcoma who began treatment six years before the presentation of this case report and for the following six years underwent ten lines of chemotherapy, achieving excellent results and a good quality of life. Among the treatments administered we observed a long response to temolozomide, an unconventional drug for this kind of disease. Conclusion Although there are few chemotherapeutic options for the management of metastatic uterine leiomyosarcoma, a small number of patients have an unexpected long lasting response to treatment. For this reason further research is needed to identify new therapeutic agents and the predictive factors for the achievement of response.

Effects of in vitro hypoxia on depolarization-stimulated accumulation of inositol phosphates in synaptosomes

International Nuclear Information System (INIS)

Huang, H.M.; Gibson, G.E.

1989-01-01

The effects of potassium and in vitro histotoxic hypoxia on phosphatidylinositol turnover in rat cortical synaptosomes were determined. [2- 3 H] Inositol prelabelled rat synaptosomes were prepared from cerebral cortex slices that had been incubated with [2- 3 H] inositol. Depolarization with 60 mM KCl increased [2- 3 H] inositol phosphates in a time dependent manner. Depolarization with 60 mM KCl increased [2- 3 H]inositol trisphosphate transiently at 5 s. K + induced rapid formation of [2- 3 H] inositol monophosphate with time. One minute of hypoxia enhance sium-stimulate [2 3 H]inositol bisphosphate and maintained an elevated level for at least 5 min. K + stimulated gradual formation of [2- 3 H] inositol monophosphate with time. One minute of hypoxia enhanced potassium-stimulated [2- 3 H] inositol bisphosphate formation. However, 30 min of hypoxia impaired potassium-stimulated accumulation of [2- 3 H]inositol phosphates. The effects of histotoxic hypoxia were all dependent upon calcium in the medium and on K + -depolarization. Thus, hypoxia altered the K + induced accumulation of inositol phosphates in prelabelled synaptosomes in a time dependent, biphasic manner that was calcium dependent

Preliminary evidence that ketamine inhibits spreading depolarizations in acute human brain injury

DEFF Research Database (Denmark)

Sakowitz, Oliver W; Kiening, Karl L; Krajewski, Kara L

2009-01-01

by the noncompetitive N-methyl-d-aspartate receptor antagonist ketamine. This restored electrocorticographic activity. CONCLUSIONS: These anecdotal electrocorticographic findings suggest that ketamine has an inhibitory effect on spreading depolarizations in humans. This is of potential interest for future...

Thermally stimulated depolarization currents in ThO2

International Nuclear Information System (INIS)

Campos, L.L.

1979-01-01

Thermally Stimulated Depolarization Currents (TSDC) have been detected in polycrystalline samples of ThO 2 in the temperature range 100K - 350K. The induced polarization is found to be due to migration of charge carriers over microscopic distances with trapping at grain boundaries. Moreover the density of charges carriers released from trapping sites, upon heating the cooled previously dc biased specimen, decreases for increasing sintering temperature, suggesting the use of the technique to the study of grain growth in the bulk of ceramic nuclear oxides [pt

Analysis of spin depolarizing effects in electron storage rings

International Nuclear Information System (INIS)

Boege, M.

1994-05-01

In this thesis spin depolarizing effects in electron storage rings are analyzed and the depolarizing effects in the HERA electron storage ring are studied in detail. At high beam energies the equilibrium polarization is limited by nonlinear effects. This will be particularly true in the case of HERA, when the socalled ''spin rotators'' are inserted which are designed to provide longitudinal electron polarization for the HERMES experiment in 1994 and later for the H1 and ZEUS experiment. It is very important to quantify the influence of these effects theoretically by a proper modelling of HERA, so that ways can be found to get a high degree of polarization in the real machine. In this thesis HERA is modelled by the Monte-Carlo tracking program SITROS which was originally written by J. Kewisch in 1982 to study the polarization in PETRA. The first part of the thesis is devoted to a detailed description of the fundamental theoretical concepts on which the program is based. Then the approximations which are needed to overcome computing time limitations are explained and their influence on the simulation result is discussed. The systematic and statistical errors are studied in detail. Extensions of the program which allow a comparison of SITROS with the results given by ''linear'' theory are explained. (orig.)

Measurements of Radioactive Contamination In Kosovo Battlefields Due to the Use of Depleted Uranium Weapons by NATO Forces

International Nuclear Information System (INIS)

Zucchetti, M.

1999-01-01

During the last war in the Balkan area (Kosovo-Serbia War, spring-summer 1999), NATO forces admitted the use of weapons containing Depleted Uranium. In particular, 30 mm bullets being fired by A-10 anti-tank aircraft and probably all Tomahawk Cruise missiles in this action contain depleted uranium

Depolarization Rayleigh scattering as a means of molecular concentration determination in plasmas

NARCIS (Netherlands)

Meulenbroeks, R.F.G.; Schram, D.C.; Jaegers, L.J.M.; Sanden, van de M.C.M.

1992-01-01

The difference in polarization for Rayleigh scattered radiation on spherically and nonspherically symmetric scattering objects has been used to obtain molecular species concentrations in plasmas of simple composition. Using a Rayleigh scattering diagnostic, the depolarized component of the scattered

Neutron depolarization measurements of HoCo2 near the magnetic phase transition

International Nuclear Information System (INIS)

Kraan, W.

1976-09-01

The magnetic phase transition in HoCo 2 at zero applied field is investigated. The Landau theory of magnetic phase transition is discussed. The experimental technique for neutron depolarization measurements in the temperature range 65-90 K is described

Sensibility analysis of fuel depletion using different nuclear fuel depletion codes

Energy Technology Data Exchange (ETDEWEB)

Martins, F.; Velasquez, C.E.; Castro, V.F.; Pereira, C.; Silva, C. A. Mello da, E-mail: felipmartins94@gmail.com, E-mail: carlosvelcab@hotmail.com, E-mail: victorfariascastro@gmail.com, E-mail: claubia@nuclear.ufmg.br, E-mail: clarysson@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

Nowadays, the utilization of different nuclear codes to perform the depletion and criticality calculations has been used to simulated nuclear reactors problems. Therefore, the goal is to analyze the sensibility of the fuel depletion of a PWR assembly using three different nuclear fuel depletion codes. The burnup calculations are performed using the codes MCNP5/ORIGEN2.1 (MONTEBURNS), KENO-VI/ORIGEN-S (TRITONSCALE6.0) and MCNPX (MCNPX/CINDER90). Each nuclear code performs the burnup using different depletion codes. Each depletion code works with collapsed energies from a master library in 1, 3 and 63 groups, respectively. Besides, each code uses different ways to obtain neutron flux that influences the depletions calculation. The results present a comparison of the neutronic parameters and isotopes composition such as criticality and nuclides build-up, the deviation in results are going to be assigned to features of the depletion code in use, such as the different radioactive decay internal libraries and the numerical method involved in solving the coupled differential depletion equations. It is also seen that the longer the period is and the more time steps are chosen, the larger the deviation become. (author)

Sensibility analysis of fuel depletion using different nuclear fuel depletion codes

International Nuclear Information System (INIS)

Martins, F.; Velasquez, C.E.; Castro, V.F.; Pereira, C.; Silva, C. A. Mello da

2017-01-01

Nowadays, the utilization of different nuclear codes to perform the depletion and criticality calculations has been used to simulated nuclear reactors problems. Therefore, the goal is to analyze the sensibility of the fuel depletion of a PWR assembly using three different nuclear fuel depletion codes. The burnup calculations are performed using the codes MCNP5/ORIGEN2.1 (MONTEBURNS), KENO-VI/ORIGEN-S (TRITONSCALE6.0) and MCNPX (MCNPX/CINDER90). Each nuclear code performs the burnup using different depletion codes. Each depletion code works with collapsed energies from a master library in 1, 3 and 63 groups, respectively. Besides, each code uses different ways to obtain neutron flux that influences the depletions calculation. The results present a comparison of the neutronic parameters and isotopes composition such as criticality and nuclides build-up, the deviation in results are going to be assigned to features of the depletion code in use, such as the different radioactive decay internal libraries and the numerical method involved in solving the coupled differential depletion equations. It is also seen that the longer the period is and the more time steps are chosen, the larger the deviation become. (author)

Long-lasting effects of maternal condition in free-ranging cervids.

Directory of Open Access Journals (Sweden)

Eric D Freeman

Full Text Available Causes of phenotypic variation are fundamental to evolutionary ecology because they influence the traits acted upon by natural selection. One such cause of phenotypic variation is a maternal effect, which is the influence of the environment experienced by a female (and her corresponding phenotype on the phenotype of her offspring (independent of the offspring's genotype. While maternal effects are well documented, the longevity and fitness impact of these effects remains unclear because it is difficult to follow free-living individuals through their reproductive lifetimes. For long-lived species, it has been suggested that maternal effects are masked by environmental variables acting on offspring in years following the period of dependence. Our objective was to use indirect measures of maternal condition to determine if maternal effects have long-lasting influences on male offspring in two species of cervid. Because antlers are sexually selected, we used measures of antler size at time of death, 1.5-21.5 years after gestation to investigate maternal effects. We quantified antler size of 11,000 male elk and mule deer born throughout the intermountain western US (6 states over nearly 30 years. Maternal condition during development was estimated indirectly using a suite of abiotic variables known to influence condition of cervids (i.e., winter severity, spring and summer temperature, and spring and summer precipitation. Antler size of male cervids was significantly associated with our indirect measure of maternal condition during gestation and lactation. Assuming the correctness of our indirect measure, our findings demonstrate that antler size is a sexually selected trait that is influenced-into adulthood-by maternal condition. This link emphasizes the importance of considering inherited environmental effects when interpreting population dynamics or examining reproductive success of long-lived organisms.

Weaver mutant mouse cerebellar granule cells respond normally to chronic depolarization

DEFF Research Database (Denmark)

Bjerregaard, Annette; Mogensen, Helle Smidt; Hack, N

1997-01-01

We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G prote...

"When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect.

Science.gov (United States)

Salmon, Stefanie J; Adriaanse, Marieke A; De Vet, Emely; Fennis, Bob M; De Ridder, Denise T D

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

When the Going Gets Tough, Who Keeps Going? Depletion Sensitivity Moderates the Ego-Depletion Effect

Directory of Open Access Journals (Sweden)

Stefanie J. Salmon

2014-06-01

Full Text Available Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

Orexins depolarize rostral ventrolateral medulla neurons and increase arterial pressure and heart rate in rats mainly via orexin 2 receptors.

Science.gov (United States)

Huang, Shang-Cheng; Dai, Yu-Wen E; Lee, Yen-Hsien; Chiou, Lih-Chu; Hwang, Ling-Ling

2010-08-01

An injection of orexin A or B into the cisterna magna or the rostral ventrolateral medulla (RVLM), where bulbospinal vasomotor neurons are located, elevated arterial pressure (AP) and heart rate (HR). We examined how orexins affected RVLM neurons to regulate cardiovascular functions by using in vitro recordings of neuronal activity of the RVLM and in vivo measurement of cardiovascular functions in rats. Orexin A and B concentration-dependently depolarized RVLM neurons. At 100 nM, both peptides excited 42% of RVLM neurons. Tetrodotoxin failed to block orexin-induced depolarization. In the presence of N-(2-methyl-6-benzoxazolyl)-N'-1, 5-naphthyridin-4-yl urea (SB-334867), an orexin 1 receptor (OX(1)R) antagonist, orexin A depolarized 42% of RVLM neurons with a smaller, but not significantly different, amplitude (4.9 +/- 0.8 versus 7.2 +/- 1.1 mV). In the presence of (2S)-1- (3,4-dihydro-6,7-dimethoxy-2(1H)-isoquinolinyl)-3,3-dimethyl-2-[(4-pyridinylmethyl)amino]-1-butanone hydrochloride (TCS OX2 29), an orexin 2 receptor (OX(2)R) antagonist, orexin A depolarized 25% of RVLM neurons with a significantly smaller amplitude (1.7 +/- 0.5 mV). Coapplication of both antagonists completely eliminated orexin A-induced depolarization. An OX(2)R agonist, [Ala(11),D-Leu(15)]-orexin B, concentration-dependently depolarized RVLM neurons. Regarding neuronal phenotypes, orexins depolarized 88% of adrenergic, 43% of nonadrenergic, and 36 to 41% of rhythmically firing RVLM neurons. Intracisternal TCS OX2 29 (3 and 10 nmol) suppressed intracisternal orexin A-induced increases of AP and HR, whereas intracisternal SB-334867 (3 and 10 nmol) had no effect on the orexin A-induced increase of HR but suppressed the orexin A-induced pressor response at 10 nmol. We concluded that orexins directly excite RVLM neurons, which include bulbospinal vasomotor neurons, and regulate cardiovascular function mainly via the OX(2)R, with a smaller contribution from the OX(1)R.

Prediction of performance in Vasaloppet through long lasting ski- ergometer and rollerski tests in cross-country skiers

DEFF Research Database (Denmark)

Mygind, Erik; Wulff, Kristian; Jensen, Mads Rosenkilde

2015-01-01

-ergometer and Rollerski field tests correlate strongly with performance in Vasaloppet and therefore might be useful test tools for recreational skiers who wish to participate in long lasting c-c competitions. Keywords: Cross-country ski training, Upper body, Exercise intensity, Field test, Body composition blood lactate......The main purpose was to investigate if long lasting cross-country (c-c) test procedures could predict performance time in ‘Vasaloppet’ and secondly the effect of a 16 weeks training period on a 90 min double poling performance test. 24 moderate trained c-c skiers participated in the study...... and completed Vasaloppet. All skiers carried out pre and post training tests in a 90 minutes ski-ergometer double poling test and a 120 minutes rollerski field test on a closed paved circuit. 19 skiers provided detailed training logs that could sufficiently establish their training preparation for Vasaloppet...

Cdk7 Is Required for Activity-Dependent Neuronal Gene Expression, Long-Lasting Synaptic Plasticity and Long-Term Memory

Directory of Open Access Journals (Sweden)

Guiqin He

2017-11-01

Full Text Available In the brain, de novo gene expression driven by learning-associated neuronal activities is critical for the formation of long-term memories. However, the signaling machinery mediating neuronal activity-induced gene expression, especially the rapid transcription of immediate-early genes (IEGs remains unclear. Cyclin-dependent kinases (Cdks are a family of serine/threonine kinases that have been firmly established as key regulators of transcription processes underling coordinated cell cycle entry and sequential progression in nearly all types of proliferative cells. Cdk7 is a subunit of transcriptional initiation factor II-H (TFIIH and the only known Cdk-activating kinase (CAK in metazoans. Recent studies using a novel Cdk7 specific covalent inhibitor, THZ1, revealed important roles of Cdk7 in transcription regulation in cancer cells. However, whether Cdk7 plays a role in the regulation of transcription in neurons remains unknown. In this study, we present evidence demonstrating that, in post-mitotic neurons, Cdk7 activity is positively correlated with neuronal activities in cultured primary neurons, acute hippocampal slices and in the brain. Cdk7 inhibition by THZ1 significantly suppressed mRNA levels of IEGs, selectively impaired long-lasting synaptic plasticity induced by 4 trains of high frequency stimulation (HFS and prevented the formation of long-term memories.

Depolarization-dependent sup 45 Ca uptake by synaptosomes of rat cerebral cortex is enhanced by L-triiodothyronine

Energy Technology Data Exchange (ETDEWEB)

Mason, G.A.; Walker, C.H.; Prange, A.J. Jr. (Univ. of North Carolina, Chapel Hill (USA))

1990-08-01

Depolarization-induced release of neurotransmitters and other secretions from nerve endings is triggered by the rapid entry of Ca++ through voltage-sensitive channels. Calcium entry is thought to occur in two distinct phases or processes: a fast-phase response to an action potential, which initiates release; and a slow phase associated with extended stimulation of the neuron. Thyroid hormones are sequestered by nerve terminals and can produce changes in behaviour and mood. They may therefore be involved in modulating central synaptic transmission. We studied the effects of L-triiodothyronine (T3), L-thyroxine (T4), reverse T3 (rT3) and D-T3 on depolarization-induced uptake of 45Ca by synaptosomes from euthyroid and hypothyroid rats. T3, but not T4, rT3, or D-T3 significantly enhanced depolarization-induced 45Ca uptake at physiologically relevant (1 to 10 nmol/L) concentrations. The stimulatory effect of 10 nmol/L T3 on depolarization-induced uptake after 2 seconds (21%) was greater than after 5 (10%) or 30 (8%) seconds, indicating that T3 enhanced primarily the fast-phase process. There was no effect of T3 or other hormones tested on nondepolarization-induced 45Ca uptake. Preincubation of synaptosomes with T3 prior to depolarization did not enhance the effect of T3; in fact, preincubations of 30 seconds or more resulted in diminished T3 effects. Preincubation of synaptosomes for 15 seconds with D-T3 or the addition of D-T3 and T3 together reduced the effect of T3. We found no difference in the effect of T3 on 45Ca uptake by synaptosomes from euthyroid and hypothyroid rats. These results suggest a novel mechanism of action of thyroid hormones in the brain.

Barium depletion in hollow cathode emitters

International Nuclear Information System (INIS)

Polk, James E.; Mikellides, Ioannis G.; Katz, Ira; Capece, Angela M.

2016-01-01

Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al 2 O 3 source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values

Meta-analysis of depleted uranium levels in the Balkan region.

Science.gov (United States)

Besic, Larisa; Muhovic, Imer; Asic, Adna; Kurtovic-Kozaric, Amina

2017-06-01

In recent years, contradicting data has been published on the connection between the presence of depleted uranium and an increased cancer incidence among military personnel deployed in the Balkans during the 1992-1999 wars. This has led to numerous research articles investigating possible depleted uranium contamination of the afflicted regions of the Balkan Peninsula, namely Bosnia & Herzegovina, Serbia, Kosovo and Montenegro. The aim of this study was to collect data from previously published reports investigating the levels of depleted uranium in the Balkans and to present the data in the form of a meta-analysis. This would provide a clear image of the extent of depleted uranium contamination after the Balkan conflict. In addition, we tested the hypothesis that there is a correlation between the levels of depleted uranium and the assumed depleted uranium-related health effects. Our results suggest that the majority of the examined sites contain natural uranium, while the area of Kosovo appears to be most heavily afflicted by depleted uranium pollution, followed by Bosnia & Herzegovina. Furthermore, the results indicate that it is not possible to make a valid correlation between the health effects and depleted uranium-contaminated areas. We therefore suggest a structured collaborative plan of action where long-term monitoring of the residents of depleted uranium-afflicted areas would be performed. In conclusion, while the possibility of depleted uranium toxicity in post-conflict regions appears to exist, there currently exists no definitive proof of such effects, due to insufficient studies of potentially afflicted populations, in addition to the lack of a common epidemiological approach in the reviewed literature. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of astrocytes in depolarization-coupled release of glutamate in cerebellar cultures

DEFF Research Database (Denmark)

Bak, Lasse K; Waagepetersen, Helle S; Schousboe, Arne

2004-01-01

Release of preloaded D-[3H]aspartate in response to depolarization induced by high potassium, N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) or the endogenous agonist glutamate was studied using cultured glutamatergic cerebellar granule neurons, cerebell...

Normal chemotaxis in Dictyostelium discoideum cells with a depolarized plasma membrane potential

NARCIS (Netherlands)

Duijn, Bert van; Vogelzang, Sake A.; Ypey, Dirk L.; Molen, Loek G. van der; Haastert, Peter J.M. van

1990-01-01

We examined a possible role for the plasma membrane potential in signal transduction during cyclic AMP-induced chemotaxis in the cellular slime mold Dictyostelium discoideum. Chemotaxis, cyclic GMP and cyclic AMP responses in cells with a depolarized membrane potential were measured. Cells can be

Depolarization ratio of polar stratospheric clouds in coastal Antarctica: comparison analysis between ground-based Micro Pulse Lidar and space-borne CALIOP observations

Directory of Open Access Journals (Sweden)

C. Córdoba-Jabonero

2013-03-01

Full Text Available Polar stratospheric clouds (PSCs play an important role in polar ozone depletion, since they are involved in diverse ozone destruction processes (chlorine activation, denitrification. The degree of that ozone reduction is depending on the type of PSCs, and hence on their occurrence. Therefore PSC characterization, mainly focused on PSC-type discrimination, is widely demanded. The backscattering (R and volume linear depolarization (δV ratios are the parameters usually used in lidar measurements for PSC detection and identification. In this work, an improved version of the standard NASA/Micro Pulse Lidar (MPL-4, which includes a built-in depolarization detection module, has been used for PSC observations above the coastal Antarctic Belgrano II station (Argentina, 77.9° S 34.6° W, 256 m a.s.l. since 2009. Examination of the MPL-4 δV feature as a suitable index for PSC-type discrimination is based on the analysis of the two-channel data, i.e., the parallel (p- and perpendicular (s- polarized MPL signals. This study focuses on the comparison of coincident δV-profiles as obtained from ground-based MPL-4 measurements during three Antarctic winters with those reported from the space-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite in the same period (83 simultaneous cases are analysed for 2009–2011 austral winter times. Three different approaches are considered for the comparison analysis between both lidar profile data sets in order to test the degree of agreement: the correlation coefficient (CC, as a measure of the relationship between both PSC vertical structures; the mean differences together with their root mean square (RMS values found between data sets; and the percentage differences (BIAS, parameter also used in profiling comparisons between CALIOP and other ground-based lidar systems. All of them are examined as a function

Isoflurane depolarizes bronchopulmonary C neurons by inhibiting transient A-type and delayed rectifier potassium channels.

Science.gov (United States)

Zhang, Zhenxiong; Zhuang, Jianguo; Zhang, Cancan; Xu, Fadi

2013-04-01

Inhalation of isoflurane (ISO), a widely used volatile anesthetic, can produce clinical tachypnea. In dogs, this response is reportedly mediated by bronchopulmonary C-fibers (PCFs), but the relevant mechanisms remain unclear. Activation of transient A-type potassium current (IA) channels and delayed rectifier potassium current (IK) channels hyperpolarizes neurons, and inhibition of both channels by ISO increases neural firing. Due to the presence of these channels in the cell bodies of rat PCFs, we determined whether ISO could stimulate PCFs to produce tachypnea in anesthetized rats, and, if so, whether this response resulted from ISO-induced depolarization of the pulmonary C neurons via the inhibition of IA and IK. We recorded ventilatory responses to 5% ISO exposure in anesthetized rats before and after blocking PCF conduction and the responses of pulmonary C neurons (extracellularly recorded) to ISO exposure. ISO-induced (1mM) changes in pulmonary C neuron membrane potential and IA/IK were tested using the perforated patch clamp technique. We found that: (1) ISO inhalation evoked a brief tachypnea (∼7s) and that this response disappeared after blocking PCF conduction; (2) the ISO significantly elevated (by 138%) the firing rate of most pulmonary C neurons (17 out of 21) in the nodose ganglion; and (3) ISO perfusion depolarized the pulmonary C neurons in the vitro and inhibited both IA and IK, and this evoked-depolarization was largely diminished after blocking both IA and IK. Our results suggest that ISO is able to stimulate PCFs to elicit tachypnea in rats, at least partly, via inhibiting IA and IK, thereby depolarizing the pulmonary C neurons. Copyright © 2013. Published by Elsevier B.V.

The 2003 Update of the ASPO Oil and Gas Depletion Model

Energy Technology Data Exchange (ETDEWEB)

Campbell, Colin; Sivertsson, Anders [Uppsala Univ. (Sweden). Hydrocarbon Depletion Study Group

2003-07-01

What we can term the ASPO Oil and Gas Depletion Model has developed over many years, based on an evolving knowledge of the resource base, culled from many sources, and evolving ideas about how to model depletion. It is sure that the estimates and forecasts are incorrect. The question is: By how much? The model recognises so-called Regular Oil, which excludes the following categories: Oil from coal and shale; Bitumen and synthetics derived therefrom; Extra Heavy Oil (<10 deg API); Heavy Oil (10-17 deg API); Deepwater Oil (>500 m); Polar Oil; Liquids from gas fields and gas plants. It has provided most oil to-date and will dominate all supply far into the future. Its depletion therefore determines the date of peak. The evidence suggests that about 896 Gb (billion barrels) had been produced to end 2002; about 871 Gb remain to produce from known fields and about 113 Gb is expected to be produced from new fields. It is convenient to set a cut-off of, say 2075, for such production, to avoid having to worry about the tail end that can drag on for a long time. A simple depletion model assumes that production declines at the current Depletion Rate (annual production as a percentage of future production) or at the Midpoint Rate in countries that have not yet reached Midpoint (namely half the total). The five main Middle East producers, which hold about half of what remains, are assumed to exercise a swing role, making up the difference between world demand and what the other countries can supply. The base case scenario assumes that consumption will be on average flat until 2010 because of recession; and that the Middle East swing role will end then, as in practice those countries will no longer have the capacity to discharge it. Whether the Iraq war results in extending or shortening the swing role remains to be seen. Adding the contributions of the other categories of oil and gas liquids gives an overall peak in 2010. Gas depletes differently, being more influenced by

The 2003 Update of the ASPO Oil and Gas Depletion Model

Energy Technology Data Exchange (ETDEWEB)

Campbell, Colin; Sivertsson, Anders [Uppsala Univ. (Sweden). Hydrocarbon Depletion Study Group

2003-07-01

What we can term the ASPO Oil and Gas Depletion Model has developed over many years, based on an evolving knowledge of the resource base, culled from many sources, and evolving ideas about how to model depletion. It is sure that the estimates and forecasts are incorrect. The question is: By how much? The model recognises so-called Regular Oil, which excludes the following categories: Oil from coal and shale; Bitumen and synthetics derived therefrom; Extra Heavy Oil (<10 deg API); Heavy Oil (10-17 deg API); Deepwater Oil (>500 m); Polar Oil; Liquids from gas fields and gas plants. It has provided most oil to-date and will dominate all supply far into the future. Its depletion therefore determines the date of peak. The evidence suggests that about 896 Gb (billion barrels) had been produced to end 2002; about 871 Gb remain to produce from known fields and about 113 Gb is expected to be produced from new fields. It is convenient to set a cut-off of, say 2075, for such production, to avoid having to worry about the tail end that can drag on for a long time. A simple depletion model assumes that production declines at the current Depletion Rate (annual production as a percentage of future production) or at the Midpoint Rate in countries that have not yet reached Midpoint (namely half the total). The five main Middle East producers, which hold about half of what remains, are assumed to exercise a swing role, making up the difference between world demand and what the other countries can supply. The base case scenario assumes that consumption will be on average flat until 2010 because of recession; and that the Middle East swing role will end then, as in practice those countries will no longer have the capacity to discharge it. Whether the Iraq war results in extending or shortening the swing role remains to be seen. Adding the contributions of the other categories of oil and gas liquids gives an overall peak in 2010. Gas depletes differently, being more influenced by

Depletion of long-acting ampicillin in goat milk following intramuscular administration.

Science.gov (United States)

Ferrini, Anna Maria; Trenta, Simona; Mannoni, Veruscka; Rosati, Remo; Coni, Ettore

2010-12-08

Although goat milk production represents today a very small percentage of the world milk market, this percentage has been growing continuously during the past 20 years. Goat milk is the basic milk supply in many developing countries and provides tasteful derivative products in developed countries. Goats, as well as all milk-producing animals, can be affected by mastitis, but goats being considered a minor species, few drugs are specifically registered for these animals; most, at least for mastitis treatment, are usually tested and registered for use in cows. This situation leads often to the adoption for goat milk of withdrawal periods defined for cows even if these extrapolations prove almost never valid for goats. In the present study, the elimination of the β-lactam antibacterial agent ampicillin in goat milk was investigated. Ampicillin was chosen because it is one of the most common antibiotics used by goat farmers against mastitis due to the fact that it is well tolerated and has short elimination times in cows. Goats were treated with long-acting ampicillin at 15 mg (kg of body weight)(-1) by double intramuscular injection at 72 h interval. Milk was collected in a 12 h milking scheme. The method used to determine the levels of ampicillin in goat milk was based on a liquid-liquid extraction of this drug from the matrix, successive derivatization with formaldehyde, and final separation by HPLC with fluorescence detection. The results point out a slow depletion of ampicillin and, consequently, a withdrawal period (13 milkings) longer than that extrapolated and authorized for cows and sheep.

Retrospective attention in short-term memory has a lasting effect on long-term memory across age.

Science.gov (United States)

Strunk, Jonathan; Morgan, Lauren; Reaves, Sarah; Verhaeghen, Paul; Duarte, Audrey

2018-04-13

Declines in both short- and long-term memory are typical of healthy aging. Recent findings suggest that retrodictive attentional cues ("retro-cues") that indicate the location of to-be-probed items in short-term memory (STM) have a lasting impact on long-term memory (LTM) performance in young adults. Whether older adults can also use retro-cues to facilitate both STM and LTM is unknown. Young and older adults performed a visual STM task in which spatially informative retro-cues or non-informative neutral-cues were presented during STM maintenance of real-world objects. We tested participants' memory at both STM and LTM delays for objects that were previously cued with retrodictive or neutral cues during STM order to measure the lasting impact of retrospective attention on LTM. Older adults showed reduced STM and LTM capacity compared to young adults. However, they showed similar magnitude retro-cue memory benefits as young adults at both STM and LTM delays. To the best of our knowledge, this is the first study to investigate whether retro-cues in STM facilitate the encoding of objects into LTM such that they are more likely to be subsequently retrieved by older adults. Our results support the idea that retrospective attention can be an effective means by which older adults can improve their short and long-term memory performance, even in the context of reduced memory capacity.

Fabrication of flower-like tin/carbon composite microspheres as long-lasting anode materials for lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Kang, Tae-Woo [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Lim, Hyung-Seok [Department of WCU Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Park, Seong-Jin [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Sun, Yang-Kook [Department of WCU Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Suh, Kyung-Do, E-mail: kdsuh@hanyang.ac.kr [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of)

2017-01-01

In this work, we report the fabrication of the flower-like tin/carbon (Sn/C) composite microspheres using sulfonated semi-interpenetrating polystyrene (SPS) microspheres as a carbon precursor. The sulfonation degree of SPS has great effects on the resulting particle size, morphology, amount of introduced Sn, and the carbonization yield of the microspheres after heat treatment. The obtained Sn/C composite microspheres were characterized by scanning electron microscopy (SEM), focused-ion beam SEM, and X-ray diffraction. The flower-like Sn/C composite electrodes exhibited higher charge-discharge capacities than those of graphite as an anode material for a lithium ion battery. In addition, they show a long lasting cyclability, even through 400 cycles. - Highlights: • Tin nanocrystals are introduced in flower-like carbon spheres with many ripples. • Long lasting cyclability is exhibited at 1 C rate up to 400 cycles. • Tin content of composite spheres depends on chemical treatment of polymer microspheres.

Neutron depolarization study of static and dynamic magnetic properties of ferromagnets

International Nuclear Information System (INIS)

Stuesser, N.

1986-01-01

In this thesis neutron depolarization experiments are performed on amorphous and crystalline ferromagnetic materials. The subjects studied are concerned with 'domain structure in magnetically weak uniaxial amorphous ferromagnetic ribbons', 'static critical behaviour at the ferromagnetic-paramagnetic phase transition', 'small magnetic anisotropy in nickel near T c ', and 'magnetization reversal in conducting ferromagnets'. 87 refs.; 37 figs.; 3 tabs

Contribution of corner reflections from oriented ice crystals to backscattering and depolarization characteristics for off-zenith lidar profiling

Science.gov (United States)

Borovoi, Anatoli G.; Konoshonkin, Alexander V.; Kustova, Natalia V.; Veselovskii, Igor A.

2018-06-01

Backscattering Mueller matrix and the depolarization and color ratios for quasi-horizontally oriented hexagonal ice plates have been calculated within the framework of the physical optics approximation. In the case of a tilted lidar, the dependence of the color and depolarization ratios on polarization of the incident light has been analyzed. It is shown that the corner reflection effect inherent to the pristine hexagonal ice crystals results in sharp peaks of both the backscattering cross section and depolarization ratio at the lidar tilts of about 30° off zenith. The experimental results obtained recently by Veselovskii et al. [13] at the lidar tilt of 43° have been interpreted as a partial manifestation of the corner reflection effect. The retrieval of the vertical profile of the ice crystal fraction consisting of quasi-horizontally oriented hexagonal plates has been demonstrated.

The tug-of-war between resource depletion and technological change in the global oil industry 1981-2009

Energy Technology Data Exchange (ETDEWEB)

Lindholt, Lars

2013-01-15

We perform an empirical analysis of the extent to which ongoing technological change through RandD activity has offset the effect of ongoing depletion on the cost of finding additional reserves of oil in eight global regions. We introduce a finding cost function that among other factors depends on the cumulative number of past RandD expenses and cumulative past production, measuring technological change and depletion, respectively. For all our regions we find significant effects of both depletion and technological change on oil finding costs from 1981 to 2009, barring cyclical variations in finding costs that could come from changes in factor prices. For almost all regions technology more than mitigated depletion until around the mid-nineties. However, we find that depletion outweighed technological progress over the last decade.(author)

Uranium and the use of depleted uranium in weaponry

International Nuclear Information System (INIS)

Roussel, R.

2000-01-01

In this brief report the author shows that the use of shells involving a load of depleted uranium might lead to lasting hazards to civil population and environment. These hazards come from the part of the shell that has been dispersed as contaminating radioactive dusts. The author describes some features of radioactivity and highlights the role of Uranium-238 as a provider of energy to the planet. (A.C.)

Depolarized inactivation overcomes impaired activation to produce DRG neuron hyperexcitability in a Nav1.7 mutation in a patient with distal limb pain.

Science.gov (United States)

Huang, Jianying; Yang, Yang; Dib-Hajj, Sulayman D; van Es, Michael; Zhao, Peng; Salomon, Jody; Drenth, Joost P H; Waxman, Stephen G

2014-09-10

Sodium channel Nav1.7, encoded by SCN9A, is expressed in DRG neurons and regulates their excitability. Genetic and functional studies have established a critical contribution of Nav1.7 to human pain disorders. We have now characterized a novel Nav1.7 mutation (R1279P) from a female human subject with distal limb pain, in which depolarized fast inactivation overrides impaired activation to produce hyperexcitability and spontaneous firing in DRG neurons. Whole-cell voltage-clamp recordings in human embryonic kidney (HEK) 293 cells demonstrated that R1279P significantly depolarizes steady-state fast-, slow-, and closed-state inactivation. It accelerates deactivation, decelerates inactivation, and facilitates repriming. The mutation increases ramp currents in response to slow depolarizations. Our voltage-clamp analysis showed that R1279P depolarizes channel activation, a change that was supported by our multistate structural modeling. Because this mutation confers both gain-of-function and loss-of-function attributes on the Nav1.7 channel, we tested the impact of R1279P expression on DRG neuron excitability. Current-clamp studies reveal that R1279P depolarizes resting membrane potential, decreases current threshold, and increases firing frequency of evoked action potentials within small DRG neurons. The populations of spontaneously firing and repetitively firing neurons were increased by expressing R1279P. These observations indicate that the dominant proexcitatory gating changes associated with this mutation, including depolarized steady-state fast-, slow-, and closed-state inactivation, faster repriming, and larger ramp currents, override the depolarizing shift of activation, to produce hyperexcitability and spontaneous firing of nociceptive neurons that underlie pain. Copyright © 2014 the authors 0270-6474/14/3412328-13$15.00/0.

Compared studies of natural and artificial deuterium depleted water

International Nuclear Information System (INIS)

Butnaru, Gallia; Mihacea, Sorina; Sirbovan, Alina; Butnariu, H.; Titescu, Gh.

2001-01-01

The biological influence of the deuterium on animals was studied insensitively in the last years. When animal cell cultures were analyzed it turned out an inhibition of the development, due to the reduced deuterium concentration. In the in vivo experiments a decreasing of the number of tumoral cells was pointed out when performing the depleted water treatment. It is obvious that the presence of deuterium in water is necessary for the development, especially for the tumoral cell proliferation. The aim of this work was to establish influence of the natural and artificial deuterium depleted water on the vegetal organisms development. For this purpose, the developmental stages of Lactuca sativa L. growth were followed. The experimental data were compared with the data obtained with distilled water. The birch, wine sap and some fruit juices are considered 'natural depleted' water sources because their deuterium content is smaller in comparison to natural water (D 2 =150 ppm). The effect of artificial deuterium depleted water (29 ppm D 2 ) was analyzed in comparison to three types of wine saps, which also have a reduced deuterium concentration (125-130 ppm D 2 ). If the deuterium depleted water was used, the germination percent and the root and shoot length were higher compared to control in the first stages. In wine sap it had a negative effect on germination and development. After three days the plants were transferred to soil and their development was followed. The foliage area was larger for all of the experimental variants compared to control. The differences were without significance when deuterium depleted water was tested but they were high and very significant in case of wine sap. The experiment pointed out a stimulative effect of the artificial deuterium depleted water. In case of wine sap the effect was negative when the contact was direct, but the growth was stimulated after the stress cessation. The first ontogenetic stages were represented by direct action

Chronic grouped social restriction triggers long-lasting immune system adaptations.

Science.gov (United States)

Tian, Rui; Hou, Gonglin; Song, Liuwei; Zhang, Jianming; Yuan, Ti-Fei

2017-05-16

Chronic stress triggers rigorous psychological and physiological changes, including immunological system adaptations. However, the effects of long-term social restriction on human immune system have not been investigated. The present study is to investigate the effect of chronic stress on immune changes in human blood, with the stress stimuli controlled.10 male volunteers were group isolated from the modern society in a 50-meter-square room for 150 days, with enriched nutrition and good living conditions provided. Serum examination of immune system markers demonstrated numerous changes in different aspects of the immune functions. The changes were observed as early as 30 days and could last for another 150 days after the termination of the restriction period (300 days' time point). The results strongly argued for the adaptation of immunological system under chronic social restriction stress in adult human, preceding a clear change in psychological conditions. The changes of these immune system factors could as well act as the serum biomarkers in clinical early-diagnosis of stress-related disorders.

Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 3: Responses to public comments

International Nuclear Information System (INIS)

1999-04-01

This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible. This volume of the Final PEIS contains the comments and DOE's responses to comments received during the comment period. Chapter 2 contains photocopies of written submissions received by DOE on the Draft PEIS; DOE's responses to those comments are listed in Chapter 3. Chapter 4 provides the oral comments received at the public hearings and DOE's responses. Chapter 5 provides indices to comments and responses arranged by commentor name and by comment number

Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

Science.gov (United States)

Wimmer, Marina C; Stirk, Steven; Hancock, Peter J B

2017-10-01

This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience.

The ultimate disposition of depleted uranium

Energy Technology Data Exchange (ETDEWEB)

1990-12-01

Significant amounts of the depleted uranium (DU) created by past uranium enrichment activities have been sold, disposed of commercially, or utilized by defense programs. In recent years, however, the demand for DU has become quite small compared to quantities available, and within the US Department of Energy (DOE) there is concern for any risks and/or cost liabilities that might be associated with the ever-growing inventory of this material. As a result, Martin Marietta Energy Systems, Inc. (Energy Systems), was asked to review options and to develop a comprehensive plan for inventory management and the ultimate disposition of DU accumulated at the gaseous diffusion plants (GDPs). An Energy Systems task team, under the chairmanship of T. R. Lemons, was formed in late 1989 to provide advice and guidance for this task. This report reviews options and recommends actions and objectives in the management of working inventories of partially depleted feed (PDF) materials and for the ultimate disposition of fully depleted uranium (FDU). Actions that should be considered are as follows. (1) Inspect UF{sub 6} cylinders on a semiannual basis. (2) Upgrade cylinder maintenance and storage yards. (3) Convert FDU to U{sub 3}O{sub 8} for long-term storage or disposal. This will include provisions for partial recovery of costs to offset those associated with DU inventory management and the ultimate disposal of FDU. Another recommendation is to drop the term tails'' in favor of depleted uranium'' or DU'' because the tails'' label implies that it is waste.'' 13 refs.

From depolarization-dependent contractions in gastrointestinal smooth muscle to aortic pulse-synchronized contractions

Directory of Open Access Journals (Sweden)

Marion SB

2014-03-01

Full Text Available Sarah B Marion, Allen W MangelRTI Health Solutions, Research Triangle Park, NC, USAAbstract: For decades, it was believed that the diameter of gastrointestinal smooth muscle cells is sufficiently narrow, and that the diffusion of calcium across the plasma membrane is sufficient, to support contractile activity. Thus, depolarization-triggered release of intracellular calcium was not believed to be operative in gastrointestinal smooth muscle. However, after the incubation of muscle segments in solutions devoid of calcium and containing the calcium chelator ethylene glycol tetraacetic acid, an alternative electrical event occurred that was distinct from normal slow waves and spikes. Subsequently, it was demonstrated in gastrointestinal smooth muscle segments that membrane depolarization associated with this alternative electrical event triggered rhythmic contractions by release of intracellular calcium. Although this concept of depolarization-triggered calcium release was iconoclastic, it has now been demonstrated in multiple gastrointestinal smooth muscle preparations. On the basis of these observations, we investigated whether a rhythmic electrical and mechanical event would occur in aortic smooth muscle under the same calcium-free conditions. The incubation of aortic segments in a solution with no added calcium plus ethylene glycol tetraacetic acid induced a fast electrical event without corresponding tension changes. On the basis of the frequency of these fast electrical events, we pursued, contrary to what has been established dogma for more than three centuries, the question of whether the smooth muscle wall of the aorta undergoes rhythmic activation during the cardiac cycle. As with depolarization-triggered contractile activity in gastrointestinal smooth muscle, it was “well known” that rhythmic activation of the aorta does not occur in synchrony with the heartbeat. In a series of experiments, however, it was demonstrated that rhythmic

Depleted uranium determination at the Novi Sad low level facility

International Nuclear Information System (INIS)

Bikit, I.; Slivka, J.; Krmar, M.; Veskovic, M.; Conkic, Lj.; Varga, E.

