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Sample records for neurogenesis long-term potentiation

  1. Enhanced Dentate Neurogenesis after Brain Injury Undermines Long-Term Neurogenic Potential and Promotes Seizure Susceptibility

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    Eric J. Neuberger

    2017-09-01

    Full Text Available Hippocampal dentate gyrus is a focus of enhanced neurogenesis and excitability after traumatic brain injury. Increased neurogenesis has been proposed to aid repair of the injured network. Our data show that an early increase in neurogenesis after fluid percussion concussive brain injury is transient and is followed by a persistent decrease compared with age-matched controls. Post-injury changes in neurogenesis paralleled changes in neural precursor cell proliferation and resulted in a long-term decline in neurogenic capacity. Targeted pharmacology to restore post-injury neurogenesis to control levels reversed the long-term decline in neurogenic capacity. Limiting post-injury neurogenesis reduced early increases in dentate excitability and seizure susceptibility. Our results challenge the assumption that increased neurogenesis after brain injury is beneficial and show that early post-traumatic increases in neurogenesis adversely affect long-term outcomes by exhausting neurogenic potential and enhancing epileptogenesis. Treatments aimed at limiting excessive neurogenesis can potentially restore neuroproliferative capacity and limit epilepsy after brain injury.

  2. NMDA and kainate receptor expression, long-term potentiation, and neurogenesis in the hippocampus of long-lived Ames dwarf mice.

    Science.gov (United States)

    Sharma, Sunita; Darland, Diane; Lei, Saobo; Rakoczy, Sharlene; Brown-Borg, Holly M

    2012-06-01

    In the current study, we investigated changes in N-methyl D-aspartate (NMDA) and kainate receptor expression, long-term potentiation (LTP), and neurogenesis in response to neurotoxic stress in long-living Ames dwarf mice. We hypothesized that Ames dwarf mice have enhanced neurogenesis that enables retention of spatial learning and memory with age and promotes neurogenesis in response to injury. Levels of the NMDA receptors (NR)1, NR2A, NR2B, and the kainate receptor (KAR)2 were increased in Ames dwarf mice, relative to wild-type littermates. Quantitative assessment of the excitatory postsynaptic potential in Schaffer collaterals in hippocampal slices from Ames dwarf mice showed an increased response in high-frequency induced LTP over time compared with wild type. Kainic acid (KA) injection was used to promote neurotoxic stress-induced neurogenesis. KA mildly increased the number of doublecortin-positive neurons in wild-type mice, but the response was significantly enhanced in the Ames dwarf mice. Collectively, these data support our hypothesis that the enhanced learning and memory associated with the Ames dwarf mouse may be due to elevated levels of NMDA and KA receptors in hippocampus and their ability to continue producing new neurons in response to neuronal damage.

  3. Long-term cognitive deficits accompanied by reduced neurogenesis after soman poisoning

    NARCIS (Netherlands)

    Joosen, M.J.A.; Jousma, E.; van den Boom, T.M.; Kuijpers, W.C.; Smit, A.B.; Lucassen, P.J.; van Helden, H.P.M.

    2009-01-01

    To date, treatment of organophosphate (OP) poisoning shows several shortcomings, and OP-victims might suffer from lasting cognitive deficits and sleep-wake disturbances. In the present study, long-term effects of soman poisoning on learning ability, memory and neurogenesis were investigated in rats,

  4. Learning-dependent neurogenesis in the olfactory bulb determines long-term olfactory memory.

    Science.gov (United States)

    Sultan, S; Mandairon, N; Kermen, F; Garcia, S; Sacquet, J; Didier, A

    2010-07-01

    Inhibitory interneurons of the olfactory bulb are subjected to permanent adult neurogenesis. Their number is modulated by learning, suggesting that they could play a role in plastic changes of the bulbar network associated with olfactory memory. Adult male C57BL/6 mice were trained in an associative olfactory task, and we analyzed long-term retention of the task 5, 30, and 90 d post-training. In parallel, we assessed the fate of these newborn cells, mapped their distribution in the olfactory bulb and measured their functional implication using the immediate early gene Zif268. In a second set of experiments, we pharmacologically modulated glutamatergic transmission and using the same behavioral task assessed the consequences on memory retention and neurogenesis. Finally, by local infusion of an antimitotic drug, we selectively blocked neurogenesis during acquisition of the task and looked at the effects on memory retention. First we demonstrated that retrieval of an associative olfactory task recruits the newborn neurons in odor-specific areas of the olfactory bulb selected to survive during acquisition of the task and that it does this in a manner that depends on the strength of learning. We then demonstrated that acquisition is not dependent on neurogenesis if long-term retention of the task is abolished by blocking neurogenesis. Adult-born neurons are thus involved in changes in the neural representation of an odor; this underlies long-term olfactory memory as the strength of learning is linked to the duration of this memory. Neurogenesis thus plays a crucial role in long-term olfactory memory.

  5. The discovery of long-term potentiation.

    Science.gov (United States)

    Lømo, Terje

    2003-04-29

    This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule cell synapses that could last for hours. In 1968, Tim Bliss came to Per Andersen's laboratory to learn about the hippocampus and field potential recording for studies of possible memory mechanisms. The two of us then followed up my preliminary results from 1966 and did the experiments that resulted in a paper that is now properly considered to be the basic reference for the discovery of LTP.

  6. Nutritional deficit and Long Term Potentiation alterations

    Directory of Open Access Journals (Sweden)

    M. Petrosino

    2009-01-01

    Full Text Available In the present work we examined the ability of prenatally malnourished offspring to produce and maintain long-term potentiation (LTP of the perforant path/dentate granule cell synapse in freely moving rats at 15,30, and 90 days of age. Population spike amplitude (PSA was calculated from dentate field potential recordings prior to and at 15, 30, 60 min. and 3, 5, 18 and 24 h following tetanization of the perforant pathway. All animals of both malnourished and well-nourished diet groups at 15 days of age showed potentiation of PSA measures but the measures obtained from 15-day-old prenatally malnourished animals were significantly less than that of age-matched, well-nourished controls. At 30 days of age, remarkable effect of tetanization was likely observed from PSA measures for this age group followed much the same pattern. At 90 days of age, PSA measures obtained from malnourished animals decreased from pretetanization levels immediately following tetanization. At this age, however, at three hours time recordings, this measure growing up to a level which did not differ significantly from that of the control group. These results indicate that the width of tetanization induced enhancement of dentate granule cell response in preweanling rats (15-day-old animals is signifacantly affected fromgestational protein malnutrition and this trend is kept in animals tested at 30 and 90 days of age. The fact, however, that considerable limitation in LTP generation was gained from prenatally malnourished animals at 90 days of age, implying that dietary rehabilitation starting at birth is an intervention strategy not capable to imbrove the effects of the gestational stress.

  7. Hypertension impairs hippocampus-related adult neurogenesis, CA1 neuron dendritic arborization and long-term memory.

    Science.gov (United States)

    Shih, Y-H; Tsai, S-F; Huang, S-H; Chiang, Y-T; Hughes, M W; Wu, S-Y; Lee, C-W; Yang, T-T; Kuo, Y-M

    2016-05-13

    Hypertension is associated with neurodegenerative diseases and cognitive impairment. Several studies using spontaneous hypertensive rats to study the effect of hypertension on memory performance and adult hippocampal neurogenesis have reached inconsistent conclusions. The contradictory findings may be related to the genetic variability of spontaneous hypertensive rats due to the conventional breeding practices. The objective of this study is to examine the effect of hypertension on hippocampal structure and function in isogenic mice. Hypertension was induced by the '2 kidneys, 1 clip' method (2K1C) which constricted one of the two renal arteries. The blood pressures of 2K1C mice were higher than the sham group on post-operation day 7 and remained high up to day 28. Mice with 2K1C-induced hypertension had impaired long-term, but not short-term, memory. Dendritic complexity of CA1 neurons and hippocampal neurogenesis were reduced by 2K1C-induced hypertension on post-operation day 28. Furthermore, 2K1C decreased the levels of hippocampal brain-derived neurotrophic factor, while blood vessel density and activation status of astrocytes and microglia were not affected. In conclusion, hypertension impairs hippocampus-associated long-term memory, dendritic arborization and neurogenesis, which may be caused by down-regulation of brain-derived neurotrophic factor signaling pathways. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Long-term potentiation and long-term depression: a clinical perspective

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    Timothy V.P. Bliss

    2011-01-01

    Full Text Available Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke.

  9. Quantification of long term emission potential from landfills

    NARCIS (Netherlands)

    Heimovaara, T.J.

    2011-01-01

    Novel approaches for the after-care of Municipal Solid Waste (MSW) landfills are based on technological measures to reduce the long term emission potential in a short time period. Biological degradation in landfills is a means to significantly reduce the long term emission potential. Leachate

  10. Long-Term Potentiation in the Motor Cortex

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    Iriki, Atsushi; Pavlides, Constantine; Keller, Asaf; Asanuma, Hiroshi

    1989-09-01

    Long-term potentiation (LTP) is a model for learning and memory processes. Tetanic stimulation of the sensory cortex produces LTP in motor cortical neurons, whereas tetanization of the ventrolateral nucleus of the thalamus, which also projects to the motor cortex, does not. However, after simultaneous high-frequency stimulation of both the sensory cortex and the ventrolateral nucleus of the thalamus, LTP of thalamic input to motor cortical neurons is induced. This associative LTP occurs only in neurons in the superficial layers of the motor cortex that receive monosynaptic input from both the sensory cortex and the ventrolateral nucleus of the thalamus. Associative LTP in the motor cortex may constitute a basis for the retention of motor skills.

  11. Induction of synaptic long-term potentiation after opioid withdrawal.

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    Drdla, Ruth; Gassner, Matthias; Gingl, Ewald; Sandkühler, Jürgen

    2009-07-10

    mu-Opioid receptor (MOR) agonists represent the gold standard for the treatment of severe pain but may paradoxically also enhance pain sensitivity, that is, lead to opioid-induced hyperalgesia (OIH). We show that abrupt withdrawal from MOR agonists induces long-term potentiation (LTP) at the first synapse in pain pathways. Induction of opioid withdrawal LTP requires postsynaptic activation of heterotrimeric guanine nucleotide-binding proteins and N-methyl-d-aspartate receptors and a rise of postsynaptic calcium concentrations. In contrast, the acute depression by opioids is induced presynaptically at these synapses. Withdrawal LTP can be prevented by tapered withdrawal and shares pharmacology and signal transduction pathways with OIH. These findings provide a previously unrecognized target to selectively combat pro-nociceptive effects of opioids without compromising opioid analgesia.

  12. Hippocampal Focal Knockout of CBP Affects Specific Histone Modifications, Long-Term Potentiation, and Long-Term Memory

    Science.gov (United States)

    Barrett, Ruth M; Malvaez, Melissa; Kramar, Eniko; Matheos, Dina P; Arrizon, Abraham; Cabrera, Sara M; Lynch, Gary; Greene, Robert W; Wood, Marcelo A

    2011-01-01

    To identify the role of the histone acetyltransferase (HAT) CREB-binding protein (CBP) in neurons of the CA1 region of the hippocampus during memory formation, we examine the effects of a focal homozygous knockout of CBP on histone modifications, gene expression, synaptic plasticity, and long-term memory. We show that CBP is critical for the in vivo acetylation of lysines on histones H2B, H3, and H4. CBP's homolog p300 was unable to compensate for the loss of CBP. Neurons lacking CBP maintained phosphorylation of the transcription factor CREB, yet failed to activate CREB:CBP-mediated gene expression. Loss of CBP in dorsal CA1 of the hippocampus resulted in selective impairments to long-term potentiation and long-term memory for contextual fear and object recognition. Together, these results suggest a necessary role for specific chromatin modifications, selectively mediated by CBP in the consolidation of memories. PMID:21508930

  13. Long-term performance potential of concentrated photovoltaic (CPV) systems

    KAUST Repository

    Burhan, Muhammad; Shahzad, Muhammad Wakil; Ng, Kim Choon

    2017-01-01

    estimation of a large PV field, the long term performance as electrical output is a more rational approach over the conventional testing methods, such as at Standard Testing Conditions (STC) and at the Nominal Operating Cell Temperature (NOCT) available

  14. Erythropoietin enhances hippocampal long-term potentiation and memory

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    El-Kordi Ahmed

    2008-09-01

    Full Text Available Abstract Background Erythropoietin (EPO improves cognition of human subjects in the clinical setting by as yet unknown mechanisms. We developed a mouse model of robust cognitive improvement by EPO to obtain the first clues of how EPO influences cognition, and how it may act on hippocampal neurons to modulate plasticity. Results We show here that a 3-week treatment of young mice with EPO enhances long-term potentiation (LTP, a cellular correlate of learning processes in the CA1 region of the hippocampus. This treatment concomitantly alters short-term synaptic plasticity and synaptic transmission, shifting the balance of excitatory and inhibitory activity. These effects are accompanied by an improvement of hippocampus dependent memory, persisting for 3 weeks after termination of EPO injections, and are independent of changes in hematocrit. Networks of EPO-treated primary hippocampal neurons develop lower overall spiking activity but enhanced bursting in discrete neuronal assemblies. At the level of developing single neurons, EPO treatment reduces the typical increase in excitatory synaptic transmission without changing the number of synaptic boutons, consistent with prolonged functional silencing of synapses. Conclusion We conclude that EPO improves hippocampus dependent memory by modulating plasticity, synaptic connectivity and activity of memory-related neuronal networks. These mechanisms of action of EPO have to be further exploited for treating neuropsychiatric diseases.

  15. Long-Term Mild, rather than Intense, Exercise Enhances Adult Hippocampal Neurogenesis and Greatly Changes the Transcriptomic Profile of the Hippocampus.

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    Koshiro Inoue

    Full Text Available Our six-week treadmill running training (forced exercise model has revealed that mild exercise (ME with an intensity below the lactate threshold (LT is sufficient to enhance spatial memory, while intense exercise (IE above the LT negates such benefits. To help understand the unrevealed neuronal and signaling/molecular mechanisms of the intensity-dependent cognitive change, in this rat model, we here investigated plasma corticosterone concentration as a marker of stress, adult hippocampal neurogenesis (AHN as a potential contributor to this ME-induced spatial memory, and comprehensively delineated the hippocampal transcriptomic profile using a whole-genome DNA microarray analysis approach through comparison with IE. Results showed that only IE had the higher corticosterone concentration than control, and that the less intense exercise (ME is better suited to improve AHN, especially in regards to the survival and maturation of newborn neurons. DNA microarray analysis using a 4 × 44 K Agilent chip revealed that ME regulated more genes than did IE (ME: 604 genes, IE: 415 genes, and only 41 genes were modified with both exercise intensities. The identified molecular components did not comprise well-known factors related to exercise-induced AHN, such as brain-derived neurotrophic factor. Rather, network analysis of the data using Ingenuity Pathway Analysis algorithms revealed that the ME-influenced genes were principally related to lipid metabolism, protein synthesis and inflammatory response, which are recognized as associated with AHN. In contrast, IE-influenced genes linked to excessive inflammatory immune response, which is a negative regulator of hippocampal neuroadaptation, were identified. Collectively, these results in a treadmill running model demonstrate that long-term ME, but not of IE, with minimizing running stress, has beneficial effects on increasing AHN, and provides an ME-specific gene inventory containing some potential regulators

  16. Observation of long term potentiation in papain-based memory devices

    KAUST Repository

    Bag, A.

    2014-06-01

    Biological synaptic behavior in terms of long term potentiation has been observed in papain-based (plant protein) memory devices (memristors) for the first time. Improvement in long term potentiation depends on pulse amplitude and width (duration). Continuous/repetitive dc voltage sweep leads to an increase in memristor conductivity leading to a long term memory in the \\'learning\\' processes.

  17. Observation of long term potentiation in papain-based memory devices

    KAUST Repository

    Bag, A.; Hota, Mrinal Kanti; Mallik, Sandipan B.; Maì ti, Chinmay Kumar

    2014-01-01

    Biological synaptic behavior in terms of long term potentiation has been observed in papain-based (plant protein) memory devices (memristors) for the first time. Improvement in long term potentiation depends on pulse amplitude and width (duration). Continuous/repetitive dc voltage sweep leads to an increase in memristor conductivity leading to a long term memory in the 'learning' processes.

  18. Long-term performance potential of concentrated photovoltaic (CPV) systems

    KAUST Repository

    Burhan, Muhammad

    2017-07-17

    Owing to the diverse photovoltaic (PV) systems’ design and technology, as well as the dynamic nature of insolation data received on the aperture surfaces, the instantaneous output from a PV system fluctuates greatly. For accurate performance estimation of a large PV field, the long term performance as electrical output is a more rational approach over the conventional testing methods, such as at Standard Testing Conditions (STC) and at the Nominal Operating Cell Temperature (NOCT) available hitherto. In this paper, the long-term performances of concentrated PVs (Cassegrain reflectors and Fresnel lens) with 2-axes tracking and a variety of PV systems, namely the stationary flat-plate PV (mono-crystalline, poly-crystalline and thin-films CIS types), is presented over a period of one year for the merit comparison of system design, under the tropical weather conditions of Singapore. From the measured field performances, the total energy output of 240.2 kW h/m/year is recorded for CPV operation in Singapore, which is nearly two folds higher than the stationary PV panels.

  19. Long term exposure to combination paradigm of environmental enrichment, physical exercise and diet reverses the spatial memory deficits and restores hippocampal neurogenesis in ventral subicular lesioned rats.

    Science.gov (United States)

    Kapgal, Vijayakumar; Prem, Neethi; Hegde, Preethi; Laxmi, T R; Kutty, Bindu M

    2016-04-01

    Subiculum is an important structure of the hippocampal formation and plays an imperative role in spatial learning and memory functions. We have demonstrated earlier the cognitive impairment following bilateral ventral subicular lesion (VSL) in rats. We found that short term exposure to enriched environment (EE) did not help to reverse the spatial memory deficits in water maze task suggesting the need for an appropriate enriched paradigm towards the recovery of spatial memory. In the present study, the efficacy of long term exposure of VSL rats to combination paradigm of environmental enrichment (EE), physical exercise and 18 C.W. diet (Combination Therapy - CT) in reversing the spatial memory deficits in Morris water maze task has been studied. Ibotenate lesioning of ventral subiculum produced significant impairment of performance in the Morris water maze and reduced the hippocampal neurogenesis in rats. Post lesion exposure to C.T. restored the hippocampal neurogenesis and improved the spatial memory functions in VSL rats. Our study supports the hypothesis that the combination paradigm is critical towards the development of an enhanced behavioral and cognitive experience especially in conditions of CNS insults and the associated cognitive dysfunctions. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Compensation for PKMζ in long-term potentiation and spatial long-term memory in mutant mice.

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    Tsokas, Panayiotis; Hsieh, Changchi; Yao, Yudong; Lesburguères, Edith; Wallace, Emma Jane Claire; Tcherepanov, Andrew; Jothianandan, Desingarao; Hartley, Benjamin Rush; Pan, Ling; Rivard, Bruno; Farese, Robert V; Sajan, Mini P; Bergold, Peter John; Hernández, Alejandro Iván; Cottrell, James E; Shouval, Harel Z; Fenton, André Antonio; Sacktor, Todd Charlton

    2016-05-17

    PKMζ is a persistently active PKC isoform proposed to maintain late-LTP and long-term memory. But late-LTP and memory are maintained without PKMζ in PKMζ-null mice. Two hypotheses can account for these findings. First, PKMζ is unimportant for LTP or memory. Second, PKMζ is essential for late-LTP and long-term memory in wild-type mice, and PKMζ-null mice recruit compensatory mechanisms. We find that whereas PKMζ persistently increases in LTP maintenance in wild-type mice, PKCι/λ, a gene-product closely related to PKMζ, persistently increases in LTP maintenance in PKMζ-null mice. Using a pharmacogenetic approach, we find PKMζ-antisense in hippocampus blocks late-LTP and spatial long-term memory in wild-type mice, but not in PKMζ-null mice without the target mRNA. Conversely, a PKCι/λ-antagonist disrupts late-LTP and spatial memory in PKMζ-null mice but not in wild-type mice. Thus, whereas PKMζ is essential for wild-type LTP and long-term memory, persistent PKCι/λ activation compensates for PKMζ loss in PKMζ-null mice.

  1. 长时程增强与长时程抑制的研究%Advances in long - term potentiation and long - term depression

    Institute of Scientific and Technical Information of China (English)

    张敬军; 夏作理

    2000-01-01

    The impairment of learning and memory function in the central nervous system(CNS)is one of the main features of aging and Alzheimer' s disease (AD). Many experimental results have showed that long- term memory(LTM) is related to long- term potentiation(LTP) and long- term depression (LTD). They intluenee each other. The relationship between LTP and LTD is complex. Therefore, it is important to study the learning and memory mechanism from LTP、LTD and gene expression in the CNS.

  2. Long term effects on potential repository sites: occurrence and diagenesis of anhydrite

    International Nuclear Information System (INIS)

    Bath, A.H.; George, I.A.; Milodowski, A.E.; Darling, W.G.

    1985-10-01

    The report deals with the long-term behaviour of anhydrite as a potential host rock for deep disposal of intermediate-level radioactive wastes. The principal long-term effect on the integrity of such a repository is the possibility of penetration of groundwater and consequent transformation to gypsum. Therefore, in order to assess the chydrological and geochemical processes of hydration in detail, mineralogical and geochemical analyses have been carried out on anhydrite samples in a drillcore taken near Darlington, United Kingdom. The results are discussed in terms of the long-term integrity of anhydrite as a repository site. (U.K.)

  3. Whole-Body Exposure to 28Si-Radiation Dose-Dependently Disrupts Dentate Gyrus Neurogenesis and Proliferation in the Short Term and New Neuron Survival and Contextual Fear Conditioning in the Long Term.