2002-01-01

Natural uranium determination in environmental samples at the low-level gamma-spectroscopy laboratory of the Faculty of Science in Novi Sad has more than 20 years long tradition. When the issue of depleted uranium emerged the experimental advantages of the measuring equipment (GMX type of HPGe detector with enhanced efficiency below 100 keV, and iron low level shielding) where fully exploited. A detection technique selective for depleted uranium was developed. The details of this method together with the results for about 100 samples (soil, plants, water, food) are presented, and discussed. (author)

Strong Resilience of Topological Codes to Depolarization

Directory of Open Access Journals (Sweden)

H. Bombin

2012-04-01

Full Text Available The inevitable presence of decoherence effects in systems suitable for quantum computation necessitates effective error-correction schemes to protect information from noise. We compute the stability of the toric code to depolarization by mapping the quantum problem onto a classical disordered eight-vertex Ising model. By studying the stability of the related ferromagnetic phase via both large-scale Monte Carlo simulations and the duality method, we are able to demonstrate an increased error threshold of 18.9(3% when noise correlations are taken into account. Remarkably, this result agrees within error bars with the result for a different class of codes—topological color codes—where the mapping yields interesting new types of interacting eight-vertex models.

The optimal timing of stimulation to induce long-lasting positive effects on episodic memory in physiological aging.

Science.gov (United States)

Manenti, Rosa; Sandrini, Marco; Brambilla, Michela; Cotelli, Maria

2016-09-15

Episodic memory displays the largest degree of age-related decline. A noninvasive brain stimulation technique that can be used to modulate memory in physiological aging is transcranial Direct Current Stimulation (tDCS). However, an aspect that has not been adequately investigated in previous studies is the optimal timing of stimulation to induce long-lasting positive effects on episodic memory function. Our previous studies showed episodic memory enhancement in older adults when anodal tDCS was applied over the left lateral prefrontal cortex during encoding or after memory consolidation with or without a contextual reminder. Here we directly compared the two studies to explore which of the tDCS protocols would induce longer-lasting positive effects on episodic memory function in older adults. In addition, we aimed to determine whether subjective memory complaints would be related to the changes in memory performance (forgetting) induced by tDCS, a relevant issue in aging research since individuals with subjective memory complaints seem to be at higher risk of later memory decline. The results showed that anodal tDCS applied after consolidation with a contextual reminder induced longer-lasting positive effects on episodic memory, conceivably through reconsolidation, than anodal tDCS during encoding. Furthermore, we reported, providing new data, a moderate negative correlation between subjective memory complaints and forgetting when anodal tDCS was applied after consolidation with a contextual reminder. This study sheds light on the best-suited timing of stimulation to induce long-lasting positive effects on memory function and might help the clinicians to select the most effective tDCS protocol to prevent memory decline. Copyright © 2016 Elsevier B.V. All rights reserved.

“When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

Science.gov (United States)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion. PMID:25009523

Severe and long-lasting diarrhea not recognized as adverse effect of metformin : A description of three elderly patients

NARCIS (Netherlands)

Lefeber, G.; Jansen, P.; Van Puijenbroek, E.

Background.- As a result of the United Kingdom Prospective Diabetes Study (UKPDS), metformin became the first choice drug for patients with diabetes. In 2009 three patients were admitted to our geriatric department for analysis of disabling long-lasting diarrhea. Metformin as causative agent was

Plants modify biological processes to ensure survival following carbon depletion: a Lolium perenne model.

Directory of Open Access Journals (Sweden)

Julia M Lee

Full Text Available BACKGROUND: Plants, due to their immobility, have evolved mechanisms allowing them to adapt to multiple environmental and management conditions. Short-term undesirable conditions (e.g. moisture deficit, cold temperatures generally reduce photosynthetic carbon supply while increasing soluble carbohydrate accumulation. It is not known, however, what strategies plants may use in the long-term to adapt to situations resulting in net carbon depletion (i.e. reduced photosynthetic carbon supply and carbohydrate accumulation. In addition, many transcriptomic experiments have typically been undertaken under laboratory conditions; therefore, long-term acclimation strategies that plants use in natural environments are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: Perennial ryegrass (Lolium perenne L. was used as a model plant to define whether plants adapt to repetitive carbon depletion and to further elucidate their long-term acclimation mechanisms. Transcriptome changes in both lamina and stubble tissues of field-grown plants with depleted carbon reserves were characterised using reverse transcription-quantitative polymerase chain reaction (RT-qPCR. The RT-qPCR data for select key genes indicated that plants reduced fructan degradation, and increased photosynthesis and fructan synthesis capacities following carbon depletion. This acclimatory response was not sufficient to prevent a reduction (P<0.001 in net biomass accumulation, but ensured that the plant survived. CONCLUSIONS: Adaptations of plants with depleted carbon reserves resulted in reduced post-defoliation carbon mobilization and earlier replenishment of carbon reserves, thereby ensuring survival and continued growth. These findings will help pave the way to improve plant biomass production, for either grazing livestock or biofuel purposes.

NOVAE WITH LONG-LASTING SUPERSOFT EMISSION THAT DRIVE A HIGH ACCRETION RATE

International Nuclear Information System (INIS)

Schaefer, Bradley E.; Collazzi, Andrew C.

2010-01-01

We identify a new class of novae characterized by the post-eruption quiescent light curve being more than roughly a factor of 10 brighter than the pre-eruption light curve. Eight novae (V723 Cas, V1500 Cyg, V1974 Cyg, GQ Mus, CP Pup, T Pyx, V4633 Sgr, and RW UMi) are separated out as being significantly distinct from other novae. This group shares a suite of uncommon properties, characterized by the post-eruption magnitude being much brighter than before eruption, short orbital periods, long-lasting supersoft emission following the eruption, a highly magnetized white dwarf (WD), and secular declines during the post-eruption quiescence. We present a basic physical picture which shows why all five uncommon properties are causally connected. In general, novae show supersoft emission due to hydrogen burning on the WD in the final portion of the eruption, and this hydrogen burning will be long-lasting if new hydrogen is poured onto the surface at a sufficient rate. Most novae do not have adequate accretion for continuous hydrogen burning, but some can achieve this if the companion star is nearby (with short orbital period) and a magnetic field channels the matter onto a small area on the WD so as to produce a locally high accretion rate. The resultant supersoft flux irradiates the companion star and drives a higher accretion rate (with a brighter post-eruption phase), which serves to keep the hydrogen burning and the supersoft flux going. The feedback loop cannot be perfectly self-sustaining, so the supersoft flux will decline over time, forcing a decline in the accretion rate and the system brightness. We name this new group after the prototype, V1500 Cyg. V1500 Cyg stars are definitely not progenitors of Type Ia supernovae. The V1500 Cyg stars have similar physical mechanisms and appearances as predicted for nova by the hibernation model, but with this group accounting for only 14% of novae.

Risk Factors of Developing Long-Lasting Breast Pain After Breast Cancer Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Lundstedt, Dan, E-mail: dan.lundstedt@vgregion.se [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Gustafsson, Magnus [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Steineck, Gunnar [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Division of Clinical Cancer Epidemiology, Department of Oncology-Pathology, the Karolinska Institute, Stockholm (Sweden); Malmstroem, Per [Skane Department of Oncology, Skane University Hospital, Lund (Sweden); Alsadius, David [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Sundberg, Agnetha [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Wilderaeng, Ulrica [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Holmberg, Erik [Oncologic Centre, Sahlgrenska University Hospital, Gothenburg (Sweden); Johansson, Karl-Axel [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Karlsson, Per [Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden)

2012-05-01

Purpose: Postoperative radiotherapy decreases breast cancer mortality. However, studies have revealed a long-lasting breast pain among some women after radiotherapy. The purpose of this study was to identify risk factors that contribute to breast pain after breast cancer radiotherapy. Methods and Materials: We identified 1,027 recurrence-free women in two cohorts of Swedish women treated for breast cancer. The women had breast-conserving surgery and postoperative radiotherapy, the breast was treated to 48 Gy in 2.4-Gy fractions or to 50 Gy in 2.0-Gy fractions. Young women received a boost of up to 16 Gy. Women with more than three lymph node metastases had locoregional radiotherapy. Systemic treatments were given according to health-care guidelines. Three to 17 years after radiotherapy, we collected data using a study-specific questionnaire. We investigated the relation between breast pain and potential risk modifiers: age at treatment, time since treatment, chemotherapy, photon energy, fractionation size, boost, loco-regional radiotherapy, axillary surgery, overweight, and smoking. Results: Eight hundred seventy-seven women (85%) returned the questionnaires. Among women up to 39 years of age at treatment, 23.1% had breast pain, compared with 8.7% among women older than 60 years (RR 2.66; 95% CI 1.33-5.36). Higher age at treatment (RR 0.96; 95% CI 0.94-0.98, annual decrease) and longer time since treatment (RR 0.93; 95% CI 0.88-0.98, annual decrease) were related to a lower occurrence of breast pain. Chemotherapy increased the occurrence of breast pain (RR 1.72; 95% CI 1.19-2.47). In the multivariable model only age and time since treatment were statistically significantly related to the occurrence of breast pain. We found no statistically significant relation between breast pain and the other potential risk modifiers. Conclusions: Younger women having undergone breast-conserving surgery with postoperative radiotherapy report a higher occurrence of long-lasting

Overcoming weak intrinsic depolarizing resonances with energy-jump

International Nuclear Information System (INIS)

Huang, H.; Ahrens, L.; Alessi, J.G.

1997-01-01

In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, significant amount of polarization was lost at 0+ν y , 12+ν y and 36+ν y , which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam circumference using the powerful AGS rf system. It clearly demonstrates that the novel energy-jump method can successfully overcome coupling resonances and weak intrinsic resonances

Rayleigh scattering and depolarization ratio in linear alkylbenzene

International Nuclear Information System (INIS)

Liu, Qian; Zhou, Xiang; Huang, Wenqian; Zhang, Yuning; Wu, Wenjie; Luo, Wentai; Yu, Miao; Zheng, Yangheng; Zhou, Li; Cao, Jun; Wang, Yifang

2015-01-01

It is planned to use linear alkylbenzene (LAB) as the organic solvent for the Jiangmen Underground Neutrino Observatory (JUNO) liquid scintillator detectors, due to its ultra-transparency. However, the current Rayleigh scattering length calculation for LAB disagrees with the experimental measurement. This paper reports for the first time that the Rayleigh scattering of LAB is anisotropic, with a depolarization ratio of 0.31±0.01(stat.)±0.01(sys.). We use an indirect method for Rayleigh scattering measurement with the Einstein–Smoluchowski–Cabannes formula, and the Rayleigh scattering length of LAB is determined to be 28.2±1.0 m at 430 nm

Energetic ion excited long-lasting ``sword'' modes in tokamak plasmas with low magnetic shear

Science.gov (United States)

Wang, Xiaogang; Zhang, Ruibin; Deng, Wei; Liu, Yi

2013-10-01

An m/ n = 1 mode driven by trapped fast ions with a sword-shape envelope of long-lasting (for hundreds of milliseconds) magnetic perturbation signals, other than conventional fishbones, is studied in this paper. The mode is usually observed in low shear plasmas. Frequency and growth rate of the mode and its harmonics are calculated and in good agreements with observations. The radial mode structure is also obtained and compared with that of fishbones. It is found that due to fast ion driven the mode differs from magnetohydrodynamic long lived modes (LLMs) observed in MAST and NSTX. On the other hand, due to the feature of weak magnetic shear, the mode is also significantly different from fishbones. The nonlinear evolution of the mode and its comparison with fishbones are further investigated to analyze the effect of the mode on energetic particle transport and confinement.

Culminating anti-malaria efforts at long lasting insecticidal net?

Directory of Open Access Journals (Sweden)

Sunil Dhiman

2014-11-01

Full Text Available Summary: Background: Long-lasting insecticidal nets (LLINs are a primary method in malaria control efforts. However, a decline in the biological efficacy and physical integrity over a period of comparatively lesser time than claimed, waning of naturally acquired immunity among regular users and misuse of LLINs are serious concerns. Search and selection of literature: The literature for the current review was searched in PubMed, SCOPUS Database and Google using combined search strings of related key-words. Literature with sufficient data and information on the current subject was selected to reach a valid conclusion. Findings: The World Health Organization (WHO has emphasized that LLINs should be considered a public good for people inhabiting malaria endemic settings. LLINs exhibited a cumulative effect on the vector density and may force anthropophilic mosquito vectors to find alternative animal hosts for blood meal. However, the physical integrity and biological activity of LLINs declines faster than the anticipated time due to different operational conditions and the spread of insecticide resistance. LLINs have been successful in reducing malaria incidences by either reducing or not allowing human exposure to the vector mosquitoes, but at the same time, LLINs debilitate the natural protective immunity against malaria parasite. Misuse of LLINs for deviant purposes is common and is a serious environmental concern, as people believe that traditional methods of prevention against malaria that have enabled them to survive through a long time are effective and sufficient. Moreover, people are often ill-informed regarding the toxic effects of LLINs. Conclusions: Specific criteria for determining the serviceable life and guidelines on the safe washing and disposal of LLINs need to be developed, kept well-informed and closely monitored. Malaria case management, environment management and community awareness to reduce the misuse of LLINs are crucial

Protection by GDNF and other trophic factors against the dopamine-depleting effects of neurotoxic doses of methamphetamine.

Science.gov (United States)

Cass, Wayne A; Peters, Laura E; Harned, Michael E; Seroogy, Kim B

2006-08-01

Repeated methamphetamine (METH) administration to animals can result in long-lasting decreases in striatal dopamine (DA) content. It has previously been shown that glial cell line-derived neurotrophic factor (GDNF) can reduce the DA-depleting effects of neurotoxic doses of METH. However, there are several other trophic factors that are protective against dopaminergic toxins. Thus, the present experiments further investigated the protective effect of GDNF as well as the protective effects of several other trophic factors. Male Fischer-344 rats were given an intracerebral injection of trophic factor (2-10 microg) 1 day before METH (5 mg/kg, s.c., 4 injections at 2-h intervals). Seven days later DA levels in the striatum were measured using high-performance liquid chromatography (HPLC). Initial experiments indicated that only intrastriatal GDNF, and not intranigral GDNF, was protective. Thereafter, all other trophic factors were administered into the striatum. Members of the GDNF family (GDNF, neurturin, and artemin) all provided significant protection against the DA-depleting effects of METH, with GDNF providing the greatest protection. Brain-derived neurotrophic factor, neurotrophin-3, acidic fibroblast growth factor, basic fibroblast growth factor, ciliary neurotrophic factor, transforming growth factor-alpha (TGF-alpha), heregulin beta1 (HRG-beta1), and amphiregulin (AR) provided no significant protection at the doses examined. These results suggest that the GDNF family of trophic factors can provide significant protection against the DA-depleting effects of neurotoxic doses of METH.

Basal Ganglia Activity Mirrors a Benefit of Action and Reward on Long-Lasting Event Memory.

Science.gov (United States)

Koster, Raphael; Guitart-Masip, Marc; Dolan, Raymond J; Düzel, Emrah

2015-12-01

The expectation of reward is known to enhance a consolidation of long-term memory for events. We tested whether this effect is driven by positive valence or action requirements tied to expected reward. Using a functional magnetic resonance imaging (fMRI) paradigm in young adults, novel images predicted gain or loss outcomes, which in turn were either obtained or avoided by action or inaction. After 24 h, memory for these images reflected a benefit of action as well as a congruence of action requirements and valence, namely, action for reward and inaction for avoidance. fMRI responses in the hippocampus, a region known to be critical for long-term memory function, reflected the anticipation of inaction. In contrast, activity in the putamen mirrored the congruence of action requirement and valence, whereas other basal ganglia regions mirrored overall action benefits on long-lasting memory. The findings indicate a novel type of functional division between the hippocampus and the basal ganglia in the motivational regulation of long-term memory consolidation, which favors remembering events that are worth acting for. © The Author 2015. Published by Oxford University Press.

Stability and morphology of Ag nanoplatelets probed by depolarized dynamic light scattering

Science.gov (United States)

Zimbone, M.; Contino, A.; Maccarrone, G.; Musumeci, P.; Lo Faro, M. J.; Calcagno, L.

2018-06-01

The stability of silver nanoplatelet (NP) suspensions prepared with different concentrations of trisodium citrate (TSC) was studied by depolarized dynamic light scattering (DDLS) and UV–vis spectrometry. The morphology of the nanoparticles, as well as the color and stability of the sols, are tuned by the concentration of the capping agent. The nanoparticles prepared with high TSC concentration (>10‑4 M) are blue triangular NPs showing a slight truncation of the tips with aging. When low TSC concentrations are used, the color of the sols changes from blue to yellow with aging time and a strong modification of the morphology occurs: the nanoparticle shape changes from triangular to spherical. Remarkably, they show a high degree of anisotropy. The aging process was followed by the UV–vis spectra and by measuring the rotational diffusion coefficient by DDLS, providing information on the nanoparticle size and shape evolution. The high intensity of depolarized signal and the high value of rotational diffusion coefficient suggest that the aging process increases the thickness and the roughness of the nanoparticles

Both cladribine and alemtuzumab may effect MS via B-cell depletion.

Science.gov (United States)

Baker, David; Herrod, Samuel S; Alvarez-Gonzalez, Cesar; Zalewski, Lukasz; Albor, Christo; Schmierer, Klaus

2017-07-01

To understand the efficacy of cladribine (CLAD) treatment in MS through analysis of lymphocyte subsets collected, but not reported, in the pivotal phase III trials of cladribine and alemtuzumab induction therapies. The regulatory submissions of the CLAD Tablets Treating Multiple Sclerosis Orally (CLARITY) (NCT00213135) cladribine and Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis, study one (CARE-MS I) (NCT00530348) alemtuzumab trials were obtained from the European Medicine Agency through Freedom of Information requests. Data were extracted and statistically analyzed. Either dose of cladribine (3.5 mg/kg; 5.25 mg/kg) tested in CLARITY reduced the annualized relapse rate to 0.16-0.18 over 96 weeks, and both doses were similarly effective in reducing the risk of MRI lesions and disability. Surprisingly, however, T-cell depletion was rather modest. Cladribine 3.5 mg/kg depleted CD4 + cells by 40%-45% and CD8 + cells by 15%-30%, whereas alemtuzumab suppressed CD4 + cells by 70%-95% and CD8 + cells by 47%-55%. However, either dose of cladribine induced 70%-90% CD19 + B-cell depletion, similar to alemtuzumab (90%). CD19 + cells slowly repopulated to 15%-25% of baseline before cladribine redosing. However, alemtuzumab induced hyperrepopulation of CD19 + B cells 6-12 months after infusion, which probably forms the substrate for B-cell autoimmunities associated with alemtuzumab. Cladribine induced only modest depletion of T cells, which may not be consistent with a marked influence on MS, based on previous CD4 + T-cell depletion studies. The therapeutic drug-response relationship with cladribine is more consistent with lasting B-cell depletion and, coupled with the success seen with monoclonal CD20 + depletion, suggests that B-cell suppression could be the major direct mechanism of action.

Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields

Energy Technology Data Exchange (ETDEWEB)

Genenko, Yuri A., E-mail: genenko@mm.tu-darmstadt.de; Hirsch, Ofer [Technische Universität Darmstadt, Darmstadt (Germany); Erhart, Paul [Chalmers University of Technology, Gothenburg (Sweden)

2014-03-14

Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is studied within a semiconductor model of ferroelectrics. It is shown that the maximum strength of local depolarization fields is rather determined by the electronic band gap than by the spontaneous polarization magnitude. Furthermore, field screening due to electronic band bending and due to presence of intrinsic defects leads to asymmetric space charge regions near the grain boundary, which produce an effective dipole layer at the surface of the grain. This results in the formation of a potential difference between the grain surface and its interior of the order of 1 V, which can be of either sign depending on defect transition levels and concentrations. Exemplary acceptor doping of BaTiO{sub 3} is shown to allow tuning of the said surface potential in the region between 0.1 and 1.3 V.

Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses.

Science.gov (United States)

Low, Lucie A; Bauer, Lucy C; Pitcher, Mark H; Bushnell, M Catherine

2016-08-01

With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the "nociceptive" central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli.

Charge movement and depolarization-contraction coupling in arthropod vs. vertebrate skeletal muscle.

OpenAIRE

Scheuer, T; Gilly, W F

1986-01-01

Voltage-dependent charge movement has been characterized in arthropod skeletal muscle. Charge movement in scorpion (Centuroides sculpturatus) muscle is distinguishable from that in vertebrate skeletal muscle by criteria of kinetics, voltage dependence, and pharmacology. The function of scorpion charge movement is gating of calcium channels in the sarcolemma, and depolarization-contraction coupling relies on calcium influx through these channels.

Exposure to severe stressors causes long-lasting dysregulation of resting and stress-induced activation of the hypothalamic-pituitary-adrenal axis.

Science.gov (United States)

Belda, Xavier; Rotllant, David; Fuentes, Silvia; Delgado, Raúl; Nadal, Roser; Armario, Antonio

2008-12-01

Exposure to some predominantly emotional (electric shock) and systemic (interleukin-1beta) stressors has been found to induce long-term sensitization of the hypothalamic-pituitary-adrenal (HPA) responsiveness to further superimposed stressors. Since exposure to immobilization on wooden boards (IMO) is a severe stressor and may have interest regarding putative animal models of post-traumatic stress disorders (PTSD), we have characterized long-lasting effects of a single exposure to IMO and other stressors on the HPA response to the same (homotypic) and to novel (heterotypic) stressors and the putative mechanisms involved. A single exposure to IMO caused a long-lasting reduction of peripheral and central responses of the HPA axis, likely to be mediated by some brain areas, such as the lateral septum and the medial amygdala. This desensitization is not explained by changes in negative glucocorticoid feedback, and, surprisingly, it is positively related to the intensity of the stressors. In contrast, the HPA response to heterotypic stressors (novel environments) was enhanced, with maximal sensitization on the day after IMO. Sensitization progressively vanished over the course of 1-2 weeks and was not modulated by IMO-induced corticosterone release. Moreover, it could not be explained by changes in the sensitivity of the HPA axis to fast or intermediate/delayed negative feedback, as evaluated 1 week after exposure to IMO, using shock as the heterotypic stressor. Long-lasting stress-induced behavioral changes reminiscent of enhanced anxiety and HPA sensitization are likely to be parallel but partially independent phenomena, the former being apparently not related to the intensity of stressors.

Transitory endolymph leakage induced hearing loss and tinnitus: depolarization, biphasic shortening and loss of electromotility of outer hair cells

Science.gov (United States)

Zenner, H. P.; Reuter, G.; Zimmermann, U.; Gitter, A. H.; Fermin, C.; LePage, E. L.

1994-01-01

There are types of deafness and tinnitus in which ruptures or massive changes in the ionic permeability of the membranes lining the endolymphatic space [e.g., of the reticular lamina (RL)] are believed to allow potassium-rich endolymph to deluge the low [K+] perilymphatic fluid (e.g., in the small spaces of Nuel). This would result in a K+ intoxication of sensory and neural structures. Acute attacks of Meniere's disease have been suggested to be an important example for this event. The present study investigated the effects of transiently elevated [K+] due to the addition of artificial endolymph to the basolateral cell surface of outer hair cells (OHC) in replicating endolymph-induced K+ intoxication of the perilymph in the small spaces of Nuel. The influence of K+ intoxication of the basolateral OHC cell surface on the transduction was then examined. Intoxication resulted in an inhibition of the physiological repolarizing K+ efflux from hair cells. This induced unwanted depolarizations of the hair cells, interfering with mechanoelectrical transduction. A pathological longitudinal OHC shortening was also found, with subsequent compression of the organ of Corti possibly influencing the micromechanics of the mechanically active OHC. Both micromechanical and electrophysiological alterations are proposed to contribute to endolymph leakage induced attacks of deafness and possibly also to tinnitus. Moreover, repeated or long-lasting K+ intoxications of OHC resulted in a chronic and complete loss of OHC motility. This is suggested to be a pathophysiological basis in some patients with chronic hearing loss resulting from Meniere's syndrome.

A new memory effect (MSD) in fully depleted SOI MOSFETs

Science.gov (United States)

Bawedin, M.; Cristoloveanu, S.; Yun, J. G.; Flandre, D.

2005-09-01

We demonstrate that the transconductance and drain current of fully depleted MOSFETs can display an interesting time-dependent hysteresis. This new memory effect, called meta-stable dip (MSD), is mainly due to the long carrier generation lifetime in the silicon film. Our parametric analysis shows that the memory window can be adjusted in view of practical applications. Various measurement conditions and devices with different doping, front oxide and silicon film thicknesses are systematically explored. The MSD effect can be generalized to several fully depleted CMOS technologies. The MSD mechanism is discussed and validated by two-dimensional simulations results.

Long-lasting effects of performance-contingent unconscious and conscious reward incentives during cued task-switching.

Science.gov (United States)

Capa, Rémi L; Bouquet, Cédric A; Dreher, Jean-Claude; Dufour, André

2013-01-01

Motivation is often thought to interact consciously with executive control, although recent studies have indicated that motivation can also be unconscious. To date, however, the effects of unconscious motivation on high-order executive control functions have not been explored. Only a few studies using subliminal stimuli (i.e., those not related to motivation, such as an arrow to prime a response) have reported short-lived effects on high-order executive control functions. Here, building on research on unconscious motivation, in which a behavior of perseverance is induced to attain a goal, we hypothesized that subliminal motivation can have long-lasting effects on executive control processes. We investigated the impact of unconscious/conscious monetary reward incentives on evoked potentials and neural activity dynamics during cued task-switching performance. Participants performed long runs of task-switching. At the beginning of each run, a reward (50 cents or 1 cent) was displayed, either subliminally or supraliminally. Participants earned the reward contingent upon their correct responses to each trial of the run. A higher percentage of runs was achieved with higher (conscious and unconscious) than lower rewards, indicating that unconscious high rewards have long-lasting behavioral effects. Event-related potential (ERP) results indicated that unconscious and conscious rewards influenced preparatory effort in task preparation, as suggested by a greater fronto-central contingent negative variation (CNV) starting at cue-onset. However, a greater parietal P3 associated with better reaction times (RTs) was observed only under conditions of conscious high reward, suggesting a larger amount of working memory invested during task performance. Together, these results indicate that unconscious and conscious motivations are similar at early stages of task-switching preparation but differ during task performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Postsynaptic Depolarization Enhances GABA Drive to Dorsomedial Hypothalamic Neurons through Somatodendritic Cholecystokinin Release.

Science.gov (United States)

Crosby, Karen M; Baimoukhametova, Dinara V; Bains, Jaideep S; Pittman, Quentin J

2015-09-23

Somatodendritically released peptides alter synaptic function through a variety of mechanisms, including autocrine actions that liberate retrograde transmitters. Cholecystokinin (CCK) is a neuropeptide expressed in neurons in the dorsomedial hypothalamic nucleus (DMH), a region implicated in satiety and stress. There are clear demonstrations that exogenous CCK modulates food intake and neuropeptide expression in the DMH, but there is no information on how endogenous CCK alters synaptic properties. Here, we provide the first report of somatodendritic release of CCK in the brain in male Sprague Dawley rats. CCK is released from DMH neurons in response to repeated postsynaptic depolarizations, and acts in an autocrine fashion on CCK2 receptors to enhance postsynaptic NMDA receptor function and liberate the retrograde transmitter, nitric oxide (NO). NO subsequently acts presynaptically to enhance GABA release through a soluble guanylate cyclase-mediated pathway. These data provide the first demonstration of synaptic actions of somatodendritically released CCK in the hypothalamus and reveal a new form of retrograde plasticity, depolarization-induced potentiation of inhibition. Significance statement: Somatodendritic signaling using endocannabinoids or nitric oxide to alter the efficacy of afferent transmission is well established. Despite early convincing evidence for somatodendritic release of neurohypophysial peptides in the hypothalamus, there is only limited evidence for this mode of release for other peptides. Here, we provide the first evidence for somatodendritic release of the satiety peptide cholecystokinin (CCK) in the brain. We also reveal a new form of synaptic plasticity in which postsynaptic depolarization results in enhancement of inhibition through the somatodendritic release of CCK. Copyright © 2015 the authors 0270-6474/15/3513160-11$15.00/0.

Long lasting attentional-context dependent visuomotor memory

OpenAIRE

Im, Hee Yeon; Bédard, Patrick; Song, Joo-Hyun

2016-01-01

Using a dual-task paradigm, we recently reported that visuomotor adaptation acquired under distraction of a secondary attention-demanding discrimination task could be remembered only when a similar distraction was present. In contrast, when tested without the distracting task, performance reverted to untrained levels (Song & Bédard, 2015). Here, we demonstrated that this newfound paradoxical benefits of consistent dual-task context lasts over one day, such that visuomotor memory retrieval is ...

Semi-empirical long-term cycle life model coupled with an electrolyte depletion function for large-format graphite/LiFePO4 lithium-ion batteries

Science.gov (United States)

Park, Joonam; Appiah, Williams Agyei; Byun, Seoungwoo; Jin, Dahee; Ryou, Myung-Hyun; Lee, Yong Min

2017-10-01

To overcome the limitation of simple empirical cycle life models based on only equivalent circuits, we attempt to couple a conventional empirical capacity loss model with Newman's porous composite electrode model, which contains both electrochemical reaction kinetics and material/charge balances. In addition, an electrolyte depletion function is newly introduced to simulate a sudden capacity drop at the end of cycling, which is frequently observed in real lithium-ion batteries (LIBs). When simulated electrochemical properties are compared with experimental data obtained with 20 Ah-level graphite/LiFePO4 LIB cells, our semi-empirical model is sufficiently accurate to predict a voltage profile having a low standard deviation of 0.0035 V, even at 5C. Additionally, our model can provide broad cycle life color maps under different c-rate and depth-of-discharge operating conditions. Thus, this semi-empirical model with an electrolyte depletion function will be a promising platform to predict long-term cycle lives of large-format LIB cells under various operating conditions.

Halo Star Lithium Depletion

International Nuclear Information System (INIS)

Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

1999-01-01

The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

Stochastic interactions of two Brownian hard spheres in the presence of depletants

International Nuclear Information System (INIS)

Karzar-Jeddi, Mehdi; Fan, Tai-Hsi; Tuinier, Remco; Taniguchi, Takashi

2014-01-01

A quantitative analysis is presented for the stochastic interactions of a pair of Brownian hard spheres in non-adsorbing polymer solutions. The hard spheres are hypothetically trapped by optical tweezers and allowed for random motion near the trapped positions. The investigation focuses on the long-time correlated Brownian motion. The mobility tensor altered by the polymer depletion effect is computed by the boundary integral method, and the corresponding random displacement is determined by the fluctuation-dissipation theorem. From our computations it follows that the presence of depletion layers around the hard spheres has a significant effect on the hydrodynamic interactions and particle dynamics as compared to pure solvent and uniform polymer solution cases. The probability distribution functions of random walks of the two interacting hard spheres that are trapped clearly shift due to the polymer depletion effect. The results show that the reduction of the viscosity in the depletion layers around the spheres and the entropic force due to the overlapping of depletion zones have a significant influence on the correlated Brownian interactions

Concentration depolarization of luminescence of Eu3+-doped glasses

International Nuclear Information System (INIS)

Bodunov, E.N.; Lebedev, V.P.; Malyshev, V.A.; Przheuskij, A.K.

1989-01-01

Experimental study of concentrational depolarization luminescence (CDL) of phosphate and germanate glasses, containing Eu 3+ ions, has been carried out. On the basis of three-body self-consistent approximation the theory of CDL is conceived, which takes into account Eu-Eu interaction of higher multipolarities. By comparing the theory with the experiment energy transfer radii for Eu-Eu dipole-dipole, dipole-quadrupole and quadrupole-quadrupole interactions are determined. The attempt to discriminate Eu-Eu interaction types in the studied range of Eu 3+ ion concentration change has failed owing to law accuracy of luminescence emittance anisotropy measurement

Mobility of adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (Coleoptera: Bostrichidae) after exposure to long-lasting insecticide netting

Science.gov (United States)

Stored products represent an enormous economic output, but insects regularly immigrate into stored products from the surrounding landscape throughout the post-harvest supply chain. Long-lasting insecticide netting (LLIN), which usually contains an impregnated pyrethroid, has been used as part of a s...

The novelty-seeking phenotype modulates the long-lasting effects of intermittent ethanol administration during adolescence.

Directory of Open Access Journals (Sweden)

Sandra Montagud-Romero

Full Text Available The aim of the present study was to investigate if a novelty-seeking phenotype mediates the long-lasting consequences of intermittent EtOH intoxication during adolescence. The hole board test was employed to classify adolescent mice as High- or Low-Novelty Seekers. Subsequently, animals were administered ethanol (1.25 or 2.5 g/kg on two consecutive days at 48-h intervals over a 14-day period. Anxiety levels--measured using the elevated plus maze- spontaneous motor activity and social interaction test were studied 3 weeks later. A different set of mice underwent the same procedure, but received only the 2.5 g/kg dose of ethanol. Three weeks later, in order to induce CPP, the same animals were administered 1 or 6 mg/kg of cocaine or 1 or 2.5 mg/kg MDMA. The results revealed a decrease in aggressive behaviors and an anxiolytic profile in HNS mice and longer latency to explore the novel object by LNS mice. Ethanol exposure enhanced the reinforcing effects of cocaine and MDMA in both groups when CPP was induced with a sub-threshold dose of the drugs. The extinguished cocaine-induced CPP (1 and 6 mg/kg was reinstated after a priming dose in HNS animals only. Our results confirm that intermittent EtOH administration during adolescence induces long-lasting effects that are manifested in adult life, and that there is an association between these effects and the novelty-seeking phenotype.

A new and specific non-NMDA receptor antagonist, FG 9065, blocks L-AP4-evoked depolarization in rat cerebral cortex.

Science.gov (United States)

Sheardown, M J

1988-04-13

L(+)-AP4 (2-amino-4-phosphonobutyrate) depolarized slices of rat cerebral cortex, when applied following a 2 min priming application of quisqualate. This response diminishes with time and is not seen after NMDA application. A new selective non-N-methyl-D-aspartate (NMDA) antagonist, 6-cyano-7-nitro-2,3-dihydroxyquinoxaline (FG 9065), inhibits the L(+)-AP4 depolarization. It is argued that the response is mediated indirectly by postsynaptic quisqualate receptors.

Strong dependence of rain-induced lidar depolarization on the illumination angle: experimental evidence and geometrical-optics interpretation.

Science.gov (United States)

Roy, G; Bissonnette, L R

2001-09-20

Backscatter and depolarization lidar measurements from clouds and precipitation are reported as functions of the elevation angle of the pointing lidar direction. We recorded the data by scanning the lidar beam (Nd:YAG) at a constant angular speed of ~3.5 degrees /s while operating at a repetition rate of 10 Hz. We show that in rain there is an evident and at times spectacular dependence on the elevation angle. That dependence appears to be sensitive to raindrop size. We have developed a three-dimensional polarization-dependent ray-tracing algorithm to calculate the backscatter and the depolarization ratio by large nonspherical droplets. We have applied it to raindrop shapes derived from existing static and dynamic (oscillating) models. We show that many of the observed complex backscatter and depolarization features can be interpreted to a good extent by geometrical optics. These results suggest that there is a definite need for more extensive calculations of the scattering phase matrix elements for large deformed raindrops as functions of the direction of illumination. Obvious applications are retrieval of information on the liquid-solid phase of precipitation and on the size and the vibration state of raindrops.

Neutron depolarization study of internal stresses in amorphous Fe40Ni40B20

International Nuclear Information System (INIS)

de Jong, M.; Sietsma, J.; Rekveldt, M.T.; van den Beukel, A.

1997-01-01

The magnetic domain structure of amorphous ferromagnets with nonzero magnetostriction is mainly determined by the internal stress state because of the magneto-elastic coupling. The stress and field dependence of the domain structure contains important information on the internal stresses in the material. The three-dimensional neutron depolarization technique has been used to study the stress- and field-dependence of the bulk domain structures in both as-quenched and annealed ribbons of the metallic glass Fe 40 Ni 40 B 20 . A three-layer domain structure model corresponding to compressive and tensile internal stresses is presented to explain the measured data. The influence of surface roughness on the interpretation of neutron depolarization measurements in amorphous ribbons is discussed. Finally, the internal stress relaxation due to the annealing is explained in terms of the viscous behaviour of the glass. copyright 1997 American Institute of Physics

Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles.

Science.gov (United States)

Plant, David R; Lynch, Gordon S; Williams, David A

2002-03-15

The effect of exogenous hydrogen peroxide (H(2)O(2)) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mM H(2)O(2) diminished the ability of the Ca(2+)-depleted SR to reload Ca(2+) in both slow (P fast twitch fibres (P fast twitch fibres by 24 +/- 5 % (P slow twitch fibres. Treatment with 1 mM H(2)O(2) also increased the peak force of low [caffeine] contracture by approximately 45% in both fibre types compared to control (P slow twitch fibres, compared to control (no H(2)O(2); P fast twitch fibres was not altered by 1 mM H(2)O(2) treatment. Equilibration with 5 mM H(2)O(2) induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mM DTT. Peak DICR was also increased approximately 40% by 5 mM H(2)O(2) in slow twitch fibres compared to control (no H(2)O(2); P slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca(2+) release during contraction and/or an increase in Ca(2+) sensitivity.

"When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T D

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

"When the going gets tough, who keeps going?" : Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

The modality effect of ego depletion: Auditory task modality reduces ego depletion.

Science.gov (United States)

Li, Qiong; Wang, Zhenhong

2016-08-01

An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Enriched but not depleted uranium affects central nervous system in long-term exposed rat.

Science.gov (United States)

Houpert, Pascale; Lestaevel, Philippe; Bussy, Cyrill; Paquet, François; Gourmelon, Patrick

2005-12-01

Uranium is well known to induce chemical toxicity in kidneys, but several other target organs, such as central nervous system, could be also affected. Thus in the present study, the effects on sleep-wake cycle and behavior were studied after chronic oral exposure to enriched or depleted uranium. Rats exposed to 4% enriched uranium for 1.5 months through drinking water, accumulated twice as much uranium in some key areas such as the hippocampus, hypothalamus and adrenals than did control rats. This accumulation was correlated with an increase of about 38% of the amount of paradoxical sleep, a reduction of their spatial working memory capacities and an increase in their anxiety. Exposure to depleted uranium for 1.5 months did not induce these effects, suggesting that the radiological activity induces the primary events of these effects of uranium.

Experimental observation of spontaneous depolarized guided acoustic-wave Brillouin scattering in side cores of a multicore fiber

Science.gov (United States)

Hayashi, Neisei; Mizuno, Yosuke; Nakamura, Kentaro; Set, Sze Yun; Yamashita, Shinji

2018-06-01

Spontaneous depolarized guided acoustic-wave Brillouin scattering (GAWBS) was experimentally observed in one of the side cores of an uncoated multicore fiber (MCF). The frequency bandwidth in the side core was up to ∼400 MHz, which is 0.5 times that in the central core. The GAWBS spectrum of the side core of the MCF included intrinsic peaks, which had different acoustic resonance frequencies from those of the central core. In addition, the spontaneous depolarized GAWBS in the central/side core was unaffected by that in the other core. These results will lead to the development of polarization/phase modulators using an MCF.

Vascular impairment as a pathological mechanism underlying long-lasting cognitive dysfunction after pediatric traumatic brain injury.

Science.gov (United States)

Ichkova, Aleksandra; Rodriguez-Grande, Beatriz; Bar, Claire; Villega, Frederic; Konsman, Jan Pieter; Badaut, Jerome

2017-12-01

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Indeed, the acute mechanical injury often evolves to a chronic brain disorder with long-term cognitive, emotional and social dysfunction even in the case of mild TBI. Contrary to the commonly held idea that children show better recovery from injuries than adults, pediatric TBI patients actually have worse outcome than adults for the same injury severity. Acute trauma to the young brain likely interferes with the fine-tuned developmental processes and may give rise to long-lasting consequences on brain's function. This review will focus on cerebrovascular dysfunction as an important early event that may lead to long-term phenotypic changes in the brain after pediatric TBI. These, in turn may be associated with accelerated brain aging and cognitive dysfunction. Finally, since no effective treatments are currently available, understanding the unique pathophysiological mechanisms of pediatric TBI is crucial for the development of new therapeutic options. Copyright © 2017 Elsevier Ltd. All rights reserved.

Depolarization-stimulated 42K+ efflux in rat aorta is calcium- and cellular volume-dependent

International Nuclear Information System (INIS)

Magliola, L.; Jones, A.W.