    Science.gov (United States)

    Whoolery, Cody W; Walker, Angela K; Richardson, Devon R; Lucero, Melanie J; Reynolds, Ryan P; Beddow, David H; Clark, K Lyles; Shih, Hung-Ying; LeBlanc, Junie A; Cole, Mara G; Amaral, Wellington Z; Mukherjee, Shibani; Zhang, Shichuan; Ahn, Francisca; Bulin, Sarah E; DeCarolis, Nathan A; Rivera, Phillip D; Chen, Benjamin P C; Yun, Sanghee; Eisch, Amelia J

    2017-11-01

    Astronauts traveling to Mars will be exposed to chronic low doses of galactic cosmic space radiation, which contains highly charged, high-energy (HZE) particles. 56 Fe-HZE-particle exposure decreases hippocampal dentate gyrus (DG) neurogenesis and disrupts hippocampal function in young adult rodents, raising the possibility of impaired astronaut cognition and risk of mission failure. However, far less is known about how exposure to other HZE particles, such as 28 Si, influences hippocampal neurogenesis and function. To compare the influence of 28 Si exposure on indices of neurogenesis and hippocampal function with previous studies on 56 Fe exposure, 9-week-old C57BL/6J and Nestin-GFP mice (NGFP; made and maintained for 10 or more generations on a C57BL/6J background) received whole-body 28 Si-particle-radiation exposure (0, 0.2 and 1 Gy, 300 MeV/n, LET 67 KeV/μ, dose rate 1 Gy/min). For neurogenesis assessment, the NGFP mice were injected with the mitotic marker BrdU at 22 h postirradiation and brains were examined for indices of hippocampal proliferation and neurogenesis, including Ki67 + , BrdU + , BrdU + NeuN + and DCX + cell numbers at short- and long-term time points (24 h and 3 months postirradiation, respectively). In the short-term group, stereology revealed fewer Ki67 + , BrdU + and DCX + cells in 1-Gy-irradiated group relative to nonirradiated control mice, fewer Ki67 + and DCX + cells in 0.2 Gy group relative to control group and fewer BrdU + and DCX + cells in 1 Gy group relative to 0.2 Gy group. In contrast to the clearly observed radiation-induced, dose-dependent reductions in the short-term group across all markers, only a few neurogenesis indices were changed in the long-term irradiated groups. Notably, there were fewer surviving BrdU + cells in the 1 Gy group relative to 0- and 0.2-Gy-irradiated mice in the long-term group. When the short- and long-term groups were analyzed by sex, exposure to radiation had a similar effect on neurogenesis indices

  4. Inducing a long-term potentiation in the dentate gyrus is sufficient to produce rapid antidepressant-like effects.

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    Kanzari, A; Bourcier-Lucas, C; Freyssin, A; Abrous, D N; Haddjeri, N; Lucas, G

    2018-03-01

    Recent hypotheses propose that one prerequisite to obtain a rapid antidepressant (AD) effect would reside in processes of synaptic reinforcement occurring within the dentate gyrus (DG) of the hippocampus independently from neurogenesis. However, to date no relationship has been established between an increased DG synaptic plasticity, and rapid AD-like action. To the best of our knowledge, this study shows for the first time that inducing a long-term potentiation (LTP) within the DG by stimulating the perforant pathway (PP) is sufficient to induce such effects. Thus, Sprague-Dawley rats having undergone a successful LTP displayed a significant reduction of immobility when passed acutely 3 days thereafter in the forced swimming test (FST). Further, in a longitudinal paradigm using the pseudo-depressed Wistar-Kyoto rat strain, LTP elicited a decrease of FST immobility after only 2 days, whereas the AD desipramine was not effective before 16 days. In both models, the influence of LTP was transient, as it was no more observed after 8-9 days. No effects were observed on the locomotor activity or on anxiety-related behavior. Theta-burst stimulation of a brain region anatomically adjacent to the PP remained ineffective in the FST. Immunoreactivity of DG cells for phosphorylated histone H3 and doublecortin were not modified three days after LTP, indicating a lack of effect on both cell proliferation and neurogenesis. Finally, depleting brain serotonin contents reduced the success rate of LTP but did not affect its subsequent AD-like effects. These results confirm the 'plastic DG' theory of rapid AD efficacy. Beyond, they point out stimulations of the entorhinal cortex, from which the PP originates, as putative new approaches in AD research.

  5. Long-term visuo-gustatory appetitive and aversive conditioning potentiate human visual evoked potentials

    DEFF Research Database (Denmark)

    Christoffersen, Gert R.J.; Laugesen, Jakob L.; Møller, Per

    2017-01-01

    Human recognition of foods and beverages are often based on visual cues associated with flavors. The dynamics of neurophysiological plasticity related to acquisition of such long-term associations has only recently become the target of investigation. In the present work, the effects of appetitive...... and aversive visuo-gustatory conditioning were studied with high density EEG-recordings focusing on late components in the visual evoked potentials (VEPs), specifically the N2-P3 waves. Unfamiliar images were paired with either a pleasant or an unpleasant juice and VEPs evoked by the images were compared...... before and 1 day after the pairings. In electrodes located over posterior visual cortex areas, the following changes were observed after conditioning: the amplitude from the N2-peak to the P3-peak increased and the N2 peak delay was reduced. The percentage increase of N2-to-P3 amplitudes...

  6. Long-Term Visuo-Gustatory Appetitive and Aversive Conditioning Potentiate Human Visual Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Gert R. J. Christoffersen

    2017-09-01

    Full Text Available Human recognition of foods and beverages are often based on visual cues associated with flavors. The dynamics of neurophysiological plasticity related to acquisition of such long-term associations has only recently become the target of investigation. In the present work, the effects of appetitive and aversive visuo-gustatory conditioning were studied with high density EEG-recordings focusing on late components in the visual evoked potentials (VEPs, specifically the N2-P3 waves. Unfamiliar images were paired with either a pleasant or an unpleasant juice and VEPs evoked by the images were compared before and 1 day after the pairings. In electrodes located over posterior visual cortex areas, the following changes were observed after conditioning: the amplitude from the N2-peak to the P3-peak increased and the N2 peak delay was reduced. The percentage increase of N2-to-P3 amplitudes was asymmetrically distributed over the posterior hemispheres despite the fact that the images were bilaterally symmetrical across the two visual hemifields. The percentage increases of N2-to-P3 amplitudes in each experimental subject correlated with the subject’s evaluation of positive or negative hedonic valences of the two juices. The results from 118 scalp electrodes gave surface maps of theta power distributions showing increased power over posterior visual areas after the pairings. Source current distributions calculated from swLORETA revealed that visual evoked currents rose as a result of conditioning in five cortical regions—from primary visual areas and into the inferior temporal gyrus (ITG. These learning-induced changes were seen after both appetitive and aversive training while a sham trained control group showed no changes. It is concluded that long-term visuo-gustatory conditioning potentiated the N2-P3 complex, and it is suggested that the changes are regulated by the perceived hedonic valence of the US.

  7. Flavonoid fisetin promotes ERK-dependent long-term potentiation and enhances memory

    Science.gov (United States)

    Maher, Pamela; Akaishi, Tatsuhiro; Abe, Kazuho

    2006-01-01

    Small molecules that activate signaling pathways used by neurotrophic factors could be useful for treating CNS disorders. Here we show that the flavonoid fisetin activates ERK and induces cAMP response element-binding protein (CREB) phosphorylation in rat hippocampal slices, facilitates long-term potentiation in rat hippocampal slices, and enhances object recognition in mice. Together, these data demonstrate that the natural product fisetin can facilitate long-term memory, and therefore it may be useful for treating patients with memory disorders. PMID:17050681

  8. BDNF Regains Function in Hippocampal Long-Term Potentiation Deficits Caused by Diencephalic Damage

    Science.gov (United States)

    Vedder, Lindsey C.; Savage, Lisa M.

    2017-01-01

    Thiamine deficiency (TD), commonly associated with chronic alcoholism, leads to diencephalic damage, hippocampal dysfunction, and spatial learning and memory deficits. We show a decrease in the magnitude of long-term potentiation (LTP) and paired-pulse facilitation (PPF) at CA3-CA1 synapses, independent of sex, following diencephalic damage…

  9. Enhanced AMPA receptor function promotes cerebellar long-term depression rather than potentiation

    NARCIS (Netherlands)

    van Beugen, Boeke J; Qiao, Xin; Simmons, Dana H; De Zeeuw, Chris I; Hansel, Christian

    2014-01-01

    Ampakines are allosteric modulators of AMPA receptors that facilitate hippocampal long-term potentiation (LTP) and learning, and have been considered for the treatment of cognition and memory deficits. Here, we show that the ampakine CX546 raises the amplitude and slows the decay time of excitatory

  10. Metabotropic action of postsynaptic kainate receptors triggers hippocampal long-term potentiation

    Czech Academy of Sciences Publication Activity Database

    Petrovič, Miloš; da Silva, S. V.; Clement, J. P.; Vyklický ml., Ladislav; Mulle, C.; González-González, I. M.; Henley, J. M.

    2017-01-01

    Roč. 20, č. 4 (2017), s. 529-539 ISSN 1097-6256 R&D Projects: GA ČR(CZ) GA17-02300S Institutional support: RVO:67985823 Keywords : hippocampus * long-term potentiation * membrane proteins Subject RIV: FH - Neurology OBOR OECD: Neuroscience s (including psychophysiology Impact factor: 17.839, year: 2016

  11. Gating of Long-Term Potentiation by Nicotinic Acetylcholine Receptors at the Cerebellum Input Stage

    NARCIS (Netherlands)

    F. Prestori (Francesca); C. Bonardi (Claudia); L. Mapelli (Lisa); P. Lombardo (Paola); R. Goselink (Rianne); M.E. de Stefano (Maria Egle); D. Gandolfi (Daniela); J. Mapelli (Jonathan); D. Bertrand (Daniel); M. Schonewille (Martijn); C.I. de Zeeuw (Chris); E. D'Angelo (Egidio)

    2013-01-01

    textabstractThe brain needs mechanisms able to correlate plastic changes with local circuit activity and internal functional states. At the cerebellum input stage, uncontrolled induction of long-term potentiation or depression (LTP or LTD) between mossy fibres and granule cells can saturate synaptic

  12. Long-term potential and actual evapotranspiration of two different forests on the Atlantic Coastal Plain

    Science.gov (United States)

    Devendra Amatya; S. Tian; Z. Dai; Ge Sun

    2016-01-01

    A reliable estimate of potential evapotranspiration (PET) for a forest ecosystem is critical in ecohydrologic modeling related with water supply, vegetation dynamics, and climate change and yet is a challenging task due to its complexity. Based on long-term on-site measured hydro-climatic data and predictions from earlier validated hydrologic modeling studies...

  13. Role of nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Pettorossi, V E

    2000-01-01

    In rat brainstem slices, we investigated the role of nitric oxide in long-term potentiation induced in the ventral portion of the medial vestibular nuclei by high-frequency stimulation of the primary vestibular afferents. The nitric oxide scavenger [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide ] and the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester were administered before and after induction of potentiation. Both drugs completely prevented long-term potentiation, whereas they did not impede the potentiation build-up, or affect the already established potentiation. These results demonstrate that the induction, but not the maintenance of vestibular long-term potentiation, depends on the synthesis and release into the extracellular medium of nitric oxide. In addition, we analysed the effect of the nitric oxide donor sodium nitroprusside on vestibular responses. Sodium nitroprusside induced long-term potentiation, as evidenced through the field potential enhancement and unit peak latency decrease. This potentiation was impeded by D, L-2-amino-5-phosphonopentanoic acid, and was reduced under blockade of synaptosomal platelet-activating factor receptors by ginkgolide B and group I metabotropic glutamate receptors by (R,S)-1-aminoindan-1, 5-dicarboxylic acid. When reduced, potentiation fully developed following the washout of antagonist, demonstrating an involvement of platelet-activating factor and group I metabotropic glutamate receptors in its full development. Potentiation induced by sodium nitroprusside was also associated with a decrease in the paired-pulse facilitation ratio, which persisted under ginkgolide B, indicating that nitric oxide increases glutamate release independently of platelet-activating factor-mediated presynaptic events. We suggest that nitric oxide, released after the activation of N-methyl-D-aspartate receptors, acts as a retrograde messenger leading to an enhancement of glutamate release to a

  14. Long-term potentiation (LTP) of human sensory-evoked potentials.

    Science.gov (United States)

    Kirk, Ian J; McNair, Nicolas A; Hamm, Jeffrey P; Clapp, Wesley C; Mathalon, Daniel H; Cavus, Idil; Teyler, Timothy J

    2010-09-01

    Long-term potentiation (LTP) is the principal candidate synaptic mechanism underlying learning and memory, and has been studied extensively at the cellular and molecular level in laboratory animals. Inquiry into the functional significance of LTP has been hindered by the absence of a human model as, until recently, LTP has only been directly demonstrated in humans in isolated cortical tissue obtained from patients undergoing surgery, where it displays properties identical to those seen in non-human preparations. In this brief review, we describe the results of paradigms recently developed in our laboratory for inducing LTP-like changes in visual-, and auditory-evoked potentials. We describe how rapid, repetitive presentation of sensory stimuli leads to a persistent enhancement of components of sensory-evoked potential in normal humans. Experiments to date, investigating the locus, stimulus specificity, and NMDA receptor dependence of these LTP-like changes suggest that they have the essential characteristics of LTP seen in experimental animals. The ability to elicit LTP from non-surgical patients will provide a human model system allowing the detailed examination of synaptic plasticity in normal subjects and may have future clinical applications in the assessment of cognitive disorders. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

  15. 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).

  16. Learning, memory and long-term potentiation are altered in Nedd4 heterozygous mice.

    Science.gov (United States)

    Camera, Daria; Coleman, Harold A; Parkington, Helena C; Jenkins, Trisha A; Pow, David V; Boase, Natasha; Kumar, Sharad; Poronnik, Philip

    2016-04-15

    The consolidation of short-term memory into long-term memory involves changing protein level and activity for the synaptic plasticity required for long-term potentiation (LTP). AMPA receptor trafficking is a key determinant of LTP and recently ubiquitination by Nedd4 has been shown to play an important role via direct action on the GluA1 subunit, although the physiological relevance of these findings are yet to be determined. We therefore investigated learning and memory in Nedd4(+/-) mice that have a 50% reduction in levels of Nedd4. These mice showed decreased long-term spatial memory as evidenced by significant increases in the time taken to learn the location of and subsequently find a platform in the Morris water maze. In contrast, there were no significant differences between Nedd4(+/+) and Nedd4(+/-) mice in terms of short-term spatial memory in a Y-maze test. Nedd4(+/-) mice also displayed a significant reduction in post-synaptic LTP measured in hippocampal brain slices. Immunofluorescence of Nedd4 in the hippocampus confirmed its expression in hippocampal neurons of the CA1 region. These findings indicate that reducing Nedd4 protein by 50% significantly impairs LTP and long-term memory thereby demonstrating an important role for Nedd4 in these processes. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Long-term potentiation and depression after unilateral labyrinthectomy in the medial vestibular nucleus of rats.

    Science.gov (United States)

    Pettorossi, Vito Enrico; Dutia, Mayank; Frondaroli, Adele; Dieni, Cristina; Grassi, Silvarosa

    2003-01-01

    We previously demonstrated in rat brainstem slices that high-frequency stimulation (HFS) of the vestibular afferents induces long-term potentiation (LTP) in the ventral part (Vp) of the medial vestibular nucleus (MVN) and long-term depression (LTD) in the dorsal part (Dp). Both LTP and LTD depend on N-methyl-D-aspartate receptor activation, which increases synaptic efficacy; however, in the Dp, LTP reverses to LTD because of the activation of gamma-aminobutyric acid-ergic neurons. Here we show that the probability of inducing long-term effects in the MVN of rat brainstem slices is altered after unilateral labyrinthectomy (UL). In fact, LTP occurs less frequently in the ventral contra-lesional side compared with sham-operated rats. In the dorsal ipsi-lesional side, LTD is reduced and LTP enhanced, while the opposite occurs in the dorsal contra-lesional side. These changes in synaptic plasticity may be useful for re-balancing the tonic discharge of the MVN of the two sides during vestibular compensation, and for enhancing the dynamic responses of the deafferented MVN neurons in the long term.

  18. Long term potentiation, but not depression, in interlamellar hippocampus CA1.

    Science.gov (United States)

    Sun, Duk-Gyu; Kang, Hyeri; Tetteh, Hannah; Su, Junfeng; Lee, Jihwan; Park, Sung-Won; He, Jufang; Jo, Jihoon; Yang, Sungchil; Yang, Sunggu

    2018-03-26

    Synaptic plasticity in the lamellar CA3 to CA1 circuitry has been extensively studied while interlamellar CA1 to CA1 connections have not yet received much attention. One of our earlier studies demonstrated that axons of CA1 pyramidal neurons project to neighboring CA1 neurons, implicating information transfer along a longitudinal interlamellar network. Still, it remains unclear whether long-term synaptic plasticity is present within this longitudinal CA1 network. Here, we investigate long-term synaptic plasticity between CA1 pyramidal cells, using in vitro and in vivo extracellular recordings and 3D holography glutamate uncaging. We found that the CA1-CA1 network exhibits NMDA receptor-dependent long-term potentiation (LTP) without direction or layer selectivity. By contrast, we find no significant long-term depression (LTD) under various LTD induction protocols. These results implicate unique synaptic properties in the longitudinal projection suggesting that the interlamellar CA1 network could be a promising structure for hippocampus-related information processing and brain diseases.

  19. A novel nicotinic agonist facilitates induction of long-term potentiation in the rat hippocampus.

    Science.gov (United States)

    Hunter, B E; de Fiebre, C M; Papke, R L; Kem, W R; Meyer, E M

    1994-02-28

    Long-term potentiation (LTP) can be modulated by a number of neurotransmitter receptors including muscarinic and GABAergic receptor types. We have found that a novel nicotinic agonist, 2,4-dimethoxybenzylidene anabaseine (DMXB), facilitated the induction of LTP in the hippocampus in a dose-dependent and mecamylamine-sensitive manner. DMXB displaced high affinity nicotinic [125I]alpha-bungarotoxin and [3H]acetylcholine binding in rat brain. Xenopus oocyte studies demonstrated that DMXB has agonist activity at alpha 7 but not alpha 4/beta 2 nicotinic receptor subtypes. These results indicated that DMXB is a novel nicotinic agonist with apparent specificity for the alpha 7/alpha-bungarotoxin nicotinic receptor subtype and indicate that nicotinic receptor activation is capable of modulating the induction of long-term potentiation.

  20. Potential Long-Term Complications of Endovascular Stent Grafting for Blunt Thoracic Aortic Injury

    Directory of Open Access Journals (Sweden)

    Larry E. Miller

    2012-01-01

    Full Text Available Blunt thoracic aortic injury (BTAI is a rare, but lethal, consequence of rapid deceleration events. Most victims of BTAI die at the scene of the accident. Of those who arrive to the hospital alive, expedient aortic intervention significantly improves survival. Thoracic endovascular aortic repair (TEVAR has been accepted as the standard of care for BTAI at many centers, primarily due to the convincing evidence of lower mortality and morbidity in comparison to open surgery. However, less attention has been given to potential long-term complications of TEVAR for BTAI. This paper focuses on these complications, which include progressive aortic expansion with aging, inadequate stent graft characteristics, device durability concerns, long-term radiation exposure concerns from follow-up computed tomography scans, and the potential for (Victims of Modern Imaging Technology VOMIT.

  1. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Directory of Open Access Journals (Sweden)

    Paul Smolen

    Full Text Available Protein synthesis-dependent, late long-term potentiation (LTP and depression (LTD at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  2. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Science.gov (United States)

    Smolen, Paul; Baxter, Douglas A; Byrne, John H

    2012-01-01

    Protein synthesis-dependent, late long-term potentiation (LTP) and depression (LTD) at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ) is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC) and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  3. Potentially inappropriate prescriptions for older patients in long-term care

    Directory of Open Access Journals (Sweden)

    Laurin Danielle

    2004-10-01

    Full Text Available Abstract Background Inappropriate medication use is a major healthcare issue for the elderly population. This study explored the prevalence of potentially inappropriate prescriptions (PIPs in long-term care in metropolitan Quebec. Methods A cross sectional chart review of 2,633 long-term care older patients of the Quebec City area was performed. An explicit criteria list for PIPs was developed based on the literature and validated by a modified Delphi method. Medication orders were reviewed to describe prescribing patterns and to determine the prevalence of PIPs. A multivariate analysis was performed to identify predictors of PIPs. Results Almost all residents (94.0% were receiving one or more prescribed medication; on average patients had 4.8 prescribed medications. A majority (54.7% of treated patients had a potentially inappropriate prescription (PIP. Most common PIPs were drug interactions (33.9% of treated patients, followed by potentially inappropriate duration (23.6%, potentially inappropriate medication (14.7% and potentially inappropriate dosage (9.6%. PIPs were most frequent for medications of the central nervous system (10.8% of prescribed medication. The likelihood of PIP increased significantly as the number of drugs prescribed increased (odds ratio [OR]: 1.38, 95% confidence interval [CI]: 1.33 – 1.43 and with the length of stay (OR: 1.78, CI: 1.43 – 2.20. On the other hand, the risk of receiving a PIP decreased with age. Conclusion Potentially inappropriate prescribing is a serious problem in the highly medicated long-term care population in metropolitan Quebec. Use of explicit criteria lists may help identify the most critical issues and prioritize interventions to improve quality of care and patient safety.

  4. Long term hydrogen production potential of concentrated photovoltaic (CPV) system in tropical weather of Singapore

    KAUST Repository

    Burhan, Muhammad

    2016-08-23

    Concentrated photovoltaic (CPV) system provides highest solar energy conversion efficiency among all the photovoltaic technologies and provides the most suitable option to convert solar energy into hydrogen, as future sustainable energy carrier. So far, only conventional flat plate PV systems are being used for almost all of the commercial applications. However, most of the studies have only shown the maximum efficiency of hydrogen production using CPV. In actual field conditions, the performance of CPV-Hydrogen system is affected by many parameter and it changes continuously during whole day operation. In this paper, the daily average and long term performances are proposed to analyze the real field potential of the CPV-Hydrogen system, which is of main interest for designers and consumers. An experimental setup is developed and a performance model is proposed to investigate the average and long term production potential of CPV-Hydrogen system. The study is carried out in tropical weather of Singapore. The maximum CPV efficiency of 27-28% and solar to hydrogen (STH) efficiency of 18%, were recorded. In addition, the CPV-Hydrogen system showed the long term average efficiency of 15.5%, for period of one year (12-months), with electrolyser rating of 47 kWh/kg and STH production potential of 218 kWh/kg. Based upon the DNI availability, the system showed hydrogen production potential of 0.153-0.553 kg/m/month, with average production of 0.43 kg/m/month. However, CPV-Hydrogen system has shown annual hydrogen production potential of 5.162 kg/m/year in tropical weather of Singapore.

  5. Is forebrain neurogenesis a potential repair mechanism after stroke?

    OpenAIRE

    Inta, Dragos; Gass, Peter

    2015-01-01

    The use of adult subventricular zone (SVZ) neurogenesis as brain repair strategy after stroke represents a hot topic in neurologic research. Recent radiocarbon-14 dating has revealed a lack of poststroke neurogenesis in the adult human neocortex; however, adult neurogenesis has been shown to occur, even under physiologic conditions, in the human striatum. Here, these results are contrasted with experimental poststroke neurogenesis in the murine brain. Both in humans and in rodents, the SVZ ge...

  6. Disinhibition mediates a form of hippocampal long-term potentiation in area CA1.

    Directory of Open Access Journals (Sweden)

    Jake Ormond

    Full Text Available The hippocampus plays a central role in memory formation in the mammalian brain. Its ability to encode information is thought to depend on the plasticity of synaptic connections between neurons. In the pyramidal neurons constituting the primary hippocampal output to the cortex, located in area CA1, firing of presynaptic CA3 pyramidal neurons produces monosynaptic excitatory postsynaptic potentials (EPSPs followed rapidly by feedforward (disynaptic inhibitory postsynaptic potentials (IPSPs. Long-term potentiation (LTP of the monosynaptic glutamatergic inputs has become the leading model of synaptic plasticity, in part due to its dependence on NMDA receptors (NMDARs, required for spatial and temporal learning in intact animals. Using whole-cell recording in hippocampal slices from adult rats, we find that the efficacy of synaptic transmission from CA3 to CA1 can be enhanced without the induction of classic LTP at the glutamatergic inputs. Taking care not to directly stimulate inhibitory fibers, we show that the induction of GABAergic plasticity at feedforward inhibitory inputs results in the reduced shunting of excitatory currents, producing a long-term increase in the amplitude of Schaffer collateral-mediated postsynaptic potentials. Like classic LTP, disinhibition-mediated LTP requires NMDAR activation, suggesting a role in types of learning and memory attributed primarily to the former and raising the possibility of a previously unrecognized target for therapeutic intervention in disorders linked to memory deficits, as well as a potentially overlooked site of LTP expression in other areas of the brain.