1987-01-01

The purpose of this study was to investigate the factors controlling membrane permeability to potassium of smooth muscle cells from rat aorta stimulated by depolarization. The increase 42 K+ efflux (change in the rate constant) induced by depolarization (application of high concentrations of potassium chloride) was inhibited significantly by the calcium antagonists diltiazem and nisoldipine. Parallel inhibitory effects on contraction were observed. Diltiazem also inhibited potassium-stimulated 36 Cl- efflux. The addition of 25-150 mM KCl to normal physiologic solution stimulated 42 K+ efflux in a concentration-dependent manner. Diltiazem suppressed potassium-stimulated 42 K+ efflux approximately 90% at 25 mM KCl and approximately 40% at 150 mM KCl. The ability of nisoldipine to inhibit 42 K+ efflux also diminished as the potassium chloride concentration was elevated. The component of efflux that was resistant to calcium antagonists probably resulted from a decrease in the electrochemical gradient for potassium. Cellular water did not change during potassium addition. Substitution of 80 and 150 mM KCl for sodium chloride produced cellular swelling and enhanced potassium-stimulated 42 K+ efflux compared with potassium chloride addition. The addition of sucrose to prevent cellular swelling reduced efflux response to potassium substitution toward that of potassium addition. A hypoosmolar physiologic solution produced an increase in the 42 K+ efflux and a contracture that were both prevented by the addition of sucrose. We concluded that the depolarization-mediated 42 K+ efflux has three components: one is calcium dependent; a second is dependent on cellular volume; and a third is resistant to inhibition by calcium antagonists

The Toxicity of Depleted Uranium

Directory of Open Access Journals (Sweden)

Wayne Briner

2010-01-01

Full Text Available Depleted uranium (DU is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

A long-lasting wireless stimulator for small mammals

Directory of Open Access Journals (Sweden)

Ian D Hentall

2013-10-01

Full Text Available The chronic effects of electrical stimulation in unrestrained awake rodents are best studied with a wireless neural stimulator that can operate unsupervised for several weeks or more. A robust, inexpensive, easily built, cranially implantable stimulator was developed to explore the restorative effects of brainstem stimulation after neurotrauma. Its connectorless electrodes directly protrude from a cuboid epoxy capsule containing all circuitry and power sources. This physical arrangement prevents fluid leaks or wire breakage and also simplifies and speeds implantation. Constant-current pulses of high compliance (34 volts are delivered from a step-up voltage regulator under microprocessor control. A slowly pulsed magnetic field controls activation state and stimulation parameters. Program status is signaled to a remote reader by interval-modulated infrared pulses. Capsule size is limited by the two batteries. Silver oxide batteries rated at 8 milliamp-hours were used routinely in 8 mm wide, 15 mm long and 4 mm high capsules. Devices of smaller contact area (5 by 12 mm but taller (6 mm were created for mice. Microstimulation of the rat’s raphe nuclei with intermittent 5-minute (50% duty cycle trains of 30 µA, 1 ms pulses at 8 or 24 Hz frequency during 12 daylight hours lasted 21.1 days ±0.8 (mean ± standard error, Kaplan-Meir censored estimate, n=128. Extended lifetimes (>6 weeks, no failures, n=16 were achieved with larger batteries (44 milliamp-hours in longer (18 mm, taller (6 mm capsules. The circuit and electrode design are versatile; simple modifications allowed durable constant-voltage stimulation of the rat’s sciatic nerve through a cylindrical cathode from a subcutaneous pelvic capsule. Devices with these general features can address in small mammals many of the biological and technical questions arising neurosurgically with prolonged peripheral or deep brain stimulation.

Long-lasting amelioration of walking trajectory in neglect after prismatic adaptation

Directory of Open Access Journals (Sweden)

Marco eRabuffetti

2013-07-01

Full Text Available In the present investigation we explored the effect of prismatic adaptation (PA applied to the upper right limb on the walking trajectory of a neglect patient with more severe neglect in far than in near space. The patient was asked to bisect a line fixed to the floor by walking across it before and after four sessions of PA distributed over a time frame of 67 days. Gait path was analysed by means of an optoelectronic motion analysis system.The walking trajectory improved following PA and the result was maintained at follow-up, fifteen months after treatment. The improvement was greater for the predicted bisection error (estimated on the basis of the trajectory extrapolated from the first walking step then for the observed bisection error (measured at line crossing.These results show that PA may act on high level spatial representation of gait trajectory rather than on lower level sensory-motor gait components and suggest that PA may have a long lasting rehabilitative effect on neglect patients showing a deviated walking trajectory.

Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

DEFF Research Database (Denmark)

Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.

2015-01-01

Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind...... of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

Effect of intermittent glutamine supplementation on skeletal muscle is not long-lasting in very old rats.

Science.gov (United States)

Meynial-Denis, D; Beaufrère, A-M; Mignon, M; Patureau Mirand, P

2013-01-01

Muscle is the major site for glutamine synthesis via glutamine synthetase (GS). This enzyme is increased 1.5-2 fold in 25-27-mo rats and may be a consequence of aging-induced stress. This stimulation is similar to the induction observed following a catabolic state such as glucocorticoid treatment (6 to 24 months). Although oral glutamine supply regulates the plasma glutamine level, nothing is known if this supplementation is interrupted before the experiment. Adult (8-mo) and very old (27-mo) female rats were exposed to intermittent glutamine supplementation for 50 % of their age lifetime. Treated rats received glutamine added to their drinking water and control rats water alone but the effect of glutamine supplementation was only studied 15 days after the last supplementation. Glutamine pretreatment discontinued 15 days before the experiment increased plasma glutamine to ~ 0.6 mM, a normal value in very old rats. However, it failed to decrease the up-regulated GS activity in skeletal muscle from very old rats. Our results suggest that long-term treatment with glutamine started before advanced age but discontinued 15 days before rat sacrifice is effective in increasing plasma glutamine to recover basal adult value and in maintaining plasma glutamine in very old rats, but has no long-lasting effect on the GS activity of skeletal muscle with advanced age.

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

International Nuclear Information System (INIS)

Alba, Martha P.; Suarez, Carlos F.; Varela, Yahson; Patarroyo, Manuel A.; Bermudez, Adriana; Patarroyo, Manuel E.

2016-01-01

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPII L 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche − rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche + orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory. - Highlights: • Stereo-electronic and topochemical rules associated with FPLLI immunological memory. • Presence of very high long-lasting antibody titres against Plasmodium falciparum Spz. • Protective memory induction associated with a binding capacity to HLA-DRβ1*. • gauche − rotamer orientation in p8 polar residue is related to is related to immunological memory.

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

Energy Technology Data Exchange (ETDEWEB)

Alba, Martha P.; Suarez, Carlos F. [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad del Rosario, Bogotá D. C. (Colombia); Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá (Colombia); Varela, Yahson [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Patarroyo, Manuel A.; Bermudez, Adriana [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad del Rosario, Bogotá D. C. (Colombia); Patarroyo, Manuel E., E-mail: mepatarr@gmail.com [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad Nacional de Colombia, Bogotá D. C. (Colombia)

2016-09-02

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPII{sub L} 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche{sup −} rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche{sup +} orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory. - Highlights: • Stereo-electronic and topochemical rules associated with FPLLI immunological memory. • Presence of very high long-lasting antibody titres against Plasmodium falciparum Spz. • Protective memory induction associated with a binding capacity to HLA-DRβ1*. • gauche{sup −} rotamer orientation in p8 polar residue is related to is related to immunological memory.

Comparative Analysis of VERA Depletion Problems

International Nuclear Information System (INIS)

Park, Jinsu; Kim, Wonkyeong; Choi, Sooyoung; Lee, Hyunsuk; Lee, Deokjung

2016-01-01

Each code has its own solver for depletion, which can produce different depletion calculation results. In order to produce reference solutions for depletion calculation comparison, sensitivity studies should be preceded for each depletion solver. The sensitivity tests for burnup interval, number of depletion zones, and recoverable energy per fission (Q-value) were performed in this paper. For the comparison of depletion calculation results, usually the multiplication factors are compared as a function of burnup. In this study, new comparison methods have been introduced by using the number density of isotope or element, and a cumulative flux instead of burnup. In this paper, optimum depletion calculation options are determined through the sensitivity study of the burnup intervals and the number of depletion intrazones. Because the depletion using CRAM solver performs well for large burnup intervals, smaller number of burnup steps can be used to produce converged solutions. It was noted that the depletion intra-zone sensitivity is only pin-type dependent. The 1 and 10 depletion intra-zones for the normal UO2 pin and gadolinia rod, respectively, are required to obtain the reference solutions. When the optimized depletion calculation options are used, the differences of Q-values are found to be a main cause of the differences of solutions. In this paper, new comparison methods were introduced for consistent code-to-code comparisons even when different kappa libraries were used in the depletion calculations

Long-lasting solar energetic electron injection during the 26 Dec 2013 widespread SEP event

Science.gov (United States)

Dresing, N.; Klassen, A.; Temmer, M.; Gomez-Herrero, R.; Heber, B.; Veronig, A.

2017-12-01

The solar energetic particle (SEP) event on 26 Dec 2013 was detected all around the Sun by the two STEREO spacecraft and close-to-Earth observers. While the two STEREOs were separated by 59 degrees and situated at the front side of the associated large coronal event, it was a backside-event for Earth. Nevertheless, significant and long-lasting solar energetic electron anisotropies together with long rise times were observed at all three viewpoints, pointing to an extended electron injection. Although the CME-driven shock appears to account for the SEP event at a first glance a more detailed view reveals a more complex scenario: A CME-CME interaction takes place during the very early phase of the SEP event. Furthermore, four hours after the onset of the event, a second component is measured at all three viewpoints on top of the first SEP increase, mainly consisting of high energy particles. We find that the CME-driven shock alone can hardly account for the observed SEP event in total but a trapping scenario together with ongoing particle acceleration is more likely.

Slow Bursting Neurons of Mouse Cortical Layer 6b Are Depolarized by Hypocretin/Orexin and Major Transmitters of Arousal.

Science.gov (United States)

Wenger Combremont, Anne-Laure; Bayer, Laurence; Dupré, Anouk; Mühlethaler, Michel; Serafin, Mauro

2016-01-01

Neurons firing spontaneously in bursts in the absence of synaptic transmission have been previously recorded in different layers of cortical brain slices. It has been suggested that such neurons could contribute to the generation of alternating UP and DOWN states, a pattern of activity seen during slow-wave sleep. Here, we show that in layer 6b (L6b), known from our previous studies to contain neurons highly responsive to the wake-promoting transmitter hypocretin/orexin (hcrt/orx), there is a set of neurons, endowed with distinct intrinsic properties, which displayed a strong propensity to fire spontaneously in rhythmic bursts. In response to small depolarizing steps, they responded with a delayed firing of action potentials which, upon higher depolarizing steps, invariably inactivated and were followed by a depolarized plateau potential and a depolarizing afterpotential. These cells also displayed a strong hyperpolarization-activated rectification compatible with the presence of an I h current. Most L6b neurons with such properties were able to fire spontaneously in bursts. Their bursting activity was of intrinsic origin as it persisted not only in presence of blockers of ionotropic glutamatergic and GABAergic receptors but also in a condition of complete synaptic blockade. However, a small number of these neurons displayed a mix of intrinsic bursting and synaptically driven recurrent UP and DOWN states. Most of the bursting L6b neurons were depolarized and excited by hcrt/orx through a direct postsynaptic mechanism that led to tonic firing and eventually inactivation. Similarly, they were directly excited by noradrenaline, histamine, dopamine, and neurotensin. Finally, the intracellular injection of these cells with dye and their subsequent Neurolucida reconstruction indicated that they were spiny non-pyramidal neurons. These results lead us to suggest that the propensity for slow rhythmic bursting of this set of L6b neurons could be directly impeded by hcrt

Human dignity as a component of a long-lasting and widespread conceptual construct.

Science.gov (United States)

Baertschi, Bernard

2014-06-01

For some decades, the concept of human dignity has been widely discussed in bioethical literature. Some authors think that this concept is central to questions of respect for human beings, whereas others are very critical of it. It should be noted that, in these debates, dignity is one component of a long-lasting and widespread conceptual construct used to support a stance on the ethical question of the moral status of an action or being. This construct has been used from Modernity onward to condemn slavery and torture as violations of human dignity. In spelling it out, we can come to a better understanding of what "dignity" means and become aware that there exists a quite useful place for this notion in our ethical thought, albeit a modest one.

Depleted-Uranium Weapons: the Whys and Wherefores

OpenAIRE

Gsponer, Andre

2003-01-01

The only military application in which depleted-uranium (DU) alloys out-perform present-day tungsten alloys is long-rod penetration into a main battle-tank's armor. However, this advantage is only on the order of 10%, and it disappears when the comparison is made in terms of actual lethality of complete anti-tank systems instead of laboratory-type steel penetration capability. Therefore, new micro- and nano-engineered tungsten alloys may soon out-perform DU alloys, enabling the production of ...

An Atlantic-Pacific ventilation seesaw across the last deglaciation

OpenAIRE

Freeman, E; Skinner, Luke Cameron; Tisserand, A; Dokken, T; Timmermann, A; Menviel, L; Friedrich, T

2015-01-01

It has been proposed that the rapid rise of atmospheric CO2across the last deglaciation was driven by the release of carbon from an extremely radiocarbon-depleted abyssal ocean reservoir that was ‘vented’ to the atmosphere primarily via the deep-and intermediate overturning loops in the Southern Ocean. While some radiocarbon observations from the intermediate ocean appear to confirm this hypothesis, others appear to refute it. Here we use radiocarbon measurements in paired benthic-and plankto...

Chronic sleep restriction induces long-lasting changes in adenosine and noradrenaline receptor density in the rat brain.

Science.gov (United States)

Kim, Youngsoo; Elmenhorst, David; Weisshaupt, Angela; Wedekind, Franziska; Kroll, Tina; McCarley, Robert W; Strecker, Robert E; Bauer, Andreas

2015-10-01

Although chronic sleep restriction frequently produces long-lasting behavioural and physiological impairments in humans, the underlying neural mechanisms are unknown. Here we used a rat model of chronic sleep restriction to investigate the role of brain adenosine and noradrenaline systems, known to regulate sleep and wakefulness, respectively. The density of adenosine A1 and A2a receptors and β-adrenergic receptors before, during and following 5 days of sleep restriction was assessed with autoradiography. Rats (n = 48) were sleep-deprived for 18 h day(-1) for 5 consecutive days (SR1-SR5), followed by 3 unrestricted recovery sleep days (R1-R3). Brains were collected at the beginning of the light period, which was immediately after the end of sleep deprivation on sleep restriction days. Chronic sleep restriction increased adenosine A1 receptor density significantly in nine of the 13 brain areas analysed with elevations also observed on R3 (+18 to +32%). In contrast, chronic sleep restriction reduced adenosine A2a receptor density significantly in one of the three brain areas analysed (olfactory tubercle which declined 26-31% from SR1 to R1). A decrease in β-adrenergic receptors density was seen in substantia innominata and ventral pallidum which remained reduced on R3, but no changes were found in the anterior cingulate cortex. These data suggest that chronic sleep restriction can induce long-term changes in the brain adenosine and noradrenaline receptors, which may underlie the long-lasting neurocognitive impairments observed in chronic sleep restriction. © 2015 European Sleep Research Society.

Intercellular K⁺ accumulation depolarizes Type I vestibular hair cells and their associated afferent nerve calyx.

Science.gov (United States)

Contini, D; Zampini, V; Tavazzani, E; Magistretti, J; Russo, G; Prigioni, I; Masetto, S

2012-12-27

Mammalian vestibular organs contain two types of sensory receptors, named Type I and Type II hair cells. While Type II hair cells are contacted by several small afferent nerve terminals, the basolateral surface of Type I hair cells is almost entirely enveloped by a single large afferent nerve terminal, called calyx. Moreover Type I, but not Type II hair cells, express a low-voltage-activated outward K(+) current, I(K,L), which is responsible for their much lower input resistance (Rm) at rest as compared to Type II hair cells. The functional meaning of I(K,L) and associated calyx is still enigmatic. By combining the patch-clamp whole-cell technique with the mouse whole crista preparation, we have recorded the current- and voltage responses of in situ hair cells. Outward K(+) current activation resulted in K(+) accumulation around Type I hair cells, since it induced a rightward shift of the K(+) reversal potential the magnitude of which depended on the amplitude and duration of K(+) current flow. Since this phenomenon was never observed for Type II hair cells, we ascribed it to the presence of a residual calyx limiting K(+) efflux from the synaptic cleft. Intercellular K(+) accumulation added a slow (τ>100ms) depolarizing component to the cell voltage response. In a few cases we were able to record from the calyx and found evidence for intercellular K(+) accumulation as well. The resulting depolarization could trigger a discharge of action potentials in the afferent nerve fiber. Present results support a model where pre- and postsynaptic depolarization produced by intercellular K(+) accumulation cooperates with neurotransmitter exocytosis in sustaining afferent transmission arising from Type I hair cells. While vesicular transmission together with the low Rm of Type I hair cells appears best suited for signaling fast head movements, depolarization produced by intercellular K(+) accumulation could enhance signal transmission during slow head movements. Copyright �

Ozone depletion, related UVB changes and increased skin cancer incidence

Science.gov (United States)

Kane, R. P.

1998-03-01

Stratospheric ozone at middle latitudes shows a seasonal variation of about +/-20%, a quasi-biennial oscillation of 1-10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10-20%, which should cause an increase in skin cancer incidence of about 20-40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974-1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and

Further insights into blood pressure induced premature beats: Transient depolarizations are associated with fast myocardial deformation upon pressure decline.

Science.gov (United States)

Haemers, Peter; Sutherland, George; Cikes, Maja; Jakus, Nina; Holemans, Patricia; Sipido, Karin R; Willems, Rik; Claus, Piet

2015-11-01

An acute increase in blood pressure is associated with the occurrence of premature ventricular complexes (PVCs). We aimed to study the timing of these PVCs with respect to afterload-induced changes in myocardial deformation in a controlled, preclinically relevant, novel closed-chest pig model. An acute left ventricular (LV) afterload challenge was induced by partial balloon inflation in the descending aorta, lasting 5-10 heartbeats (8 pigs; 396 inflations). Balloon inflation enhanced the reflected wave (augmentation index 30% ± 8% vs 59% ± 6%; P blood pressure by 35% ± 4%. This challenge resulted in a more abrupt LV pressure decline, which was delayed beyond ventricular repolarization (rate of pressure decline 0.16 ± 0.01 mm Hg/s vs 0.27 ± 0.04 mm Hg/ms; P pressure 1 ± 12 ms vs 36 ± 9 ms; P = .008), during which the velocity of myocardial shortening at the basal septum increased abruptly (ie, postsystolic shortening) (peak strain rate -0.6 ± 0.5 s(-1) vs -2.5 ± 0.8 s(-1); P pressure decline, with increased postsystolic shortening, and not at peak pressure, that PVCs occur (22% of inflations). These PVCs preferentially occurred at the basal and apical segments. In the same regions, monophasic action potentials demonstrated the appearance of delayed afterdepolarization-like transient depolarizations as origin of PVCs. An acute blood pressure increase results in a more abrupt LV pressure decline, which is delayed after ventricular repolarization. This has a profound effect on myocardial mechanics with enhanced postsystolic shortening. Coincidence with induced transient depolarizations and PVCs provides support for the mechanoelectrical origin of pressure-induced premature beats. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Collisional broadening of depolarized spectral lines of hydrogen gases at low temperatures

International Nuclear Information System (INIS)

Hout, K.D. van den.

1978-01-01

Experimental results are presented for the collisional broadening and shift of H 2 , D 2 and HD rotational Raman and depolarized Rayleigh lines at various temperatures between 25 K and 300 K. These are then discussed within the context of current theoretical concepts. For a few temperatures the line broadening cross sections are also reported as a function of the ortho-para composition for H 2 and D 2 . (C.F.)

B cell depletion reduces T cell activation in pancreatic islets in a murine autoimmune diabetes model.

Science.gov (United States)

Da Rosa, Larissa C; Boldison, Joanne; De Leenheer, Evy; Davies, Joanne; Wen, Li; Wong, F Susan

2018-06-01

Type 1 diabetes is a T cell-mediated autoimmune disease characterised by the destruction of beta cells in the islets of Langerhans, resulting in deficient insulin production. B cell depletion therapy has proved successful in preventing diabetes and restoring euglycaemia in animal models of diabetes, as well as in preserving beta cell function in clinical trials in the short term. We aimed to report a full characterisation of B cell kinetics post B cell depletion, with a focus on pancreatic islets. Transgenic NOD mice with a human CD20 transgene expressed on B cells were injected with an anti-CD20 depleting antibody. B cells were analysed using multivariable flow cytometry. There was a 10 week delay in the onset of diabetes when comparing control and experimental groups, although the final difference in the diabetes incidence, following prolonged observation, was not statistically significant (p = 0.07). The co-stimulatory molecules CD80 and CD86 were reduced on stimulation of B cells during B cell depletion and repopulation. IL-10-producing regulatory B cells were not induced in repopulated B cells in the periphery, post anti-CD20 depletion. However, the early depletion of B cells had a marked effect on T cells in the local islet infiltrate. We demonstrated a lack of T cell activation, specifically with reduced CD44 expression and effector function, including IFN-γ production from both CD4 + and CD8 + T cells. These CD8 + T cells remained altered in the pancreatic islets long after B cell depletion and repopulation. Our findings suggest that B cell depletion can have an impact on T cell regulation, inducing a durable effect that is present long after repopulation. We suggest that this local effect of reducing autoimmune T cell activity contributes to delay in the onset of autoimmune diabetes.

Seizures, refractory status epilepticus, and depolarization block as endogenous brain activities

Science.gov (United States)

El Houssaini, Kenza; Ivanov, Anton I.; Bernard, Christophe; Jirsa, Viktor K.

2015-01-01

Epilepsy, refractory status epilepticus, and depolarization block are pathological brain activities whose mechanisms are poorly understood. Using a generic mathematical model of seizure activity, we show that these activities coexist under certain conditions spanning the range of possible brain activities. We perform a detailed bifurcation analysis and predict strategies to escape from some of the pathological states. Experimental results using rodent data provide support of the model, highlighting the concept that these pathological activities belong to the endogenous repertoire of brain activities.

Selection of a management strategy for depleted uranium hexafluoride

International Nuclear Information System (INIS)

Patton, S.E.; Hanrahan, E.J.; Bradley, C.E.

1995-01-01

A consequence of the uranium enrichment process used in the United States (US) is the accumulation of a significant amount of depleted uranium hexafluoride (UF 6 ). Currently, approximately 560,000 metric tons of the material are stored at three different sites. The US Department of Energy (DOE) has recently initiated a program to consider alternative strategies for the cost-effective and environmentally safe long-term management of this inventory of depleted UF 6 . The program involves a technology and engineering assessment of proposed management options (use/reuse, conversion, storage, or disposal) and an analysis of the potential environmental impacts and life-cycle costs of alternative management strategies. The information obtained from the studies will be used by the DOE to select a preferred long-term management strategy. The selection and implementation of a management strategy will involve consideration of a number of important issues such as environmental, health, and safety effects; the balancing of risks versus costs in a context of reduced government spending; socioeconomic implications, including effects on the domestic and international uranium industry; the technical status of proposed uses or technologies; and public involvement in the decision making process. Because of its provisions for considering a wide range of relevant issues and involving the public, this program has become a model for future DOE materials disposition programs. This paper presents an overview of the Depleted Uranium Hexafluoride Management Program. Technical findings of the program to date are presented, and major issues involved in selecting and implementing a management strategy are discussed

Ozone-depleting Substances (ODS)

Data.gov (United States)

U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

Mitochondrial depolarization in yeast zygotes inhibits clonal expansion of selfish mtDNA.

Science.gov (United States)

Karavaeva, Iuliia E; Golyshev, Sergey A; Smirnova, Ekaterina A; Sokolov, Svyatoslav S; Severin, Fedor F; Knorre, Dmitry A

2017-04-01

Non-identical copies of mitochondrial DNA (mtDNA) compete with each other within a cell and the ultimate variant of mtDNA present depends on their relative replication rates. Using yeast Saccharomyces cerevisiae cells as a model, we studied the effects of mitochondrial inhibitors on the competition between wild-type mtDNA and mutant selfish mtDNA in heteroplasmic zygotes. We found that decreasing mitochondrial transmembrane potential by adding uncouplers or valinomycin changes the competition outcomes in favor of the wild-type mtDNA. This effect was significantly lower in cells with disrupted mitochondria fission or repression of the autophagy-related genes ATG8 , ATG32 or ATG33 , implying that heteroplasmic zygotes activate mitochondrial degradation in response to the depolarization. Moreover, the rate of mitochondrially targeted GFP turnover was higher in zygotes treated with uncoupler than in haploid cells or untreated zygotes. Finally, we showed that vacuoles of zygotes with uncoupler-activated autophagy contained DNA. Taken together, our data demonstrate that mitochondrial depolarization inhibits clonal expansion of selfish mtDNA and this effect depends on mitochondrial fission and autophagy. These observations suggest an activation of mitochondria quality control mechanisms in heteroplasmic yeast zygotes. © 2017. Published by The Company of Biologists Ltd.

Fast-switching optically isotropic liquid crystal nano-droplets with improved depolarization and Kerr effect by doping high k nanoparticles.

Science.gov (United States)

Kim, Byeonggon; Kim, Hyun Gyu; Shim, Gyu-Yeop; Park, Ji-Sub; Joo, Kyung-Il; Lee, Dong-Jin; Lee, Joun-Ho; Baek, Ji-Ho; Kim, Byeong Koo; Choi, Yoonseuk; Kim, Hak-Rin

2018-01-10

We proposed and analyzed an optically isotropic nano-droplet liquid crystal (LC) doped with high k nanoparticles (NPs), exhibiting enhanced Kerr effects, which could be operated with reduced driving voltages. For enhancing the contrast ratio together with the light efficiencies, the LC droplet sizes were adjusted to be shorter than the wavelength of visible light to reduce depolarization effects by optical scattering of the LC droplets. Based on the optical analysis of the depolarization effects, the influence of the relationship between the LC droplet size and the NP doping ratio on the Kerr effect change was investigated.

Depolarization of fluorescence of polyatomic molecules in noble gas solvents

Science.gov (United States)

Blokhin, A. P.; Gelin, M. F.; Kalosha, I. I.; Matylitsky, V. V.; Erohin, N. P.; Barashkov, M. V.; Tolkachev, V. A.

2001-10-01

The collisional depolarization of fluorescence is studied for p-quarterphenyl (PQP) in He, Ar, Xe solvents, under pressures ranging from zero to nearly atmospheric. The results are interpreted within the Keilson-Storer model of the orientational relaxation and smooth rigid body collision dynamics. This allows us to estimate the rate of the angular momentum scrambling due to encounters of PQP with its partners. The collisions are shown to be neither strong nor weak, so that the averaged number of encounters giving rise to the PQP angular momentum randomization equals to 33 (PQP-He), 4.5 (PQP-Ar), and 2.1 (PQP-Xe).

Depolarization corrections to the coercive field in thin-film ferroelectrics

International Nuclear Information System (INIS)

Dawber, M; Chandra, P; Littlewood, P B; Scott, J F

2003-01-01

Empirically, the coercive field needed to reverse the polarization in a ferroelectric increases with decreasing film thickness. For ferroelectric films of 100 μm to 100 nm in thickness the coercive field has been successfully described by a semi-empirical scaling law. Accounting for depolarization corrections, we show that this scaling behaviour is consistent with field measurements of ultrathin ferroelectric capacitors down to one nanometre in film thickness. Our results also indicate that the minimum film thickness, determined by a polarization instability, can be tuned by the choice of electrodes, and recommendations for next-generation ferroelectric devices are discussed. (letter to the editor)

Depolarization corrections to the coercive field in thin-film ferroelectrics

CERN Document Server

Dawber, M; Littlewood, P B; Scott, J F

2003-01-01

Empirically, the coercive field needed to reverse the polarization in a ferroelectric increases with decreasing film thickness. For ferroelectric films of 100 mu m to 100 nm in thickness the coercive field has been successfully described by a semi-empirical scaling law. Accounting for depolarization corrections, we show that this scaling behaviour is consistent with field measurements of ultrathin ferroelectric capacitors down to one nanometre in film thickness. Our results also indicate that the minimum film thickness, determined by a polarization instability, can be tuned by the choice of electrodes, and recommendations for next-generation ferroelectric devices are discussed. (letter to the editor)

Effect of ouabain on the gamma-[3H]aminobutyric acid uptake and release in the absence of Ca(+)+ and K(+)-depolarization

International Nuclear Information System (INIS)

Santos, M.S.; Goncalves, P.P.; Carvalho, A.P.

1990-01-01

The effect of ouabain on the uptake of tritiated [ 3 H]GABA and on its release in the absence of Ca(+)+ was studied in brain cortex synaptosomes. Ouabain, in the absence of Ca(+)+ and K(+)-depolarization, induces the release of [ 3 H]GABA with half-maximal effect occurring at a concentration of about 7 X 10(-6) M. Parallel measurements of the effects of ouabain on the [ 3 H]GABA uptake and the Na+,K(+)-adenosine triphosphatase activity show that ouabain inhibits both mechanisms and that the half-maximal effect also occurs at about the same ouabain concentration. Although [ 3 H]GABA release is stimulated by ouabain, it appears that the inhibition of [ 3 H]GABA uptake is due to a direct effect on the uptake mechanism, inasmuch as the initial velocity of the process is inhibited by ouabain. Ouabain requires extracellular Na+ for [ 3 H]GABA release and for membrane depolarization and, in the absence of Na+, ouabain does not cause either [ 3 H]GABA release or membrane depolarization. No significant changes in the Na+ gradients occur under conditions which permit release of [ 3 H]GABA, but the Na+,K(+)-adenosine triphosphatase activity is inhibited, which may be responsible for membrane depolarization, which in turn may cause [ 3 H]GABA release or inhibit its uptake

Linear Depolarization of Lidar Returns by Aged Smoke Particles

Science.gov (United States)

Mishchenko, Michael I.; Dlugach, Janna M.; Liu, Li

2016-01-01

We use the numerically exact (superposition) T-matrix method to analyze recent measurements of the backscattering linear depolarization ratio (LDR) for a plume of aged smoke at lidar wavelengths ranging from 355 to 1064 nm. We show that the unique spectral dependence of the measured LDRs can be modeled, but only by assuming expressly nonspherical morphologies of smoke particles containing substantial amounts of nonabsorbing (or weakly absorbing) refractory materials such as sulfates. Our results demonstrate that spectral backscattering LDR measurements can be indicative of the presence of morphologically complex smoke particles, but additional (e.g., passive polarimetric or bistatic lidar) measurements may be required for a definitive characterization of the particle morphology and composition.

Evaluation of nuclides with closely spaced values of depletion constants in transmutation chains

International Nuclear Information System (INIS)

Vukadin, Z.S.

1977-01-01

New method of calculating nuclide concentrations in a transmutation chain is developed in this thesis. Method is based on originally derived recurrence formulas for expansion series of depletion functions and on originally obtained, nonsingular, Bateman coefficients. Explicit expression for the nuclide concentrations in a transmutation chain is obtained. This expression can be used as it stands for arbitrary values of nuclides depletion constants. By computing hypothetical transmutation chains and neptunium series, method is compared with the Bateman analytical solution, with the approximate solutions and with the matrix exponential method. It comes out that the method presented in this thesis is suitable for calculating very long depletion chains even in the case of some closely spaced and/or equal values of nuclide depletion constants. Though, presented method is of great practical applicability in a number of nuclear physics problems that are dealing with the nuclide transmutations: starting from the studies of the stellar evolution up to the design of nuclear reactors (author) [sr

A neutron depolarization study of magnetic inhomogeneities in weak-link superconductors

International Nuclear Information System (INIS)

Zhuchenko, N.K.; Yagud, R.Z.

1993-01-01

Neutron depolarization measurements in the mixed state of both high-T c and low-T c weak-link superconductors have been carried out. Samples of YBCO, BSCCO, SnMo 6 S 8 and 0.5 Nb-0.5 Ti of different magnetic prehistory were analyzed at temperatures T 4.2 K under applied magnetic fields II <= 16.5 kOe. We ascribe the appearance of magnetic inhomogeneities and their hysteresis behaviour to the interaction between dipole magnetic fields (diamagnetic and paramagnetic ones) and applied magnetic fields

Adapting to an initial self-regulatory task cancels the ego depletion effect.

Science.gov (United States)

Dang, Junhua; Dewitte, Siegfried; Mao, Lihua; Xiao, Shanshan; Shi, Yucai

2013-09-01

The resource-based model of self-regulation provides a pessimistic view of self-regulation that people are destined to lose their self-control after having engaged in any act of self-regulation because these acts deplete the limited resource that people need for successful self-regulation. The cognitive control theory, however, offers an alternative explanation and suggests that the depletion effect reflects switch costs between different cognitive control processes recruited to deal with demanding tasks. This account implies that the depletion effect will not occur once people have had the opportunity to adapt to the self-regulatory task initially engaged in. Consistent with this idea, the present study showed that engaging in a demanding task led to performance deficits on a subsequent self-regulatory task (i.e. the depletion effect) only when the initial demanding task was relatively short but not when it was long enough for participants to adapt. Our results were unrelated to self-efficacy, mood, and motivation. Copyright © 2013 Elsevier Inc. All rights reserved.

“When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, S.J.; Adriaanse, M.A.; Vet, de E.W.M.L.; Fennis, B.M.; Ridder, de D.T.D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

Terrestrial ozone depletion due to a Milky Way gamma-ray burst

Science.gov (United States)

Thomas, Brian C.

Gamma-Ray Bursts (GRBs) are short, incredibly powerful astrophysical events which produce a flux of radiation detectable across the observable universe. A GRB within our own galaxy could cause major damage to the Earth's biosphere. Rate estimates suggest that at least one GRB has occurred within a dangerous range (about 2 kpc) in the last billion years. The gamma radiation from such a burst would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar UVB radiation reaching the surface. This radiation is harmful to life, causing sunburn and damaging DNA. In addition, NO 2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of a GRB. We have simulated bursts delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have computed DNA damage caused by increased solar UVB radiation, reduction in solar visible light due to NO 2 opacity; and deposition of nitrates through rainout of HNO 3 . For a "typical" burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 years after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. We find DNA damage of up to 16 times the normal annual global average, with greatest damage occurring at low to mid latitudes. We find reductions in visible sunlight of a few percent, primarily in the polar regions. Nitrate deposition similar to or slightly greater than that currently caused by lightning is also observed. We find support in our results for the hypothesis that the

A single footshock causes long-lasting hypoactivity in unknown environments that is dependent on the development of contextual fear conditioning.

Science.gov (United States)

Daviu, Núria; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

2010-09-01

Exposure to a single session of footshocks induces long-lasting inhibition of activity in unknown environments that markedly differ from the shock context. Interestingly, these effects are not necessarily associated to an enhanced anxiety and interpretation of this hypoactivity remains unclear. In the present experiment we further studied this phenomenon in male Sprague-Dawley rats. In a first experiment, a session of three shocks resulted in hypoactivity during exposure, 6-12days later, to three different unknown environments. This altered behaviour was not accompanied by a greater hypothalamic-pituitary-adrenal (HPA) activation, although greater HPA activation paralleling higher levels of freezing was observed in the shock context. In a second experiment we used a single shock and two procedures, one with pre-exposure to the context before the shock and another with immediate shock that did not induce contextual fear conditioning. Hypoactivity and a certain level of generalization of fear (freezing) to the unknown environments only appeared in the group that developed fear conditioning, but no evidence for enhanced anxiety in the elevated plus-maze was found in any group. The results suggest that if animals are able to associate an aversive experience with a distinct unknown environment, they would display more cautious behaviour in any unknown environment and such strategy persists despite repeated experience with different environments. This long-lasting cautious behaviour was not associated to greater HPA response to the unknown environment that was however observed in the shock context. The present findings raised some concerns about interpretation of long-lasting behavioural changes caused by brief stressors. Copyright 2010 Elsevier Inc. All rights reserved.

Ego Depletion Impairs Implicit Learning

Science.gov (United States)

Thompson, Kelsey R.; Sanchez, Daniel J.; Wesley, Abigail H.; Reber, Paul J.

2014-01-01

Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent. PMID:25275517

Ego depletion impairs implicit learning.

Directory of Open Access Journals (Sweden)

Kelsey R Thompson

Full Text Available Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

Ego depletion impairs implicit learning.

Science.gov (United States)

Thompson, Kelsey R; Sanchez, Daniel J; Wesley, Abigail H; Reber, Paul J

2014-01-01

Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

The Southern Ocean's role in carbon exchange during the last deglaciation.

Science.gov (United States)

Burke, Andrea; Robinson, Laura F

2012-02-03

Changes in the upwelling and degassing of carbon from the Southern Ocean form one of the leading hypotheses for the cause of glacial-interglacial changes in atmospheric carbon dioxide. We present a 25,000-year-long Southern Ocean radiocarbon record reconstructed from deep-sea corals, which shows radiocarbon-depleted waters during the glacial period and through the early deglaciation. This depletion and associated deep stratification disappeared by ~14.6 ka (thousand years ago), consistent with the transfer of carbon from the deep ocean to the surface ocean and atmosphere via a Southern Ocean ventilation event. Given this evidence for carbon exchange in the Southern Ocean, we show that existing deep-ocean radiocarbon records from the glacial period are sufficiently depleted to explain the ~190 per mil drop in atmospheric radiocarbon between ~17 and 14.5 ka.

Exposure to nature counteracts aggression after depletion.

Science.gov (United States)

Wang, Yan; She, Yihan; Colarelli, Stephen M; Fang, Yuan; Meng, Hui; Chen, Qiuju; Zhang, Xin; Zhu, Hongwei

2018-01-01

Acts of self-control are more likely to fail after previous exertion of self-control, known as the ego depletion effect. Research has shown that depleted participants behave more aggressively than non-depleted participants, especially after being provoked. Although exposure to nature (e.g., a walk in the park) has been predicted to replenish resources common to executive functioning and self-control, the extent to which exposure to nature may counteract the depletion effect on aggression has yet to be determined. The present study investigated the effects of exposure to nature on aggression following depletion. Aggression was measured by the intensity of noise blasts participants delivered to an ostensible opponent in a competition reaction-time task. As predicted, an interaction occurred between depletion and environmental manipulations for provoked aggression. Specifically, depleted participants behaved more aggressively in response to provocation than non-depleted participants in the urban condition. However, provoked aggression did not differ between depleted and non-depleted participants in the natural condition. Moreover, within the depletion condition, participants in the natural condition had lower levels of provoked aggression than participants in the urban condition. This study suggests that a brief period of nature exposure may restore self-control and help depleted people regain control over aggressive urges. © 2017 Wiley Periodicals, Inc.

Magnetic-field dependence of impurity-induced muon depolarization in noble metals

International Nuclear Information System (INIS)

Schillaci, M.E.; Heffner, R.H.; Hutson, R.L.; Leon, M.; Cooke, D.W.; Dodds, S.A.; Richards, P.M.; MacLaughlin, D.E.; Boekema, C.

1983-01-01

We have measured the magnetic-field dependence of the muon depolarization rate up to 5 kOe in AuGd (350 ppM), AgGd (340 ppM) and AgEr (300 ppM). A simple model which includes both dipolar and nearest-neighbor contact interactions between the muon and the magnetic impurity does not fit the data. An axial crystal-field interaction, arising from the electric-field gradient induced by the muon at the site of the impurity, is found to dominate the Hamiltonian, and may have a large effect on the field dependence

Magnetic field dependence of impurity-induced muon depolarization in noble metals

Energy Technology Data Exchange (ETDEWEB)

Schillaci, M.E.; Heffner, R.H.; Hutson, R.L.; Leon, M.; Cooke, D.W.; Yaouanc, A. (Los Alamos National Lab., NM (USA)); Dodds, S.A. (Rice Univ., Houston, TX (USA). Dept. of Physics); Richards, P.M. (Sandia National Labs., Albuquerque, NM (USA)); MacLaughlin, D.E. (California Univ., Riverside (USA)); Boekema, C. (Texas Tech Univ., Lubbock (USA))

1984-01-01

The authors have measured the magnetic field dependence of the muon depolarization rate up to 5 kOe in AuGd (350 ppm), AgGd (340 ppm) and AgEr (300 ppm). A simple model which includes both dipolar and nearest-neighbor contact interactions between the muon and the magnetic impurity does not fit the data. An axial crystal-field interaction, arising from the electric field gradient induced by the muon at the site of the impurity, is found to dominate the Hamiltonian, and may have a large effect on the field dependence.

Cat odor causes long-lasting contextual fear conditioning and increased pituitary-adrenal activation, without modifying anxiety.

Science.gov (United States)

Muñoz-Abellán, Cristina; Daviu, Nuria; Rabasa, Cristina; Nadal, Roser; Armario, Antonio

2009-10-01

A single exposure to a cat or cat odors has been reported by some groups to induce contextual and auditory fear conditioning and long-lasting changes in anxiety-like behaviour, but there is no evidence for parallel changes in biological stress markers. In the present study we demonstrated in male rats that exposure to a novel environment containing a cloth impregnated with cat fur odor resulted in avoidance of the odor, lower levels of activity and higher pituitary-adrenal (PA) response as compared to those exposed to the novel environment containing a clean cloth, suggesting increased levels of stress in the former animals. When re-exposed 9 days later to the same environment with a clean cloth, previously cat fur exposed rats again showed avoidance of the cloth area and lower levels of activity, suggesting development of contextual fear conditioning, which again was associated with a higher PA activation. In contrast, unaltered both anxiety-like behaviour and PA responsiveness to an elevated plus-maze were found 7 days after cat odor exposure. It is concluded that: (i) PA activation is able to reflect both the stressful properties of cat fur odor and odor-induced contextual fear conditioning; (ii) development of cat odor-induced contextual fear conditioning is independent of the induction of long-lasting changes in anxiety-like behaviour; and (iii) greater PA activation during exposure to the odor context is not explained by non-specific sensitization of the PA axis caused by previous exposure to cat fur odor.

Lactate per se improves the excitability of depolarized rat skeletal muscle by reducing the Cl- conductance

DEFF Research Database (Denmark)

de Paoli, Frank Vincenzo; Ørtenblad, Niels; Pedersen, Thomas Holm

2010-01-01

Studies on rats have shown that lactic acid can improve excitability and function of depolarized muscles. The effect has been related to the ensuing reduction in intracellular pH causing inhibition of muscle fibre Cl- channels. Since, however, several carboxylic acids with structural similarities...... to lactate can inhibit muscle Cl- channels it is possible that lactate per se can increase muscle excitability by exerting a direct effect on these channels. We therefore examined effects of lactate on the function of intact muscles and skinned fibres together with effects on pH and Cl- conductance....... In muscles where extracellular compound action potentials (M-waves) and tetanic force response to excitation were reduced by 82±4 and 83±2 %, respectively, by depolarization with 11 mM extracellular K+, both M-waves and force exhibited an up to 4-fold increase when 20 mM lactate was added. This effect...