  7. Intelligent power wheelchair use in long-term care: potential users' experiences and perceptions.

    Science.gov (United States)

    Rushton, Paula W; Mortenson, Ben W; Viswanathan, Pooja; Wang, Rosalie H; Miller, William C; Hurd Clarke, Laura

    2017-10-01

    Long-term care (LTC) residents with cognitive impairments frequently experience limited mobility and participation in preferred activities. Although a power wheelchair could mitigate some of these mobility and participation challenges, this technology is often not prescribed for this population due to safety concerns. An intelligent power wheelchair (IPW) system represents a potential intervention that could help to overcome these concerns. The purpose of this study was to explore a) how residents experienced an IPW that used three different modes of control and b) what perceived effect the IPW would have on their daily lives. We interviewed 10 LTC residents with mild or moderate cognitive impairment twice, once before and once after testing the IPW. Interviews were conducted using a semi-structured interview guide, audio recorded and transcribed verbatim for thematic analyses. Our analyses identified three overarching themes: (1) the difference an IPW would make, (2) the potential impact of the IPW on others and (3) IPW-related concerns. Findings from this study confirm the need for and potential benefits of IPW use in LTC. Future studies will involve testing IPW improvements based on feedback and insights from this study. Implications for rehabilitation Intelligent power wheelchairs may enhance participation and improve safety and feelings of well-being for long-term care residents with cognitive impairments. Intelligent power wheelchairs could potentially have an equally positive impact on facility staff, other residents, and family and friends by decreasing workload and increasing safety.

  8. Alpha2-adrenoceptor modulation of long-term potentiation elicited in vivo in rat occipital cortex.

    Science.gov (United States)

    Mondaca, Mauricio; Hernández, Alejandro; Pérez, Hernán; Valladares, Luis; Sierralta, Walter; Fernández, Victor; Soto-Moyano, Rubén

    2004-09-24

    Pretreatment with the alpha(2)-adrenoceptor agonist clonidine (31.25, 62.5, or 125 microg/kg, i.p.) dose-dependently reduced long-term potentiation (LTP) elicited in vivo in the occipital cortex of anesthetized rats, whereas pretreatment with the alpha(2)-adrenoceptor antagonist yohimbine (0.133, 0.4, or 1.2 mg/kg, i.p.) increased neocortical LTP in a dose-dependent fashion. These effects could be related to the reported disruptive and facilitatory actions induced on memory formation by pretreatment with alpha(2)-adrenoceptor agonists and antagonists, respectively.

  9. Long term effects on potential repository sites: the alteration of the Lower Oxford Clay during weathering

    International Nuclear Information System (INIS)

    Milowdowski, A.E.; Bloodworth, A.J.; Wilmot, R.D.

    1985-09-01

    The report is one of a short series describing work carried out to investigate the long-term effects of various geological processes on the performance of both shallow and deep repositories for low and intermediate-level radioactive wastes. This paper deals with the alteration as a result of weathering of the Lower Oxford Clay, a potential host rock for shallow disposal of wastes. A description of the Lower Oxford Clay is given, along with the weathering of argillaceous rocks. Investigations of the weathering at the Elstow Storage Depot are described, as well as the implications for radioactive waste disposal. (U.K.)

  10. 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.

  11. Exogenous glutamate induces short and long-term potentiation in the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Frondaroli, A; Pessia, M; Pettorossi, V E

    2001-08-08

    In rat brain stem slices, high concentrations of exogenous glutamate induce long-term potentiation (LTP) of the field potentials evoked in the medial vestibular nuclei (MVN) by vestibular afferent stimulation. At low concentrations, glutamate can also induce short-term potentiation (STP), indicating that LTP and STP are separate events depending on the level of glutamatergic synapse activation. LTP and STP are prevented by blocking NMDA receptors and nitric oxide (NO) synthesis. Conversely, blocking platelet-activating factor (PAF) and group I metabotropic glutamate receptors only prevents the full development of LTP. Moreover, in the presence of blocking agents, glutamate causes transient inhibition, suggesting that when potentiation is impeded, exogenous glutamate can activate presynaptic mechanisms that reduce glutamate release.

  12. Melatonin administration impairs visuo-spatial performance and inhibits neocortical long-term potentiation in rats.

    Science.gov (United States)

    Soto-Moyano, Rubén; Burgos, Héctor; Flores, Francisco; Valladares, Luis; Sierralta, Walter; Fernández, Victor; Pérez, Hernán; Hernández, Paula; Hernández, Alejandro

    2006-10-01

    Melatonin has been shown to inhibit long-term potentiation (LTP) in hippocampal slices of rats. Since LTP may be one of the main mechanisms by which memory traces are encoded and stored in the central nervous system, it is possible that melatonin could modulate cognitive performance by interfering with the cellular and/or molecular mechanisms involved in LTP. We investigated in rats the effects of intraperitoneally-administered melatonin (0.1, 1 and 10 mg/kg), its saline-ethanol solvent, or saline alone, on the acquisition of visuo-spatial memory as well as on the ability of the cerebral cortex to develop LTP in vivo. Visuo-spatial performance was assessed daily in rats, for 10 days, in an 8-arm radial maze, 30 min after they received a single daily dose of melatonin. Visual cortex LTP was determined in sodium pentobarbital anesthetized rats (65 mg/kg i.p.), by potentiating transcallosal evoked responses with a tetanizing train (312 Hz, 500 ms duration) 30 min after administration of a single dose of melatonin. Results showed that melatonin impaired visuo-spatial performance in rats, as revealed by the greater number of errors committed and time spent to solve the task in the radial maze. Melatonin also prevented the induction of neocortical LTP. It is concluded that melatonin, at the doses utilized in this study, could alter some forms of neocortical plasticity involved in short- and long-term visuo-spatial memories in rats.

  13. Long-term antibiotic delivery by chitosan-based composite coatings with bone regenerative potential

    Science.gov (United States)

    Ordikhani, F.; Simchi, A.

    2014-10-01

    Composite coatings with bone-bioactivity and drug-eluting capacity are considered as promising materials for titanium bone implants. In this work, drug-eluting chitosan-bioactive glass coatings were fabricated by a single-step electrophoretic deposition technique. Drug-loading and -releasing capacity of the composite coatings were carried out using the vancomycin antibiotic. Uniform coatings with a thickness of ∼55 μm containing 23.7 wt% bioactive glass particles and various amounts of the antibiotic (380-630 μg/cm2) were produced. The coatings were bioactive in terms of apatite-forming ability in simulated body fluid and showed favorable cell adhesion and growth. In vitro biological tests also indicated that the composite coatings had better cellular affinity than pristine chitosan coatings. The in vitro elution kinetics of the composite coating revealed an initial burst release of around 40% of the drug within the first elution step of 1 h and following by a continuous eluting over 4 weeks, revealing long-term drug-delivering potential. Antibacterial tests using survival assay against Gram-positive Staphylococcus aureus bacteria determined the effect of vancomycin release on reduction of infection risk. Almost no bacteria were survived on the coatings prepared from the EPD suspension containing ≥0.5 g/l vancomycin. The developed chitosan-based composite coatings with bone bioactivity and long-term drug-delivery ability may be potentially useful for metallic implants to reduce infection risk.

  14. Cholinergic pairing with visual activation results in long-term enhancement of visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Jun Il Kang

    Full Text Available Acetylcholine (ACh contributes to learning processes by modulating cortical plasticity in terms of intensity of neuronal activity and selectivity properties of cortical neurons. However, it is not known if ACh induces long term effects within the primary visual cortex (V1 that could sustain visual learning mechanisms. In the present study we analyzed visual evoked potentials (VEPs in V1 of rats during a 4-8 h period after coupling visual stimulation to an intracortical injection of ACh analog carbachol or stimulation of basal forebrain. To clarify the action of ACh on VEP activity in V1, we individually pre-injected muscarinic (scopolamine, nicotinic (mecamylamine, alpha7 (methyllycaconitine, and NMDA (CPP receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual stimulation significantly increased VEP amplitude (56% during a 6 h period. Pre-treatment with scopolamine, mecamylamine and CPP completely abolished this long-term enhancement, while alpha7 inhibition induced an instant increase of VEP amplitude. This suggests a role of ACh in facilitating visual stimuli responsiveness through mechanisms comparable to LTP which involve nicotinic and muscarinic receptors with an interaction of NMDA transmission in the visual cortex.

  15. Long-term potentiation expands information content of hippocampal dentate gyrus synapses.

    Science.gov (United States)

    Bromer, Cailey; Bartol, Thomas M; Bowden, Jared B; Hubbard, Dusten D; Hanka, Dakota C; Gonzalez, Paola V; Kuwajima, Masaaki; Mendenhall, John M; Parker, Patrick H; Abraham, Wickliffe C; Sejnowski, Terrence J; Harris, Kristen M

    2018-03-06

    An approach combining signal detection theory and precise 3D reconstructions from serial section electron microscopy (3DEM) was used to investigate synaptic plasticity and information storage capacity at medial perforant path synapses in adult hippocampal dentate gyrus in vivo. Induction of long-term potentiation (LTP) markedly increased the frequencies of both small and large spines measured 30 minutes later. This bidirectional expansion resulted in heterosynaptic counterbalancing of total synaptic area per unit length of granule cell dendrite. Control hemispheres exhibited 6.5 distinct spine sizes for 2.7 bits of storage capacity while LTP resulted in 12.9 distinct spine sizes (3.7 bits). In contrast, control hippocampal CA1 synapses exhibited 4.7 bits with much greater synaptic precision than either control or potentiated dentate gyrus synapses. Thus, synaptic plasticity altered total capacity, yet hippocampal subregions differed dramatically in their synaptic information storage capacity, reflecting their diverse functions and activation histories.

  16. Persistent inhibition of hippocampal long-term potentiation in vivo by learned helplessness stress.

    Science.gov (United States)

    Ryan, Benedict K; Vollmayr, Barbara; Klyubin, Igor; Gass, Peter; Rowan, Michael J

    2010-06-01

    The persistent cognitive disruptive effects of stress have been strongly implicated in the pathophysiology of depression and post-traumatic stress disorder. Here we examined factors influencing the time course of recovery from the inhibitory effect of acute inescapable stressors on the ability to induce long-term potentiation (LTP) in the dorsal hippocampus in vivo. We tested different forms of LTP, different stressors and different inbred strains of rats. Acute elevated platform stress completely, but transiently (learned helplessness, inhibited LTP for at least 4 weeks. Contrary to expectations, there was no clear relationship between the ability of the footshock to trigger helpless behavior, a model of stress-induced depression, and the magnitude of LTP inhibition. Moreover, LTP did not appear to be affected by genetic susceptibility to learned helplessness, a model of genetic vulnerability to depression. This long-lasting synaptic plasticity disruption may underlie persistent impairment of hippocampus-dependent cognition by excessive acute inescapable stress.

  17. Long-term potentiation in the amygdala: a cellular mechanism of fear learning and memory.

    Science.gov (United States)

    Sigurdsson, Torfi; Doyère, Valérie; Cain, Christopher K; LeDoux, Joseph E

    2007-01-01

    Much of the research on long-term potentiation (LTP) is motivated by the question of whether changes in synaptic strength similar to LTP underlie learning and memory. Here we discuss findings from studies on fear conditioning, a form of associative learning whose neural circuitry is relatively well understood, that may be particularly suited for addressing this question. We first review the evidence suggesting that fear conditioning is mediated by changes in synaptic strength at sensory inputs to the lateral nucleus of the amygdala. We then discuss several outstanding questions that will be important for future research on the role of synaptic plasticity in fear learning. The results gained from these studies may shed light not only on fear conditioning, but may also help unravel more general cellular mechanisms of learning and memory.