Short-Term Dosage Regimen for Stimulation-Induced Long-Lasting Desynchronization

Directory of Open Access Journals (Sweden)

Thanos Manos

2018-04-01

Full Text Available In this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS robustly induces an anti-kindling at low intensities e.g., if the CR stimulation frequency (i.e., stimulus pattern repetition rate is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce

Short-Term Dosage Regimen for Stimulation-Induced Long-Lasting Desynchronization.

Science.gov (United States)

Manos, Thanos; Zeitler, Magteld; Tass, Peter A

2018-01-01

In this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR) stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS) robustly induces an anti-kindling at low intensities e.g., if the CR stimulation frequency (i.e., stimulus pattern repetition rate) is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS) turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce long

Depletion of superfluidity in a disordered non-equilibrium quantum condensate

Energy Technology Data Exchange (ETDEWEB)

Janot, Alexander; Rosenow, Bernd [Institut fuer Theoretische Physik, Universitaet Leipzig, 04009 Leipzig (Germany); Hyart, Timo [Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Eastham, Paul [School of Physics, Trinity College, Dublin 2 (Ireland)

2013-07-01

Observations of quantum coherence in driven systems, e.g. polariton condensates, have strongly stimulated experimental as well as theoretical efforts during the last decade. We analyze the superfluid stiffness of a non-equilibrium quantum-condensate in a disordered environment taking gain and loss of particles into account. To this end a modified effective Gross-Pitaevskii equation is employed. We find that the disorder-driven depletion of superfluidity is strongly enhanced due to the gain-loss mechanism. It turns out that the condensate remains stiff at finite length scales only.

Multi-scale entropic depletion phenomena in polymer liquids

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Debapriya [Department of Materials Science, University of Illinois, Urbana, Illinois 61801 (United States); Schweizer, Kenneth S., E-mail: kschweiz@illinois.edu [Department of Materials Science, University of Illinois, Urbana, Illinois 61801 (United States); Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

2015-06-07

We apply numerical polymer integral equation theory to study the entropic depletion problem for hard spheres dissolved in flexible chain polymer melts and concentrated solutions over an exceptionally wide range of polymer radius of gyration to particle diameter ratios (R{sub g}/D), particle-monomer diameter ratios (D/d), and chain lengths (N) including the monomer and oligomer regimes. Calculations are performed based on a calibration of the effective melt packing fraction that reproduces the isobaric dimensionless isothermal compressibility of real polymer liquids. Three regimes of the polymer-mediated interparticle potential of mean force (PMF) are identified and analyzed in depth. (i) The magnitude of the contact attraction that dominates thermodynamic stability scales linearly with D/d and exhibits a monotonic and nonperturbative logarithmic increase with N ultimately saturating in the long chain limit. (ii) A close to contact repulsive barrier emerges that grows linearly with D/d and can attain values far in excess of thermal energy for experimentally relevant particle sizes and chain lengths. This raises the possibility of kinetic stabilization of particles in nanocomposites. The barrier grows initially logarithmically with N, attains a maximum when 2R{sub g} ∼ D/2, and then decreases towards its asymptotic long chain limit as 2R{sub g} ≫ D. (iii) A long range (of order R{sub g}) repulsive, exponentially decaying component of the depletion potential emerges when polymer coils are smaller than, or of order, the nanoparticle diameter. Its amplitude is effectively constant for 2R{sub g} ≤ D. As the polymer becomes larger than the particle, the amplitude of this feature decreases extremely rapidly and becomes negligible. A weak long range and N-dependent component of the monomer-particle pair correlation function is found which is suggested to be the origin of the long range repulsive PMF. Implications of our results for thermodynamics and miscibility are

Coherence and polarization speckle generated by a rough-surfaced retardation plate depolarizer

DEFF Research Database (Denmark)

Ma, Ning; Hanson, Steen Grüner; Takeda, Mitsuo

2015-01-01

of position introducing random phase differences between the two orthogonal components of the electric vector. Under the assumption of Gaussian statistics with zero mean, the surface model for the depolarizer of the rough-surfaced retardation plate is obtained. The propagation of the modulated fields through...... any quadratic optical system is examined within the framework of the complex ABCD matrix theory to show how the degree of coherence and polarization of the beam changes on propagation, including propagation in free space...

Kinetics of depletion interactions

NARCIS (Netherlands)

Vliegenthart, G.A.; Schoot, van der P.P.A.M.

2003-01-01

Depletion interactions between colloidal particles dispersed in a fluid medium are effective interactions induced by the presence of other types of colloid. They are not instantaneous but built up in time. We show by means of Brownian dynamics simulations that the static (mean-field) depletion force

Molecular Paleoclimate Reconstructions over the Last 9 ka from a Peat Sequence in South China

Science.gov (United States)

Wang, Xinxin; Huang, Xianyu; Sachse, Dirk; Ding, Weihua; Xue, Jiantao

2016-01-01

To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions (δ13C and δD values) of long-chain n-alkanes in a peat core from the Shiwangutian (SWGT) peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the δ13C values of the long-chain n-alkanes can be a proxy for humidity, while the δD values of the long-chain n-alkanes primarily recorded the moisture source δD signal during 9–1.8 ka BP and responded to the dry climate during 1.8–0.3 ka BP. Together with the average chain length (ACL) and the carbon preference index (CPI) data, the climate evolution over last 9 ka in the SWGT peatland can be divided into three stages. During the first stage (9–5 ka BP), the δ13C values were depleted and CPI and Paq values were low, while ACL values were high. They reveal a period of warm and wet climate, which is regarded as the Holocene optimum. The second stage (5–1.8 ka BP) witnessed a shift to relatively cool and dry climate, as indicated by the more positive δ13C values and lower ACL values. During the third stage (1.8–0.3 ka BP), the δ13C, δD, CPI and Paq values showed marked increase and ACL values varied greatly, implying an abrupt change to cold and dry conditions. This climate pattern corresponds to the broad decline in Asian monsoon intensity through the latter part of the Holocene. Our results do not support a later Holocene optimum in south China as suggested by previous studies. PMID:27505008

Molecular Paleoclimate Reconstructions over the Last 9 ka from a Peat Sequence in South China.

Directory of Open Access Journals (Sweden)

Xinxin Wang

Full Text Available To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions (δ13C and δD values of long-chain n-alkanes in a peat core from the Shiwangutian (SWGT peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the δ13C values of the long-chain n-alkanes can be a proxy for humidity, while the δD values of the long-chain n-alkanes primarily recorded the moisture source δD signal during 9-1.8 ka BP and responded to the dry climate during 1.8-0.3 ka BP. Together with the average chain length (ACL and the carbon preference index (CPI data, the climate evolution over last 9 ka in the SWGT peatland can be divided into three stages. During the first stage (9-5 ka BP, the δ13C values were depleted and CPI and Paq values were low, while ACL values were high. They reveal a period of warm and wet climate, which is regarded as the Holocene optimum. The second stage (5-1.8 ka BP witnessed a shift to relatively cool and dry climate, as indicated by the more positive δ13C values and lower ACL values. During the third stage (1.8-0.3 ka BP, the δ13C, δD, CPI and Paq values showed marked increase and ACL values varied greatly, implying an abrupt change to cold and dry conditions. This climate pattern corresponds to the broad decline in Asian monsoon intensity through the latter part of the Holocene. Our results do not support a later Holocene optimum in south China as suggested by previous studies.

Training Lymnaea in the presence of a predator scent results in a long-lasting ability to form enhanced long-term memory.

Science.gov (United States)

Forest, Jeremy; Sunada, Hiroshi; Dodd, Shawn; Lukowiak, Ken

2016-06-01

Lymnaea exposed to crayfish effluent (CE) gain an enhanced ability to form long-term memory (LTM). We test the hypothesis that a single CE exposure and operant conditioning training leads to long lasting changes in the capability of snails to form LTM when tested in pond water four weeks later. We trained both juvenile and adult snails with a single 0.5 h training session in CE and show that LTM was present 24 h later. Snails trained in a similar manner in just pond water show no LTM. We then asked if such training in CE conferred enhanced memory forming capabilities on these snails four weeks later. That is, would LTM be formed in these snails four weeks later following a single 0.5 h training session in pond water? We found that both adult and juvenile snails previously trained in CE one month previously had enhanced LTM formation abilities. The injection of a DNA methylation blocker, 5-AZA, prior to training in adult snails blocked enhanced LTM formation four weeks later. Finally, this enhanced LTM forming ability was not passed on to the next generation of snails.

Forest calcium depletion and biotic retention along a soil nitrogen gradient

Science.gov (United States)

Perakis, Steven S.; Sinkhorn, Emily R.; Catricala, Christina; Bullen, Thomas D.; Fitzpatrick, John A.; Hynicka, Justin D.; Cromack, Kermit

2013-01-01

High nitrogen (N) accumulation in terrestrial ecosystems can shift patterns of nutrient limitation and deficiency beyond N toward other nutrients, most notably phosphorus (P) and base cations (calcium [Ca], magnesium [Mg], and potassium [K]). We examined how naturally high N accumulation from a legacy of symbiotic N fixation shaped P and base cation cycling across a gradient of nine temperate conifer forests in the Oregon Coast Range. We were particularly interested in whether long-term legacies of symbiotic N fixation promoted coupled N and organic P accumulation in soils, and whether biotic demands by non-fixing vegetation could conserve ecosystem base cations as N accumulated. Total soil N (0–100 cm) pools increased nearly threefold across the N gradient, leading to increased nitrate leaching, declines in soil pH from 5.8 to 4.2, 10-fold declines in soil exchangeable Ca, Mg, and K, and increased mobilization of aluminum. These results suggest that long-term N enrichment had acidified soils and depleted much of the readily weatherable base cation pool. Soil organic P increased with both soil N and C across the gradient, but soil inorganic P, biomass P, and P leaching loss did not vary with N, implying that historic symbiotic N fixation promoted soil organic P accumulation and P sufficiency for non-fixers. Even though soil pools of Ca, Mg, and K all declined as soil N increased, only Ca declined in biomass pools, suggesting the emergence of Ca deficiency at high N. Biotic conservation and tight recycling of Ca increased in response to whole-ecosystem Ca depletion, as indicated by preferential accumulation of Ca in biomass and surface soil. Our findings support a hierarchical model of coupled N–Ca cycling under long-term soil N enrichment, whereby ecosystem-level N saturation and nitrate leaching deplete readily available soil Ca, stimulating biotic Ca conservation as overall supply diminishes. We conclude that a legacy of biological N fixation can increase N

Toxicity of Depleted Uranium Dust Particles: Results of a New Model

International Nuclear Information System (INIS)

Zucchetti, M.

2013-01-01

Depleted uranium (DU) is mostly composed of U-238, a naturally radioactive isotope. Concerning chemical toxicity, uranium, being a heavy metal, is known to have toxic effects on specific organs in the body, the kidneys in particular. Its effects are similar to those of other heavy metals, such as lead and cadmium. Scientific evidence resulting both from in vitro and in vivo analyses shows that current models of the mechanisms of toxicity of uranium dust are not fully satisfactory. They should be refined in order to obtain more effective responses and predictions regarding health effects. In particular, radiotoxicity potential of Depleted Uranium dust originated by military use of this material for ammunition must be re-evaluated taking into account the bystander effect, the dose enhancing effect and other minor phenomena. Uranium dust has both chemical and radiological toxicity: the synergistic aspect of the two effects has to be accounted for, in order to arrive to a complete description of the phenomenon. The combination of the two different toxicities (chemical and radiological) of depleted uranium is attempted here for the first time, approaching the long-term effects of Depleted Uranium, and in particular the carcinogenetic effects. A case study (Balkan war, 1999) is discussed. (Author)

Measurement of the depolarization in the elastic proton scattering on 1H, 27Al, and 89Y in the low energy range

International Nuclear Information System (INIS)

Schmitt, R.

1986-01-01

With the Erlangen QDQ magnetic spectrometer angular distributions of the depolarization in the elastic scattering of protons on 27 Al, 89 Y at 11 MeV and 1 H at 12 MeV were measured. The evaluation was performed for yttrium and aluminium by adding of additional terms in the optical model which regard the spin-spin interaction. The optical-model parameter without spin-spin potentials were stated by measurements of the cross section and the analyzing power in the 4π scattering chamber in Erlangen at several energies. The calculation of the depolarization which emerges because of the spin-spin interaction was performed by means of DWBA. The depolarization of the proton-proton scattering was evaluated by scattering-phase analysis. The fits were thereby performed on analyzing-power data. The electrical P-wave scattering phases resulted to δ 10 = 4.442±0.121, δ 11 = -2.515±0.026, and δ 12 = 0.937±0.038 (all in degrees). (orig./HSI) [de

Contribution of α-adrenoceptors to depolarization and contraction evoked by continuous asynchronous sympathetic nerve activity in rat tail artery

Science.gov (United States)

Brock, J A; McLachlan, E M; Rayner, S E

1997-01-01

The effects of continuous but asynchronous nerve activity induced by ciguatoxin (CTX-1) on the membrane potential and contraction of smooth muscle cells have been investigated in rat proximal tail arteries isolated in vitro. These effects have been compared with those produced by the continuous application of phenylephrine (PE).CTX-1 (0.4 nM) and PE (10 μM) produced a maintained depolarization of the arterial smooth muscle that was almost completely blocked by α-adrenoceptor blockade. In both cases, the depolarization was more sensitive to the selective α2-adrenoceptor antagonist, idazoxan (0.1 μM), than to the selective α1-adrenoceptor antagonist, prazosin (0.01 μM).In contrast, the maintained contraction of the tail artery induced by CTX-1 (0.2 nM) and PE (2 and 10 μM) was more sensitive to prazosin (0.01) μM, than to idazoxan (0.01 μM). In combination, these antagonists almost completely inhibited contraction to both agents.Application of the calcium channel antagonist, nifedipine (1 μM), had no effect on the depolarization induced by either CTX-1 or PE but maximally reduced the force of the maintained contraction to both agents by about 50%.We conclude that the constriction of the tail artery induced by CTX-1, which mimics the natural discharge of postganglionic perivascular axons, is due almost entirely to α-adrenoceptor activation. The results indicate that neuronally released noradrenaline activates more than one α-adrenoceptor subtype. The depolarization is dependent primarily on α2-adrenoceptor activation whereas the contraction is dependent primarily on α1-adrenoceptor activation. The links between α-adrenoceptor activation and the voltage-dependent and voltage-independent mechanisms that deliver Ca2+ to the contractile apparatus appear to be complex. PMID:9113373

A Preliminary Assessment of the Adjuster Rod Depletion Effect in the CANDU Reactor

International Nuclear Information System (INIS)

Kim, Yonghee; Roh, Gyuhong; Kim, Won Young; Kim, Hak Sung; Park, Joo Hwan

2008-01-01

Lifetime of the Wolsong-1 CANDU reactor, which will be shutdown in April, 2009. Major reactor components such as the pressure tube are to be replaced and it is expected that the CANDU reactor can be operated for additional 25-30 years. Meanwhile, all the reactivity devices including the adjuster rods (ADJ) are supposed to be continuously used without any change. In the CANDU reactor, 21 stainless steel (SS) ADJs are used to control the core power distribution and compensate for some reactivity loss during several abnormal cases. The ADJs are normally fully inserted and the SS absorber should undergo a slow depletion through neutron irradiation for a long time. In April, 2009, the accumulated FPY (Full Power Day) of Wolsong-1 is about 23 years. Depletion of ADJs should result in a smaller ADJ worth and a higher fuel burnup and the core power distribution should also be affected by the ADJ depletion. In this work, the effects of the ADJ depletion have been assessed in terms of ADJ worth, time-average core characteristics

Maternal-pup interaction disturbances induce long-lasting changes in the newborn rat pulmonary vasculature.

Science.gov (United States)

Shifrin, Yulia; Sadeghi, Sina; Pan, Jingyi; Jain, Amish; Fajardo, Andres F; McNamara, Patrick J; Belik, Jaques

2015-11-15

The factors accounting for the pathological maintenance of a high pulmonary vascular (PV) resistance postnatally remain elusive, but neonatal stressors may play a role in this process. Cross-fostering in the immediate neonatal period is associated with adult-onset vascular and behavioral changes, likely triggered by early-in-life stressors. In hypothesizing that fostering newborn rats induces long-lasting PV changes, we evaluated them at 14 days of age during adulthood and compared the findings with animals raised by their biological mothers. Fostering resulted in reduced maternal-pup contact time when compared with control newborns. At 2 wk of age, fostered rats exhibited reduced pulmonary arterial endothelium-dependent relaxation secondary to downregulation of tissue endothelial nitric oxide synthase expression and tetrahydrobiopterin deficiency-induced uncoupling. These changes were associated with neonatal onset-increased ANG II receptor type 1 expression, PV remodeling, and right ventricular hypertrophy that persisted into adulthood. The pulmonary arteries of adult-fostered rats exhibited a higher contraction dose response to ANG II and thromboxane A2, the latter of which was abrogated by the oxidant scavenger Tempol. In conclusion, fostering-induced neonatal stress induces long-standing PV changes modulated via the renin-angiotensin system. Copyright © 2015 the American Physiological Society.

Health and environmental problems of using antiarmour munitions containing depleted uranium core

International Nuclear Information System (INIS)

Matousek, J.

2006-01-01

In the 1970s, core of depleted uranium commenced to be introduced into the breakthrough antitank munitions of various calibers and types in order to considerably enhance their effectiveness due to extremely high density in comparison with steel. The health and environmental threats of using this munitions and other weaponry where depleted uranium has been utilised as counterbalance stem from the pyrophoric character of uranium, burnt due to material deformation and friction when penetrating armour targets creating thus highly respirable aerosol of uranium oxides that are deposited in alveoli after being inhaled or in other tissues after being ingested. Composition and main properties of depleted uranium are presented. Chronic effects of deposited particles of uranium oxides are due to internal irradiation of sensitive organs at proceeding radioactive decay accompanied with alpha irradiation. Long-term internal irradiation by radionuclides producing alpha-rays leads to proved risk of increased incidence of carcinoma and leukaemia not to speak on chronic chemical toxicity of uranium, independent of its isotopic composition. Environmental impact of extensive use of munitions with depleted uranium in the recent armed conflicts is assessed. (authors)

Fully Depleted Charge-Coupled Devices

International Nuclear Information System (INIS)

Holland, Stephen E.

2006-01-01

We have developed fully depleted, back-illuminated CCDs that build upon earlier research and development efforts directed towards technology development of silicon-strip detectors used in high-energy-physics experiments. The CCDs are fabricated on the same type of high-resistivity, float-zone-refined silicon that is used for strip detectors. The use of high-resistivity substrates allows for thick depletion regions, on the order of 200-300 um, with corresponding high detection efficiency for near-infrared and soft x-ray photons. We compare the fully depleted CCD to the p-i-n diode upon which it is based, and describe the use of fully depleted CCDs in astronomical and x-ray imaging applications

Deuterium - depleted water. Achievements and perspectives

International Nuclear Information System (INIS)

Titescu, Gh.; Stefanescu, I.; Saros-Rogobete, I.

2001-01-01

Deuterium - depleted water represents water that has an isotopic content lower than 145 ppm D/(D+H) which is the natural isotopic content of water. The research conducted at ICSI Ramnicu Valcea, regarding deuterium - depleted water were completed by the following patents: - technique and installation for deuterium - depleted water production; - distilled water with low deuterium content; - technique and installation for the production of distilled water with low deuterium content; - mineralized water with low deuterium content and technique to produce it. The gold and silver medals won at international salons for inventions confirmed the novelty of these inventions. Knowing that deuterium content of water has a big influence on living organisms, beginning with 1996, the ICSI Ramnicu Valcea, deuterium - depleted water producer, co-operated with Romanian specialized institutes for biological effects' evaluation of deuterium - depleted water. The role of natural deuterium in living organisms was examined by using deuterium - depleted water instead of natural water. These investigations led to the following conclusions: 1. deuterium - depleted water caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the deuterium - depleted water persists after the removal of the vascular endothelium; -2. animals treated with deuterium - depleted water showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defence mechanism; 3, deuterium - depleted water stimulates immune defence reactions, represented by the opsonic, bactericidal and phagocyte capacity of the immune system, together with increase in the numbers of polymorphonuclear neutrophils; 4. investigations regarding artificial

Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

International Nuclear Information System (INIS)

Yau, A.W.; Whalen, B.A.; Harris, F.R.; Gattinger, R.L.; Pongratz, M.B.; Bernhardt, P.A.

1985-01-01

In an ionospheric depletion experiment where chemically reactive vapors such as H 2 O and CO 2 are injected into the O + dominant F region to accelerate the plasma recombination rate and to reduce the plasma density, the ion composition in the depleted region is modified, and photometric emissions are produced. We compare in situ ion composition, density, and photometric measurements from two ionospheric depletion experiments with predictions from chemical modeling. The two injections, Waterhole I and III, were part of an auroral perturbation experiment and occurred in different ambient conditions. In both injections a core region of greater than fivefold plasma depletion was observed over roughly-equal5-km diameter within seconds of the injection, surrounded by an outer region of less drastic and slower depletion. In Waterhole I the plasma density was depleted tenfold over a 30-km diamter region after 2 min. The ambient O + density was drastically reduced, and the molecular O + 2 abundance was enhanced fivehold in the depletion region. OH airglow emission associated with the depletion was observed with a peak emission intensity of roughly-equal1 kR. In Waterhole III the ambient density was a decade lower, and the plasma depletion was less drastic, being twofold over 30 km after 2 min. The airglow emissions were also much less intense and below measurement sensitivity (30 R for the OH 306.4-nm emission; 50 R for the 630.0-nm emission)

Plasma membrane potential depolarization and cytosolic calcium flux are early events involved in tomato (Solanum lycopersicon) plant-to-plant communication.

Science.gov (United States)

Zebelo, Simon A; Matsui, Kenji; Ozawa, Rika; Maffei, Massimo E

2012-11-01

Tomato plants respond to herbivory by emitting volatile organic compounds (VOCs), which are released into the surrounding atmosphere. We analyzed the tomato herbivore-induced VOCs and tested the ability of tomato receiver plants to detect tomato donor volatiles by analyzing early responses, including plasma membrane potential (V(m)) variations and cytosolic calcium ([Ca²⁺](cyt)) fluxes. Receiver tomato plants responded within seconds to herbivore-induced VOCs with a strong V(m) depolarization, which was only partly recovered by fluxing receiver plants with clean air. Among emitted volatiles, we identified by GC-MS some green leaf volatiles (GLVs) such as (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, the monoterpene α-pinene, and the sesquiterpene β-caryophyllene. GLVs were found to exert the stronger V(m) depolarization, when compared to α-pinene and β-caryophyllene. Furthermore, V(m) depolarization was found to increase with increasing GLVs concentration. GLVs were also found to induce a strong [Ca²⁺](cyt) increase, particularly when (Z)-3-hexenyl acetate was tested both in solution and with a gas. On the other hand, α-pinene and β-caryophyllene, which also induced a significant V(m) depolarization with respect to controls, did not exert any significant effect on [Ca²⁺](cyt) homeostasis. Our results show for the first time that plant perception of volatile cues (especially GLVs) from the surrounding environment is mediated by early events, occurring within seconds and involving the alteration of the plasma membrane potential and the [Ca²⁺](cyt) flux. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Too Depleted to Try? Testing the Process Model of Ego Depletion in the Context of Unhealthy Snack Consumption.

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Haynes, Ashleigh; Kemps, Eva; Moffitt, Robyn

2016-11-01

The process model proposes that the ego depletion effect is due to (a) an increase in motivation toward indulgence, and (b) a decrease in motivation to control behaviour following an initial act of self-control. In contrast, the reflective-impulsive model predicts that ego depletion results in behaviour that is more consistent with desires, and less consistent with motivations, rather than influencing the strength of desires and motivations. The current study sought to test these alternative accounts of the relationships between ego depletion, motivation, desire, and self-control. One hundred and fifty-six undergraduate women were randomised to complete a depleting e-crossing task or a non-depleting task, followed by a lab-based measure of snack intake, and self-report measures of motivation and desire strength. In partial support of the process model, ego depletion was related to higher intake, but only indirectly via the influence of lowered motivation. Motivation was more strongly predictive of intake for those in the non-depletion condition, providing partial support for the reflective-impulsive model. Ego depletion did not affect desire, nor did depletion moderate the effect of desire on intake, indicating that desire may be an appropriate target for reducing unhealthy behaviour across situations where self-control resources vary. © 2016 The International Association of Applied Psychology.

T-matrix modeling of linear depolarization by morphologically complex soot and soot-containing aerosols

International Nuclear Information System (INIS)

Mishchenko, Michael I.; Liu, Li; Mackowski, Daniel W.

2013-01-01

We use state-of-the-art public-domain Fortran codes based on the T-matrix method to calculate orientation and ensemble averaged scattering matrix elements for a variety of morphologically complex black carbon (BC) and BC-containing aerosol particles, with a special emphasis on the linear depolarization ratio (LDR). We explain theoretically the quasi-Rayleigh LDR peak at side-scattering angles typical of low-density soot fractals and conclude that the measurement of this feature enables one to evaluate the compactness state of BC clusters and trace the evolution of low-density fluffy fractals into densely packed aggregates. We show that small backscattering LDRs measured with ground-based, airborne, and spaceborne lidars for fresh smoke generally agree with the values predicted theoretically for fluffy BC fractals and densely packed near-spheroidal BC aggregates. To reproduce higher lidar LDRs observed for aged smoke, one needs alternative particle models such as shape mixtures of BC spheroids or cylinders. -- Highlights: ► New superposition T-matrix code is applied to soot aerosols. ► Quasi-Rayleigh side-scattering peak in linear depolarization (LD) is explained. ► LD measurements can be used for morphological characterization of soot aerosols

Depleted uranium hexafluoride (DUF6) management system--a decision tool

International Nuclear Information System (INIS)

Gasper, J.R.; Sutter, R.J.; Avci, H.I.

1995-01-01

The Depleted Uranium Hexafluoride (DUF 6 ) Management System (DMS) is being developed as a decision tool to provide cost and risk data for evaluation of short-and long-term management strategies for depleted uranium. It can be used to assist decision makers on a programmatic or site-specific level. Currently, the DMS allows evaluation of near-term cylinder management strategies such as storage yard improvements, cylinder restocking, and reconditioning. The DMS has been designed to provide the user with maximum flexibility for modifying data and impact factors (e.g., unit costs and risk factors). Sensitivity analysis can be performed on all key parameters such as cylinder corrosion rate, inspection frequency, and impact factors. Analysis may be conducted on a system-wide, site, or yard basis. The costs and risks from different scenarios may be compared in graphic or tabular format. Ongoing development of the DMS will allow similar evaluation of long-term management strategies such as conversion to other chemical forms. The DMS is a Microsoft Windows 3.1 based, stand-alone computer application. It can be operated on a 486 or faster computer with VGA, 4 MB of RAM, and 10 MB of disk space

The Toxicity of Depleted Uranium

OpenAIRE

Briner, Wayne

2010-01-01

Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

Effective fiber hypertrophy in satellite cell-depleted skeletal muscle

Science.gov (United States)

McCarthy, John J.; Mula, Jyothi; Miyazaki, Mitsunori; Erfani, Rod; Garrison, Kelcye; Farooqui, Amreen B.; Srikuea, Ratchakrit; Lawson, Benjamin A.; Grimes, Barry; Keller, Charles; Van Zant, Gary; Campbell, Kenneth S.; Esser, Karyn A.; Dupont-Versteegden, Esther E.; Peterson, Charlotte A.

2011-01-01

An important unresolved question in skeletal muscle plasticity is whether satellite cells are necessary for muscle fiber hypertrophy. To address this issue, a novel mouse strain (Pax7-DTA) was created which enabled the conditional ablation of >90% of satellite cells in mature skeletal muscle following tamoxifen administration. To test the hypothesis that satellite cells are necessary for skeletal muscle hypertrophy, the plantaris muscle of adult Pax7-DTA mice was subjected to mechanical overload by surgical removal of the synergist muscle. Following two weeks of overload, satellite cell-depleted muscle showed the same increases in muscle mass (approximately twofold) and fiber cross-sectional area with hypertrophy as observed in the vehicle-treated group. The typical increase in myonuclei with hypertrophy was absent in satellite cell-depleted fibers, resulting in expansion of the myonuclear domain. Consistent with lack of nuclear addition to enlarged fibers, long-term BrdU labeling showed a significant reduction in the number of BrdU-positive myonuclei in satellite cell-depleted muscle compared with vehicle-treated muscle. Single fiber functional analyses showed no difference in specific force, Ca2+ sensitivity, rate of cross-bridge cycling and cooperativity between hypertrophied fibers from vehicle and tamoxifen-treated groups. Although a small component of the hypertrophic response, both fiber hyperplasia and regeneration were significantly blunted following satellite cell depletion, indicating a distinct requirement for satellite cells during these processes. These results provide convincing evidence that skeletal muscle fibers are capable of mounting a robust hypertrophic response to mechanical overload that is not dependent on satellite cells. PMID:21828094

Enhanced heavy oil recovery on depleted long core system by CH{sub 4} and CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Shi, R.; Kantzas, A. [Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory

2008-10-15

As demand for energy continues to increase and production of conventional oil declines, additional development of heavy oil and bitumen recovery processes and technologies is required in order to meet future energy demands. However, if productions are to be achieved economically, heavy oil viscosity must be reduced. Two methods are normally used to reduce heavy oil viscosity, notably thermal processes such as steam assisted gravity drainage and solvent processes. This paper described a laboratory study of potential post-cold production strategies for heavy oil reservoirs. Methane and carbon dioxide were injected in two depleted long cores. The purpose of the study was to improve understanding of the heavy oil solution gas drive mechanism and to assess methane and carbon dioxide recharging as a potential recovery method for heavy oil reservoirs. It also sought to establish a baseline for comparison against one another. The paper described the methodology and provided a summary of previous production history. It was concluded that the saturation and production time difference between the glass beads core and the sandpack core indicate the permeability difference between the two cores. 12 refs., 2 tabs., 14 figs.

Automotive industry program and strategy for control of ozone depleting substances and greenhouse gases

International Nuclear Information System (INIS)

Pound, F.R.; Stirling, P.J.

1990-01-01

This paper outlines the program status and strategy for the short and long term periods for ozone depleting substances and greenhouse gases from both stationary sources in manufacturing plants and mobile sources in motor vehicles. 5 refs

Adiabatic Siberian snake turn-on and acceleration through depolarizing resonances

International Nuclear Information System (INIS)

Koulsha, A.V.; Anferov, V.A.; Baiod, R.

1993-01-01

The authors plan to install in the IUCF Cooler Ring a rampable partial (30%) Siberian snake to test if the spin polarization is preserved during adiabatic turn-on. They also plan to use this ramped snake to accelerate polarized protons to 370 MeV while passing through two depolarizing resonances. The Siberian snake will consist of two small rampable warm solenoids placed symmetrically on either side of the exciting cold 2 T·m solenoid which would run dc at about 0.5 T·m. Ramping each warm magnet from about -0.25T·m to + 0.25 T·m. Recent experiments showed that turning on the snake in 100 msec at 370 MeV causes no serious beam loss

Cocaine Self-Administration Produces Long-Lasting Alterations in Dopamine Transporter Responses to Cocaine

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Siciliano, Cody A.; Fordahl, Steve C.

2016-01-01

Cocaine addiction is a debilitating neuropsychiatric disorder characterized by uncontrolled cocaine intake, which is thought to be driven, at least in part, by cocaine-induced deficits in dopamine system function. A decreased ability of cocaine to elevate dopamine levels has been repeatedly observed as a consequence of cocaine use in humans, and preclinical work has highlighted tolerance to cocaine's effects as a primary determinant in the development of aberrant cocaine taking behaviors. Here we determined that cocaine self-administration in rats produced tolerance to the dopamine transporter-inhibiting effects of cocaine in the nucleus accumbens core, which was normalized following a 14 or 60 d abstinence period; however, although these rats appeared to be similar to controls, a single self-administered infusion of cocaine at the end of abstinence, even after 60 d, fully reinstated tolerance to cocaine's effects. A single cocaine infusion in a naive rat had no effect on cocaine potency, demonstrating that cocaine self-administration leaves the dopamine transporter in a “primed” state, which allows for cocaine-induced plasticity to be reinstated by a subthreshold cocaine exposure. Further, reinstatement of cocaine tolerance was accompanied by decreased cocaine-induced locomotion and escalated cocaine intake despite extended abstinence from cocaine. These data demonstrate that cocaine leaves a long-lasting imprint on the dopamine system that is activated by re-exposure to cocaine. Further, these results provide a potential mechanism for severe cocaine binge episodes, which occur even after sustained abstinence from cocaine, and suggest that treatments aimed at transporter sites may be efficacious in promoting binge termination following relapse. SIGNIFICANCE STATEMENT Tolerance is a DSM-V criterion for substance abuse disorders. Abusers consistently show reduced subjective effects of cocaine concomitant with reduced effects of cocaine at its main site of action

Regional strategies for the accelerating global problem of groundwater depletion

Science.gov (United States)

Aeschbach-Hertig, Werner; Gleeson, Tom

2012-12-01

Groundwater--the world's largest freshwater resource--is critically important for irrigated agriculture and hence for global food security. Yet depletion is widespread in large groundwater systems in both semi-arid and humid regions of the world. Excessive extraction for irrigation where groundwater is slowly renewed is the main cause of the depletion, and climate change has the potential to exacerbate the problem in some regions. Globally aggregated groundwater depletion contributes to sea-level rise, and has accelerated markedly since the mid-twentieth century. But its impacts on water resources are more obvious at the regional scale, for example in agriculturally important parts of India, China and the United States. Food production in such regions can only be made sustainable in the long term if groundwater levels are stabilized. To this end, a transformation is required in how we value, manage and characterize groundwater systems. Technical approaches--such as water diversion, artificial groundwater recharge and efficient irrigation--have failed to balance regional groundwater budgets. They need to be complemented by more comprehensive strategies that are adapted to the specific social, economic, political and environmental settings of each region.

Deuterium-depleted water. Romanian achievements and perspective

International Nuclear Information System (INIS)

Stefanescu, Ion; Saros-Rogobete, Irina; Titescu, Gheorghe

2001-01-01

Deuterium-depleted water has an isotopic content smaller than 145 ppm D/(D+H) which is the natural isotopic content of water. Beginning with 1996 ICSI Rm. Valcea, deuterium-depleted water producer, co-operated with Romanian specialized institutes for biological effect's evaluation of deuterium-depleted water. These investigations lead to the following conclusions: - Deuterium-depleted water caused a tendency towards the increase of the basal tonus, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tonus and vascular reactivity produced by the deuterium-depleted water persist after the removal of the vascular endothelium; - Animals treated with deuterium-depleted water showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action; - Deuterium-depleted water stimulates immune defence reactions and increases the numbers of polymorphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with deuterium-depleted water fecundated solutions confirmed favourable influence in embryo growth stage and resistance in subsequent growth stages; - It was studied germination, growth and quantitative character's variability in plants; one can remark the favourable influence of deuterium-depleted water on biological process in plants in various ontogenetic stages; - The deuterium depletion in seawater produces the diminution of the water spectral energy related to an increased metabolism of Tetraselmis Suecica. (authors)

Microwave Synthesis of a Long-Lasting Phosphor

Science.gov (United States)

Filhol, Jean-Sebastien; Zitoun, David; Bernaud, Laurent; Manteghetti, Alain

2009-01-01

Efficient glow-in-the-dark materials are usually difficult to synthesize and need complex experiments with long reaction times that are not appropriate for conventional lab teaching. Therefore, we describe a new experimental procedure that allows the production of one of the most efficient "glow-in-the-dark" materials (SrAl[subscript 2]O[subscript…

Long-lasting Effects of Minocycline on Behavior in Young but not Adult Fragile X Mice

Science.gov (United States)

Dansie, Lorraine E.; Phommahaxay, Kelly; Okusanya, Ayodeji G.; Uwadia, Jessica; Huang, Mike; Rotschafer, Sarah E.; Razak, Khaleel A.; Ethell, Douglas W.; Ethell, Iryna M.

2013-01-01

Fragile X Syndrome (FXS) is the most common single-gene inherited form of intellectual disability with behaviors characteristic of autism. People with FXS display childhood seizures, hyperactivity, anxiety, developmental delay, attention deficits, and visual-spatial memory impairment, as well as a propensity for obsessive-compulsive disorder (OCD). Several of these aberrant behaviors and FXS-associated synaptic irregularities also occur in “fragile X mental retardation gene” knock-out (Fmr1 KO) mice. We previously reported that minocycline promotes the maturation of dendritic spines - postsynaptic sites for excitatory synapses - in the developing hippocampus of Fmr1 KO mice, which may underlie the beneficial effects of minocycline on anxiolytic behavior in young Fmr1 KO mice. In this study, we compared the effectiveness of minocycline treatment in young and adult Fmr1 KO mice, and determined the dependence of behavioral improvements on short-term versus long-term minocycline administration. We found that 4 and 8 week long treatments significantly reduced locomotor activity in both young and adult Fmr1 KO mice. Some behavioral improvements persisted in young mice post-treatment, but in adults the beneficial effects were lost soon after minocycline treatment was stopped. We also show, for the first time, that minocycline treatment partially attenuates the number and severity of audiogenic seizures in Fmr1 KO mice. This report provides further evidence that minocycline treatment has immediate and long-lasting benefits on FXS-associated behaviors in the Fmr1 KO mouse model. PMID:23660195

Spreading depolarization-modulating drugs and delayed cerebral ischemia after subarachnoid hemorrhage : A hypothesis-generating retrospective clinical study

NARCIS (Netherlands)

Hamming, Arend M.; Mulder, Inge A.; Gathier, Celine S.; van den Bergh, Walter M.; Dankbaar, Jan Willem; Hoff, Reinier G.; Vandertop, W. Peter; Verbaan, Dagmar; Ferrari, Michel D.; Rinkel, Gabriel J. E.; Algra, Ale; Wermer, Marieke J. H.

2016-01-01

Background: Delayed cerebral ischemia (DCI) occurs in approximately one-third of patients with aneurysmal subarachnoid hemorrhage (aSAH). A proposed underlying mechanism for DCI is spreading depolarization (SD). Our aim was to, retrospectively, investigate the influence of the use of SD-modulating

Serotonergic neurotransmission in emotional processing: New evidence from long-term recreational poly-drug ecstasy use.

Science.gov (United States)

Laursen, Helle Ruff; Henningsson, Susanne; Macoveanu, Julian; Jernigan, Terry L; Siebner, Hartwig R; Holst, Klaus K; Skimminge, Arnold; Knudsen, Gitte M; Ramsoy, Thomas Z; Erritzoe, David

2016-12-01

The brain's serotonergic system plays a crucial role in the processing of emotional stimuli, and several studies have shown that a reduced serotonergic neurotransmission is associated with an increase in amygdala activity during emotional face processing. Prolonged recreational use of ecstasy (3,4-methylene-dioxymethamphetamine [MDMA]) induces alterations in serotonergic neurotransmission that are comparable to those observed in a depleted state. In this functional magnetic resonance imaging (fMRI) study, we investigated the responsiveness of the amygdala to emotional face stimuli in recreational ecstasy users as a model of long-term serotonin depletion. Fourteen ecstasy users and 12 non-using controls underwent fMRI to measure the regional neural activity elicited in the amygdala by male or female faces expressing anger, disgust, fear, sadness, or no emotion. During fMRI, participants made a sex judgement on each face stimulus. Positron emission tomography with 11 C-DASB was additionally performed to assess serotonin transporter (SERT) binding in the brain. In the ecstasy users, SERT binding correlated negatively with amygdala activity, and accumulated lifetime intake of ecstasy tablets was associated with an increase in amygdala activity during angry face processing. Conversely, time since the last ecstasy intake was associated with a trend toward a decrease in amygdala activity during angry and sad face processing. These results indicate that the effects of long-term serotonin depletion resulting from ecstasy use are dose-dependent, affecting the functional neural basis of emotional face processing. © The Author(s) 2016.

Depolarization-induced release of [(3)H]D-aspartate from GABAergic neurons caused by reversal of glutamate transporters

DEFF Research Database (Denmark)

Jensen, J B; Pickering, D S; Schousboe, A

2000-01-01

if glutamate in addition to gamma-aminobutyric acid (GABA) could be released from these cultures. The neurons were preloaded with [(3)H]D-aspartate and subsequently its release was followed during depolarization induced by a high potassium concentration or the alpha-amino-3-hydroxy-5-methyl-4......-isoxazolepropionic acid (AMPA) receptor agonists, AMPA and kainate. Depolarization of the neurons with 55 mM potassium increased the release of [(3)H]D-aspartate by more than 10-fold. When the non-specific calcium-channel blockers cobalt or lanthanum were included in the stimulation buffer with potassium......, the release of [(3)H]D-aspartate was decreased by about 40%. These results indicated that some of the released [(3)H]D-aspartate might originate from a vesicular pool. When AMPA was applied to the neurons, the release of [(3)H]D-aspartate was increased 2-fold and could not be prevented or decreased...

NERIS workshop. Lasting contaminations and land development. After Fukushima: the possibility of a lasting radioactive contamination

International Nuclear Information System (INIS)

2011-11-01

The document contains the contributions proposed during a workshop and the content of discussions after these contributions. For the first day, case studies are thus reported and commented: land contamination in Japan after the Fukushima accident, the CENTRACO plant accident, medium and long term stakes within the context of a lasting contamination by pesticides (the case of chlordecone pollution in the French West Indies), the complex and multiple actor challenges in the case of long duration radiological contamination for land agriculture, a lasting contamination in urban environment (the case of Metaleurop). The second session addressed the conditions and means for preparedness of local actors to a lasting radioactive contamination: the Norwegian approach, how to take the post-accidental perspective into account in the local safeguard plans, the PRIME project (research project on radio-ecological sensitivity indices and multi-criteria methods applied to the environment of an industrial territory), the pilot radiation protection project of the Montbeliard district, the OPAL project (to provide the local information commissions with post-accidental zoning information on the different French nuclear sites)

Simultaneous and long-lasting hydrophilization of inner and outer wall surfaces of polytetrafluoroethylene tubes by transferring atmospheric pressure plasmas

International Nuclear Information System (INIS)

Chen, Faze; Song, Jinlong; Huang, Shuai; Xu, Wenji; Sun, Jing; Liu, Xin; Xu, Sihao; Xia, Guangqing; Yang, Dezheng

2016-01-01

Plasma hydrophilization is a general method to increase the surface free energy of materials. However, only a few works about plasma modification focus on the hydrophilization of tube inner and outer walls. In this paper, we realize simultaneous and long-lasting plasma hydrophilization on the inner and outer walls of polytetrafluoroethylene (PTFE) tubes by atmospheric pressure plasmas (APPs). Specifically, an Ar atmospheric pressure plasma jet (APPJ) is used to modify the PTFE tube’s outer wall and meanwhile to induce transferred He APP inside the PTFE tube to modify its inner wall surface. The optical emission spectrum (OES) shows that the plasmas contain many chemically active species, which are known as enablers for various applications. Water contact angle (WCA) measurements, x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) are used to characterize the plasma hydrophilization. Results demonstrate that the wettability of the tube walls are well improved due to the replacement of the surface fluorine by oxygen and the change of surface roughness. The obtained hydrophilicity decreases slowly during more than 180 d aging, indicating a long-lasting hydrophilization. The results presented here clearly demonstrate the great potential of transferring APPs for surface modification of the tube’s inner and outer walls simultaneously. (paper)

The schizophrenia-associated Kv11.1-3.1 isoform results in reduced current accumulation during repetitive brief depolarizations.

Directory of Open Access Journals (Sweden)

Juliane Heide

Full Text Available Recent genome wide association studies identified a brain and primate specific isoform of a voltage-gated potassium channel, referred to as Kv11.1-3.1, which is significantly associated with schizophrenia. The 3.1 isoform replaces the first 102 amino acids of the most abundant isoform (referred to as Kv11.1-1A with six unique amino acids. Here we show that the Kv11.1-3.1 isoform has faster rates of channel deactivation but a slowing of the rates of inactivation compared to the Kv11.1-1A isoform. The Kv11.1-3.1 isoform also has a significant depolarizing shift in the voltage-dependence of steady-state inactivation. The consequence of the altered gating kinetics is that there is lower current accumulation for Kv11.1-3.1 expressing cells during repetitive action potential firing compared to Kv11.1-1A expressing cells, which in turn will result in longer lasting trains of action potentials. Increased expression of Kv11.1-3.1 channels in the brain of schizophrenia patients might therefore contribute to disorganized neuronal firing.

Statistical implications in Monte Carlo depletions - 051

International Nuclear Information System (INIS)

Zhiwen, Xu; Rhodes, J.; Smith, K.

2010-01-01

As a result of steady advances of computer power, continuous-energy Monte Carlo depletion analysis is attracting considerable attention for reactor burnup calculations. The typical Monte Carlo analysis is set up as a combination of a Monte Carlo neutron transport solver and a fuel burnup solver. Note that the burnup solver is a deterministic module. The statistical errors in Monte Carlo solutions are introduced into nuclide number densities and propagated along fuel burnup. This paper is towards the understanding of the statistical implications in Monte Carlo depletions, including both statistical bias and statistical variations in depleted fuel number densities. The deterministic Studsvik lattice physics code, CASMO-5, is modified to model the Monte Carlo depletion. The statistical bias in depleted number densities is found to be negligible compared to its statistical variations, which, in turn, demonstrates the correctness of the Monte Carlo depletion method. Meanwhile, the statistical variation in number densities generally increases with burnup. Several possible ways of reducing the statistical errors are discussed: 1) to increase the number of individual Monte Carlo histories; 2) to increase the number of time steps; 3) to run additional independent Monte Carlo depletion cases. Finally, a new Monte Carlo depletion methodology, called the batch depletion method, is proposed, which consists of performing a set of independent Monte Carlo depletions and is thus capable of estimating the overall statistical errors including both the local statistical error and the propagated statistical error. (authors)

Uranium and the War: The effects of depleted uranium weapons in Iraq

International Nuclear Information System (INIS)

Jon williams

2007-01-01

The U.S. Army revealed in March 2003 that it dropped between 320 and 390 tons of depleted uranium during the Gulf War-the first time the material was ever used in combat-and it is estimated that more still has been dropped during the current invasion, though there have been no official counts as yet. Nuclear weapons and nuclear power plants require highly radioactive uranium, so the uranium 238 is removed from the naturally occurring uranium by a process known as enrichment. Depleted uranium is the by-product of the uranium enrichment process. Depleted uranium was a major topic of discussion during a Feb. 24 forum at Santa Cruz with speakers from the Iraq Veterans Against War (IVAW). The panel consisted of five members of the IVAW chapter in Olympia, Washington who visited Santa Cruz as part of a speaking tour of the west coast. These members of the IVAW believe that their experiences in the Gulf War were the beginnings of what will be a long-term health problem in the region. A study conducted by the Pentagon in 2002 predicted that every future battlefield will be contaminated with depleted uranium. Up-to-date health information from Iraq is difficult to come by. But a November report from Al-jazeera concluded that the cancer rate in Iraq has increased tenfold, and the number of birth defects has multiplied fivefold times since the 1991 war. The increase is believed to be caused by depleted uranium.

Sedimentary constraints on the duration of the Marinoan Oxygen-17 Depletion (MOSD) event

Science.gov (United States)

Killingsworth, Bryan A.; Hayles, Justin A.; Zhou, Chuanming; Bao, Huiming

2013-10-01

The ∼635 Ma Marinoan glaciation is marked by dramatic Earth system perturbations. Deposition of nonmass-dependently 17O-depleted sulfate (SO42-) in worldwide postglacial sediments is, thus far, unique to this glaciation. It is proposed that an extremely high-pCO2 atmosphere can result in highly 17O-depleted atmospheric O2, or the Marinoan Oxygen-17 Depletion (MOSD) event. This anomalous 17O signal was imparted to sulfate of oxidative weathering origin. However, 17O-depleted sulfate occurs in limited sedimentary intervals, suggesting that Earth surface conditions conducive to the MOSD had a finite duration. An MOSD duration can, therefore, provide much needed constraint on modeling Earth system responses at that time. Unfortunately, the sulfate 17O record is often sparse or lacks radiometric dates. Here, we report 11 barite layers from a post-Marinoan dolostone sequence at Wushanhu in the South China Block. The 17O depletion fluctuates in magnitude in lower layers but is persistently absent up section, providing the most confident first and last sedimentary appearance of the anomaly. δ13C chemostratigraphy is used to correlate the Wushanhu section to two proximal sections on the same shallow platform that lack barite layers but have published U-Pb dates that occur in dolostone and shale. Assuming a similar pattern and rate for carbonate and shale deposition among the different sections, we estimate the MOSD duration at 0-0.99 My. This number can be further constrained by new radiometric dates from equivalent sequences worldwide, thus underpinning models on the nonsteady-state Earth system response in the immediate aftermath of the Marinoan meltdown.

Long Island Sound Water Temperatures During the Last Two Thousand Years

Science.gov (United States)

Warren, C. E.; Varekamp, J. C.; Thomas, E.

2010-12-01

The Long Island Sound (LIS), sometimes called the “urban sea”, is a large estuary in the heavily populated coastal zone between New York City and the Connecticut - Rhode Island border. LIS has seen dramatic environmental shifts since colonial times, including major changes in aquatic food extraction, land use, contaminant and nutrient inputs, and climate change. Annual seasonal hypoxic/anoxic events, especially common in westernmost LIS, have been identified as potentially severe stressors for LIS biota including valuable fisheries species such as lobsters and shellfish. These conditions develop when the Sound becomes stratified in midsummer and oxygen consumption from the oxidation of organic matter exceeds oxygen resupply from the atmosphere or photosynthesis. Severity, lateral extent and frequency of hypoxia/anoxia is influenced by the amount of organic matter available for oxidation, both marine organic matter (produced by algal blooms in response to influx of N-rich effluents from waste water treatment plants) and terrestrial organic matter. These events are also influenced by the severity of stratification, determined by differences in density from temperature and salinity gradients of surface and bottom waters. Studies of cores in western and central LIS, dated using Hg-pollution profiles, 210Pb - 137Cs, and 14C, indicate that eutrophication and hypoxia have occurred in LIS only over the last ~150 years, with the possible exception of the Narrows (closest to NY) where it may have occurred before colonial times. Salinity decreased as well over the last 150 years, possibly due to changes in land use or deflection of fresh water from the Hudson River. Temperature variability in LIS over the last few thousand years has not been clearly documented, as several paleotemperature proxies are difficult to use in estuarine settings. Oxygen isotope values of carbonate microfossils are influenced by salinity fluctuations, and Mg/Ca values in these shells may be

Bimodal Long-lasting Components in Short Gamma-Ray Bursts: Promising Electromagnetic Counterparts to Neutron Star Binary Mergers

Energy Technology Data Exchange (ETDEWEB)

Kisaka, Shota; Sakamoto, Takanori [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa, 252-5258 (Japan); Ioka, Kunihito, E-mail: kisaka@phys.aoyama.ac.jp, E-mail: tsakamoto@phys.aoyama.ac.jp, E-mail: kunihito.ioka@yukawa.kyoto-u.ac.jp [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

2017-09-10

Long-lasting emission of short gamma-ray bursts (GRBs) is crucial to reveal the physical origin of the central engine as well as to detect electromagnetic (EM) counterparts to gravitational waves (GWs) from neutron star binary mergers. We investigate 65 X-ray light curves of short GRBs, which is six times more than previous studies, by combining both Swift /BAT and XRT data. The light curves are found to consist of two distinct components at >5 σ with bimodal distributions of luminosity and duration, i.e., extended (with a timescale of ≲10{sup 3} s) and plateau emission (with a timescale of ≳10{sup 3} s), which are likely the central engine activities, but not afterglows. The extended emission has an isotropic energy comparable to the prompt emission, while the plateau emission has ∼0.01–1 times this energy. Half (50%) of our sample has both components, while the other half is consistent with having both components. This leads us to conjecture that almost all short GRBs have both the extended and plateau emission. The long-lasting emission can be explained by the jets from black holes with fallback ejecta, and could power macronovae (or kilonovae) like GRB 130603B and GRB 160821B. Based on the observed properties, we quantify the detectability of EM counterparts to GWs, including the plateau emission scattered to the off-axis angle, with CALET /HXM, INTEGRAL /SPI-ACS, Fermi /GBM, MAXI /GSC, Swift /BAT, XRT, the future ISS-Lobster /WFI, Einstein Probe /WXT, and eROSITA .

Depleted uranium hexafluoride: The source material for advanced shielding systems

Energy Technology Data Exchange (ETDEWEB)

Quapp, W.J.; Lessing, P.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Cooley, C.R. [Department of Technology, Germantown, MD (United States)

1997-02-01

The U.S. Department of Energy (DOE) has a management challenge and financial liability problem in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. DOE is evaluating several options for the disposition of this UF{sub 6}, including continued storage, disposal, and recycle into a product. Based on studies conducted to date, the most feasible recycle option for the depleted uranium is shielding in low-level waste, spent nuclear fuel, or vitrified high-level waste containers. Estimates for the cost of disposal, using existing technologies, range between $3.8 and $11.3 billion depending on factors such as the disposal site and the applicability of the Resource Conservation and Recovery Act (RCRA). Advanced technologies can reduce these costs, but UF{sub 6} disposal still represents large future costs. This paper describes an application for depleted uranium in which depleted uranium hexafluoride is converted into an oxide and then into a heavy aggregate. The heavy uranium aggregate is combined with conventional concrete materials to form an ultra high density concrete, DUCRETE, weighing more than 400 lb/ft{sup 3}. DUCRETE can be used as shielding in spent nuclear fuel/high-level waste casks at a cost comparable to the lower of the disposal cost estimates. Consequently, the case can be made that DUCRETE shielded casks are an alternative to disposal. In this case, a beneficial long term solution is attained for much less than the combined cost of independently providing shielded casks and disposing of the depleted uranium. Furthermore, if disposal is avoided, the political problems associated with selection of a disposal location are also avoided. Other studies have also shown cost benefits for low level waste shielded disposal containers.

FIELD TOPOLOGY ANALYSIS OF A LONG-LASTING CORONAL SIGMOID

International Nuclear Information System (INIS)

Savcheva, A. S.; Van Ballegooijen, A. A.; DeLuca, E. E.

2012-01-01

We present the first field topology analysis based on nonlinear force-free field (NLFFF) models of a long-lasting coronal sigmoid observed in 2007 February with the X-Ray Telescope on Hinode. The NLFFF models are built with the flux rope insertion method and give the three-dimensional coronal magnetic field as constrained by observed coronal loop structures and photospheric magnetograms. Based on these models, we have computed horizontal maps of the current and the squashing factor Q for 25 different heights in the corona for all six days of the evolution of the region. We use the squashing factor to quantify the degree of change of the field line linkage and to identify prominent quasi-separatrix layers (QSLs). We discuss the major properties of these QSL maps and devise a way to pick out important QSLs since our calculation cannot reach high values of Q. The complexity in the QSL maps reflects the high degree of fragmentation of the photospheric field. We find main QSLs and current concentrations that outline the flux rope cavity and that become characteristically S-shaped during the evolution of the sigmoid. We note that, although intermittent bald patches exist along the length of the sigmoid during its whole evolution, the flux rope remains stable for several days. However, shortly after the topology of the field exhibits hyperbolic flux tubes (HFT) on February 7 and February 12 the sigmoid loses equilibrium and produces two B-class flares and associated coronal mass ejections (CMEs). The location of the most elevated part of the HFT in our model coincides with the inferred locations of the two flares. Therefore, we suggest that the presence of an HFT in a coronal magnetic configuration may be an indication that the system is ready to erupt. We offer a scenario in which magnetic reconnection at the HFT drives the system toward the marginally stable state. Once this state is reached, loss of equilibrium occurs via the torus instability, producing a CME.

Chloride regulates afferent arteriolar contraction in response to depolarization

DEFF Research Database (Denmark)

Hansen, P B; Jensen, B L; Skott, O

1998-01-01

-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...... afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...... antagonist diltiazem (10(-6) mol/L) abolished K+-induced contractions. Bicarbonate did not modify the sensitivity to chloride. Norepinephrine (10(-6) mol/L) induced full contraction in depolarized vessels even in the absence of chloride. Iodide and nitrate were substituted for chloride with no inhibitory...

Depletion of elements in shock-driven gas

International Nuclear Information System (INIS)

Gondhalekar, P.M.

1985-01-01

The depletion of elements in shocked gas in supernova remnants and in interstellar bubbles is examined. It is shown that elements are depleted in varying degrees in gas filaments shocked to velocities up to 200 km s -1 and that large differences in depletions are observed in gas filaments shocked to similar velocities. In the shocked gas the depletion of an element appears to be correlated with the electron density (or the neutral gas density) in the filaments. This correlation, if confirmed, is similar to the correlation between depletion and mean density of gas in the clouds in interstellar space. (author)

Evidence for a role of transporter-mediated currents in the depletion of brain serotonin induced by serotonin transporter substrates.

Science.gov (United States)

Baumann, Michael H; Bulling, Simon; Benaderet, Tova S; Saha, Kusumika; Ayestas, Mario A; Partilla, John S; Ali, Syed F; Stockner, Thomas; Rothman, Richard B; Sandtner, Walter; Sitte, Harald H

2014-05-01

Serotonin (5-HT) transporter (SERT) substrates like fenfluramine and 3,4-methylenedioxymethamphetamine cause long-term depletion of brain 5-HT, while certain other substrates do not. The 5-HT deficits produced by SERT substrates are dependent upon transporter proteins, but the exact mechanisms responsible are unclear. Here, we compared the pharmacology of several SERT substrates: fenfluramine, d-fenfluramine, 1-(m-chlorophenyl)piperazine (mCPP) and 1-(m-trifluoromethylphenyl)piperainze (TFMPP), to establish relationships between acute drug mechanisms and the propensity for long-term 5-HT depletions. In vivo microdialysis was carried out in rat nucleus accumbens to examine acute 5-HT release and long-term depletion in the same subjects. In vitro assays were performed to measure efflux of [(3)H]5-HT in rat brain synaptosomes and transporter-mediated ionic currents in SERT-expressing Xenopus oocytes. When administered repeatedly to rats (6 mg/kg, i.p., four doses), all drugs produce large sustained elevations in extracellular 5-HT (>5-fold) with minimal effects on dopamine. Importantly, 2 weeks after dosing, only rats exposed to fenfluramine and d-fenfluramine display depletion of brain 5-HT. All test drugs evoke fluoxetine-sensitive efflux of [(3)H]5-HT from synaptosomes, but d-fenfluramine and its bioactive metabolite d-norfenfluramine induce significantly greater SERT-mediated currents than phenylpiperazines. Our data confirm that drug-induced 5-HT release probably does not mediate 5-HT depletion. However, the magnitude of transporter-mediated inward current may be a critical factor in the cascade of events leading to 5-HT deficits. This hypothesis warrants further study, especially given the growing popularity of designer drugs that target SERT.

Depleted uranium hexafluoride management program : data compilation for the K-25 site

International Nuclear Information System (INIS)

Hartmann, H. M.

2001-01-01

This report is a compilation of data and analyses for the K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The data were collected and the analyses were done in support of the U.S. Department of Energy (DOE) 1999 Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted Uranium Hexafluoride (DOE/EIS-0269). The report describes the affected environment at the K-25 site and summarizes the potential environmental impacts that could result from continued cylinder storage and preparation of cylinders for shipment at the site. It is probable that the cylinders at the K-25 site will be shipped to another site for conversion. Because conversion and long-term storage of the entire inventory at the K-25 site are highly unlikely, these data are not presented in this report. DOE's preferred alternative is to begin converting the depleted uranium hexafluoride inventory as soon as possible to either uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation.

Science.gov (United States)

Hannon, Eilis; Chand, Annisa N; Evans, Mark D; Wong, Chloe C Y; Grubb, Matthew S; Mill, Jonathan

2015-07-01

Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm), although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506) to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type Ca V 1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation

Directory of Open Access Journals (Sweden)

Eilis Hannon

2015-07-01

Full Text Available Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm, although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506 to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type CaV1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

Eastern South Pacific water mass geometry during the last glacial-interglacial transition

Science.gov (United States)

De Pol-Holz, R.; Reyes, D.; Mohtadi, M.

2012-12-01

The eastern South Pacific is characterized today by a complex thermocline structure where large salinity and oxygen changes as a function of depth coexist. Surface waters from tropical origin float on top of subantarctic fresher water (the so-called 'shallow salinity minimum of the eastern south Pacific'), which in turn, flow above aged equatorial and deeper recently ventilated Antarctic Intermediate waters. Little is known however about the water mass geometry changes that could have occurred during the last glacial maximum boundary conditions (about 20,000 years before the present), despite this information being critical for the assessment of potential mechanisms that have been proposed as explanations for the deglacial onset of low oxygen conditions in the area and the atmospheric CO2 increase during the same time. Here we present benthic and planktonic foraminifera stable isotope and radiocarbon data from a set of sediment cores from the Chilean continental margin covering a large -yet still limited- geographical area and depth range. Sedimentations rates were relatively high (>10 cm/kyr) precluding major caveats from bioturbation in all of our archives. The distribution of δ13C of ΣCO2 shows the presence of a very depleted (δ13C < -1‰ V-PDB) water mass overlaying more recently ventilated waters at intermediate depths as indicated by thermocline foraminifer dwellers being more depleted in 13C than the benthic species. The origin of this depleted end-member is probably upwelling from the Southern Ocean as expressed by the radiocarbon content and the large reservoir effect associated with the last glacial maximum and the beginning of the deglaciation along the margin. Our data suggest that the Tropical waters that today bath the lower latitude cores was displaced by surface waters of southern origin and therefore in line with the evidence of a latitudinal shift of the frontal systems.

Are relative depletions altered inside diffuse clouds?

International Nuclear Information System (INIS)

Joseph, C.L.

1988-01-01

The data of Jenkins, Savage, and Spitzer (1986) were used to analyze interstellar abundances and depletions of Fe, P, Mg, and Mn toward 37 stars, spanning nearly 1.0 (dex) in mean line-of-sight depletion. It was found that the depletions of these elements are linearly correlated and do not show evidence of differences in the rates of depletion or sputtering from one element to another. For a given level of overall depletion, the sightline-to-sightline rms variance in the depletion for each of these elements was less than 0.16 (dex), which is significantly smaller than is the element-to-element variance. The results suggest that, for most diffuse lines of sight, the relative abundances of these elements are set early in the lifetime of the grains and are not altered significantly thereafter. 53 references

Simulation of the depletion voltage evolution of the ATLAS Pixel Detector

CERN Document Server

Beyer, Julien-christopher; The ATLAS collaboration

2017-01-01

The ATLAS Pixel detector has been operating since 2010 and consists of hybrid pixel modules where the sensitive elements are planar n-in-n sensors. In order to investigate and predict the evolution of the depletion voltage and of the leakage current in the different layers, a fully analytical implementation of the Hamburg model was derived. The parameters of the model, describing the dependence of the depletion voltage (U_depl) on fluence, temperature and time were tuned with a fit to the available measurements of Udepl in the last years of operation. A particular emphasis is put on the B-Layer, where the highest fluence has been accumulated up to now. A precise input of temperature and radiation dose is generated from the on-module temperature monitoring and the luminosity data. The analysis is then also extended to the Insertable B-Layer (IBL), installed at the end of Run-1, where we expect the fastest evolution of the radiation damage with luminosity, due to its closer position to the interaction point. Di...

Interstellar depletion anomalies and ionization potentials

International Nuclear Information System (INIS)

Tabak, R.G.

1979-01-01

Satellite observations indicate that (1) most elements are depleted from the gas phase when compared to cosmic abundances, (2) some elements are several orders of magnitude more depleted than others, and (3) these depletions vary from cloud to cloud. Since the most likely possibility is that the 'missing' atoms are locked into grains, depletions occur either by accretion onto core particles in interstellar clouds or earlier, during the period of primary grain formation. If the latter mechanism is dominant, then the most important depletion parameter is the condensation temperature of the elements and their various compounds. However, this alone is not sufficient to explain all the observed anomalies. It is shown that electrostatic effects - under a wide variety of conditions- can enormously enhance the capture cross-section of the grain. It is suggested that this mechanism can also account for such anomalies as the apparent 'overabundance' of the alkali metals in the gas phase. (orig.)

Developmental exposure to the SSRI citalopram causes long-lasting behavioural effects in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Kellner, M; Porseryd, T; Porsch-Hällström, I; Borg, B; Roufidou, C; Olsén, K H

2018-01-01

Selective Serotonin re-uptake inhibitors (SSRIs) are a class of psychotropic drugs used to treat depression in both adolescents and pregnant or breast-feeding mothers as well as in the general population. Recent research on rodents points to long-lasting behavioural effects of pre- and perinatal exposure to SSRIs which last into adulthood. In fish however, studies on effects of developmental exposure to SSRIs appears to be non-existent. In order to study effects of developmental SSRI exposure in fish, three-spine sticklebacks were exposed to 1.5 µg/l of the SSRI citalopram in the ambient water for 30 days, starting two days post-fertilisation. After approximately 100 days of remediation in clean water the fish were put through an extensive battery of behavioural tests. Feeding behaviour was tested as the number of bites against a piece of food and found to be increased in the exposed fish. Aggression levels were measured as the number of bites against a mirror image during 10 min and was also found to be significantly increased in the exposed fish. Novel tank behaviour and locomotor activity was tested in an aquarium that had a horizontal line drawn half-way between the bottom and the surface. Neither the latency to the first transition to the upper half, nor the number of transitions or the total time spent in the upper half was affected by treatment. Locomotor activity was significantly reduced in the exposed fish. The light/dark preference was tested in an aquarium where the bottom and walls were black on one side and white on the other. The number of transitions to the white side was significantly reduced in the exposed fish but there was no effect on the latency to the first transition or the total time spent in the white half. The results in the current study indicate that developmental SSRI exposure causes long-lasting behavioural effects in fish and contribute to the existing knowledge about SSRIs as environmental pollutants.

Nuclear Data Uncertainty Propagation in Depletion Calculations Using Cross Section Uncertainties in One-group or Multi-group

Energy Technology Data Exchange (ETDEWEB)

Díez, C.J., E-mail: cj.diez@upm.es [Dpto. de Ingeníera Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain); Cabellos, O. [Dpto. de Ingeníera Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain); Instituto de Fusión Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain); Martínez, J.S. [Dpto. de Ingeníera Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain)

2015-01-15

Several approaches have been developed in last decades to tackle nuclear data uncertainty propagation problems of burn-up calculations. One approach proposed was the Hybrid Method, where uncertainties in nuclear data are propagated only on the depletion part of a burn-up problem. Because only depletion is addressed, only one-group cross sections are necessary, and hence, their collapsed one-group uncertainties. This approach has been applied successfully in several advanced reactor systems like EFIT (ADS-like reactor) or ESFR (Sodium fast reactor) to assess uncertainties on the isotopic composition. However, a comparison with using multi-group energy structures was not carried out, and has to be performed in order to analyse the limitations of using one-group uncertainties.

Nuclear Data Uncertainty Propagation in Depletion Calculations Using Cross Section Uncertainties in One-group or Multi-group

International Nuclear Information System (INIS)

Díez, C.J.; Cabellos, O.; Martínez, J.S.

2015-01-01

Several approaches have been developed in last decades to tackle nuclear data uncertainty propagation problems of burn-up calculations. One approach proposed was the Hybrid Method, where uncertainties in nuclear data are propagated only on the depletion part of a burn-up problem. Because only depletion is addressed, only one-group cross sections are necessary, and hence, their collapsed one-group uncertainties. This approach has been applied successfully in several advanced reactor systems like EFIT (ADS-like reactor) or ESFR (Sodium fast reactor) to assess uncertainties on the isotopic composition. However, a comparison with using multi-group energy structures was not carried out, and has to be performed in order to analyse the limitations of using one-group uncertainties

Nuclear Data Uncertainty Propagation in Depletion Calculations Using Cross Section Uncertainties in One-group or Multi-group

Science.gov (United States)

Díez, C. J.; Cabellos, O.; Martínez, J. S.

2015-01-01

Several approaches have been developed in last decades to tackle nuclear data uncertainty propagation problems of burn-up calculations. One approach proposed was the Hybrid Method, where uncertainties in nuclear data are propagated only on the depletion part of a burn-up problem. Because only depletion is addressed, only one-group cross sections are necessary, and hence, their collapsed one-group uncertainties. This approach has been applied successfully in several advanced reactor systems like EFIT (ADS-like reactor) or ESFR (Sodium fast reactor) to assess uncertainties on the isotopic composition. However, a comparison with using multi-group energy structures was not carried out, and has to be performed in order to analyse the limitations of using one-group uncertainties.

Long-lasting hippocampal synaptic protein loss in a mouse model of posttraumatic stress disorder.

Directory of Open Access Journals (Sweden)

Leonie Herrmann

Full Text Available Despite intensive research efforts, the molecular pathogenesis of posttraumatic stress disorder (PTSD and especially of the hippocampal volume loss found in the majority of patients suffering from this anxiety disease still remains elusive. We demonstrated before that trauma-induced hippocampal shrinkage can also be observed in mice exhibiting a PTSD-like syndrome. Aiming to decipher the molecular correlates of these trans-species posttraumatic hippocampal alterations, we compared the expression levels of a set of neurostructural marker proteins between traumatized and control mice at different time points after their subjection to either an electric footshock or mock treatment which was followed by stressful re-exposure in several experimental groups. To our knowledge, this is the first systematic in vivo study analyzing the long-term neuromolecular sequelae of acute traumatic stress combined with re-exposure. We show here that a PTSD-like syndrome in mice is accompanied by a long-lasting reduction of hippocampal synaptic proteins which interestingly correlates with the strength of the generalized and conditioned fear response but not with the intensity of hyperarousal symptoms. Furthermore, we demonstrate that treatment with the serotonin reuptake inhibitor (SSRI fluoxetine is able to counteract both the PTSD-like syndrome and the posttraumatic synaptic protein loss. Taken together, this study demonstrates for the first time that a loss of hippocampal synaptic proteins is associated with a PTSD-like syndrome in mice. Further studies will have to reveal whether these findings are transferable to PTSD patients.

Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

Science.gov (United States)

Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

2009-12-01

Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

Time-on-task effects in children with and without ADHD: depletion of executive resources or depletion of motivation?

Science.gov (United States)

Dekkers, Tycho J; Agelink van Rentergem, Joost A; Koole, Alette; van den Wildenberg, Wery P M; Popma, Arne; Bexkens, Anika; Stoffelsen, Reino; Diekmann, Anouk; Huizenga, Hilde M

2017-12-01

Children with attention-deficit/hyperactivity disorder (ADHD) are characterized by deficits in their executive functioning and motivation. In addition, these children are characterized by a decline in performance as time-on-task increases (i.e., time-on-task effects). However, it is unknown whether these time-on-task effects should be attributed to deficits in executive functioning or to deficits in motivation. Some studies in typically developing (TD) adults indicated that time-on-task effects should be interpreted as depletion of executive resources, but other studies suggested that they represent depletion of motivation. We, therefore, investigated, in children with and without ADHD, whether there were time-on-task effects on executive functions, such as inhibition and (in)attention, and whether these were best explained by depletion of executive resources or depletion of motivation. The stop-signal task (SST), which generates both indices of inhibition (stop-signal reaction time) and attention (reaction time variability and errors), was administered in 96 children (42 ADHD, 54 TD controls; aged 9-13). To differentiate between depletion of resources and depletion of motivation, the SST was administered twice. Half of the participants was reinforced during second task performance, potentially counteracting depletion of motivation. Multilevel analyses indicated that children with ADHD were more affected by time-on-task than controls on two measures of inattention, but not on inhibition. In the ADHD group, reinforcement only improved performance on one index of attention (i.e., reaction time variability). The current findings suggest that time-on-task effects in children with ADHD occur specifically in the attentional domain, and seem to originate in both depletion of executive resources and depletion of motivation. Clinical implications for diagnostics, psycho-education, and intervention are discussed.

Design and Optimization of Die Preforming Process for Long Last-stage Blade of Nuclear Power

Directory of Open Access Journals (Sweden)

He Xiaomao

2017-01-01

Full Text Available The long last-stage blade is a key component of the steam turbine of nuclear conventional island. The die preforming process for a new technology that provides billets for near-net-shape roll-forging process was designed, the effects of the forging temperature, friction coefficient, flash land’s height and die’s outer fillet radius on the die forging force and forging energy were studied by using the orthogonal experiment method, the primary and secondary order of the four factors were analysed by using range analysis method, and the optimal combination of the factors was obtained. By means of numerical simulation and physical experiment, the die preforming process that can provide qualified billets for the subsequent roll-forging process was verified, and the PZS1120f electric screw press can meet the requirements of the die preforming process.

Membrane depolarization increases ryanodine sensitivity to Ca2+ release to the cytosol in L6 skeletal muscle cells: Implications for excitation-contraction coupling.

Science.gov (United States)

Pitake, Saumitra; Ochs, Raymond S

2016-04-01

The dihydropyridine receptor in the plasma membrane and the ryanodine receptor in the sarcoplasmic reticulum are known to physically interact in the process of excitation-contraction coupling. However, the mechanism for subsequent Ca(2+) release through the ryanodine receptor is unknown. Our lab has previously presented evidence that the dihydropyridine receptor and ryanodine receptor combine as a channel for the entry of Ca(2+) under resting conditions, known as store operated calcium entry. Here, we provide evidence that depolarization during excitation-contraction coupling causes the dihydropyridine receptor to disengage from the ryanodine receptor. The newly freed ryanodine receptor can then transport Ca(2+) from the sarcoplasmic reticulum to the cytosol. Experimentally, this should more greatly expose the ryanodine receptor to exogenous ryanodine. To examine this hypothesis, we titrated L6 skeletal muscle cells with ryanodine in resting and excited (depolarized) states. When L6 muscle cells were depolarized with high potassium or exposed to the dihydropyridine receptor agonist BAYK-8644, known to induce dihydropyridine receptor movement within the membrane, ryanodine sensitivity was enhanced. However, ryanodine sensitivity was unaffected when Ca(2+) was elevated without depolarization by the ryanodine receptor agonist chloromethylcresol, or by increasing Ca(2+) concentration in the media. Ca(2+) entry currents (from the extracellular space) during excitation were strongly inhibited by ryanodine, but Ca(2+) entry currents in the resting state were not. We conclude that excitation releases the ryanodine receptor from occlusion by the dihydropyridine receptor, enabling Ca(2+) release from the ryanodine receptor to the cytosol. © 2015 by the Society for Experimental Biology and Medicine.

Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, Axel; Ashurova, Mohira B. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Jabbari, Sarah, E-mail: brandenb@nordita.org [School of Mathematical Sciences and Monash Centre for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)

2017-08-20

A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the dynamo. Line-of-sight observations of polarized emission are synthesized to explore the feasibility of using the local reduction of Faraday depolarization to infer the sign of helicity of magnetic fields in the solar corona. This approach was previously identified as an observational diagnostic in the context of galactic magnetic fields. Based on our simulations, we show that this method can be successful in the solar context if sufficient statistics are gathered by using averages over ring segments in the corona separately for the regions north and south of the solar equator.

Tuning of electrostatic vs. depletion interaction in deciding the phase behavior of nanoparticle-polymer system

Energy Technology Data Exchange (ETDEWEB)

Kumar, Sugam, E-mail: sugam@barc.gov.in; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, H-5232 PSI Villigen (Switzerland)

2015-06-24

Nanoparticle-polymer system interestingly show a re-entrant phase behavior where charge stabilized silica nanoparticles (phase I) undergo particle clustering (phase II) and then back to individual particles (phase I) as a function of polymer concentration. Such phase behavior arises as a result of dominance of various interactions (i) nanoparticle-nanoparticle electrostatic repulsion (ii) polymer induced attractive depletion between nanoparticles and (iii) polymer-polymer repulsion, at different concentration regimes. Small-angle neutron scattering (SANS) has been used to study the evolution of interaction during this re-entrant phase behavior of nanoparticles by contrast-marching the polymer. The SANS data have been modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The degree of both of these parts has been separately tuned by varying the polymer concentration and ionic strength of the solution. Both of these parts are found to have long-range nature. At low polymer concentrations, the electrostatic repulsion dominates over the depletion attraction. The magnitude and the range of the depletion interaction increase with the polymer concentration leading to nanoparticle clustering. At higher polymer concentrations, the increased polymer-polymer repulsion reduces the strength of depletion leading to re-entrant phase behavior. The clusters formed under depletion attraction are found to have surface fractal morphology.

Tuning of electrostatic vs. depletion interaction in deciding the phase behavior of nanoparticle-polymer system

International Nuclear Information System (INIS)

Kumar, Sugam; Aswal, V. K.; Kohlbrecher, J.

2015-01-01

Nanoparticle-polymer system interestingly show a re-entrant phase behavior where charge stabilized silica nanoparticles (phase I) undergo particle clustering (phase II) and then back to individual particles (phase I) as a function of polymer concentration. Such phase behavior arises as a result of dominance of various interactions (i) nanoparticle-nanoparticle electrostatic repulsion (ii) polymer induced attractive depletion between nanoparticles and (iii) polymer-polymer repulsion, at different concentration regimes. Small-angle neutron scattering (SANS) has been used to study the evolution of interaction during this re-entrant phase behavior of nanoparticles by contrast-marching the polymer. The SANS data have been modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The degree of both of these parts has been separately tuned by varying the polymer concentration and ionic strength of the solution. Both of these parts are found to have long-range nature. At low polymer concentrations, the electrostatic repulsion dominates over the depletion attraction. The magnitude and the range of the depletion interaction increase with the polymer concentration leading to nanoparticle clustering. At higher polymer concentrations, the increased polymer-polymer repulsion reduces the strength of depletion leading to re-entrant phase behavior. The clusters formed under depletion attraction are found to have surface fractal morphology

Subchronic steroid administration induces long lasting changes in neurochemical and behavioral response to cocaine in rats.

Science.gov (United States)

Kailanto, Sanna; Kankaanpää, Aino; Seppälä, Timo

2011-11-01

The abuse of anabolic androgenic steroids (AASs), such as nandrolone, is not only a problem in the world of sports but is associated with the polydrug use of non-athletes. Among other adverse effects, AAS abuse has been associated with long term or even persistent psychiatric problems. We have previously found that nandrolone decanoate treatment could produce prolonged changes in rats' brain reward circuits associated to drug dependence. The aim in this study was to evaluate whether AAS-induced neurochemical and behavioral changes are reversible. The increases in extracellular dopamine (DA) and serotonin (5-HT) concentration, as well as stereotyped behavior and locomotor activity (LMA) evoked by cocaine were attenuated by pretreatment with nandrolone. The recovery period, which was needed for the DA system to return back to the basic level, was fairly long compared to the dosing period of the steroid. In the 5-HT system, the time that system needed to return back to the basal level, was even longer than in the DA system. The attenuation was still seen though there were no detectable traces of nandrolone in the blood samples. Given that accumbal outflow of DA and 5-HT, as well as LMA and stereotyped behavior are all related to reward of stimulant drugs, this study suggests that nandrolone decanoate has significant, long-lasting but reversible effects on the rewarding properties of cocaine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Specification for the VERA Depletion Benchmark Suite

Energy Technology Data Exchange (ETDEWEB)

Kim, Kang Seog [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-12-17

CASL-X-2015-1014-000 iii Consortium for Advanced Simulation of LWRs EXECUTIVE SUMMARY The CASL neutronics simulator MPACT is under development for the neutronics and T-H coupled simulation for the pressurized water reactor. MPACT includes the ORIGEN-API and internal depletion module to perform depletion calculations based upon neutron-material reaction and radioactive decay. It is a challenge to validate the depletion capability because of the insufficient measured data. One of the detoured methods to validate it is to perform a code-to-code comparison for benchmark problems. In this study a depletion benchmark suite has been developed and a detailed guideline has been provided to obtain meaningful computational outcomes which can be used in the validation of the MPACT depletion capability.

Development of the point-depletion code DEPTH

International Nuclear Information System (INIS)

She, Ding; Wang, Kan; Yu, Ganglin

2013-01-01

Highlights: ► The DEPTH code has been developed for the large-scale depletion system. ► DEPTH uses the data library which is convenient to couple with MC codes. ► TTA and matrix exponential methods are implemented and compared. ► DEPTH is able to calculate integral quantities based on the matrix inverse. ► Code-to-code comparisons prove the accuracy and efficiency of DEPTH. -- Abstract: The burnup analysis is an important aspect in reactor physics, which is generally done by coupling of transport calculations and point-depletion calculations. DEPTH is a newly-developed point-depletion code of handling large burnup depletion systems and detailed depletion chains. For better coupling with Monte Carlo transport codes, DEPTH uses data libraries based on the combination of ORIGEN-2 and ORIGEN-S and allows users to assign problem-dependent libraries for each depletion step. DEPTH implements various algorithms of treating the stiff depletion systems, including the Transmutation trajectory analysis (TTA), the Chebyshev Rational Approximation Method (CRAM), the Quadrature-based Rational Approximation Method (QRAM) and the Laguerre Polynomial Approximation Method (LPAM). Three different modes are supported by DEPTH to execute the decay, constant flux and constant power calculations. In addition to obtaining the instantaneous quantities of the radioactivity, decay heats and reaction rates, DEPTH is able to calculate the integral quantities by a time-integrated solver. Through calculations compared with ORIGEN-2, the validity of DEPTH in point-depletion calculations is proved. The accuracy and efficiency of depletion algorithms are also discussed. In addition, an actual pin-cell burnup case is calculated to illustrate the DEPTH code performance in coupling with the RMC Monte Carlo code

Erythrocyte depletion from bone marrow: performance evaluation after 50 clinical-scale depletions with Spectra Optia BMC.

Science.gov (United States)

Kim-Wanner, Soo-Zin; Bug, Gesine; Steinmann, Juliane; Ajib, Salem; Sorg, Nadine; Poppe, Carolin; Bunos, Milica; Wingenfeld, Eva; Hümmer, Christiane; Luxembourg, Beate; Seifried, Erhard; Bonig, Halvard

2017-08-11

Red blood cell (RBC) depletion is a standard graft manipulation technique for ABO-incompatible bone marrow (BM) transplants. The BM processing module for Spectra Optia, "BMC", was previously introduced. We here report the largest series to date of routine quality data after performing 50 clinical-scale RBC-depletions. Fifty successive RBC-depletions from autologous (n = 5) and allogeneic (n = 45) BM transplants were performed with the Spectra Optia BMC apheresis suite. Product quality was assessed before and after processing for volume, RBC and leukocyte content; RBC-depletion and stem cell (CD34+ cells) recovery was calculated there from. Clinical engraftment data were collected from 26/45 allogeneic recipients. Median RBC removal was 98.2% (range 90.8-99.1%), median CD34+ cell recovery was 93.6%, minimum recovery being 72%, total product volume was reduced to 7.5% (range 4.7-23.0%). Products engrafted with expected probability and kinetics. Performance indicators were stable over time. Spectra Optia BMC is a robust and efficient technology for RBC-depletion and volume reduction of BM, providing near-complete RBC removal and excellent CD34+ cell recovery.

Genome-wide RNA profiling of long-lasting stem cell-like memory CD8 T cells induced by Yellow Fever vaccination in humans

Directory of Open Access Journals (Sweden)

Silvia A. Fuertes Marraco

2015-09-01

Full Text Available The live-attenuated Yellow Fever (YF vaccine YF-17D induces a broad and polyfunctional CD8 T cell response in humans. Recently, we identified a population of stem cell-like memory CD8 T cells induced by YF-17D that persists at stable frequency for at least 25 years after vaccination. The YF-17D is thus a model system of human CD8 T cell biology that furthermore allows to track and study long-lasting and antigen-specific human memory CD8 T cells. Here, we describe in detail the sample characteristics and preparation of a microarray dataset acquired for genome-wide gene expression profiling of long-lasting YF-specific stem cell-like memory CD8 T cells, compared to the reference CD8 T cell differentiation subsets from total CD8 T cells. We also describe the quality controls, annotations and exploratory analyses of the dataset. The microarray data is available from the Gene Expression Omnibus (GEO public repository with accession number GSE65804.