  18. Nuclear protein phosphatase-1: an epigenetic regulator of fear memory and amygdala long-term potentiation.

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    Koshibu, K; Gräff, J; Mansuy, I M

    2011-01-26

    Complex brain diseases and neurological disorders in human generally result from the disturbance of multiple genes and signaling pathways. These disturbances may derive from mutations, deletions, translocations or rearrangements of specific gene(s). However, over the past years, it has become clear that such disturbances may also derive from alterations in the epigenome affecting several genes simultaneously. Our work recently demonstrated that epigenetic mechanisms in the adult brain are in part regulated by protein phosphatase 1 (PP1), a protein Ser/Thr phosphatase that negatively regulates hippocampus-dependent long-term memory (LTM) and synaptic plasticity. PP1 is abundant in brain structures involved in emotional processing like the amygdala, it may therefore be involved in the regulation of fear memory, a form of memory related to post-traumatic stress disorder (PTSD) in human. Here, we demonstrate that PP1 is a molecular suppressor of fear memory and synaptic plasticity in the amygdala that can control chromatin remodeling in neurons. We show that the selective inhibition of the nuclear pool of PP1 in amygdala neurons significantly alters posttranslational modifications (PTMs) of histones and the expression of several memory-associated genes. These alterations correlate with enhanced fear memory, and with an increase in long-term potentiation (LTP) that is transcription-dependent. Our results underscore the importance of nuclear PP1 in the amygdala as an epigenetic regulator of emotional memory, and the relevance of protein phosphatases as potential targets for therapeutic treatment of brain disorders like PTSD. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications.

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    Galea, L A M; Wainwright, S R; Roes, M M; Duarte-Guterman, P; Chow, C; Hamson, D K

    2013-11-01

    The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress. © 2013 British Society for Neuroendocrinology.

  20. Influence of visual experience on developmental shift from long-term depression to long-term potentiation in the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, Silvarosa; Dieni, Cristina; Frondaroli, Adele; Pettorossi, Vito Enrico

    2004-11-01

    The influence of visual experience deprivation on changes in synaptic plasticity during postnatal development was studied in the ventral part of the rat medial vestibular nuclei (vMVN). We analysed the differences in the occurrence, expressed as a percentage, of long-term depression (LTD) and long-term potentiation (LTP) induced by high frequency stimulation (HFS) of the primary vestibular afferents in rats reared in the light (LR) and those in the dark (DR). In LR rats, HFS only induced LTD in the early stages of development, but the occurrence of LTD progressively decreased to zero before their eyes opened, while that of LTP enhanced from zero to about 50%. Once the rats' eyes had opened, LTD was no longer inducible while LTP occurrence gradually reached the normal adult value (70%). In DR rats, a similar shift from LTD to LTP was observed before their eyes opened, showing only a slightly slower LTD decay and LTP growth, and the LTD annulment was delayed by 1 day. By contrast, the time courses of LTD and LTP development in DR and LR rats showed remarkable differences following eye opening. In fact, LTD occurrence increased to about 50% in a short period of time and remained high until the adult stage. In addition, the occurrence of LTP slowly decreased to less than 20%. The effect of light-deprivation was reversible, since the exposure of DR rats to light, 5 days after eye opening, caused a sudden disappearance of LTD and a partial recover of LTP occurrence. In addition, we observed that a week of light deprivation in LR adult rats did not affect the normal adult LTP occurrence. These results provide evidence that in a critical period of development visual input plays a crucial role in shaping synaptic plasticity of the vMVN, and suggest that the visual guided shift from LTD to LTP during development may be necessary to refine and consolidate vestibular circuitry.

  1. Effect of modafinil on learning performance and neocortical long-term potentiation in rats.

    Science.gov (United States)

    Burgos, Héctor; Castillo, Amparo; Flores, Osvaldo; Puentes, Gustavo; Morgan, Carlos; Gatica, Arnaldo; Cofré, Christian; Hernández, Alejandro; Laurido, Claudio; Constandil, Luis

    2010-10-30

    Modafinil is a novel wake-promoting agent whose effects on cognitive performance have begun to be addressed at both preclinical and clinical level. The present study was designed to investigate in rats the effects of chronic modafinil administration on cognitive performance by evaluating: (i) working and reference memories in an Olton 4×4 maze, and (ii) learning of a complex operant conditioning task in a Skinner box. In addition, the effect of modafinil on the ability of the rat frontal cortex to develop long-term potentiation (LTP) was also studied. Chronic modafinil did not significantly modify working memory errors but decreased long-term memory errors on the Olton 4×4 maze, meaning that the drug may have a favourable profile on performance of visuo-spatial tasks (typically, a hippocampus-dependent task) when chronically administered. On the other hand, chronic modafinil resulted in a marked decrease of successful responses in a complex operant conditioning learning, which means that repeated administration of the drug influences negatively problem-solving abilities when confronting the rat to a sequencing task (typically, a prefrontal cortex-dependent task). In addition, in vivo electrophysiology showed that modafinil resulted in impaired capacity of the rat prefrontal cortex to develop LTP following tetanization. It is concluded that modafinil can improve the performance of spatial tasks that depend almost exclusively on hippocampal functioning, but not the performance in tasks including a temporal factor where the prefrontal cortex plays an important role. The fact that modafinil together with preventing operant conditioning learning was also able to block LTP induction in the prefrontal cortex, suggests that the drug could interfere some critical component required for LTP can be developed, thereby altering neuroplastic capabilities of the prefrontal cortex. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Involvement of microglia activation in the lead induced long-term potentiation impairment.

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    Ming-Chao Liu

    Full Text Available Exposure of Lead (Pb, a known neurotoxicant, can impair spatial learning and memory probably via impairing the hippocampal long-term potentiation (LTP as well as hippocampal neuronal injury. Activation of hippocampal microglia also impairs spatial learning and memory. Thus, we raised the hypothesis that activation of microglia is involved in the Pb exposure induced hippocampal LTP impairment and neuronal injury. To test this hypothesis and clarify its underlying mechanisms, we investigated the Pb-exposure on the microglia activation, cytokine release, hippocampal LTP level as well as neuronal injury in in vivo or in vitro model. The changes of these parameters were also observed after pretreatment with minocycline, a microglia activation inhibitor. Long-term low dose Pb exposure (100 ppm for 8 weeks caused significant reduction of LTP in acute slice preparations, meanwhile, such treatment also significantly increased hippocampal microglia activation as well as neuronal injury. In vitro Pb-exposure also induced significantly increase of microglia activation, up-regulate the release of cytokines including tumor necrosis factor-alpha (TNF-α, interleukin-1β (IL-1β and inducible nitric oxide synthase (iNOS in microglia culture alone as well as neuronal injury in the co-culture with hippocampal neurons. Inhibiting the microglia activation with minocycline significantly reversed the above-mentioned Pb-exposure induced changes. Our results showed that Pb can cause microglia activation, which can up-regulate the level of IL-1β, TNF-α and iNOS, these proinflammatory factors may cause hippocampal neuronal injury as well as LTP deficits.

  3. Long-term variability of the thunderstorm and hail potential in Europe

    Science.gov (United States)

    Mohr, Susanna; Kunz, Michael; Speidel, Johannes; Piper, David

    2016-04-01

    Severe thunderstorms and associated hazardous weather events such as hail frequently cause considerable damage to buildings, crops, and automobiles, resulting in large monetary costs in many parts of Europe and the world. To relate single extreme hail events to the historic context and to estimate their return periods and possible trends related to climate change, long-term statistics of hail events are required. Due to the local-scale nature of hail and a lack of suitable observation systems, however, hailstorms are not captured reliably and comprehensively for a long period of time. In view of this fact, different proxies (indirect climate data) obtained from sounding stations and regional climate models can be used to infer the probability and intensity of thunderstorms or hailstorms. In contrast to direct observational data, such proxies are available homogeneously over a long time period. The aim of the study is to investigate the potential for severe thunderstorms and their changes over past decades. Statistical analyses of sounding data show that the convective potential over the past 20 - 30 years has significantly increased over large parts of Central Europe, making severe thunderstorms more likely. A similar picture results from analyses of weather types that are most likely associated with damaging hailstorms. These weather patterns have increased, even if only slightly but nevertheless statistically significantly, in the time period from 1971 to 2000. To improve the diagnostics of hail events in regional climate models, a logistic hail model has been developed by means of a multivariate analysis method. The model is based on a combination of appropriate hail-relevant meteorological parameters. The output of the model is a new index that estimates the potential of the atmosphere for hailstorm development, referred to as potential hail index (PHI). Applied to a high-resolved reanalysis run for Europe driven by NCEP/NCAR1, long-term changes of the PHI for

  4. Long-term potentiation in hilar circuitry modulates gating by the dentate gyrus.

    Science.gov (United States)

    Wright, Brandon J; Jackson, Meyer B

    2014-07-16

    The dentate gyrus serves as a gateway to the hippocampus, filtering and processing sensory inputs as an animal explores its environment. The hilus occupies a strategic position within the dentate gyrus from which it can play a pivotal role in these functions. Inputs from dentate granule cells converge on the hilus, and excitatory hilar mossy cells redistribute these signals back to granule cells to transform a pattern of cortical input into a new pattern of output to the hippocampal CA3 region. Using voltage-sensitive dye to image electrical activity in rat hippocampal slices, we explored how long-term potentiation (LTP) of different excitatory synapses modifies the flow of information. Theta burst stimulation of the perforant path potentiated responses throughout the molecular layer, but left responses in the CA3 region unchanged. By contrast, theta burst stimulation of the granule cell layer potentiated responses throughout the molecular layer, as well as in the CA3 region. Theta burst stimulation of the granule cell layer potentiated CA3 responses not only to granule cell layer stimulation but also to perforant path stimulation. Potentiation of responses in the CA3 region reflected NMDA receptor-dependent LTP of upstream synapses between granule cells and mossy cells, with no detectable contribution from NMDA receptor-independent LTP of local CA3 mossy fiber synapses. Potentiation of transmission to the CA3 region required LTP in both granule cell→mossy cell and mossy cell→granule cell synapses. This bidirectional plasticity enables hilar circuitry to regulate the flow of information through the dentate gyrus and on to the hippocampus. Copyright © 2014 the authors 0270-6474/14/349743-11$15.00/0.

  5. Sauroxine reduces memory retention in rats and impairs hippocampal long-term potentiation generation.

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    Vallejo, Mariana; Carlini, Valeria; Gabach, Laura; Ortega, M G; L Cabrera, José; de Barioglio, Susana Rubiales; Pérez, Mariela; Agnese, Alicia M

    2017-07-01

    In the present paper it was investigated the role of sauroxine, an alkaloid of Phlegmariurus saururus, as a modulator of some types of learning and memory, considering the potential nootropic properties previously reported for the alkaloid extract and the main alkaloid sauroine. Sauroxine was isolated by means of an alkaline extraction, purified by several chromatographic techniques, and assayed in electrophysiological experiments on rat hippocampus slices, tending towards the elicitation of the long-term potentiation (LTP) phenomena. It was also studied the effects of intrahippocampal administration of sauroxine on memory retention in vivo using a Step-down test. Being the bio distribution of a drug an important parameter to be considered, the concentration of sauroxine in rat brain was determined by GLC-MS. Sauroxine blocked LTP generation at both doses used, 3.65 and 3.610 -2 μM. In the behavioral test, the animals injected with this alkaloid (3.6510 -3 nmol) exhibited a significant decrease on memory retention compared with control animals. It was also showed that sauroxine reached the brain (3.435μg/g tissue), after an intraperitoneal injection, displaying its ability to cross the blood-brain barrier. Thus, sauroxine demonstrated to exert an inhibition on these mnemonic phenomena. The effect here established for 1 is defeated by other constituents according to the excellent results obtained for P. saururus alkaloid extract as well as for the isolated alkaloid sauroine. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Neural 17β-estradiol facilitates long-term potentiation in the hippocampal CA1 region.