Methods for the detection and serum depletion of porcine galectin-3.

Science.gov (United States)

Eliaz, Isaac; Patil, Aarti; Navarro-Alvarez, Nalu; Wang, Zhirui; Eliaz, Amity; Weil, Elaine; Wilk, Barry; Sachs, David H; Huang, Christene A

2017-10-01

Circulating galectin-3 (Gal-3) is elevated in systemic inflammatory disorders, fibrotic diseases, and in cancers. Gal-3 is a promising cancer target where it promotes tumorigenesis and metastasis, as well as in renal, pulmonary, hepatic, and cardiovascular diseases, because of its role as a driver of fibrotic remodeling. This reports goal was to establish methods for the detection and removal of porcine Gal-3 that will enable further studies of the therapeutic potential of Gal-3 depletion by apheresis in porcine disease models. The long-term aim is to develop a safe, effective method of removing Gal-3 via apheresis as a standalone therapeutic tool and as an adjuvant to other therapies. Purified recombinant porcine Gal-3 was prepared and used as the standard for development of a porcine Gal-3 enzyme-linked immunosorbent assay (ELISA). Different affinity column matrices that incorporated either a rat IgG2a anti-Gal-3 monoclonal antibody or carbohydrate ligand were assessed for depletion of Gal-3 from porcine serum. A porcine Gal-3 ELISA with a linear range from 0.3 to 20 ng/mL was able to detect native porcine Gal-3 in both fetal (∼150-200 ng/mL) and juvenile (∼5-15 ng/mL) porcine serum samples. Use of an anti-Gal-3 monoclonal antibody affinity column depleted Gal-3 from porcine serum to at least 313 pg/mL, the limit of ELISA detection. Methods have been developed for the detection and depletion of porcine Gal-3. These methods will be used to study the specific effects of Gal-3 depletion via apheresis in porcine models of disease. © 2017 Wiley Periodicals, Inc.

Future emission scenarios for chemicals that may deplete stratospheric ozone

International Nuclear Information System (INIS)

Hammitt, J.K; Camm, Frank; Mooz, W.E.; Wolf, K.A.; Bamezai, Anil; Connel, P.S.; Wuebbles, D.J.

1990-01-01

Scenarios are developed for long-term future emissions of seven of the most important manmade chemicals that may deplete ozone and the corresponding effect on stratospheric ozone concentrations is calculated using a one-dimensional atmospheric model. The scenarios are based on detailed analysis of the markets for products that use these chemicals and span a central 90% probability interval for the chemicals joint effect on calculated ozone abundance, assuming no additional regulations. (author). 22 refs., 2 figs., 5 tabs

The Last Interglacial-Glacial cycle (MIS 5-2) re-examined based on long proxy records from central and northern Europe

Science.gov (United States)

Helmens, Karin F.

2014-02-01

Current multi-proxy studies on a long sediment sequence preserved at Sokli (N Finland), i.e. in the central area of Fennoscandian glaciations, are drastically changing classic ideas of glaciations, vegetation and climate in northern Europe during the Late Pleistocene. The sediments in the Sokli basin have escaped major glacial erosion due to non-typical bedrock conditions. In this review, the Sokli record is compared in great detail with other long proxy records from central, temperate and northern, boreal Europe. These comprise the classic records of La Grande Pile (E France) and Oerel (N Germany) and more recently obtained records from Horoszki Duże (E Poland) and Lake Yamozero (NW Russia). The focus of the review is on pollen, lithology and macrofossil- and insect-based temperature inferences. The long records are further compared with recent proxy data from nearby terrestrial sites as well as with the rapidly accumulating high-resolution proxy data from the ocean realm. The comparison allows a re-examination of the environmental history and climate evolution of the Last Interglacial-Glacial (LI-G) cycle (MIS 5-2). It shows that environmental and climate conditions during MIS 5 (ca 130-70 ka BP) were distinctly different from those during MIS 4-2 (ca 70-15 ka BP). MIS 5 is characterized by three long forested intervals (broadly corresponding to MIS 5e, 5c, 5a), both in temperate and northern boreal Europe. These mild periods were interrupted by two short, relatively cold and dry intervals (MIS 5d and 5b) with mountain-centered glaciation in Fennoscandia. Millennial scale climate events were superimposed upon these longer lasting climate fluctuations. The time interval encompassing MIS 4-2 shows open vegetation. It is characterized by two glacial maxima (MIS 4 and 2) with sub-continental scale glaciation over northern Europe and dry conditions in strongly continental eastern European settings. High amplitude climate oscillations of millennial duration

Long lasting effect of physical stress on the LVEF

International Nuclear Information System (INIS)

Cholewinski, W.; Stefaniak, B.; Poniatowicz-Frasunek, E.; Tarkowska, A.

2003-01-01

Animal and clinical studies have shown that exercise can deteriorate myocardial contractile function. The aim of this study was to examine whether the decrease of LVEF measured with gated SPECT lasts as long as 3 hours after exercise. 46 patients with CAD and a control group comprising 10 healthy subjects were studied. All patients underwent myocardial perfusion gated SPECT with 99m Tc-tetrofosmin at rest and during stress. SPECT was started 1 hour p.i. at rest and twice - 1 hour and 3 hours after injection at stress. LVEF values were calculated by the method of Germano, using QGS software. LVEF values measured at all time points were significantly lower in CAD patients than in control group. In normals mean LVEF values 1 h after rest injection were similar to those obtained 1 and 3 hours after stress injection (59.0 ± 4.1 v. 60.0 ± 5.9 v. 58.0 ± 4.6, respectively; p > 0.05). One hour post exercise a decrease of LVEF was observed in 2 patients and 3 hours after injection also in 2 patients. CAD subjects showed slightly lower LVEF values determined 1h after stress than 1 hour after rest injection (50.8 ± 13.6 v. 49.3 ± 12.8; p < 0.05). More expressed reduction of LVEF was observed 3 hours after stress injection as compared to both rest and stress study (50.8 ± 13.6 v. 46.0 ± 12.2; p < 0.001 and 49.3 ± 12.8 v. 6.0 ± 12.2; p < 0.001, respectively). One hour post exercise, a decrease of LVEF values was observed in 18 patients and 3 hours after injection in 36 patients out of 46. In the majority of patients with CAD physical stress applied for the purposes of myocardial perfusion SPECT study results in an impairment of the LV function. The impairment of the LVEF caused by physical stress is observed 1 hour after exercise, but it increases markedly in frequency and grows stronger during the next 2 hours. Patients with CAD who underwent cardiac examination connected with physical stress should remain under observation for several hours after termination of

Tryptophan depletion affects compulsive behaviour in rats

DEFF Research Database (Denmark)

Merchán, A; Navarro, S V; Klein, A B

2017-01-01

investigated whether 5-HT manipulation, through a tryptophan (TRP) depletion by diet in Wistar and Lister Hooded rats, modulates compulsive drinking in schedule-induced polydipsia (SIP) and locomotor activity in the open-field test. The levels of dopamine, noradrenaline, serotonin and its metabolite were......-depleted HD Wistar rats, while the LD Wistar and the Lister Hooded rats did not exhibit differences in SIP. In contrast, the TRP-depleted Lister Hooded rats increased locomotor activity compared to the non-depleted rats, while no differences were found in the Wistar rats. Serotonin 2A receptor binding...

Revisiting Antarctic Ozone Depletion

Science.gov (United States)

Grooß, Jens-Uwe; Tritscher, Ines; Müller, Rolf

2015-04-01

Antarctic ozone depletion is known for almost three decades and it has been well settled that it is caused by chlorine catalysed ozone depletion inside the polar vortex. However, there are still some details, which need to be clarified. In particular, there is a current debate on the relative importance of liquid aerosol and crystalline NAT and ice particles for chlorine activation. Particles have a threefold impact on polar chlorine chemistry, temporary removal of HNO3 from the gas-phase (uptake), permanent removal of HNO3 from the atmosphere (denitrification), and chlorine activation through heterogeneous reactions. We have performed simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) employing a recently developed algorithm for saturation-dependent NAT nucleation for the Antarctic winters 2011 and 2012. The simulation results are compared with different satellite observations. With the help of these simulations, we investigate the role of the different processes responsible for chlorine activation and ozone depletion. Especially the sensitivity with respect to the particle type has been investigated. If temperatures are artificially forced to only allow cold binary liquid aerosol, the simulation still shows significant chlorine activation and ozone depletion. The results of the 3-D Chemical Transport Model CLaMS simulations differ from purely Lagrangian longtime trajectory box model simulations which indicates the importance of mixing processes.

Nogo receptor 1 regulates formation of lasting memories

Science.gov (United States)

Karlén, Alexandra; Karlsson, Tobias E.; Mattsson, Anna; Lundströmer, Karin; Codeluppi, Simone; Pham, Therese M.; Bäckman, Cristina M.; Ögren, Sven Ove; Åberg, Elin; Hoffman, Alexander F.; Sherling, Michael A.; Lupica, Carl R.; Hoffer, Barry J.; Spenger, Christian; Josephson, Anna; Brené, Stefan; Olson, Lars

2009-01-01

Formation of lasting memories is believed to rely on structural alterations at the synaptic level. We had found that increased neuronal activity down-regulates Nogo receptor-1 (NgR1) in brain regions linked to memory formation and storage, and postulated this to be required for formation of lasting memories. We now show that mice with inducible overexpression of NgR1 in forebrain neurons have normal long-term potentiation and normal 24-h memory, but severely impaired month-long memory in both passive avoidance and swim maze tests. Blocking transgene expression normalizes these memory impairments. Nogo, Lingo-1, Troy, endogenous NgR1, and BDNF mRNA expression levels were not altered by transgene expression, suggesting that the impaired ability to form lasting memories is directly coupled to inability to down-regulate NgR1. Regulation of NgR1 may therefore serve as a key regulator of memory consolidation. Understanding the molecular underpinnings of synaptic rearrangements that carry lasting memories may facilitate development of treatments for memory dysfunction. PMID:19915139

Continuous operation of RODOS in case of long lasting releases

International Nuclear Information System (INIS)

Raskob, W.; Paesler-Sauer, J.; Rafat, M.

2003-01-01

users who want to explore the impact of long term countermeasures in more detail. The users has also the option to set the time (in days after the first release) at which they consider the release to be ended or all significant deposition to have occurred. This will be entered interactively via the user interface. This will enable the user to start the consideration of countermeasures after the majority of the release has occurred, as some releases might have a very long, low level tail, and it would be unrealistic to expect decision makers to wait until deposition had completely stopped in such circumstances. This approach also recognizes that deposition will not end everywhere on the same day. The demonstration will exemplify the continuous automatic operation of RODOS using a release scenarios lasting over several days. On-line meteorological data measured at Forschungszentrum Karlsruhe, assumed to be the release point, will be used as input for the diagnostic calculations performed automatically within a distance range of 160 km x 160 km every 10 minutes. Numerical weather forecast from the German Weather Service, updated every 12 hours, will be used for prognostic calculations repeated in the same calculation area every hour. In parallel, the European wide numerical weather forecasts calculated by the ALADIN model, run by the Austrian Weather service and updated every 12 hours, are used to calculate in interactive RODOS runs the longer distance contamination. All functions of RODOS and its broad spectrum of results will be presented by the demonstration team. In particular, the necessity of emergency actions and countermeasure and their consequences in terms of areas affected, radiation doses and resources needed can be tracked with the ongoing activity release. (author)

Long-lasting insecticidal nets are synergistic with mass drug administration for interruption of lymphatic filariasis transmission in Nigeria.

Directory of Open Access Journals (Sweden)

Abel Eigege

Full Text Available In central Nigeria Anopheles mosquitoes transmit malaria and lymphatic filariasis (LF. The strategy used for interrupting LF transmission in this area is annual mass drug administration (MDA with albendazole and ivermectin, but after 8 years of MDA, entomological evaluations in sentinel villages showed continued low-grade mosquito infection rates of 0.32%. After long-lasting insecticidal net (LLIN distribution by the national malaria program in late 2010, however, we were no longer able to detect infected vectors over a 24-month period. This is evidence that LLINs are synergistic with MDA in interrupting LF transmission.

Separation and recovery method for depleted uranium from spent fuel

International Nuclear Information System (INIS)

Imoto, Yoshie; Fujita, Reiko.

1993-01-01

Spent oxide fuels are reduced in a molten salt of CaCl 2 -CaF 2 to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing uranium and long time management for uranium. (T.M.)

Can Long-lasting Insecticide-treated Bednets with Holes Protect Children from Malaria?

Science.gov (United States)

Nonaka, Daisuke; Maazou, Abani; Yamagata, Shigeo; Oumarou, Issofou; Uchida, Takako; Jg Yacouba, Honoré; Toma, Nami; Takeuchi, Rie; Kobayashi, Jun; Mizoue, Tetsuya

2014-09-01

Although long-lasting insecticide-treated bednets (LLINs) have been widely used for malaria control, little is known about how the condition of LLINs affects the risk of malaria infection. The objective of this cross-sectional study was to examine the association between the use of LLINs with holes and caregiver-reported malaria diagnosed in children under five years of age (U5). Data were collected in Boboye health district, Niger, in 2010. Surveyors conducted interviews and bednet inspections in 1,034 households. If a household had a U5 child, the surveyor asked the caregiver whether the child had experienced a fever episode in the past two weeks that entailed standard treatment for uncomplicated malaria at a healthcare facility. The authors analyzed the association between the use of LLINs with holes and caregiver-reported malaria episodes in U5 children using logistic regression, adjusted for possible confounders. Of the 1,165 children included in the analysis, approximately half (53.3%) used an intact LLIN while far fewer (10.6%) used a LLIN with holes. Compared to children using an intact LLIN, children using a LLIN with holes were significantly more likely to have a caregiver-reported malaria episode (8.7% vs. 17.1%; odds ratio: 2.23; 95% confidence interval: 1.24-4.01). In this study site, LLINs with holes were less protective than intact LLINs.

Long-lasting effects of perinatal asphyxia on exploration, memory and incentive downshift.

Science.gov (United States)

Galeano, Pablo; Blanco Calvo, Eduardo; Madureira de Oliveira, Diêgo; Cuenya, Lucas; Kamenetzky, Giselle Vanesa; Mustaca, Alba Elisabeth; Barreto, George Emilio; Giraldez-Alvarez, Lisandro Diego; Milei, José; Capani, Francisco

2011-10-01

Perinatal asphyxia remains as one of the most important causes of death and disability in children, without an effective treatment. Moreover, little is known about the long-lasting behavioral consequences of asphyxia at birth. Therefore, the main aim of the present study was to investigate the motor, emotional and cognitive functions of adult asphyctic rats. Experimental subjects consisted of rats born vaginally (CTL), by cesarean section (C+), or by cesarean section following 19 min of asphyxia (PA). At three months of age, animals were examined in a behavioral test battery including elevated plus maze, open field, Morris water maze, and an incentive downshift procedure. Results indicated that groups did not differ in anxiety-related behaviors, although a large variability was observed in the asphyctic group and therefore, the results are not completely conclusive. In addition, PA and C+ rats showed a deficit in exploration of new environments, but to a much lesser extent in the latter group. Spatial reference and working memory impairments were also found in PA rats. Finally, when animals were downshifted from a 32% to a 4% sucrose solution, an attenuated suppression of consummatory behavior was observed in PA rats. These results confirmed and extended those reported previously about the behavioral alterations associated with acute asphyxia around birth. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

ANATOMY OF DEPLETED INTERPLANETARY CORONAL MASS EJECTIONS

Energy Technology Data Exchange (ETDEWEB)

Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B. IV, E-mail: mkocher@umich.edu [Department of Climate and Space Sciences and Engineering, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 (United States)

2017-01-10

We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE /SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C{sup 6+}/C{sup 5+} and O{sup 7+}/O{sup 6+} depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

Recurrence formulas for evaluating expansion series of depletion functions

International Nuclear Information System (INIS)

Vukadin, Z.

1991-01-01

A high-accuracy analytical method for solving the depletion equations for chains of radioactive nuclides is based on the formulation of depletion functions. When all the arguments of the depletion function are too close to each other, series expansions of the depletion function have to be used. However, the high-accuracy series expressions for the depletion functions of high index become too complicated. Recursion relations are derived which enable an efficient high-accuracy evaluation of the depletion functions with high indices. (orig.) [de

Implications of insecticide resistance for malaria vector control with long-lasting insecticidal nets: a WHO-coordinated, prospective, international, observational cohort study.

Science.gov (United States)

Kleinschmidt, Immo; Bradley, John; Knox, Tessa Bellamy; Mnzava, Abraham Peter; Kafy, Hmooda Toto; Mbogo, Charles; Ismail, Bashir Adam; Bigoga, Jude D; Adechoubou, Alioun; Raghavendra, Kamaraju; Cook, Jackie; Malik, Elfatih M; Nkuni, Zinga José; Macdonald, Michael; Bayoh, Nabie; Ochomo, Eric; Fondjo, Etienne; Awono-Ambene, Herman Parfait; Etang, Josiane; Akogbeto, Martin; Bhatt, Rajendra M; Chourasia, Mehul Kumar; Swain, Dipak K; Kinyari, Teresa; Subramaniam, Krishanthi; Massougbodji, Achille; Okê-Sopoh, Mariam; Ogouyemi-Hounto, Aurore; Kouambeng, Celestin; Abdin, Mujahid Sheikhedin; West, Philippa; Elmardi, Khalid; Cornelie, Sylvie; Corbel, Vincent; Valecha, Neena; Mathenge, Evan; Kamau, Luna; Lines, Jonathan; Donnelly, Martin James

2018-04-09

Scale-up of insecticide-based interventions has averted more than 500 million malaria cases since 2000. Increasing insecticide resistance could herald a rebound in disease and mortality. We aimed to investigate whether insecticide resistance was associated with loss of effectiveness of long-lasting insecticidal nets and increased malaria disease burden. This WHO-coordinated, prospective, observational cohort study was done at 279 clusters (villages or groups of villages in which phenotypic resistance was measurable) in Benin, Cameroon, India, Kenya, and Sudan. Pyrethroid long-lasting insecticidal nets were the principal form of malaria vector control in all study areas; in Sudan this approach was supplemented by indoor residual spraying. Cohorts of children from randomly selected households in each cluster were recruited and followed up by community health workers to measure incidence of clinical malaria and prevalence of infection. Mosquitoes were assessed for susceptibility to pyrethroids using the standard WHO bioassay test. Country-specific results were combined using meta-analysis. Between June 2, 2012, and Nov 4, 2016, 40 000 children were enrolled and assessed for clinical incidence during 1·4 million follow-up visits. 80 000 mosquitoes were assessed for insecticide resistance. Long-lasting insecticidal net users had lower infection prevalence (adjusted odds ratio [OR] 0·63, 95% CI 0·51-0·78) and disease incidence (adjusted rate ratio [RR] 0·62, 0·41-0·94) than did non-users across a range of resistance levels. We found no evidence of an association between insecticide resistance and infection prevalence (adjusted OR 0·86, 0·70-1·06) or incidence (adjusted RR 0·89, 0·72-1·10). Users of nets, although significantly better protected than non-users, were nevertheless subject to high malaria infection risk (ranging from an average incidence in net users of 0·023, [95% CI 0·016-0·033] per person-year in India, to 0·80 [0·65-0·97] per person

Study on in-situ electrochemical impedance spectroscopy measurement of anodic reaction in SO_2 depolarized electrolysis process

International Nuclear Information System (INIS)

Xue Lulu; Zhang Ping; Chen Songzhe; Wang Laijun

2014-01-01

SO_2 depolarized electrolysis (SDE) is the pivotal reaction in hybrid sulfur process, one of the most promising approaches for mass hydrogen production without CO_2 emission. The net result of hybrid sulfur process is to split water into hydrogen and oxygen at a relatively low voltage, which will dramatically decrease the energy consumption for the production of hydrogen. The potential loss of SDE process could be separated into four components, i.e. reversible cell potential, anode overpotential, cathode overpotential and ohmic loss. So far, it has been identified that the total cell potential for the SO_2 depolarized electrolyzer is dominantly controlled by sulfuric acid concentration of the anolyte and electrolysis temperature of the electrolysis process. In this work, an in-situ Electrochemical Impedance Spectroscopy (EIS) measurement of the anodic SDE reaction was conducted. Results show that anodic overpotential is mainly resulted from the SO_2 oxidation reaction other than ohmic resistance or mass transfer limitation. This study extends the understanding to SDE process and gives suggestions for the further improvement of the SDE performance. (author)

Legal requirements for long-lasting radioactive waste disposal; Rechtliche Anforderungen der Beseitigung hochradioaktiver langlebiger Abfaelle

Energy Technology Data Exchange (ETDEWEB)

Giesselmann, Matthias

2016-07-01

The topic of nuclear disposal has been treated in juridical regard up to now only rudimentary. To this day the federation has not met the legal obligation existing for roughly 40 years to set up a plant for the safekeeping and for the permanent storage of highly-radioactive waste. Repeatedly changed disposal-conceptual approaches have contributed perpetually to a temporal shift of the ''dumping question'' into an uncertain future. Against this background it seems necessary on to examine whether such a ''politics of ephemeral solution attempts'' is legally to be accepted (any longer). Hence, including the recently remitted site selection law the author works out extensively the removal regime applying in Germany for highly radioactive long-lasting rubbish and verifies his compatibility with the European law, the German constitutional law and the thematically relevant International treaty law.

Effects of Educational Intervention on Long-Lasting Insecticidal Nets Use in a Malarious Area, Southeast Iran

Directory of Open Access Journals (Sweden)

Abdol Hossein Madani

2012-04-01

Full Text Available Long-lasting insecticidal nets (LLINs have been advocated as an effective tool against malaria transmission. However, success of this community based intervention largely depends on the knowledge and practice regarding malaria and its prevention. According to the national strategy plan on evaluation of LLINs (Olyset nets, this study was conducted to determine the perceptions and practices about malaria and to improve use of LLINs in Bashagard district, one of the important foci of malaria in southeast Iran. The study area comprised 14 villages that were randomized in two clusters and designated as LLINs and untreated nets. Each of households in both clusters received two bed nets by the free distribution and delivery. After one month quantitative data collection method was used to collect information regarding the objectives of the study. On the basis of this information, an educational program was carried out in both areas to increase motivation for use of bed nets. Community knowledge and practice regarding malaria and LLIN use assessed pre- and post-educational program. The data were analyzed using SPSS ver.16 software. At baseline, 77.5% of respondents in intervention and 69.4 % in control area mentioned mosquito bite as the cause of malaria, this awareness increased significantly in intervention (90.3% and control areas (87.9%, following the educational program. A significant increase also was seen in the proportion of households who used LLINs the previous night (92.5% compared with untreated nets (87.1%. Educational status was an important predictor of LLINs use. Regular use of LLIN was considerably higher than the targeted coverage (80% which recommended by World Heaths Organization. About 81.1% and 85.3% of respondents from LLIN and control areas reported that mosquito nuisance and subsequent malaria transmission were the main determinants of bed net use. These findings highlight a need for educational intervention in implementation of

A single exposure to immobilization causes long-lasting pituitary-adrenal and behavioral sensitization to mild stressors.

Science.gov (United States)

Belda, Xavier; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

2008-11-01

We have previously reported that a single exposure to immobilization (IMO) in rats causes a long-term desensitization of the hypothalamic-pituitary-adrenal (HPA) response to the same (homotypic) stressor. Since there are reports showing that a single exposure to other stressors causes sensitization of the HPA response to heterotypic stressors and increases anxiety-like behavior, we studied in the present work the long-term effects of IMO on behavioral and HPA response to mild superimposed stressors. In Experiments 1 and 2, adult male Sprague-Dawley rats were subjected to 2 h of IMO and then exposed for 5 min to the elevated plus-maze (EPM) at 1, 3 or 7 days after IMO. Blood samples were taken at 15 min after initial exposure to the EPM. Increases in anxiety-like behavior and HPA responsiveness to the EPM were found at all times post-IMO. Changes in the resting levels of HPA hormones did not explain the enhanced HPA responsiveness to the EPM (Experiment 3). In Experiments 4 and 5, we studied the effects of a single exposure to a shorter session of IMO (1 h) on behavioral and HPA responses to a brief and mild session of foot-shocks done 10 days after IMO. Neither previous IMO nor exposure to shocks in control rats modified behavior in the EPM. However, a brief session of shocks in previously IMO-exposed rats dramatically increased anxiety in the EPM. HPA and freezing responses to shocks were similar in control and previous IMO groups. Therefore, a single exposure to IMO appears to induce long-lasting HPA and behavioral sensitization to mild superimposed stressors, although the two responses are likely to be at least partially independent. Long-term effects of IMO on the susceptibility to stress-induced endocrine and emotional disturbances may be relevant to the characterization of animal models of post-traumatic stress.

Dielectric relaxation of 2-ethyl-1-hexanol around the glass transition by thermally stimulated depolarization currents.

Science.gov (United States)

Arrese-Igor, S; Alegría, A; Colmenero, J

2015-06-07

We explore new routes for characterizing the Debye-like and α relaxation in 2-ethyl-1-hexanol (2E1H) monoalcohol by using low frequency dielectric techniques including thermally stimulated depolarization current (TSDC) techniques and isothermal depolarization current methods. In this way, we have improved the resolution of the overlapped processes making it possible the analysis of the data in terms of a mode composition as expected for a chain-like response. Furthermore the explored ultralow frequencies enabled to study dynamics at relatively low temperatures close to the glass transition (Tg). Results show, on the one hand, that Debye-like and α relaxation timescales dramatically approach to each other upon decreasing temperature to Tg. On the other hand, the analysis of partial polarization TSDC data confirms the single exponential character of the Debye-like relaxation in 2E1H and rules out the presence of Rouse type modes in the scenario of a chain-like response. Finally, on crossing the glass transition, the Debye-like relaxation shows non-equilibrium effects which are further emphasized by aging treatment and would presumably emerge as a result of the arrest of the structural relaxation below Tg.

Transient Treg depletion enhances therapeutic anti‐cancer vaccination

Science.gov (United States)

Aston, Wayne J.; Chee, Jonathan; Khong, Andrea; Cleaver, Amanda L.; Solin, Jessica N.; Ma, Shaokang; Lesterhuis, W. Joost; Dick, Ian; Holt, Robert A.; Creaney, Jenette; Boon, Louis; Robinson, Bruce; Lake, Richard A.

2016-01-01

Abstract Introduction Regulatory T cells (Treg) play an important role in suppressing anti‐ immunity and their depletion has been linked to improved outcomes. To better understand the role of Treg in limiting the efficacy of anti‐cancer immunity, we used a Diphtheria toxin (DTX) transgenic mouse model to specifically target and deplete Treg. Methods Tumor bearing BALB/c FoxP3.dtr transgenic mice were subjected to different treatment protocols, with or without Treg depletion and tumor growth and survival monitored. Results DTX specifically depleted Treg in a transient, dose‐dependent manner. Treg depletion correlated with delayed tumor growth, increased effector T cell (Teff) activation, and enhanced survival in a range of solid tumors. Tumor regression was dependent on Teffs as depletion of both CD4 and CD8 T cells completely abrogated any survival benefit. Severe morbidity following Treg depletion was only observed, when consecutive doses of DTX were given during peak CD8 T cell activation, demonstrating that Treg can be depleted on multiple occasions, but only when CD8 T cell activation has returned to base line levels. Finally, we show that even minimal Treg depletion is sufficient to significantly improve the efficacy of tumor‐peptide vaccination. Conclusions BALB/c.FoxP3.dtr mice are an ideal model to investigate the full therapeutic potential of Treg depletion to boost anti‐tumor immunity. DTX‐mediated Treg depletion is transient, dose‐dependent, and leads to strong anti‐tumor immunity and complete tumor regression at high doses, while enhancing the efficacy of tumor‐specific vaccination at low doses. Together this data highlight the importance of Treg manipulation as a useful strategy for enhancing current and future cancer immunotherapies. PMID:28250921

The Last Straw

CERN Multimedia

McFarlane, K.W.

2002-01-01

On 4 December 2002 at Hampton University, we completed processing the 'straws' for the Barrel TRT. The straws are plastic tubes 4 mm in diameter and 1.44 m long. More than 52 thousand straws will be used to build the drift tube detectors in the Barrel TRT. The picture shows some members of the Hampton production team ceremonially cutting the last straw to its final precise length. The production team, responsible for processing 64 thousand straws, included Jacquelyn Hodges, Carolyn Griffin, Princess Wilkins, Aida Kelly, Alan Fry, and (not pictured) Chuck Long, Nedra Peeples, and Hilda Williams. The straws have a cosmopolitan history. First, plastic film from a U.S. company was shipped to Russia to be coated with conductive materials and adhesive. The coated film was slit into long ribbons and sent to the UK to be wound into tubes. The tubes were then sent to two ATLAS collaborators in Russia, PNPI (Gatchina) and JINR (Dubna), where they were reinforced with carbon fibres to make them stiff and accuratel...

Binding of long-lasting local anesthetics to lipid emulsions.

Science.gov (United States)

Mazoit, Jean-Xavier; Le Guen, Régine; Beloeil, Hélène; Benhamou, Dan

2009-02-01

Rapid infusion of lipid emulsion has been proposed to treat local anesthetic toxicity. The authors wanted to test the buffering properties of two commercially available emulsions made of long- and of long- and medium-chain triglycerides. Using the shake-flask method, the authors measured the solubility and binding of racemic bupivacaine, levobupivacaine, and ropivacaine to diluted Intralipid (Fresenius Kabi, Paris, France) and Medialipide (B-Braun, Boulogne, France). The apparent distribution coefficient expressed as the ratio of mole fraction was 823 +/- 198 and 320 +/- 65 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, at 500 mg in the Medialipide/buffer emulsion; and 1,870 +/- 92 and 1,240 +/- 14 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, in the Intralipid/buffer emulsion. Decreasing the pH from 7.40 to 7.00 of the Medialipide/buffer emulsion led to a decrease in ratio of molar concentration from 121 +/- 3.8 to 46 +/- 2.8 for bupivacaine, and to a lesser extent from 51 +/- 4.0 to 31 +/- 1.6 for ropivacaine. The capacity of the 1% emulsions was 871 and 2,200 microM for the 1% Medialipide and Intralipid emulsions, respectively. The dissociation constant was 818 and 2,120 microM for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively. Increasing the temperature from 20 to 37 degrees C led to a greater increase in affinity for ropivacaine (55%) than for bupivacaine (27%). When the pH of the buffer was decreased from 7.40 to 7.00, the affinity was decreased by a factor of 1.68, similar for both anesthetics. The solubility of long-acting local anesthetics in lipid emulsions and the high capacity of binding of these emulsions most probably explain their clinical efficacy in case of toxicity. The long-chain triglyceride emulsion Intralipid appears to be about 2.5 times more efficacious than the 50/50 medium-chain/long-chain Medialipide emulsion. Also, because of their higher hydrophobicity

Evaluation of new tools for malaria vector control in Cameroon: focus on long lasting insecticidal nets.

Science.gov (United States)

Etang, Josiane; Nwane, Philippe; Piameu, Michael; Manga, Blaise; Souop, Daniel; Awono-Ambene, Parfait

2013-01-01

From 2006 to 2011, biological activity of insecticides for Indoor Residual Spraying (IRS), conventional treatment of nets (CTNs) or long lasting insecticidal nets (LLINs) was evaluated before their approval in Cameroon. The objective of the study was to select the best tools for universal malaria vector control coverage. Bioassays were performed using WHO cones and the Kisumu susceptible strain of Anopheles gambiae s.s.. Among tested products, residual activity and wash resistance of Alpha-cypermethrin LLINs (Interceptor) and CTNs (Fendona) were assessed during 5 months in the Ntougou neighborhood. All the 14 tested products were found effective (95-100% knockdown and mortality rates), although a significant decrease of efficacy was seen with lambda-cyhalothrinWP IRS, alpha-cypermethrin CTNs and LLINs (peducation toward universal coverage of malaria vector control in Cameroon.

EPRI depletion benchmark calculations using PARAGON

International Nuclear Information System (INIS)

Kucukboyaci, Vefa N.

2015-01-01

Highlights: • PARAGON depletion calculations are benchmarked against the EPRI reactivity decrement experiments. • Benchmarks cover a wide range of enrichments, burnups, cooling times, and burnable absorbers, and different depletion and storage conditions. • Results from PARAGON-SCALE scheme are more conservative relative to the benchmark data. • ENDF/B-VII based data reduces the excess conservatism and brings the predictions closer to benchmark reactivity decrement values. - Abstract: In order to conservatively apply burnup credit in spent fuel pool criticality analyses, code validation for both fresh and used fuel is required. Fresh fuel validation is typically done by modeling experiments from the “International Handbook.” A depletion validation can determine a bias and bias uncertainty for the worth of the isotopes not found in the fresh fuel critical experiments. Westinghouse’s burnup credit methodology uses PARAGON™ (Westinghouse 2-D lattice physics code) and its 70-group cross-section library, which have been benchmarked, qualified, and licensed both as a standalone transport code and as a nuclear data source for core design simulations. A bias and bias uncertainty for the worth of depletion isotopes, however, are not available for PARAGON. Instead, the 5% decrement approach for depletion uncertainty is used, as set forth in the Kopp memo. Recently, EPRI developed a set of benchmarks based on a large set of power distribution measurements to ascertain reactivity biases. The depletion reactivity has been used to create 11 benchmark cases for 10, 20, 30, 40, 50, and 60 GWd/MTU and 3 cooling times 100 h, 5 years, and 15 years. These benchmark cases are analyzed with PARAGON and the SCALE package and sensitivity studies are performed using different cross-section libraries based on ENDF/B-VI.3 and ENDF/B-VII data to assess that the 5% decrement approach is conservative for determining depletion uncertainty

Axon-Schwann cell interaction in the squid nerve fibre.

Science.gov (United States)

Villegas, J

1972-09-01

The electrical properties of Schwann cells and the effects of neuronal impulses on their membrane potential have been studied in the giant nerve fibre of the squid.1. The behaviour of the Schwann cell membrane to current injection into the cell was ohmic. No impulse-like responses were observed with displacements of 35 mV in the membrane potential. The resistance of the Schwann cell membrane was found to be approximately 10(3) Omega cm(2).2. A long-lasting hyperpolarization is observed in the Schwann cells following the conduction of impulse trains by the axon. Whereas the propagation of a single impulse had little effect, prolonged stimulation of the fibre at 250 impulses/sec was followed by a hyperpolarization of the Schwann cell that gradually declined over a period of several minutes.3. The prolonged effects of nerve impulse trains on the Schwann cell were similar to those produced by depolarizing current pulses applied to the axon by the voltage-clamp technique. Thus, a series of depolarizing pulses in the axon was followed by a long-lasting hyperpolarization of the Schwann cells. In contrast, the application of a series of hyperpolarizing 100 mV pulses at a frequency of 1/sec had no apparent effects.4. Changes in the external potassium concentration did not reproduce the long-lasting effects of nerve excitation.5. The hyperpolarizing effects of impulse trains were abolished by the incubation of the nerve fibre in a sea-water solution containing trypsin.6. These findings are discussed in relation to the possible mechanisms that might be responsible for the long-lasting hyperpolarizations of the Schwann cells.

Depletion sensitivity predicts unhealthy snack purchases.

Science.gov (United States)

Salmon, Stefanie J; Adriaanse, Marieke A; Fennis, Bob M; De Vet, Emely; De Ridder, Denise T D

2016-01-01

The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose weight on snack purchase behavior were explored. Participants included in the study were instructed to report every snack they bought over the course of one week. The dependent variables were the number of healthy and unhealthy snacks purchased. The results of the present study demonstrate that depletion sensitivity predicts the amount of unhealthy (but not healthy) snacks bought. The more sensitive people are to depletion, the more unhealthy snacks they buy. Moreover, there was some tentative evidence that this relation is more pronounced for people with a weak as opposed to a strong goal to lose weight, suggesting that a strong goal to lose weight may function as a motivational buffer against self-control failures. All in all, these findings provide evidence for the external validity of depletion sensitivity and the relevance of this construct in the domain of eating behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isotopic depletion with Monte Carlo

International Nuclear Information System (INIS)

Martin, W.R.; Rathkopf, J.A.

1996-06-01

This work considers a method to deplete isotopes during a time- dependent Monte Carlo simulation of an evolving system. The method is based on explicitly combining a conventional estimator for the scalar flux with the analytical solutions to the isotopic depletion equations. There are no auxiliary calculations; the method is an integral part of the Monte Carlo calculation. The method eliminates negative densities and reduces the variance in the estimates for the isotope densities, compared to existing methods. Moreover, existing methods are shown to be special cases of the general method described in this work, as they can be derived by combining a high variance estimator for the scalar flux with a low-order approximation to the analytical solution to the depletion equation

Long-term changes and spatio-temporal variability of the growing season temperature in Europe during the last Millennium

Science.gov (United States)

Guiot, Joel; Corona, Christophe

2010-05-01

A gridded reconstruction of April to September temperature was produced for Europe based on tree-rings, documentaries, pollen and ice cores. The majority of the proxy series have an annual resolution. For a better inference of long-term climate variations, they were completed by number of low resolution data (decadal or more), mostly on pollen and ice-core data. An original spectral analogue method was devised to deal with this heterogeneous dataset, and especially to preserve the long-term variations and the variability of the temperature series. It is the condition is to make pertinent the comparison of the recent climate changes to a broader context of 1400 years. The reconstruction of the April-September temperature was validated with a Jack-knife technique, and it was also compared with other spatially gridded temperature reconstructions, literature data, and glacier advance and retreat curves. We also attempted to relate the spatial distribution of European temperature anomalies to known solar and volcanic forcings. We found that (1) our results are sound back to A.D. 750; (2) conditions during the last decade have exceeded all those known during the last millennium; (3) before the 20th century, cold periods can partly be explained by low solar activity and/or high volcanic activity and that Medieval Warm Period (MWP) is consistent with a high solar activity; (4) during the 20th century, however only anthropogenic forcing can explain the exceptionally high temperature rise; (5) based on an analysis of the distribution of extreme temperatures, the maximum event of the Medieval Period (1.1°C higher than the 1960-1990 reference period) had a return period of more than 1000 years, but this recently fell to less than 26 years; (6) all decades before AD 1350 were warm on average but relatively heterogeneous, while the last decade was homogeneously warmer. These results support the fact that we are facing an unprecedented changing climate in Europe unlike any known

Long-distance signaling within Coleus x hybridus leaves; mediated by changes in intra-leaf CO2?

Science.gov (United States)

Stahlberg, R.; Van Volkenburgh, E.; Cleland, R. E.

2001-01-01

Rapid long-distance signaling in plants can occur via several mechanisms, including symplastic electric coupling and pressure waves. We show here in variegated Coleus leaves a rapid propagation of electrical signals that appears to be caused by changes in intra-leaf CO2 concentrations. Green leaf cells, when illuminated, undergo a rapid depolarization of their membrane potential (Vm) and an increase in their apoplastic pH (pHa) by a process that requires photosynthesis. This is followed by a slower hyperpolarization of Vm and apoplastic acidification, which do not require photosynthesis. White (chlorophyll-lacking) leaf cells, when in isolated white leaf segments, show only the slow response, but when in mixed (i.e. green and white) segments, the rapid Vm depolarization and increase in pHa propagate over more than 10 mm from the green to the white cells. Similarly, these responses propagate 12-20 mm from illuminated to unilluminated green cells. The fact that the propagation of these responses is eliminated when the leaf air spaces are infiltrated with solution indicates that the signal moves in the apoplast rather than the symplast. A depolarization of the mesophyll cells is induced in the dark by a decrease in apoplastic CO2 but not by an increase in pHa. These results support the hypothesis that the propagating signal for the depolarization of the white mesophyll cells is a photosynthetically induced decrease in the CO2 level of the air spaces throughout the leaf.

Depolarization changes during acute myocardial ischemia by evaluation of QRS slopes: standard lead and vectorial approach.

Science.gov (United States)

Romero, Daniel; Ringborn, Michael; Laguna, Pablo; Pahlm, Olle; Pueyo, Esther

2011-01-01

Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward ( ℑ(US)) and downward ( ℑ(DS) ) slopes of the R wave as well as the upward ( ℑ(TS)) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of ℑ(US), ℑ(DS), and ℑ(TS) that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that ℑ(US), ℑ(DS), and ℑ(TS) present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change ( ℜ(ℑ)) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for ℑ(US) and ℑ(DS), respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The ℑ(TS) index presented a similar behavior to that of ℑ(DS). The timing for the occurrence of significant changes in ℑ(US) and ℑ(DS) varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative ℑ(DS) changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.

On the long-lasting sequences of coral reef terraces from SE Sulawesi (Indonesia): Distribution, formation, and global significance

Science.gov (United States)

Pedoja, Kevin; Husson, Laurent; Bezos, Antoine; Pastier, Anne-Morwenn; Imran, Andy Muhammad; Arias-Ruiz, Camilo; Sarr, Anta-Clarisse; Elliot, Mary; Pons-Branchu, Edwige; Nexer, Maëlle; Regard, Vincent; Hafidz, Abdul; Robert, Xavier; Benoit, Laurent; Delcaillau, Bernard; Authemayou, Christine; Dumoulin, Caroline; Choblet, Gaël

2018-05-01

Many islands of the eastern Indonesian Archipelago exhibit Late Cenozoic sequences of coral reef terraces. In SE Sulawesi, on the Tukang Besi and Buton archipelagos, we identified 23 islands bearing such sequences. Remote sensing imagery and field mapping combined to U/Th and 14C dating enable to establish a chronologic framework of the reef terrace sequences from Wangi-Wangi, Buton as well as on the neighbouring, smaller islands of Ular, Siumpu and Kadatua. We identified the terraces from the last interglacial maximum (MIS 5e) at elevations lower than 20 m except on W Kadatua where it is raised at 34 ± 5 m. Such elevations yield low to moderate Upper Pleistocene uplift rates (<0.3 mm yr-1). On SE Buton Island, a sequence culminates at 650 m and includes at least 40 undated strandlines. Next to this exceptional sequence, on the Sampolawa Peninsula, 18 strandlines culminate at 430 m. Dated samples at the base of this sequence (<40 m) yield mean Middle Pleistocene uplift rates of 0.14 ± 0.09 mm yr-1. Extrapolation of these uplift rates compared to the geological setting suggests that the sequences of the Sampolawa Peninsula provide a record of sea-level high-stands for the last 3.8 ± 0.6 Ma. The sequences on SE Buton Island therefore constitute the best preserved long-lasting geomorphic record of Plio-Quaternary sea-level stands worldwide.

Microscopic to macroscopic depletion model development for FORMOSA-P

International Nuclear Information System (INIS)

Noh, J.M.; Turinsky, P.J.; Sarsour, H.N.

1996-01-01

Microscopic depletion has been gaining popularity with regard to employment in reactor core nodal calculations, mainly attributed to the superiority of microscopic depletion in treating spectral history effects during depletion. Another trend is the employment of loading pattern optimization computer codes in support of reload core design. Use of such optimization codes has significantly reduced design efforts to optimize reload core loading patterns associated with increasingly complicated lattice designs. A microscopic depletion model has been developed for the FORMOSA-P pressurized water reactor (PWR) loading pattern optimization code. This was done for both fidelity improvements and to make FORMOSA-P compatible with microscopic-based nuclear design methods. Needless to say, microscopic depletion requires more computational effort compared with macroscopic depletion. This implies that microscopic depletion may be computationally restrictive if employed during the loading pattern optimization calculation because many loading patterns are examined during the course of an optimization search. Therefore, the microscopic depletion model developed here uses combined models of microscopic and macroscopic depletion. This is done by first performing microscopic depletions for a subset of possible loading patterns from which 'collapsed' macroscopic cross sections are obtained. The collapsed macroscopic cross sections inherently incorporate spectral history effects. Subsequently, the optimization calculations are done using the collapsed macroscopic cross sections. Using this approach allows maintenance of microscopic depletion level accuracy without substantial additional computing resources

Assessing groundwater depletion and dynamics using GRACE and InSAR: Potential and limitations

Science.gov (United States)

Castellazzi, Pascal; Martel, Richard; Galloway, Devin L.; Longuevergne, Laurent; Rivera, Alfonso

2016-01-01

In the last decade, remote sensing of the temporal variation of ground level and gravity has improved our understanding of groundwater dynamics and storage. Mass changes are measured by GRACE (Gravity Recovery and Climate Experiment) satellites, whereas ground deformation is measured by processing synthetic aperture radar satellites data using the InSAR (Interferometry of Synthetic Aperture Radar) techniques. Both methods are complementary and offer different sensitivities to aquifer system processes. GRACE is sensitive to mass changes over large spatial scales (more than 100,000 km2). As such, it fails in providing groundwater storage change estimates at local or regional scales relevant to most aquifer systems, and at which most groundwater management schemes are applied. However, InSAR measures ground displacement due to aquifer response to fluid-pressure changes. InSAR applications to groundwater depletion assessments are limited to aquifer systems susceptible to measurable deformation. Furthermore, the inversion of InSAR-derived displacement maps into volume of depleted groundwater storage (both reversible and largely irreversible) is confounded by vertical and horizontal variability of sediment compressibility. During the last decade, both techniques have shown increasing interest in the scientific community to complement available in situ observations where they are insufficient. In this review, we present the theoretical and conceptual bases of each method, and present idealized scenarios to highlight the potential benefits and challenges of combining these techniques to remotely assess groundwater storage changes and other aspects of the dynamics of aquifer systems.

Conditioned taste aversion prevents the long-lasting BDNF-induced enhancement of synaptic transmission in the insular cortex: A metaplastic effect.

Science.gov (United States)

Rivera-Olvera, Alejandro; Rodríguez-Durán, Luis F; Escobar, Martha L

2016-04-01

Homeostatic plasticity mechanisms dynamically adjust synaptic strengths to promote stability that is crucial for memory storage. Metaplasticity is an example of these forms of plasticity that modify the capacity of synapses to experience subsequent Hebbian modifications. In particular, training in several behavioral tasks modifies the ability to induce long-term potentiation (LTP). Recently, we have reported that prior training in conditioned taste aversion (CTA) prevents the subsequent induction of LTP generated by high frequency stimulation in the projection from the basolateral nucleus of the amygdala (Bla) to the insular cortex (IC). One of the key molecular players that underlie long-term synaptic plasticity is brain-derived neurotrophic factor (BDNF). Previous studies from our group reported that acute microinfusion of BDNF in the IC induces a lasting potentiation of synaptic efficacy at the Bla-IC projection. Thus, the aim of the present study was to analyze whether CTA training modifies the ability to induce subsequent BDNF-induced potentiation of synaptic transmission in the Bla-IC projection in vivo. Accordingly, CTA trained rats received intracortical microinfusion of BDNF in order to induce lasting potentiation 48h after the aversion test. Our results show that CTA training prevents the induction of in vivo BDNF-LTP in the Bla-IC projection. The present results provide evidence that CTA modulates BDNF-dependent changes in IC synaptic strength. Copyright © 2016 Elsevier Inc. All rights reserved.

Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

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Xiaoshan Zhou

Full Text Available Thymidine kinase 2 (TK2 deficiency in humans causes mitochondrial DNA (mtDNA depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/- that progressively loses its mtDNA. The TK2(-/- mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/- mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/- mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/- mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/- mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

Science.gov (United States)

Zhou, Xiaoshan; Kannisto, Kristina; Curbo, Sophie; von Döbeln, Ulrika; Hultenby, Kjell; Isetun, Sindra; Gåfvels, Mats; Karlsson, Anna

2013-01-01

Thymidine kinase 2 (TK2) deficiency in humans causes mitochondrial DNA (mtDNA) depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/-)) that progressively loses its mtDNA. The TK2(-/-) mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/-) mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/-) mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/-) mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/-) mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

The relationship between the apparent diffusion coefficient measured by magnetic resonance imaging, anoxic depolarization, and glutamate efflux during experimental cerebral ischemia.

Science.gov (United States)

Harris, N G; Zilkha, E; Houseman, J; Symms, M R; Obrenovitch, T P; Williams, S R

2000-01-01

A reduction in the apparent diffusion coefficient (ADC) of water measured by magnetic resonance imaging (MRI) has been shown to occur early after cerebrovascular occlusion. This change may be a useful indicator of brain tissue adversely affected by inadequate blood supply. The objective of this study was to test the hypothesis that loss of membrane ion homeostasis and depolarization can occur simultaneously with the drop in ADC. Also investigated was whether elevation of extracellular glutamate ([GLU]e) would occur before ADC changes. High-speed MRI of the trace of the diffusion tensor (15-second time resolution) was combined with simultaneous recording of the extracellular direct current (DC) potential and on-line [GLU]e from the striatum of the anesthetized rat. After a control period, data were acquired during remote middle cerebral artery occlusion for 60 minutes, followed by 30 minutes of reperfusion, and cardiac arrest-induced global ischemia. After either focal or global ischemia, the ADC was reduced by 10 to 25% before anoxic depolarization occurred. After either insult, the time for half the maximum change in ADC was significantly shorter than the corresponding DC potential parameter (P potential and did not peak until much later after either ischemic insult. This study demonstrates that ADC changes can occur before membrane depolarization and that high [GLU]e has no involvement in the early rapid ADC decrease.

Depleted depletion drives polymer swelling in poor solvent mixtures.

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Stuehn, Torsten; Kremer, Kurt

2017-11-09

Establishing a link between macromolecular conformation and microscopic interaction is a key to understand properties of polymer solutions and for designing technologically relevant "smart" polymers. Here, polymer solvation in solvent mixtures strike as paradoxical phenomena. For example, when adding polymers to a solvent, such that all particle interactions are repulsive, polymer chains can collapse due to increased monomer-solvent repulsion. This depletion induced monomer-monomer attraction is well known from colloidal stability. A typical example is poly(methyl methacrylate) (PMMA) in water or small alcohols. While polymer collapse in a single poor solvent is well understood, the observed polymer swelling in mixtures of two repulsive solvents is surprising. By combining simulations and theoretical concepts known from polymer physics and colloidal science, we unveil the microscopic, generic origin of this collapse-swelling-collapse behavior. We show that this phenomenon naturally emerges at constant pressure when an appropriate balance of entropically driven depletion interactions is achieved.

Is Ego Depletion Real? An Analysis of Arguments.

Science.gov (United States)

Friese, Malte; Loschelder, David D; Gieseler, Karolin; Frankenbach, Julius; Inzlicht, Michael

2018-03-01

An influential line of research suggests that initial bouts of self-control increase the susceptibility to self-control failure (ego depletion effect). Despite seemingly abundant evidence, some researchers have suggested that evidence for ego depletion was the sole result of publication bias and p-hacking, with the true effect being indistinguishable from zero. Here, we examine (a) whether the evidence brought forward against ego depletion will convince a proponent that ego depletion does not exist and (b) whether arguments that could be brought forward in defense of ego depletion will convince a skeptic that ego depletion does exist. We conclude that despite several hundred published studies, the available evidence is inconclusive. Both additional empirical and theoretical works are needed to make a compelling case for either side of the debate. We discuss necessary steps for future work toward this aim.

Depletion-induced biaxial nematic states of boardlike particles

International Nuclear Information System (INIS)

Belli, S; Van Roij, R; Dijkstra, M

2012-01-01

With the aim of investigating the stability conditions of biaxial nematic liquid crystals, we study the effect of adding a non-adsorbing ideal depletant on the phase behavior of colloidal hard boardlike particles. We take into account the presence of the depletant by introducing an effective depletion attraction between a pair of boardlike particles. At fixed depletant fugacity, the stable liquid-crystal phase is determined through a mean-field theory with restricted orientations. Interestingly, we predict that for slightly elongated boardlike particles a critical depletant density exists, where the system undergoes a direct transition from an isotropic liquid to a biaxial nematic phase. As a consequence, by tuning the depletant density, an easy experimental control parameter, one can stabilize states of high biaxial nematic order even when these states are unstable for pure systems of boardlike particles. (paper)

?Just-in-Time? Battery Charge Depletion Control for PHEVs and E-REVs for Maximum Battery Life

Energy Technology Data Exchange (ETDEWEB)

DeVault, Robert C [ORNL

2009-01-01

Conventional methods of vehicle operation for Plug-in Hybrid Vehicles first discharge the battery to a minimum State of Charge (SOC) before switching to charge sustaining operation. This is very demanding on the battery, maximizing the number of trips ending with a depleted battery and maximizing the distance driven on a depleted battery over the vehicle s life. Several methods have been proposed to reduce the number of trips ending with a deeply discharged battery and also eliminate the need for extended driving on a depleted battery. An optimum SOC can be maintained for long battery life before discharging the battery so that the vehicle reaches an electric plug-in destination just as the battery reaches the minimum operating SOC. These Just-in-Time methods provide maximum effective battery life while getting virtually the same electricity from the grid.

Self-Regulatory Capacities Are Depleted in a Domain-Specific Manner.

Science.gov (United States)

Zhang, Rui; Stock, Ann-Kathrin; Rzepus, Anneka; Beste, Christian

2017-01-01

Performing an act of self-regulation such as making decisions has been suggested to deplete a common limited resource, which impairs all subsequent self-regulatory actions (ego depletion theory). It has however remained unclear whether self-referred decisions truly impair behavioral control even in seemingly unrelated cognitive domains, and which neurophysiological mechanisms are affected by these potential depletion effects. In the current study, we therefore used an inter-individual design to compare two kinds of depletion, namely a self-referred choice-based depletion and a categorization-based switching depletion, to a non-depleted control group. We used a backward inhibition (BI) paradigm to assess the effects of depletion on task switching and associated inhibition processes. It was combined with EEG and source localization techniques to assess both behavioral and neurophysiological depletion effects. The results challenge the ego depletion theory in its current form: Opposing the theory's prediction of a general limited resource, which should have yielded comparable effects in both depletion groups, or maybe even a larger depletion in the self-referred choice group, there were stronger performance impairments following a task domain-specific depletion (i.e., the switching-based depletion) than following a depletion based on self-referred choices. This suggests at least partly separate and independent resources for various cognitive control processes rather than just one joint resource for all self-regulation activities. The implications are crucial to consider for people making frequent far-reaching decisions e.g., in law or economy.

Muscarinic Long-Term Enhancement of Tonic and Phasic GABAA Inhibition in Rat CA1 Pyramidal Neurons

Science.gov (United States)

Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

2016-01-01

Acetylcholine (ACh) regulates network operation in the hippocampus by controlling excitation and inhibition in rat CA1 pyramidal neurons (PCs), the latter through gamma-aminobutyric acid type-A receptors (GABAARs). Although, the enhancing effects of ACh on GABAARs have been reported (Dominguez et al., 2014, 2015), its role in regulating tonic GABAA inhibition has not been explored in depth. Therefore, we aimed at determining the effects of the activation of ACh receptors on responses mediated by synaptic and extrasynaptic GABAARs. Here, we show that under blockade of ionotropic glutamate receptors ACh, acting through muscarinic type 1 receptors, paired with post-synaptic depolarization induced a long-term enhancement of tonic GABAA currents (tGABAA) and puff-evoked GABAA currents (pGABAA). ACh combined with depolarization also potentiated IPSCs (i.e., phasic inhibition) in the same PCs, without signs of interactions of synaptic responses with pGABAA and tGABAA, suggesting the contribution of two different GABAA receptor pools. The long-term enhancement of GABAA currents and IPSCs reduced the excitability of PCs, possibly regulating plasticity and learning in behaving animals. PMID:27833531

Strong Depletion in Hybrid Perovskite p-n Junctions Induced by Local Electronic Doping.

Science.gov (United States)

Ou, Qingdong; Zhang, Yupeng; Wang, Ziyu; Yuwono, Jodie A; Wang, Rongbin; Dai, Zhigao; Li, Wei; Zheng, Changxi; Xu, Zai-Quan; Qi, Xiang; Duhm, Steffen; Medhekar, Nikhil V; Zhang, Han; Bao, Qiaoliang

2018-04-01

A semiconductor p-n junction typically has a doping-induced carrier depletion region, where the doping level positively correlates with the built-in potential and negatively correlates with the depletion layer width. In conventional bulk and atomically thin junctions, this correlation challenges the synergy of the internal field and its spatial extent in carrier generation/transport. Organic-inorganic hybrid perovskites, a class of crystalline ionic semiconductors, are promising alternatives because of their direct badgap, long diffusion length, and large dielectric constant. Here, strong depletion in a lateral p-n junction induced by local electronic doping at the surface of individual CH 3 NH 3 PbI 3 perovskite nanosheets is reported. Unlike conventional surface doping with a weak van der Waals adsorption, covalent bonding and hydrogen bonding between a MoO 3 dopant and the perovskite are theoretically predicted and experimentally verified. The strong hybridization-induced electronic coupling leads to an enhanced built-in electric field. The large electric permittivity arising from the ionic polarizability further contributes to the formation of an unusually broad depletion region up to 10 µm in the junction. Under visible optical excitation without electrical bias, the lateral diode demonstrates unprecedented photovoltaic conversion with an external quantum efficiency of 3.93% and a photodetection responsivity of 1.42 A W -1 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper-induced activation of TRP channels promotes extracellular calcium entry and activation of CaMs and CDPKs leading to copper entry and membrane depolarization in Ulva compressa

Directory of Open Access Journals (Sweden)

Melissa eGómez

2015-03-01

Full Text Available In order to identify channels involved in membrane depolarization, Ulva compressa was incubated with agonists of TRP channels C5, A1 and V1 and the level of intracellular calcium was detected. Agonists of TRPC5, A1 and V1 induced increases in intracellular calcium at 4, 9 and 12 min of exposure, respectively, and antagonists of TRPC5, A1 and V1 corresponding to SKF-96365 (SKF, HC-030031 (HC and capsazepin (CPZ, respectively, inhibited calcium increases indicating that functional TRPs exist in U. compressa. In addition, copper excess induced increases in intracellular calcium at 4, 9 and 12 min which were inhibited by SKF, HC and CPZ, respectively, indicating that copper activate TRPC5, A1 and V1 channels. Moreover, copper-induced calcium increases were inhibited by EGTA, a non-permeable calcium chelating agent, but not by thapsigargin, an inhibitor of endoplasmic reticulum (ER calcium ATPase, indicating that activation of TRPs leads to extracellular calcium entry. Furthermore, copper-induced calcium increases were not inhibited by W-7, an inhibitor of CaMs, and staurosporine, an inhibitor of CDPKs, indicating that extracellular calcium entry did not require CaMs and CDPKs activation. In addition, copper induced membrane depolarization events at 4, 8 and 11 min and these events were inhibited by SKF, HC, CPZ and bathocuproine, a specific copper chelating agent, indicating copper entry through TRP channels leading to membrane depolarization. Moreover, membrane depolarization events were inhibited by W-7 and staurosporine, indicating that CaMs and CDPKs are required in order to activate TRPs to allow copper entry. Thus, light-dependent copper-induced activation TRPC5, A1 and V1 promotes extracellular calcium entry leading to activation of CaMs and CDPKs which, in turn, promotes copper entry through these TRP channels leading to membrane depolarization.

Sol–gel synthesis of long-lasting phosphors CdSiO3: Mn2+, RE3+ (RE = Tb, Eu, Nd) and luminescence mechanism research

International Nuclear Information System (INIS)

Qu, Xiaofei; Cao, Lixin; Liu, Wei; Su, Ge; Wang, Pingping; Schultz, Isabel

2012-01-01

Highlights: ► New long-lasting CdSiO 3 : Mn 2+ , RE 3+ (RE = Tb, Eu, Nd) phosphors were synthesized by a sol–gel method. ► The afterglow performance of the CdSiO 3 : Mn 2+ , Eu 3+ phosphor was the best. ► The role of RE 3+ co-doped into the CdSiO 3 : Mn 2+ matrix was discussed in this paper. -- Abstract: Mn 2+ and RE 3+ (RE = Tb, Eu, Nd) co-doped CdSiO 3 orange phosphors were prepared at 1050 °C by a sol–gel method. The phase and crystallinity of the synthesized materials were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The luminescence characteristics were analyzed using photoluminescence (PL) spectra, afterglow decay curves, long-lasting phosphorescence spectra, and thermoluminescence (TL) spectra. Due to the difference in co-doped rare earth ionic radii, it varied greatly in trap density and trap depth caused by the different defects deriving from RE 3+ ions co-doping into the CdSiO 3 : Mn 2+ host. The afterglow intensity and time for these samples increased as follows: CdSiO 3 : Mn 2+ 0.2%, Nd 3+ 0.8% 3 : Mn 2+ 0.4%, Tb 3+ 0.8% 3 : Mn 2+ 0.4%, Eu 3+ 0.3%. CdSiO 3 : Mn 2+ 0.4%, Eu 3+ 0.3% had the best afterglow properties, which could be due to the proper traps formed by Eu 3+ ions co-doping into the host. The role of RE 3+ co-doped into the CdSiO 3 : Mn 2+ matrix and the possible long-lasting phosphorescence process was also discussed in this paper.

Long-Lasting Cranial Nerve III Palsy as a Presenting Feature of Chronic Inflammatory Demyelinating Polyneuropathy

Directory of Open Access Journals (Sweden)

Rossella Spataro

2015-01-01

Full Text Available We describe a patient with chronic inflammatory demyelinating polyneuropathy (CIDP in which an adduction deficit and ptosis in the left eye presented several years before the polyneuropathy. A 52-year-old man presented with a 14-year history of unremitting diplopia, adduction deficit, and ptosis in the left eye. At the age of 45 a mild bilateral foot drop and impaired sensation in the four limbs appeared, with these symptoms showing a progressive course. The diagnostic workup included EMG/ENG which demonstrated reduced conduction velocity with bilateral and symmetrical sensory and motor involvement. Cerebrospinal fluid studies revealed a cytoalbuminologic dissociation. A prolonged treatment with corticosteroids allowed a significant improvement of the limb weakness. Diplopia and ptosis remained unchanged. This unusual form of CIDP presented as a long-lasting isolated cranial nerve palsy. A diagnostic workup for CIDP should therefore be performed in those patients in which an isolated and unremitting cranial nerve palsy cannot be explained by common causes.

Renal dysfunction induced by long-term exposure to depleted uranium in rats

Energy Technology Data Exchange (ETDEWEB)

Zhu, Guoying; Xiang, Xiqiao; Chen, Xiao; Wang, Lihua; Hu, Heping; Weng, Shifang [Fudan University, Institute of Radiation Medicine, Shanghai (China)

2009-01-15

Depleted uranium (DU) is a kind of radioactive heavy metal which can enter into the body via inhalation (aerosols), ingestion (drinking and eating) and wounds (embedded), and causes chemical and/or radiation-induced toxicities. In this study, male Sprague Dawley rats were surgically implanted in gastrocnemius muscle with DU fragments at three dose levels (low-dose, medium-dose and high-dose), with biologically inert tantalum (Ta) fragments served as controls. At 1 day, 7 days, and 3, 6, and 12 months after implantation, the rats were euthanized and tissue samples were collected, and uranium levels were measured in a variety of tissues by inductively coupled plasma-mass spectrometry (ICP-MS) to analyze the dynamic changes and distribution of uranium in rats. Thereafter, at 3, 6 and 12 months after implantation, the rats were euthanized after the collection of 24 h urine, blood and kidney samples were collected for analysis of DU-induced renal histopathologic changes and renal dysfunction. It was observed that DU concentrations in all the DU implanted groups were higher than that in Ta control group, and DU concentrations in the kidney increased with the implanted times, peaked at the 90 days after implantation, with a high correlation to the implanted DU doses, and then began to decrease gradually and slowly, and the DU concentrations in kidney still maintained at a relatively high level even at the 360 days after implantation. Otherwise, chronic DU contamination could induce the pathological changes of renal glomeruli, tubules and mesenchyme, such as interstitial fibrosis, enlarged interstice of renal tubular epithelial cells, tumefactions and necrosis of epithelial cells, shrinkage and disappearance of cavity of Bowman's capsule. By TEM, it was shown that the basement membrane of glomerulus was incrassated, mitochondrial of kidney proximal tubule had visible tumefaction and became bigger, and the mitochondrial cristae became shorter and disorderly in

Renal dysfunction induced by long-term exposure to depleted uranium in rats

International Nuclear Information System (INIS)

Zhu, Guoying; Xiang, Xiqiao; Chen, Xiao; Wang, Lihua; Hu, Heping; Weng, Shifang

2009-01-01

Depleted uranium (DU) is a kind of radioactive heavy metal which can enter into the body via inhalation (aerosols), ingestion (drinking and eating) and wounds (embedded), and causes chemical and/or radiation-induced toxicities. In this study, male Sprague Dawley rats were surgically implanted in gastrocnemius muscle with DU fragments at three dose levels (low-dose, medium-dose and high-dose), with biologically inert tantalum (Ta) fragments served as controls. At 1 day, 7 days, and 3, 6, and 12 months after implantation, the rats were euthanized and tissue samples were collected, and uranium levels were measured in a variety of tissues by inductively coupled plasma-mass spectrometry (ICP-MS) to analyze the dynamic changes and distribution of uranium in rats. Thereafter, at 3, 6 and 12 months after implantation, the rats were euthanized after the collection of 24 h urine, blood and kidney samples were collected for analysis of DU-induced renal histopathologic changes and renal dysfunction. It was observed that DU concentrations in all the DU implanted groups were higher than that in Ta control group, and DU concentrations in the kidney increased with the implanted times, peaked at the 90 days after implantation, with a high correlation to the implanted DU doses, and then began to decrease gradually and slowly, and the DU concentrations in kidney still maintained at a relatively high level even at the 360 days after implantation. Otherwise, chronic DU contamination could induce the pathological changes of renal glomeruli, tubules and mesenchyme, such as interstitial fibrosis, enlarged interstice of renal tubular epithelial cells, tumefactions and necrosis of epithelial cells, shrinkage and disappearance of cavity of Bowman's capsule. By TEM, it was shown that the basement membrane of glomerulus was incrassated, mitochondrial of kidney proximal tubule had visible tumefaction and became bigger, and the mitochondrial cristae became shorter and disorderly in alignment

Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.

Science.gov (United States)

Punrat, Eakkasit; Chuanuwatanakul, Suchada; Kaneta, Takashi; Motomizu, Shoji; Chailapakul, Orawon

2013-11-15

An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.5 V vs. Ag/AgCl in a supporting electrolyte solution of 1M hydrochloric acid. Under optimal conditions and the applied potentials, the electrode demonstrated that it can be used for a long time without a renewal process. The linear range for the determination of arsenic(III) was 1-100 μg L(-1), and the limit of detection (LOD) in standard solutions was as low as 0.03 μg L(-1) for a deposition time of 120 s and sample volume of 1 mL. This method was used to determine the concentration of arsenic(III) in water samples with satisfactory results. The LOD in real samples was found to be 0.5 μg L(-1). In addition, speciation between arsenic(III) and arsenic(V) has been achieved with the proposed method using deposition potentials of -0.5 V and -1.5 V for the determination of the arsenic(III) concentration and the total arsenic concentration, respectively; the results were acceptable. The proposed method is an automated system that offers a less expensive alternative for determining trace amounts of inorganic arsenic. © 2013 Elsevier B.V. All rights reserved.

Netting the malaria menace: Distribution and utilization of long-lasting insecticidal net in a malaria endemic area in Bankura, West Bengal

OpenAIRE

D K Mukhopadhyay; S S Basu; D Roy; N Das; F Akbar; GN Sarkar

2016-01-01

Background & objectives: Long-lasting insecticidal net (LLIN) is considered to be a highly effective intervention against malaria under National Vector Borne Disease Control Programme in India. A cross-sectional study was undertaken to assess the coverage and utilization of LLIN and the factors related thereto. Methods: A survey of 1300 households was carried out in Ranibandh block of Bankura district in West Bengal, India, using lot quality assurance sampling (LQAS) method. Coverage/util...

Podocyte Depletion in Thin GBM and Alport Syndrome.

Science.gov (United States)

Wickman, Larysa; Hodgin, Jeffrey B; Wang, Su Q; Afshinnia, Farsad; Kershaw, David; Wiggins, Roger C

2016-01-01

The proximate genetic cause of both Thin GBM and Alport Syndrome (AS) is abnormal α3, 4 and 5 collagen IV chains resulting in abnormal glomerular basement membrane (GBM) structure/function. We previously reported that podocyte detachment rate measured in urine is increased in AS, suggesting that podocyte depletion could play a role in causing progressive loss of kidney function. To test this hypothesis podometric parameters were measured in 26 kidney biopsies from 21 patients aged 2-17 years with a clinic-pathologic diagnosis including both classic Alport Syndrome with thin and thick GBM segments and lamellated lamina densa [n = 15] and Thin GBM cases [n = 6]. Protocol biopsies from deceased donor kidneys were used as age-matched controls. Podocyte depletion was present in AS biopsies prior to detectable histologic abnormalities. No abnormality was detected by light microscopy at 70% podocyte depletion. Low level proteinuria was an early event at about 25% podocyte depletion and increased in proportion to podocyte depletion. These quantitative data parallel those from model systems where podocyte depletion is the causative event. This result supports a hypothesis that in AS podocyte adherence to the GBM is defective resulting in accelerated podocyte detachment causing progressive podocyte depletion leading to FSGS-like pathologic changes and eventual End Stage Kidney Disease. Early intervention to reduce podocyte depletion is projected to prolong kidney survival in AS.

Depletion sensitivity predicts unhealthy snack purchases

NARCIS (Netherlands)

Salmon, Stefanie J.; Adriaanse, Marieke A.; Fennis, Bob M.; De Vet, Emely; De Ridder, Denise T D

2016-01-01

The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose

Real depletion in nodal diffusion codes

International Nuclear Information System (INIS)

Petkov, P.T.

2002-01-01

The fuel depletion is described by more than one hundred fuel isotopes in the advanced lattice codes like HELIOS, but only a few fuel isotopes are accounted for even in the advanced steady-state diffusion codes. The general assumption that the number densities of the majority of the fuel isotopes depend only on the fuel burnup is seriously in error if high burnup is considered. The real depletion conditions in the reactor core differ from the asymptotic ones at the stage of lattice depletion calculations. This study reveals which fuel isotopes should be explicitly accounted for in the diffusion codes in order to predict adequately the real depletion effects in the core. A somewhat strange conclusion is that if the real number densities of the main fissionable isotopes are not explicitly accounted for in the diffusion code, then Sm-149 should not be accounted for either, because the net error in k-inf is smaller (Authors)

The effect of massage therapy and/or exercise therapy on subacute or long-lasting neck pain--the Stockholm neck trial (STONE): study protocol for a randomized controlled trial.

Science.gov (United States)

Skillgate, Eva; Bill, Anne-Sylvie; Côté, Pierre; Viklund, Peter; Peterson, Anna; Holm, Lena W

2015-09-16

Neck pain is a major health problem in populations worldwide and an economic burden in modern societies due to its high prevalence and costs in terms of health care expenditures and lost productivity. Massage and exercise therapy are widely used management options for neck pain. However, there is a lack of scientific evidence regarding their effectiveness for subacute and long-lasting neck pain. This study protocol describes a randomized controlled trial aiming to determine the effect of massage and/or exercise therapy on subacute and long-lasting neck pain over the course of 1 year. A randomized controlled trial in which at least 600 study participants with subacute or long-lasting nonspecific neck pain will be recruited and randomly allocated to one of four treatment arms: massage therapy (A), exercise therapy (B), exercise therapy plus massage therapy (C) and advice to stay active (D). The study has an E-health approach, and study participants are being recruited through advertising with a mix of traditional and online marketing channels. Web-based self-report questionnaires measure the main outcomes at 7, 12, 26 and 52 weeks after inclusion. The primary outcomes are a clinically important improvement in pain intensity and pain-related disability at follow-up, measured with a modified version of the Chronic Pain Questionnaire (CPQ). The secondary outcomes are global improvement, health-related quality of life (EQ-5D), sick leave, drug consumption and healthcare utilization. Adverse events are measured by questionnaires at return visits to the clinic, and automated text messages (SMSes) survey neck pain intensity and pain-related disability every week over one year. The results of this study will provide clinicians and stakeholders much needed knowledge to plan medical care for subacute and long-lasting neck pain disorders. Current Controlled Trials ISRCTN01453590. Date of registration: 3 July 2014.

Gas generation matrix depletion quality assurance project plan

International Nuclear Information System (INIS)

1998-01-01

The Los Alamos National Laboratory (LANL) is to provide the necessary expertise, experience, equipment and instrumentation, and management structure to: Conduct the matrix depletion experiments using simulated waste for quantifying matrix depletion effects; and Conduct experiments on 60 cylinders containing simulated TRU waste to determine the effects of matrix depletion on gas generation for transportation. All work for the Gas Generation Matrix Depletion (GGMD) experiment is performed according to the quality objectives established in the test plan and under this Quality Assurance Project Plan (QAPjP)

Long-term Potentiation Decay and Poor Long-lasting Memory Process in the Wild Rodents Proechimys from Brazil's Amazon Rainforest.

Science.gov (United States)

Guimarães Marques, Marcia J; Reyes-Garcia, Selvin Z; Marques-Carneiro, José E; Lopes-Silva, Leonardo B; Andersen, Monica L; Cavalheiro, Esper A; Scorza, Fulvio A; Scorza, Carla A

2018-01-01

that LTP decays rapidly over time reaching basal levels at 90 min after theta-burst stimulation in Proechimys , contrasting to the stable LTP found in the Wistar rats which was observed throughout 3-h recording period. These findings suggest a link between the LTP decay and the lack of 24-h long-lasting memory process in Proechimys . Nevertheless, why early-phase LTP in Proechimys decays very rapidly remains to be elucidated.

Experimental and analytical study of oxygen depletion in stirred cell suspensions

International Nuclear Information System (INIS)

Whillans, D.W.; Rauth, A.M.

1980-01-01

The determination and maintenance of constant low but non-zero levels of oxygen is critical in the study of the radiation chemical interactions of nitroimidazoles in mammalian cells in vitro. As well, many of these chemicals have increased toxicity toward hypoxic compared to aerobic cells, although absolute hypoxia probably is not required. Both of these phenomena must be investigated in systems where significant consumption of oxygen takes place, either through radiation depletion or by cellular metabolism. In this paper an analysis has been made of the form of oxygen depletion in stirred cell suspensions with overlying gas phase, and it has been found to conform to the relationship (C[t] - C/sub infinity/) = (C[0] - C/sub infinity/) exp(-k 1 t), where C/sub infinity/ = C/sub g/ - R/k 1 . Here C[t] is the oxygen tension throughout the solution; C/sub g/, the equivalent level in the overlying gas phase; R (concentration units per sec), the depletion rate; k 1 (sec/sup -1/), a physical constant independent of oxygen concentration and depletion rate; and C/sub infinity/, the oxygen level in solution approached at long times. This relationship has been confirmed in detail using a Clark-type oxygen sensor and a high-stability amplifier design due to Koch. Since oxygen levels down to a few hundred parts per million can be determined with accuracy, it has been possible to measure precisely the oxygen levels present in our experimental systems. Implications of these results for the interpretation of data obtained in stirred cell suspension with overlying gas phase under conditions of consumption are discussed

Hsp90 depletion goes wild

OpenAIRE

Siegal, Mark L; Masel, Joanna

2012-01-01

Abstract Hsp90 reveals phenotypic variation in the laboratory, but is Hsp90 depletion important in the wild? Recent work from Chen and Wagner in BMC Evolutionary Biology has discovered a naturally occurring Drosophila allele that downregulates Hsp90, creating sensitivity to cryptic genetic variation. Laboratory studies suggest that the exact magnitude of Hsp90 downregulation is important. Extreme Hsp90 depletion might reactivate transposable elements and/or induce aneuploidy, in addition to r...

Regret causes ego-depletion and finding benefits in the regrettable events alleviates ego-depletion.

Science.gov (United States)

Gao, Hongmei; Zhang, Yan; Wang, Fang; Xu, Yan; Hong, Ying-Yi; Jiang, Jiang

2014-01-01

This study tested the hypotheses that experiencing regret would result in ego-depletion, while finding benefits (i.e., "silver linings") in the regret-eliciting events counteracted the ego-depletion effect. Using a modified gambling paradigm (Experiments 1, 2, and 4) and a retrospective method (Experiments 3 and 5), five experiments were conducted to induce regret. Results revealed that experiencing regret undermined performance on subsequent tasks, including a paper-and-pencil calculation task (Experiment 1), a Stroop task (Experiment 2), and a mental arithmetic task (Experiment 3). Furthermore, finding benefits in the regret-eliciting events improved subsequent performance (Experiments 4 and 5), and this improvement was mediated by participants' perceived vitality (Experiment 4). This study extended the depletion model of self-regulation by considering emotions with self-conscious components (in our case, regret). Moreover, it provided a comprehensive understanding of how people felt and performed after experiencing regret and after finding benefits in the events that caused the regret.

Is gas in the Orion nebula depleted

International Nuclear Information System (INIS)

Aiello, S.; Guidi, I.

1978-01-01

Depletion of heavy elements has been recognized to be important in the understanding of the chemical composition of the interstellar medium. This problem is also relevant to the study of H II regions. In this paper the gaseous depletion in the physical conditions of the Orion nebula is investigated. The authors reach the conclusion that very probably no depletion of heavy elements, due to sticking on dust grains, took place during the lifetime of the Orion nebula. (Auth.)

Including environmental concerns in management strategies for depleted uranium hexafluoride

International Nuclear Information System (INIS)

Goldberg, M.; Avci, H.I.; Bradley, C.E.

1995-01-01

One of the major programs within the Office of Nuclear Energy, Science, and Technology of the US Department of Energy (DOE) is the depleted uranium hexafluoride (DUF 6 ) management program. The program is intended to find a long-term management strategy for the DUF 6 that is currently stored in approximately 46,400 cylinders at Paducah, KY; Portsmouth, OH; and Oak Ridge, TN, USA. The program has four major components: technology assessment, engineering analysis, cost analysis, and the environmental impact statement (EIS). From the beginning of the program, the DOE has incorporated the environmental considerations into the process of strategy selection. Currently, the DOE has no preferred alternative. The results of the environmental impacts assessment from the EIS, as well as the results from the other components of the program, will be factored into the strategy selection process. In addition to the DOE's current management plan, other alternatives continued storage, reuse, or disposal of depleted uranium, will be considered in the EIS. The EIS is expected to be completed and issued in its final form in the fall of 1997

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

Science.gov (United States)

Kawauchi, Satoko; Nishidate, Izumi; Nawashiro, Hiroshi; Sato, Shunichi

2014-03-01

To understand the pathophysiology of ischemic stroke, in vivo imaging of the brain tissue viability and related spreading depolarization is crucial. In the infarct core, impairment of energy metabolism causes anoxic depolarization (AD), which considerably increases energy consumption, accelerating irreversible neuronal damage. In the peri-infarct penumbra region, where tissue is still reversible despite limited blood flow, peri-infarct depolarization (PID) occurs, exacerbating energy deficit and hence expanding the infarct area. We previously showed that light-scattering signal, which is sensitive to cellular/subcellular structural integrity, was correlated with AD and brain tissue viability in a rat hypoxia-reoxygenation model. In the present study, we performed transcranial NIR diffuse reflectance imaging of the rat brain during middle cerebral artery (MCA) occlusion and examined whether the infarct core and PIDs can be detected. Immediately after occluding the left MCA, light scattering started to increase focally in the occlusion site and a bright region was generated near the occlusion site and spread over the left entire cortex, which was followed by a dark region, showing the occurrence of PID. The PID was generated repetitively and the number of times of occurrence in a rat ranged from four to ten within 1 hour after occlusion (n=4). The scattering increase in the occlusion site was irreversible and the area with increased scattering expanded with increasing the number of PIDs, indicating an expansion of the infarct core. These results suggest the usefulness of NIR diffuse reflectance signal to visualize spatiotemporal changes in the infarct area and PIDs.

Depolarization of the electron spin in storage rings by nonlinear spin-orbit coupling

International Nuclear Information System (INIS)

Kewisch, J.

1985-10-01

Electrons and positrons which circulate in the storage ring are polarized at the emission of synchrotron radiation by the so called Sokolov-Ternov effect. This polarization is on the one hand of large interest for the study of the weak interaction, on the other hand it can be used for the accurate measurement of the beam energy and by this of the mass of elementary particles. The transverse and longitudinal particle vibrations simultaneously excited by the synchrotron radiation however can effect that this polarization is destroyed. This effect is called spin-orbit coupling. For the calculation of the spin-orbit coupling the computer program SITROS was written. This program is a tracking program: The motion of some sample particles and their spin vectors are calculated for some thousand circulations. From this the mean depolarization and by extrapolation the degree of polarization of the equilibrium state is determined. Contrarily to the known program SLIM which is based on perturbational calculations in SITROS the nonlinear forces in the storage ring can be regarded. By this the calculation of depolarizing higher order resonances is made possible. In this thesis the equations of motion for the orbital and spin motion of the electrons are derived which form the base for the program SITROS. The functions of the program and the approximations necessary for the saving of calculational time are explained. The comparison of the SITROS results with the measurement results obtained at the PETRA storage ring shows that the SITROS program is a useful means for the planning and calculation of storage rings with polarized electron beams. (orig.) [de

Ribosomal dimerization factor YfiA is the major protein synthesized after abrupt glucose depletion in Lactococcus lactis.

Science.gov (United States)

Breüner, Anne; Frees, Dorte; Varmanen, Pekka; Boguta, Anna Monika; Hammer, Karin; Martinussen, Jan; Kilstrup, Mogens

2016-10-01

We analysed the response of the model bacterium Lactococcus lactis to abrupt depletion of glucose after several generations of exponential growth. Glucose depletion resulted in a drastic drop in the energy charge accompanied by an extremely low GTP level and an almost total arrest of protein synthesis. Strikingly, the cell prioritized the continued synthesis of a few proteins, of which the ribosomal dimerization factor YfiA was the most highly expressed. Transcriptome analysis showed no immediate decrease in total mRNA levels despite the lowered nucleotide pools and only marginally increased levels of the yfiA transcript. Severe up-regulation of genes in the FruR, CcpA, ArgR and AhrC regulons were consistent with a downshift in carbon and energy source. Based upon the results, we suggest that transcription proceeded long enough to record the transcriptome changes from activation of the FruR, CcpA, ArgR and AhrC regulons, while protein synthesis stopped due to an extremely low GTP concentration emerging a few minutes after glucose depletion. The yfiA deletion mutant exhibited a longer lag phase upon replenishment of glucose and a faster death rate after prolonged starvation supporting that YfiA-mediated ribosomal dimerization is important for keeping long-term starved cells viable and competent for growth initiation.

Nature gives us strength: exposure to nature counteracts ego-depletion.

Science.gov (United States)

Chow, Jason T; Lau, Shun

2015-01-01

Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

Depleted uranium oxides as spent-nuclear-fuel waste-package invert and backfill materials

International Nuclear Information System (INIS)

Forsberg, C.W.; Haire, M.J.

1997-01-01

A new technology has been proposed in which depleted uranium, in the form of oxides or silicates, is placed around the outside of the spent nuclear fuel waste packages in the geological repository. This concept may (1) reduce the potential for repository nuclear criticality events and (2) reduce long-term release of radionuclides from the repository. As a new concept, there are significant uncertainties

Use and acceptance of long lasting insecticidal net screens for dengue prevention in Acapulco, Guerrero, Mexico.