    Science.gov (United States)

    Grassi, S; Tozzi, A; Costa, C; Tantucci, M; Colcelli, E; Scarduzio, M; Calabresi, P; Pettorossi, V E

    2011-09-29

    In the hippocampal formation many neuromodulators are possibly implied in the synaptic plasticity such as the long-term potentiation (LTP) induced by high-frequency stimulation (HFS) of afferent fibers. We investigated the involvement of locally synthesized neural 17β-estradiol (nE(2)) in the induction of HFS-LTP in hippocampal slices from male rats by stimulating the Schaffer collateral fibers and recording the evoked field excitatory postsynaptic potential (fEPSP) in the CA1 region. We demonstrated that either the blockade of nE(2) synthesis by the aromatase inhibitor letrozole, or the antagonism of E(2) receptors (ERs) by ICI 182,780 did not prevent the induction of HFS-LTP, but reduced its amplitude by ∼60%, without influencing its maintenance. Moreover, letrozole and ICI 182,780 did not affect the first short-term post-tetanic component of LTP and the paired-pulse facilitation (PPF). These findings demonstrate that nE(2) plays an important role in the induction phase of HFS-dependent LTP. Since the basal responses were not affected by the blocking agents, we suggest that the synthesis of nE(2) is induced or enhanced by HFS through aromatase activation. In this context, the local production of nE(2) seems to be a very effective mechanism to modulate the amplitude of LTP. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Basolateral amygdala inactivation impairs learning-induced long-term potentiation in the cerebellar cortex.

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    Lan Zhu

    Full Text Available Learning to fear dangerous situations requires the participation of basolateral amygdala (BLA. In the present study, we provide evidence that BLA is necessary for the synaptic strengthening occurring during memory formation in the cerebellum in rats. In the cerebellar vermis the parallel fibers (PF to Purkinje cell (PC synapse is potentiated one day following fear learning. Pretraining BLA inactivation impaired such a learning-induced long-term potentiation (LTP. Similarly, cerebellar LTP is affected when BLA is blocked shortly, but not 6 h, after training. The latter result shows that the effects of BLA inactivation on cerebellar plasticity, when present, are specifically related to memory processes and not due to an interference with sensory or motor functions. These data indicate that fear memory induces cerebellar LTP provided that a heterosynaptic input coming from BLA sets the proper local conditions. Therefore, in the cerebellum, learning-induced plasticity is a heterosynaptic phenomenon that requires inputs from other regions. Studies employing the electrically-induced LTP in order to clarify the cellular mechanisms of memory should therefore take into account the inputs arriving from other brain sites, considering them as integrative units. Based on previous and the present findings, we proposed that BLA enables learning-related plasticity to be formed in the cerebellum in order to respond appropriately to new stimuli or situations.

  8. Ammonia inhibits long-term potentiation via neurosteroid synthesis in hippocampal pyramidal neurons.

    Science.gov (United States)

    Izumi, Y; Svrakic, N; O'Dell, K; Zorumski, C F

    2013-03-13

    Neurosteroids are a class of endogenous steroids synthesized in the brain that are believed to be involved in the pathogenesis of neuropsychiatric disorders and memory impairment. Ammonia impairs long-term potentiation (LTP), a synaptic model of learning, in the hippocampus, a brain region involved in memory acquisition. Although mechanisms underlying ammonia-mediated LTP inhibition are not fully understood, we previously found that the activation of N-methyl-d-aspartate receptors (NMDARs) is important. Based on this, we hypothesize that metabolic stressors, including hyperammonemia, promote untimely NMDAR activation and result in neural adaptations that include the synthesis of allopregnanolone (alloP) and other GABA-potentiating neurosteroids that dampen neuronal activity and impair LTP and memory formation. Using an antibody against 5α-reduced neurosteroids, we found that 100 μM ammonia acutely enhanced neurosteroid immunostaining in pyramidal neurons in the CA1 region of rat hippocampal slices. The enhanced staining was blocked by finasteride, a selective inhibitor of 5α-reductase, a key enzyme required for alloP synthesis. Finasteride also overcame LTP inhibition by 100 μM ammonia, as did picrotoxin, an inhibitor of GABA-A receptors. These results indicate that GABA-enhancing neurosteroids, synthesized locally within pyramidal neurons, contribute significantly to ammonia-mediated synaptic dysfunction. These results suggest that the manipulation of neurosteroid synthesis could provide a strategy to improve cognitive function in individuals with hyperammonemia. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Overexpression of Protein Kinase Mζ in the Hippocampus Enhances Long-Term Potentiation and Long-Term Contextual But Not Cued Fear Memory in Rats.

    Science.gov (United States)

    Schuette, Sven R M; Fernández-Fernández, Diego; Lamla, Thorsten; Rosenbrock, Holger; Hobson, Scott

    2016-04-13

    The persistently active protein kinase Mζ (PKMζ) has been found to be involved in the formation and maintenance of long-term memory. Most of the studies investigating PKMζ, however, have used either putatively unselective inhibitors or conventional knock-out animal models in which compensatory mechanisms may occur. Here, we overexpressed an active form of PKMζ in rat hippocampus, a structure highly involved in memory formation, and embedded in several neural networks. We investigated PKMζ's influence on synaptic plasticity using electrophysiological recordings of basal transmission, paired pulse facilitation, and LTP and combined this with behavioral cognitive experiments addressing formation and retention of both contextual memory during aversive conditioning and spatial memory during spontaneous exploration. We demonstrate that hippocampal slices overexpressing PKMζ show enhanced basal transmission, suggesting a potential role of PKMζ in postsynaptic AMPAR trafficking. Moreover, the PKMζ-overexpressing slices augmented LTP and this effect was not abolished by protein-synthesis blockers, indicating that PKMζ induces enhanced LTP formation in a protein-synthesis-independent manner. In addition, we found selectively enhanced long-term memory for contextual but not cued fear memory, underlining the theory of the hippocampus' involvement in the contextual aspect of aversive reinforced tasks. Memory for spatial orientation during spontaneous exploration remained unaltered, suggesting that PKMζ may not affect the neural circuits underlying spontaneous tasks that are different from aversive tasks. In this study, using an overexpression strategy as opposed to an inhibitor-based approach, we demonstrate an important modulatory role of PKMζ in synaptic plasticity and selective memory processing. Most of the literature investigating protein kinase Mζ (PKMζ) used inhibitors with selectivity that has been called into question or conventional knock-out animal

  10. Developmental shift from long-term depression to long-term potentiation in the rat medial vestibular nuclei: role of group I metabotropic glutamate receptors.

    Science.gov (United States)

    Puyal, Julien; Grassi, Silvarosa; Dieni, Cristina; Frondaroli, Adele; Demêmes, Danielle; Raymond, Jaqueline; Pettorossi, Vito Enrico

    2003-12-01

    The effects of high frequency stimulation (HFS) of the primary vestibular afferents on synaptic transmission in the ventral part of the medial vestibular nuclei (vMVN) were studied during postnatal development and compared with the changes in the expression of the group I metabotropic glutamate receptor (mGluR) subtypes, mGluR1 and mGluR5. During the first stages of development, HFS always induced a mGluR5- and GABAA-dependent long-term depression (LTD) which did not require NMDA receptor and mGluR1 activation. The probability of inducing LTD decreased progressively throughout the development and it was zero at about the end of the second postnatal week. Conversely, long-term potentiation (LTP) appeared at the beginning of the second week and its occurrence increased to reach the adult value at the end of the third week. Of interest, the sudden change in the LTP frequency occurred at the time of eye opening, about the end of the second postnatal week. LTP depended on NMDA receptor and mGluR1 activation. In parallel with the modifications in synaptic plasticity, we observed that the expression patterns and localizations of mGluR5 and mGluR1 in the medial vestibular nuclei (MVN) changed during postnatal development. At the earlier stages the mGluR1 expression was minimal, then increased progressively. In contrast, mGluR5 expression was initially high, then decreased. While mGluR1 was exclusively localized in neuronal compartments and concentrated at the postsynaptic sites at all stages observed, mGluR5 was found mainly in neuronal compartments at immature stages, then preferentially in glial compartments at mature stages. These results provide the first evidence for a progressive change from LTD to LTP accompanied by a distinct maturation expression of mGluR1 and mGluR5 during the development of the MVN.

  11. The evidence for hippocampal long-term potentiation as a basis of memory for simple tasks

    Directory of Open Access Journals (Sweden)

    Iván Izquierdo

    2008-03-01

    Full Text Available Long-term potentiation (LTP is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally supported this hypothesis: a memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the same region; bhippocampal LTP in this region accompanies memory formation of that task and of another similar task. However, CA1 LTP and the accompanying memory processes can be dissociated, and in addition plastic events in several other brain regions(amygdala, entorhinal cortex, parietal cortex are also necessary for memory formation of the one-trial task, and perhaps of many others.A potenciação de longa duração (LTP é o aumento de respostas pós-sinápticas durante horas, dias ou semanas após a breve estimulação repetitiva de aferentes pre-sinápticos. Foi proposto durante 30 anos ser a base da memória de longa duração. Vários achados recentes finalmente apoiaram esta hipótese: a a formação da memória de esquiva inibitória adquirida numa sessão depende de uma cadeia de processos moleculares na região CA1 do hipocampo quase idêntica à da LTP nessa mesma região; b LTP hipocampal nessa região acompanha a formação da memóría dessa tarefa e de outra semelhante. No entanto, a LTP de CA1 e os processos de memória podem ser dissociados e, fora disso, processos plásticos em outras regiões cerebrais (amígdala, córtex entorrinal, córtex parietal também são necessários para a formação da memória da tarefa de uma sessão e talvez de muitas outras.

  12. Stimulus Intensity-dependent Modulations of Hippocampal Long-term Potentiation by Basolateral Amygdala Priming

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    Zexuan eLi

    2012-05-01

    Full Text Available There is growing realization that the relationship between memory and stress/emotionality is complicated, and may include both memory enhancing and memory impairing aspects. It has been suggested that the underlying mechanisms involve amygdalar modulation of hippocampal synaptic plasticity, such as long-term potentiation (LTP. We recently reported that while in CA1 basolateral amygdala (BLA priming impaired theta stimulation induced LTP, it enhanced LTP in the dentate gyrus (DG. However, emotional and stressfull experiences were found to activate synaptic plasticity within the BLA, rasing the possibility that BLA modulation of other brain regions may be altered as well, as it may depend on the way the BLA is activated or is responding. In previous studies BLA priming stimulation was relatively weak (1V, 50 µs pulse duration. In the present study we assessed the effects of two stronger levels of BLA priming stimulation (1V or 2V, 100 µs pulse duration on LTP induction in hippocampal DG and CA1, in anesthetized rats. Results show that 1V-BLA priming stimulation enhanced but 2V-BLA priming stimulation impaired DG LTP; however, both levels of BLA priming stimulation impaired CA1 LTP, suggesting that modulation of hippocampal synaptic plasticity by amygdala is dependent on the degree of amygdala activation. These findings suggest that plasticity induced within the amygdala, by stressful experiences induces a form of metaplasticity that would alter the way the amygdala may modulate memory-related processes in other brain areas, such as the hippocampus.