Science.gov (United States)

Jones, Catrin H; Benítez-Valladares, David; Guillermo-May, Guillermo; Dzul-Manzanilla, Felipe; Che-Mendoza, Azael; Barrera-Pérez, Mario; Selem-Salas, Celia; Chablé-Santos, Juan; Sommerfeld, Johannes; Kroeger, Axel; O'Dempsey, Timothy; Medina-Barreiro, Anuar; Manrique-Saide, Pablo

2014-08-14

Dengue, recognized by the WHO as the most important mosquito-borne viral disease in the world, is a growing problem. Currently, the only effective way of preventing dengue is vector control. Standard methods have shown limited effect, and there have been calls to develop new integrated vector management approaches. One novel tool, protecting houses with long lasting insecticidal screens on doors and windows, is being trialled in a cluster randomised controlled trial by a joint UADY/WHO TDR/IDRC study in various districts of Acapulco, Mexico, with exceptionally high levels of crime and insecurity.This study investigated the community's perspectives of long lasting insecticidal screens on doors and windows in homes and in schools, in order to ascertain their acceptability, to identify challenges to further implementation and opportunities for future improvements. This was a sequential mixed-methods study. The quantitative arm contained a satisfaction survey administered to 288 houses that had received the intervention examining their perspectives of both the intervention and dengue prevention in general. The qualitative arm consisted of Focus Group Discussions (FGDs) with those who had accepted the intervention and key informant interviews with: schoolteachers to discuss the use of the screens in schools, program staff, and community members who had refused the intervention. Overall satisfaction and acceptance of the screens was very high, with only some operational and technical complaints relating to screen fragility and the installation process. However, the wider social context of urban violence and insecurity was a major barrier to screen acceptance. Lack of information dissemination and community collaboration were identified as project weaknesses. The screens are widely accepted by the population, but the project implementation could be improved by reassuring the community of its legitimacy in the context of insecurity. More community engagement and better

Synthetic sex pheromone in a long-lasting lure attracts the visceral leishmaniasis vector, Lutzomyia longipalpis, for up to 12 weeks in Brazil.

Directory of Open Access Journals (Sweden)

Daniel P Bray

2014-03-01

Full Text Available Current control methodologies have not prevented the spread of visceral leishmaniasis (VL across Brazil. Here, we describe the development of a new tool for controlling the sand fly vector of the disease: a long-lasting lure, which releases a synthetic male sex pheromone, attractive to both sexes of Lutzomyia longipalpis. This device could be used to improve the effectiveness of residual insecticide spraying as a means of sand fly control, attracting L. longipalpis to insecticide-treated animal houses, where they could be killed in potentially large numbers over a number of weeks. Different lure designs releasing the synthetic pheromone (±-9-methylgermacrene-B (CAS 183158-38-5 were field-tested in Araçatuba, São Paulo (SP. Experiments compared numbers of sand flies caught overnight in experimental chicken sheds with pheromone lures, to numbers caught in control sheds without pheromone. Prototype lures, designed to last one night, were first used to confirm the attractiveness of the pheromone in SP, and shown to attract significantly more flies to test sheds than controls. Longer-lasting lures were tested when new, and at fortnightly intervals. Lures loaded with 1 mg of pheromone did not attract sand flies for more than two weeks. However, lures loaded with 10 mg of pheromone, with a releasing surface of 15 cm2 or 7.5 cm2, attracted female L. longipalpis for up to ten weeks, and males for up to twelve weeks. Approximately five times more sand flies were caught with 7.5 cm2 10 mg lures when first used than occurred naturally in non-experimental chicken resting sites. These results demonstrate that these lures are suitably long-lasting and attractive for use in sand fly control programmes in SP. To our knowledge, this is the first sex pheromone-based technology targeting an insect vector of a neglected human disease. Further studies should explore the general applicability of this approach for combating other insect-borne diseases.

Lithium depletion and rotation in main-sequence stars

International Nuclear Information System (INIS)

Balachandran, S.

1990-01-01

Lithium abundances were measured in nearly 200 old disk-population F stars to examine the effects of rotational braking on the depletion of Li. The sample was selected to be slightly evolved off the main sequence so that the stars have completed all the Li depletion they will undergo on the main sequence. A large scatter in Li abundances in the late F stars is found, indicating that the Li depletion is not related to age and spectral type alone. Conventional depletion mechanisms like convective overshoot and microscopic diffusion are unable to explain Li depletion in F stars with thin convective envelopes and are doubly taxed to explain such a scatter. No correlation is found between Li abundance and the present projected rotational velocity and some of the most rapid rotators are undepleted, ruling out meridional circulation as the cause of Li depletion. There is a somewhat larger spread in Li abundances in the spun-down late F stars compared to the early F stars which should remain rotationally unaltered on the main sequence. 85 refs

Groundwater Depletion in the West Liaohe River Basin, China and Its Implications Revealed by GRACE and In Situ Measurements

Directory of Open Access Journals (Sweden)

Yulong Zhong

2018-03-01

Full Text Available The West Liaohe River Basin (WLRB is one of the most sensitive areas to climate change in China and an important grain production base in the Inner Mongolia Autonomous Region of China. Groundwater depletion in this region is becoming a critical issue. Here, we used the Gravity Recovery and Climate Experiment (GRACE satellite data and in situ well observations to estimate groundwater storage (GWS variations and discussed the driving factors of GWS changes in the WLRB. GRACE detects a GWS decline rate of −0.92 ± 0.49 km3/yr in the WLRB during 2005–2011, consistent with the estimate from in situ observations (−0.96 ± 0.19 km3/yr. This long-term GWS depletion is attributed to reduced precipitation and extensive groundwater overexploitation in the 2000s. Long-term groundwater level observations and reconstructed total water storage variations since 1980 show favorable agreement with precipitation anomalies at interannual timescales, both of which are significantly influenced by the El Niño-Southern Oscillation (ENSO. Generally, the WLRB receives more/less precipitation during the El Niño/La Niña periods. One of the strongest El Niño events on record in 1997–1998 and a subsequent strong La Niña drastically transform the climate of WLRB into a decade-long drought period, and accelerate the groundwater depletion in the WLRB after 1998. This study demonstrates the significance of integrating satellite observations, ground-based measurements, and climatological data for interpreting regional GWS changes from a long-term perspective.

Chronic potassium depletion increases adrenal progesterone production that is necessary for efficient renal retention of potassium.

Science.gov (United States)

Elabida, Boutaïna; Edwards, Aurélie; Salhi, Amel; Azroyan, Anie; Fodstad, Heidi; Meneton, Pierre; Doucet, Alain; Bloch-Faure, May; Crambert, Gilles

2011-08-01

Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.

Department of Energy depleted uranium recycle

International Nuclear Information System (INIS)

Kosinski, F.E.; Butturini, W.G.; Kurtz, J.J.

1994-01-01

With its strategic supply of depleted uranium, the Department of Energy is studying reuse of the material in nuclear radiation shields, military hardware, and commercial applications. the study is expected to warrant a more detailed uranium recycle plan which would include consideration of a demonstration program and a program implementation decision. Such a program, if implemented, would become the largest nuclear material recycle program in the history of the Department of Energy. The bulk of the current inventory of depleted uranium is stored in 14-ton cylinders in the form of solid uranium hexafluoride (UF 6 ). The radioactive 235 U content has been reduced to a concentration of 0.2% to 0.4%. Present estimates indicate there are about 55,000 UF 6 -filled cylinders in inventory and planned operations will provide another 2,500 cylinders of depleted uranium each year. The United States government, under the auspices of the Department of Energy, considers the depleted uranium a highly-refined strategic resource of significant value. A possible utilization of a large portion of the depleted uranium inventory is as radiation shielding for spent reactor fuels and high-level radioactive waste. To this end, the Department of Energy study to-date has included a preliminary technical review to ascertain DOE chemical forms useful for commercial products. The presentation summarized the information including preliminary cost estimates. The status of commercial uranium processing is discussed. With a shrinking market, the number of chemical conversion and fabrication plants is reduced; however, the commercial capability does exist for chemical conversion of the UF 6 to the metal form and for the fabrication of uranium radiation shields and other uranium products. Department of Energy facilities no longer possess a capability for depleted uranium chemical conversion

Chronic inhibition, self-control and eating behavior: test of a 'resource depletion' model.

Directory of Open Access Journals (Sweden)

Martin S Hagger

Full Text Available The current research tested the hypothesis that individuals engaged in long-term efforts to limit food intake (e.g., individuals with high eating restraint would have reduced capacity to regulate eating when self-control resources are limited. In the current research, body mass index (BMI was used as a proxy for eating restraint based on the assumption that individuals with high BMI would have elevated levels of chronic eating restraint. A preliminary study (Study 1 aimed to provide evidence for the assumed relationship between eating restraint and BMI. Participants (N = 72 categorized into high or normal-range BMI groups completed the eating restraint scale. Consistent with the hypothesis, results revealed significantly higher scores on the weight fluctuation and concern for dieting subscales of the restraint scale among participants in the high BMI group compared to the normal-range BMI group. The main study (Study 2 aimed to test the hypothesized interactive effect of BMI and diminished self-control resources on eating behavior. Participants (N = 83 classified as having high or normal-range BMI were randomly allocated to receive a challenging counting task that depleted self-control resources (ego-depletion condition or a non-depleting control task (no depletion condition. Participants then engaged in a second task in which required tasting and rating tempting cookies and candies. Amount of food consumed during the taste-and-rate task constituted the behavioral dependent measure. Regression analyses revealed a significant interaction effect of these variables on amount of food eaten in the taste-and-rate task. Individuals with high BMI had reduced capacity to regulate eating under conditions of self-control resource depletion as predicted. The interactive effects of BMI and self-control resource depletion on eating behavior were independent of trait self-control. Results extend knowledge of the role of self-control in regulating eating

Radiosensitization of CHO cells by the combination of glutathione depletion and low concentrations of oxygen: The effect of different levels of GSH depletion

International Nuclear Information System (INIS)

Clark, E.P.; Epp, E.R.; Zachgo, E.A.; Biaglow, J.E.

1984-01-01

Recently, the authors have examined the effect of GSH depletion by BSO on CHO cells equilibrated with oxygen at various concentrations (0.05-4.0%) and irradiated with 50 kVp x-rays. This is of interest because of the uncertain radiosensitizing effect GSH depletion may have on cells equilibrated with low oxygen concentrations. GSH depletion (0.1 mM BSO/24 hrs reduced [GSH] ≅ 10% of control) enhanced the radiosensitizing action of moderate (0.4-4.0%) concentrations of oxygen, i.e., GSH depletion reduced the [O/sub 2/] necessary to achieve an equivalent ER by ≅ 2-3 fold. However, GSH depletion was much more effective as a rediosensitizer when cells were equilibrated with low (<0.4%) concentrations of oxygen, i.e., GSH depletion reduced the [O/sub 2/] necessary to achieve an equivalent ER by 8-10 fold. Furthermore, while the addition of exogenous 5 mM GSH restored the ER to that observed when GSH was not depleted, the intracellular [GSH] was not increased. The results of these studies carried out at different levels of GSH depletion are presented

Inter-tester reliability of selected clinical tests for long-lasting temporomandibular disorders.

Science.gov (United States)

Julsvoll, Elisabeth Heggem; Vøllestad, Nina Køpke; Opseth, Gro; Robinson, Hilde Stendal

2017-09-01

Clinical tests used to examine patients with temporomandibular disorders vary in methodological quality, and some are not tested for reliability. The purpose of this cross-sectional study was to evaluate inter-tester reliability of clinical tests and a cluster of tests used to examine patients with long-lasting temporomandibular disorders. Forty patients with pain in the temporomandibular area treated by health-professionals were included. They were between 18-70 years, had 65 symptomatic (33 right/32 left) and 15 asymptomatic joints. Two manual therapists examined all participants with selected tests. Percentage agreement and the kappa coefficient ( k ) with 95% confidence interval (CI) were used to evaluate the tests with categorical outcomes. For tests with continuous outcomes, the relative inter-tester reliability was assessed by the intraclass-correlation-coefficient (ICC 3,1 , 95% CI) and the absolute reliability was calculated by the smallest detectable change (SDC). The best reliability among single tests was found for the dental stick test, the joint-sound test ( k  = 0.80-1.0) and range of mouth-opening (ICC 3,1 (95% CI) = 0.97 (0.95-0.98) and SDC = 4 mm). The reliability of cluster of tests was excellent with both four and five positive tests out of seven. The reliability was good to excellent for the clinical tests and the cluster of tests when performed by experienced therapists. The tests are feasible for use in the clinical setting. They require no advanced equipment and are easy to perform.

How Ego Depletion Affects Sexual Self-Regulation: Is It More Than Resource Depletion?

Science.gov (United States)

Nolet, Kevin; Rouleau, Joanne-Lucine; Benbouriche, Massil; Carrier Emond, Fannie; Renaud, Patrice

2015-12-21

Rational thinking and decision making are impacted when in a state of sexual arousal. The inability to self-regulate arousal can be linked to numerous problems, like sexual risk taking, infidelity, and sexual coercion. Studies have shown that most men are able to exert voluntary control over their sexual excitation with various levels of success. Both situational and dispositional factors can influence self-regulation achievement. The goal of this research was to investigate how ego depletion, a state of low self-control capacity, interacts with personality traits-propensities for sexual excitation and inhibition-and cognitive absorption, to cause sexual self-regulation failure. The sexual responses of 36 heterosexual males were assessed using penile plethysmography. They were asked to control their sexual arousal in two conditions, with and without ego depletion. Results suggest that ego depletion has opposite effects based on the trait sexual inhibition, as individuals moderately inhibited showed an increase in performance while highly inhibited ones showed a decrease. These results challenge the limited resource model of self-regulation and point to the importance of considering how people adapt to acute and high challenging conditions.

Domain wall motion and magnetization reversal processes in a FeSi picture frame single crystal studied by the time-dependent neutron depolarization technique

International Nuclear Information System (INIS)

Schaik, F.J. van.

1979-01-01

The three dimensional neutron depolarization technique, which gives detailed information about the static properties of ferromagnetic materials, has been extended to a method by means of which the time dependence of magnetic phenomena can be studied. The measurement of the neutron depolarization against time is made possible by applying a periodical magnetic field on the investigated specimen and by continuous sampling of the transmitted neutron intensity in time channels, which are started synchronously with the applied field. The technique has been used in the study of the magnetic domain structure at room temperature of a (010) [001] picture frame FeSi single crystal (3.5 wt.% Si) with outer dimensions of (15 x 10 x 0.26) mm and a frame width of 2.78 mm. (Auth.)

Depolarization by K+ and glutamate activates different neurotransmitter release mechanisms in GABAergic neurons: vesicular versus non-vesicular release of GABA

DEFF Research Database (Denmark)

Belhage, B; Hansen, Gert Helge; Schousboe, A

1993-01-01

differences in the mode of action of the two depolarizing stimuli were reflected in the properties of the increase in [Ca++]i elicited by 55 mM K+ and 100 microM glutamate, respectively. The K(+)-induced increase in [Ca++]i was reduced by both verapamil and Ca(++)-free media whereas the corresponding...... neurotransmitter glutamate (100 microM). Both depolarizing stimuli exerted prompt increases in the release of preloaded [3H]GABA as well as in [Ca++]i. However, the basic properties of transmitter release and the increase in [Ca++]i under a variety of conditions were different during stimulation with K...... was also reduced by organic (verapamil) and inorganic (Co++) Ca++ channel blockers but was insensitive to the GABA transport inhibitor SKF 89976A. In contrast, the second phase was less sensitive to nocodazole and Ca++ channel antagonists but could be inhibited by SKF 89976A. The glutamate-induced [3H...

The new MCNP6 depletion capability

International Nuclear Information System (INIS)

Fensin, M. L.; James, M. R.; Hendricks, J. S.; Goorley, J. T.

2012-01-01

The first MCNP based in-line Monte Carlo depletion capability was officially released from the Radiation Safety Information and Computational Center as MCNPX 2.6.0. Both the MCNP5 and MCNPX codes have historically provided a successful combinatorial geometry based, continuous energy, Monte Carlo radiation transport solution for advanced reactor modeling and simulation. However, due to separate development pathways, useful simulation capabilities were dispersed between both codes and not unified in a single technology. MCNP6, the next evolution in the MCNP suite of codes, now combines the capability of both simulation tools, as well as providing new advanced technology, in a single radiation transport code. We describe here the new capabilities of the MCNP6 depletion code dating from the official RSICC release MCNPX 2.6.0, reported previously, to the now current state of MCNP6. NEA/OECD benchmark results are also reported. The MCNP6 depletion capability enhancements beyond MCNPX 2.6.0 reported here include: (1) new performance enhancing parallel architecture that implements both shared and distributed memory constructs; (2) enhanced memory management that maximizes calculation fidelity; and (3) improved burnup physics for better nuclide prediction. MCNP6 depletion enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code. The enhancements described here help provide a powerful capability as well as dictate a path forward for future development to improve the usefulness of the technology. (authors)

The New MCNP6 Depletion Capability

International Nuclear Information System (INIS)

Fensin, Michael Lorne; James, Michael R.; Hendricks, John S.; Goorley, John T.

2012-01-01

The first MCNP based inline Monte Carlo depletion capability was officially released from the Radiation Safety Information and Computational Center as MCNPX 2.6.0. Both the MCNP5 and MCNPX codes have historically provided a successful combinatorial geometry based, continuous energy, Monte Carlo radiation transport solution for advanced reactor modeling and simulation. However, due to separate development pathways, useful simulation capabilities were dispersed between both codes and not unified in a single technology. MCNP6, the next evolution in the MCNP suite of codes, now combines the capability of both simulation tools, as well as providing new advanced technology, in a single radiation transport code. We describe here the new capabilities of the MCNP6 depletion code dating from the official RSICC release MCNPX 2.6.0, reported previously, to the now current state of MCNP6. NEA/OECD benchmark results are also reported. The MCNP6 depletion capability enhancements beyond MCNPX 2.6.0 reported here include: (1) new performance enhancing parallel architecture that implements both shared and distributed memory constructs; (2) enhanced memory management that maximizes calculation fidelity; and (3) improved burnup physics for better nuclide prediction. MCNP6 depletion enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code. The enhancements described here help provide a powerful capability as well as dictate a path forward for future development to improve the usefulness of the technology.

Ecological considerations of natural and depleted uranium

International Nuclear Information System (INIS)

Hanson, W.C.

1980-01-01

Depleted 238 U is a major by-product of the nuclear fuel cycle for which increasing use is being made in counterweights, radiation shielding, and ordnance applications. This paper (1) summarizes the pertinent literature on natural and depleted uranium in the environment, (2) integrates results of a series of ecological studies conducted at Los Alamos Scientific Laboratory (LASL) in New Mexico where 70,000 kg of depleted and natural uranium has been expended to the environment over the past 34 years, and (3) synthesizes the information into an assessment of the ecological consequences of natural and depleted uranium released to the environment by various means. Results of studies of soil, plant, and animal communities exposed to this radiation and chemical environment over a third of a century provide a means of evaluating the behavior and effects of uranium in many contexts

Mantle depletion and metasomatism recorded in orthopyroxene in highly depleted peridotites

DEFF Research Database (Denmark)

Scott, James; Liu, Jingao; Pearson, D. Graham

2016-01-01

Although trace element concentrations in clinopyroxene serve as a useful tool for assessing the depletion and enrichment history of mantle peridotites, this is not applicable for peridotites in which the clinopyroxene component has been consumed (~ 25% partial melting). Orthopyroxene persists in ...

Effective insect repellent formulation in both surfactantless and classical microemulsions with a long-lasting protection for human beings.

Science.gov (United States)

Drapeau, Jeremy; Verdier, Marie; Touraud, Didier; Kröckel, Ulla; Geier, Martin; Rose, Andreas; Kunz, Werner

2009-06-01

The aim of this work is to develop a new generation of repellent products with a long-lasting protection based on a natural component, para-menthane-3,8-diol (PMD). The active is first rendered soluble in a surfactantless microemulsion (H(2)O/(i)PrOH/PMD) and then in classical microemulsions. The presence of self-associated nanostructures is detected by dynamic light scattering (DLS). A synergetic system of surfactants (Cremophor) RH40 and Texapon N70) is used. Additionally, 2-ethylhexane-1,3-diol and ethyl (-)-(S)-lactate are incorporated. The final product contains, as main components, 46% of H(2)O, 25% of (i)PrOH, 20% of non-H(2)O-soluble PMD, and only 4% of surfactants. Investigations of lasting protection on human volunteers are carried out using a cage test bioassay protocol and Aedes aegypti mosquitoes. A complete protection of 315 min is found on the test persons using the surfactantless microemulsion. An extension is observed with the final formulation to reach a mean of complete protection of 385 min. This study demonstrates that alternative formulations using a natural active instead of synthetic chemicals like N,N-diethyl-m-methylbenzamide (DEET) can be efficient for human protection against mosquitoes.

NOMAD: a nodal microscopic analysis method for nuclear fuel depletion

International Nuclear Information System (INIS)

Rajic, H.L.; Ougouag, A.M.

1987-01-01

Recently developed assembly homogenization techniques made possible very efficient global burnup calculations based on modern nodal methods. There are two possible ways of modeling the global depletion process: macroscopic and microscopic depletion models. Using a microscopic global depletion approach NOMAD (NOdal Microscopic Analysis Method for Nuclear Fuel Depletion), a multigroup, two- and three-dimensional, multicycle depletion code was devised. The code uses the ILLICO nodal diffusion model. The formalism of the ILLICO methodology is extended to treat changes in the macroscopic cross sections during a depletion cycle without recomputing the coupling coefficients. This results in a computationally very efficient method. The code was tested against a well-known depletion benchmark problem. In this problem a two-dimensional pressurized water reactor is depleted through two cycles. Both cycles were run with 1 x 1 and 2 x 2 nodes per assembly. It is obvious that the one node per assembly solution gives unacceptable results while the 2 x 2 solution gives relative power errors consistently below 2%

The study of necessity of verification-methods for Depleted Uranium

International Nuclear Information System (INIS)

Park, J. B.; Ahn, S. H.; Ahn, G. H.; Chung, S. T.; Shin, J. S.

2006-01-01

ROK has tried to establish management system for depleted uranium from 2004, and ROK achieved some results in this field including management software, management skill, and the list of company using the nuclear material. But, the studies for the depleted uranium are insufficient exclude the studies of KAERI. In terms of SSAC, we have to study more about whether the depleted uranium is really dangerous material or not and how is the depleted uranium diverted to the nuclear weapon. The depleted uranium was controlled by the item counting in the national system for the small quantity nuclear material. We don't have unique technical methods to clarify the depleted uranium on-the-spot inspection not laboratory scale. Therefore, I would like to suggest of the necessity of the verification methods for depleted uranium. Furthermore, I would like to show you the methods of the verification of the depleted uranium in national system up to now

The enhancements and testing for the MCNPX depletion capability

International Nuclear Information System (INIS)

Fensin, M. L.; Hendricks, J. S.; Anghaie, S.

2008-01-01

Monte Carlo-linked depletion methods have gained recent interest due to the ability to more accurately model true system physics and better track the evolution of temporal nuclide inventory by simulating the actual physical process. The integration of INDER90 into the MCNPX Monte Carlo radiation transport code provides a completely self-contained Monte- Carlo-linked depletion capability in a single Monte Carlo code that is compatible with most nuclear criticality (KCODE) particle tracking features in MCNPX. MCNPX depletion tracks all necessary reaction rates and follows as many isotopes as cross section data permits in order to achieve a highly accurate temporal nuclide inventory solution. We describe here the depletion methodology dating from the original linking of MONTEBURNS and MCNP to the first public release of the integrated capability (MCNPX 2. 6.B, June, 2006) that has been reported previously. Then we further detail the many new depletion capability enhancements since then leading to the present capability. The H.B. Robinson benchmark calculation results are also reported. The new MCNPX depletion capability enhancements include: (1) allowing the modeling of as large a system as computer memory capacity permits; (2) tracking every fission product available in ENDF/B VII. 0; (3) enabling depletion in repeated structures geometries such as repeated arrays of fuel pins; (4) including metastable isotopes in burnup; and (5) manually changing the concentrations of key isotopes during different time steps to simulate changing reactor control conditions such as dilution of poisons to maintain criticality during burnup. These enhancements allow better detail to model the true system physics and also improve the robustness of the capability. The H.B. Robinson benchmark calculation was completed in order to determine the accuracy of the depletion solution. Temporal nuclide computations of key actinide and fission products are compared to the results of other

Distinct behavioral consequences of short-term and prolonged GABAergic depletion in prefrontal cortex and dorsal hippocampus

Directory of Open Access Journals (Sweden)

Judith M. Reichel

2015-01-01

Full Text Available GABAergic interneurons are essential for a functional equilibrium between excitatory and inhibitory impulses throughout the CNS. Disruption of this equilibrium can lead to various neurological or neuropsychiatric disorders such as epileptic seizures or schizophrenia. Schizophrenia itself is clinically defined by negative- (e.g. depression and positive- (e.g. hallucinations symptoms as well as cognitive dysfunction. GABAergic interneurons are proposed to play a central role in the etiology and progression of schizophrenia; however, the specific mechanisms and the time-line of symptom development as well as the distinct involvement of cortical and hippocampal GABAergic interneurons in the etiology of schizophrenia-related symptoms are still not conclusively resolved.Previous work demonstrated that GABAergic interneurons can be selectively depleted in adult mice by means of saporin-conjugated anti-vesicular GABA transporter antibodies (SAVAs in vitro and in vivo. Given their involvement in Schizophrenia-related disease etiology, we ablated GABAergic interneurons in the medial prefrontal cortex (mPFC and dorsal hippocampus (dHPC in adult male C57BL/6N mice. Subsequently we assessed alterations in anxiety, sensory processing, hyperactivity and cognition after long-term (>14 days and short-term (< 14 days GABAergic depletion. Long-term GABAergic depletion in the mPFC resulted in a decrease in sensorimotor-gating and impairments in cognitive flexibility. Notably, the same treatment at the level of the dHPC completely abolished spatial learning capabilities. Short-term GABAergic depletion in the dHPC revealed a transient hyperactive phenotype as well as marked impairments regarding the acquisition of a spatial memory. In contrast, recall of a spatial memory was not affected by the same intervention. These findings emphasize the importance of functional local GABAergic networks for the encoding but not the recall of hippocampus-dependent spatial memories.

Rat hypocretin/orexin neurons are maintained in a depolarized state by TRPC channels.

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Vesna Cvetkovic-Lopes

Full Text Available In a previous study we proposed that the depolarized state of the wake-promoting hypocretin/orexin (hcrt/orx neurons was independent of synaptic inputs as it persisted in tetrodotoxin and low calcium/high magnesium solutions. Here we show first that these cells are hyperpolarized when external sodium is lowered, suggesting that non-selective cation channels (NSCCs could be involved. As canonical transient receptor channels (TRPCs are known to form NSCCs, we looked for TRPCs subunits using single-cell RT-PCR and found that TRPC6 mRNA was detectable in a small minority, TRPC1, TRPC3 and TRPC7 in a majority and TRPC4 and 5 in the vast majority (∼90% of hcrt/orx neurons. Using intracellular applications of TRPC antibodies against subunits known to form NSCCs, we then found that only TRPC5 antibodies elicited an outward current, together with hyperpolarization and inhibition of the cells. These effects were blocked by co-application of a TRPC5 antigen peptide. Voltage-clamp ramps in the presence or absence of TRPC5 antibodies indicated the presence of a current with a reversal potential close to -15 mV. Application of the non-selective TRPC channel blocker, flufenamic acid, had a similar effect, which could be occluded in cells pre-loaded with TRPC5 antibodies. Finally, using the same TRPC5 antibodies we found that most hcrt/orx cells show immunostaining for the TRPC5 subunit. These results suggest that hcrt/orx neurons are endowed with a constitutively active non-selective cation current which depends on TRPC channels containing the TRPC5 subunit and which is responsible for the depolarized and active state of these cells.

β-Hydroxybutyrate is the preferred substrate for GABA and glutamate synthesis while glucose is indispensable during depolarization in cultured GABAergic neurons.

Science.gov (United States)

Lund, Trine M; Obel, Linea F; Risa, Øystein; Sonnewald, Ursula

2011-08-01

The ketogenic diet has multiple beneficial effects not only in treatment of epilepsy, but also in that of glucose transporter 1 deficiency, cancer, Parkinson's disease, obesity and pain. Thus, there is an increasing interest in understanding the mechanism behind this metabolic therapy. Patients on a ketogenic diet reach high plasma levels of ketone bodies, which are used by the brain as energy substrates. The interaction between glucose and ketone bodies is complex and there is still controversy as to what extent it affects the homeostasis of the neurotransmitters glutamate, aspartate and GABA. The present study was conducted to study this metabolic interaction in cultured GABAergic neurons exposed to different combinations of (13)C-labeled and unlabeled glucose and β-hydroxybutyrate. Depolarization was induced and the incorporation of (13)C into glutamate, GABA and aspartate was analyzed. The presence of β-hydroxybutyrate together with glucose did not affect the total GABA content but did, however, decrease the aspartate content to a lower value than when either glucose or β-hydroxybutyrate was employed alone. When combinations of the two substrates were used (13)C-atoms from β-hydroxybutyrate were found in all three amino acids to a greater extent than (13)C-atoms from glucose, but only the (13)C contribution from [1,6-(13)C]glucose increased upon depolarization. In conclusion, β-hydroxybutyrate was preferred over glucose as substrate for amino acid synthesis but the total content of aspartate decreased when both substrates were present. Furthermore only the use of glucose increased upon depolarization. Copyright © 2011 Elsevier B.V. All rights reserved.

The depolarizing action of GABA in cultured hippocampal neurons is not due to the absence of ketone bodies.

Science.gov (United States)

Waddell, Jaylyn; Kim, Jimok; Alger, Bradley E; McCarthy, Margaret M

2011-01-01

Two recent reports propose that the depolarizing action of GABA in the immature brain is an artifact of in vitro preparations in which glucose is the only energy source. The authors argue that this does not mimic the physiological environment because the suckling rats use ketone bodies and pyruvate as major sources of metabolic energy. Here, we show that availability of physiologically relevant levels of ketone bodies has no impact on the excitatory action of GABA in immature cultured hippocampal neurons. Addition of β-hydroxybutyrate (BHB), the primary ketone body in the neonate rat, affected neither intracellular calcium elevation nor membrane depolarizations induced by the GABA-A receptor agonist muscimol, when assessed with calcium imaging or perforated patch-clamp recording, respectively. These results confirm that the addition of ketone bodies to the extracellular environment to mimic conditions in the neonatal brain does not reverse the chloride gradient and therefore render GABA hyperpolarizing. Our data are consistent with the existence of a genuine "developmental switch" mechanism in which GABA goes from having a predominantly excitatory role in immature cells to a predominantly inhibitory one in adults.

26 CFR 1.611-1 - Allowance of deduction for depletion.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Allowance of deduction for depletion. 1.611-1... depletion. (a) Depletion of mines, oil and gas wells, other natural deposits, and timber—(1) In general... mines, oil and gas wells, other natural deposits, and timber, a reasonable allowance for depletion. In...

Rising intracellular zinc by membrane depolarization and glucose in insulin-secreting clonal HIT-T15 beta cells.

Science.gov (United States)

Slepchenko, Kira G; Li, Yang V

2012-01-01

Zinc (Zn(2+)) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30-60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

CESAR5.3: Isotopic depletion for Research and Testing Reactor decommissioning

Science.gov (United States)

Ritter, Guillaume; Eschbach, Romain; Girieud, Richard; Soulard, Maxime

2018-05-01

CESAR stands in French for "simplified depletion applied to reprocessing". The current version is now number 5.3 as it started 30 years ago from a long lasting cooperation with ORANO, co-owner of the code with CEA. This computer code can characterize several types of nuclear fuel assemblies, from the most regular PWR power plants to the most unexpected gas cooled and graphite moderated old timer research facility. Each type of fuel can also include numerous ranges of compositions like UOX, MOX, LEU or HEU. Such versatility comes from a broad catalog of cross section libraries, each corresponding to a specific reactor and fuel matrix design. CESAR goes beyond fuel characterization and can also provide an evaluation of structural materials activation. The cross-sections libraries are generated using the most refined assembly or core level transport code calculation schemes (CEA APOLLO2 or ERANOS), based on the European JEFF3.1.1 nuclear data base. Each new CESAR self shielded cross section library benefits all most recent CEA recommendations as for deterministic physics options. Resulting cross sections are organized as a function of burn up and initial fuel enrichment which allows to condensate this costly process into a series of Legendre polynomials. The final outcome is a fast, accurate and compact CESAR cross section library. Each library is fully validated, against a stochastic transport code (CEA TRIPOLI 4) if needed and against a reference depletion code (CEA DARWIN). Using CESAR does not require any of the neutron physics expertise implemented into cross section libraries generation. It is based on top quality nuclear data (JEFF3.1.1 for ˜400 isotopes) and includes up to date Bateman equation solving algorithms. However, defining a CESAR computation case can be very straightforward. Most results are only 3 steps away from any beginner's ambition: Initial composition, in core depletion and pool decay scenario. On top of a simple utilization architecture

The Abiotic Depletion Potential: Background, Updates, and Future

Directory of Open Access Journals (Sweden)

Lauran van Oers

2016-03-01

Full Text Available Depletion of abiotic resources is a much disputed impact category in life cycle assessment (LCA. The reason is that the problem can be defined in different ways. Furthermore, within a specified problem definition, many choices can still be made regarding which parameters to include in the characterization model and which data to use. This article gives an overview of the problem definition and the choices that have been made when defining the abiotic depletion potentials (ADPs for a characterization model for abiotic resource depletion in LCA. Updates of the ADPs since 2002 are also briefly discussed. Finally, some possible new developments of the impact category of abiotic resource depletion are suggested, such as redefining the depletion problem as a dilution problem. This means taking the reserves in the environment and the economy into account in the reserve parameter and using leakage from the economy, instead of extraction rate, as a dilution parameter.

Carnitine supplementation and depletion: tissue carnitines and enzymes in fatty acid oxidation.

Science.gov (United States)

Negrao, C E; Ji, L L; Schauer, J E; Nagle, F J; Lardy, H A

1987-07-01

Sixty-two male rats were randomly assigned into a 3 X 2 X 2 factorial design containing 12 groups according to carnitine treatment, exercise training (treadmill, 1 h, 5 times/wk, 8 wk, 26.8 m/min, 15% grade), and physical activity [rested for 60 h before they were killed or with an acute bout of exercise (1 h, 26.8 m/min, 15% grade) immediately before they were killed]. Isotonic saline was injected intraperitoneally 5 times/wk in the controls, whereas 750 mg/kg of L- or D-carnitine, respectively, were injected in the supplemented and depleted treatment groups. A significant increase in free and short-chain acyl carnitine concentration in skeletal muscle and heart was observed in L-carnitine supplemented rats, whereas a significant reduction in skeletal muscle, heart, and liver occurred in rats depleted of L-carnitine. Long-chain acyl carnitine in all tissues was not altered by carnitine treatment; training increased plasma and liver concentrations, whereas acute exercise decreased skeletal muscle and increased liver concentrations. An acute bout of exercise significantly increased short-chain acylcarnitine in liver, regardless of carnitine and/or training effects. beta-Hydroxyacyl-CoA dehydrogenase activity in skeletal muscle was induced by training but reduced by depletion. Carnitine acetyltransferase (CAT) was significantly increased in heart by L-carnitine supplementation, whereas it was reduced by depletion in skeletal muscle. Exercise training significantly increased CAT activity in skeletal muscle but not in heart, whereas acute exercise significantly increased activity in both tissues. Carnitine palmitoyltransferase activity was increased by acute exercise in the heart in only the supplemented and exercise-trained rats.

Cost and cost effectiveness of long-lasting insecticide-treated bed nets - a model-based analysis

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Pulkki-Brännström Anni-Maria

2012-04-01

Full Text Available Abstract Background The World Health Organization recommends that national malaria programmes universally distribute long-lasting insecticide-treated bed nets (LLINs. LLINs provide effective insecticide protection for at least three years while conventional nets must be retreated every 6-12 months. LLINs may also promise longer physical durability (lifespan, but at a higher unit price. No prospective data currently available is sufficient to calculate the comparative cost effectiveness of different net types. We thus constructed a model to explore the cost effectiveness of LLINs, asking how a longer lifespan affects the relative cost effectiveness of nets, and if, when and why LLINs might be preferred to conventional insecticide-treated nets. An innovation of our model is that we also considered the replenishment need i.e. loss of nets over time. Methods We modelled the choice of net over a 10-year period to facilitate the comparison of nets with different lifespan (and/or price and replenishment need over time. Our base case represents a large-scale programme which achieves high coverage and usage throughout the population by distributing either LLINs or conventional nets through existing health services, and retreats a large proportion of conventional nets regularly at low cost. We identified the determinants of bed net programme cost effectiveness and parameter values for usage rate, delivery and retreatment cost from the literature. One-way sensitivity analysis was conducted to explicitly compare the differential effect of changing parameters such as price, lifespan, usage and replenishment need. Results If conventional and long-lasting bed nets have the same physical lifespan (3 years, LLINs are more cost effective unless they are priced at more than USD 1.5 above the price of conventional nets. Because a longer lifespan brings delivery cost savings, each one year increase in lifespan can be accompanied by a USD 1 or more increase in price

Thermally stimulated depolarization currents in the natural fluorite; Correntes de despolarizacao termicamente estimuladas na fluorita natural

Energy Technology Data Exchange (ETDEWEB)

Valerio, Mario Ernesto Giroldo

1986-12-31

The present work deals with natural calcium fluoride from Criciuma, Santa Catarina. Thermally Stimulated Depolarization Currents (TSDC) can be used to determine the properties of dipole defects present in this crystal. The TSDC spectrum of this material shows three bands in the temperature range of 80 to 450 K. The first one, at 130 K, is due the dipoles formed by a trivalent impurity and an interstitial fluorine ion in the next nearest position of an impurity ion (nn R{sub s}{sup 3+} -F{sub i}{sup -}). The second one, at 102 k, is due to the presence of small aggregates of dipoles (like a dimer). The last band, at 360 k is due to the formation of Large Clusters. The continuous distribution model gave the best fit for these bands with mean activation energies of 0.41 eV, 0.595 eV and 1.02 eV for the first, second and third band respectively. Thermal treatments can modify the number of dipoles, dimers and clusters present in the crystal. The variation in the areas under each band can be used to measure this effect. In this work we used thermal treatments between 15 minutes and 10 hours and temperatures between 200 deg C and 500 deg C. For thermal treatments at 300 deg C, the dipoles and dimers are created and the clusters are destroyed as the time of thermal treatment increases. At 400 deg C the clusters are created and the dipoles and dimers and 350 deg C for the clusters. (author) 60 refs., 41 figs., 1 tab.

Thermally stimulated depolarization currents in the natural fluorite; Correntes de despolarizacao termicamente estimuladas na fluorita natural

Energy Technology Data Exchange (ETDEWEB)

Valerio, Mario Ernesto Giroldo

1987-12-31

The present work deals with natural calcium fluoride from Criciuma, Santa Catarina. Thermally Stimulated Depolarization Currents (TSDC) can be used to determine the properties of dipole defects present in this crystal. The TSDC spectrum of this material shows three bands in the temperature range of 80 to 450 K. The first one, at 130 K, is due the dipoles formed by a trivalent impurity and an interstitial fluorine ion in the next nearest position of an impurity ion (nn R{sub s}{sup 3+} -F{sub i}{sup -}). The second one, at 102 k, is due to the presence of small aggregates of dipoles (like a dimer). The last band, at 360 k is due to the formation of Large Clusters. The continuous distribution model gave the best fit for these bands with mean activation energies of 0.41 eV, 0.595 eV and 1.02 eV for the first, second and third band respectively. Thermal treatments can modify the number of dipoles, dimers and clusters present in the crystal. The variation in the areas under each band can be used to measure this effect. In this work we used thermal treatments between 15 minutes and 10 hours and temperatures between 200 deg C and 500 deg C. For thermal treatments at 300 deg C, the dipoles and dimers are created and the clusters are destroyed as the time of thermal treatment increases. At 400 deg C the clusters are created and the dipoles and dimers and 350 deg C for the clusters. (author) 60 refs., 41 figs., 1 tab.

Long-term Potentiation Decay and Poor Long-lasting Memory Process in the Wild Rodents Proechimys from Brazil’s Amazon Rainforest

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Marcia J. Guimarães Marques

2018-01-01

recordings revealed that LTP decays rapidly over time reaching basal levels at 90 min after theta-burst stimulation in Proechimys, contrasting to the stable LTP found in the Wistar rats which was observed throughout 3-h recording period. These findings suggest a link between the LTP decay and the lack of 24-h long-lasting memory process in Proechimys. Nevertheless, why early-phase LTP in Proechimys decays very rapidly remains to be elucidated.

Long-term Potentiation Decay and Poor Long-lasting Memory Process in the Wild Rodents Proechimys from Brazil’s Amazon Rainforest

Science.gov (United States)

Guimarães Marques, Marcia J.; Reyes-Garcia, Selvin Z.; Marques-Carneiro, José E.; Lopes-Silva, Leonardo B.; Andersen, Monica L.; Cavalheiro, Esper A.; Scorza, Fulvio A.; Scorza, Carla A.

2018-01-01

that LTP decays rapidly over time reaching basal levels at 90 min after theta-burst stimulation in Proechimys, contrasting to the stable LTP found in the Wistar rats which was observed throughout 3-h recording period. These findings suggest a link between the LTP decay and the lack of 24-h long-lasting memory process in Proechimys. Nevertheless, why early-phase LTP in Proechimys decays very rapidly remains to be elucidated. PMID:29410617