  13. Novel environments enhance the induction and maintenance of long-term potentiation in the dentate gyrus.

    Science.gov (United States)

    Davis, Cyndy D; Jones, Floretta L; Derrick, Brian E

    2004-07-21

    The induction of long-term potentiation (LTP) in the hippocampal formation can be modulated by different behavioral states. However, few studies have addressed modulation of LTP during behavioral states in which the animal is likely acquiring new information. Here, we demonstrate that both the induction and the longevity of LTP in the dentate gyrus are enhanced when LTP is induced during the initial exploration of a novel environment. These effects are independent from locomotor activity, changes in brain temperature, and theta rhythm. Previous exposure to the novel environment attenuated this enhancement, suggesting that the effects of novelty habituate with familiarity. LTP longevity also was enhanced when induced in familiar environments containing novel objects. Together, these data indicate that both LTP induction and maintenance are enhanced when LTP is induced while rats investigate novel stimuli. We suggest that novelty initiates a transition of the hippocampal formation to a mode that is particularly conducive to synaptic plasticity, a process that could allow for new learning while preserving the stability of previously stored information. In addition, LTP induced in novel environments elicited a sustained late LTP. This suggests that a single synaptic population can display distinct profiles of LTP maintenance and that this depends on the animal's behavioral state during its induction. Furthermore, the duration of LTP enhanced by novelty parallels the time period during which the hippocampal formation is thought necessary for memory, consistent with the view that dentate LTP is of a duration sufficient to sustain memory in the hippocampal formation.

  14. Gating of long-term potentiation by nicotinic acetylcholine receptors at the cerebellum input stage.

    Directory of Open Access Journals (Sweden)

    Francesca Prestori

    Full Text Available The brain needs mechanisms able to correlate plastic changes with local circuit activity and internal functional states. At the cerebellum input stage, uncontrolled induction of long-term potentiation or depression (LTP or LTD between mossy fibres and granule cells can saturate synaptic capacity and impair cerebellar functioning, which suggests that neuromodulators are required to gate plasticity processes. Cholinergic systems innervating the cerebellum are thought to enhance procedural learning and memory. Here we show that a specific subtype of acetylcholine receptors, the α7-nAChRs, are distributed both in cerebellar mossy fibre terminals and granule cell dendrites and contribute substantially to synaptic regulation. Selective α7-nAChR activation enhances the postsynaptic calcium increase, allowing weak mossy fibre bursts, which would otherwise cause LTD, to generate robust LTP. The local microperfusion of α7-nAChR agonists could also lead to in vivo switching of LTD to LTP following sensory stimulation of the whisker pad. In the cerebellar flocculus, α7-nAChR pharmacological activation impaired vestibulo-ocular-reflex adaptation, probably because LTP was saturated, preventing the fine adjustment of synaptic weights. These results show that gating mechanisms mediated by specific subtypes of nicotinic receptors are required to control the LTD/LTP balance at the mossy fibre-granule cell relay in order to regulate cerebellar plasticity and behavioural adaptation.

  15. Cytokines and cytokine networks target neurons to modulate long-term potentiation.

    Science.gov (United States)

    Prieto, G Aleph; Cotman, Carl W

    2017-04-01

    Cytokines play crucial roles in the communication between brain cells including neurons and glia, as well as in the brain-periphery interactions. In the brain, cytokines modulate long-term potentiation (LTP), a cellular correlate of memory. Whether cytokines regulate LTP by direct effects on neurons or by indirect mechanisms mediated by non-neuronal cells is poorly understood. Elucidating neuron-specific effects of cytokines has been challenging because most brain cells express cytokine receptors. Moreover, cytokines commonly increase the expression of multiple cytokines in their target cells, thus increasing the complexity of brain cytokine networks even after single-cytokine challenges. Here, we review evidence on both direct and indirect-mediated modulation of LTP by cytokines. We also describe novel approaches based on neuron- and synaptosome-enriched systems to identify cytokines able to directly modulate LTP, by targeting neurons and synapses. These approaches can test multiple samples in parallel, thus allowing the study of multiple cytokines simultaneously. Hence, a cytokine networks perspective coupled with neuron-specific analysis may contribute to delineation of maps of the modulation of LTP by cytokines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 12-lipoxygenase regulates hippocampal long-term potentiation by modulating L-type Ca2+ channels

    Science.gov (United States)

    DeCostanzo, Anthony J.; Voloshyna, Iryna; Rosen, Zev B.; Feinmark, Steven J.; Siegelbaum, Steven A.

    2010-01-01

    Although long-term potentiation (LTP) has been intensely studied, there is disagreement as to which molecules mediate and modulate LTP. This is partly due to the presence of mechanistically distinct forms of LTP that are induced by different patterns of stimulation and that depend on distinct Ca2+ sources. Here we report a novel role for the arachidonic acid-metabolizing enzyme 12-lipoxygenase (12-LO) in LTP at CA3-CA1 hippocampal synapses that is dependent on the pattern of tetanic stimulation. We find that 12-LO activity is required for the induction of LTP in response to a theta-burst stimulation (TBS) protocol, which depends on Ca2+ influx through both NMDA receptors and L-type voltage-gated Ca2+ channels. In contrast, LTP induced by 100 Hz tetanic stimulation, which requires Ca2+ influx through NMDA receptors but not L-type channels, does not require 12-LO. We find that 12-LO regulates LTP by enhancing postsynaptic somatodendritic Ca2+ influx through L-type channels during theta burst stimulation, an action exerted via 12(S)-HPETE, a downstream metabolite of 12-LO. These results help define the role of a long-disputed signaling enzyme in LTP. PMID:20130191

  17. Short-term plasticity and long-term potentiation mimicked in single inorganic synapses

    Science.gov (United States)

    Ohno, Takeo; Hasegawa, Tsuyoshi; Tsuruoka, Tohru; Terabe, Kazuya; Gimzewski, James K.; Aono, Masakazu

    2011-08-01

    Memory is believed to occur in the human brain as a result of two types of synaptic plasticity: short-term plasticity (STP) and long-term potentiation (LTP; refs , , , ). In neuromorphic engineering, emulation of known neural behaviour has proven to be difficult to implement in software because of the highly complex interconnected nature of thought processes. Here we report the discovery of a Ag2S inorganic synapse, which emulates the synaptic functions of both STP and LTP characteristics through the use of input pulse repetition time. The structure known as an atomic switch, operating at critical voltages, stores information as STP with a spontaneous decay of conductance level in response to intermittent input stimuli, whereas frequent stimulation results in a transition to LTP. The Ag2S inorganic synapse has interesting characteristics with analogies to an individual biological synapse, and achieves dynamic memorization in a single device without the need of external preprogramming. A psychological model related to the process of memorizing and forgetting is also demonstrated using the inorganic synapses. Our Ag2S element indicates a breakthrough in mimicking synaptic behaviour essential for the further creation of artificial neural systems that emulate characteristics of human memory.

  18. Discovering long-term potentiation (LTP) - recollections and reflections on what came after.

    Science.gov (United States)

    Lømo, T

    2018-02-01

    Chance events led me to a lifelong career in scientific research. They paved the way for being the first to see long-term potentiation of synaptic efficiency (LTP) in Per Andersen's laboratory in Oslo in 1966. Here I describe my way to this discovery and the experiments with Tim Bliss in 1968-1969 that led to Bliss and Lømo, 1973. Surprisingly, we later failed to reproduce these results. I discuss possible reasons for this failure, which made us both leave LTP research, in my case for good, in Tim's case for several years. After 30 years of work in a different field, I renewed my interest in the hippocampus and LTP in the early 2000s and published, for the first time, results that I had obtained 40 years earlier. Here I present my take on how interest in and research on LTP evolved after the early years. This includes a discussion of the functions of hippocampus as seen in those early days, the case of patient H.M., Donald Hebb's place in the story, the search for 'memory molecules' such as PKMζ, and the primary site for LTP expression (pre- and/or post-synaptic?). Throughout, I reflect on my life in science, how science is done and what drives it. The reflections are quite personal and I admit to mixed feelings about broadcasting them. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  19. Long-term potentiation in spinal nociceptive pathways as a novel target for pain therapy

    Directory of Open Access Journals (Sweden)

    Liu Xian-Guo

    2011-03-01

    Full Text Available Abstract Long-term potentiation (LTP in nociceptive spinal pathways shares several features with hyperalgesia and has been proposed to be a cellular mechanism of pain amplification in acute and chronic pain states. Spinal LTP is typically induced by noxious input and has therefore been hypothesized to contribute to acute postoperative pain and to forms of chronic pain that develop from an initial painful event, peripheral inflammation or neuropathy. Under this assumption, preventing LTP induction may help to prevent the development of exaggerated postoperative pain and reversing established LTP may help to treat patients who have an LTP component to their chronic pain. Spinal LTP is also induced by abrupt opioid withdrawal, making it a possible mechanism of some forms of opioid-induced hyperalgesia. Here, we give an overview of targets for preventing LTP induction and modifying established LTP as identified in animal studies. We discuss which of the various symptoms of human experimental and clinical pain may be manifestations of spinal LTP, review the pharmacology of these possible human LTP manifestations and compare it to the pharmacology of spinal LTP in rodents.

  20. Attenuation of hippocampal mossy fiber long-term potentiation by low micromolar concentrations of zinc.

    Science.gov (United States)

    Takeda, Atsushi; Kanno, Shingo; Sakurada, Naomi; Ando, Masaki; Oku, Naoto

    2008-10-01

    The role of zinc in long-term potentiation (LTP) at hippocampal mossy fiber synapses is controversial because of the contrary results obtained when using zinc chelators. On the basis of the postulation that exogenous zinc enhances the action of zinc released from mossy fibers, mossy fiber LTP after tetanic stimulation (100 Hz, 1 sec) was checked in the presence of exogenous zinc at low micromolar concentrations. Mossy fiber LTP was significantly attenuated in the presence of 5-30 microM ZnCl(2), and the amplitude of field excitatory postsynaptic potentials 60 min after tetanic stimulation was decreased to almost the basal level. Mossy fiber LTP was also attenuated in the presence of 5 microM ZnCl(2) 5 min after tetanic stimulation. The present study is the first to demonstrate that low micromolar concentrations of zinc attenuate mossy fiber LTP. When mossy fiber LTP was induced in the presence of CaEDTA and ZnAF-2 DA, a membrane-impermeable and a membrane-permeable zinc chelator, respectively, extracellular and intracellular chelation of zinc enhanced a transient posttetanic potentiation (PTP) without altering LTP. It is likely that zinc released by tetanic stimulation is immediately taken up into the mossy fibers and attenuates mossy fiber PTP. These results suggest that attenuation of PTP rather than LTP at mossy fiber synapses is a more physiological role for endogenous zinc. Targeting molecules of zinc in mossy fiber LTP seem to be different between during and after LTP induction because of the differential synaptic activity between them. (c) 2008 Wiley-Liss, Inc.

  1. Long-term potentiation protects rat hippocampal slices from the effects of acute hypoxia.

    Science.gov (United States)

    Youssef, F F; Addae, J I; McRae, A; Stone, T W

    2001-07-13

    We have previously shown that long-term potentiation (LTP) decreases the sensitivity of glutamate receptors in the rat hippocampal CA1 region to exogenously applied glutamate agonists. Since the pathophysiology of hypoxia/ischemia involves increased concentration of endogenous glutamate, we tested the hypothesis that LTP could reduce the effects of hypoxia in the hippocampal slice. The effects of LTP on hypoxia were measured by the changes in population spike potentials (PS) or field excitatory post-synaptic potentials (fepsps). Hypoxia was induced by perfusing the slice with (i) artificial CSF which had been pre-gassed with 95%N2/5% CO2; (ii) artificial CSF which had not been pre-gassed with 95% O2/5% CO2; or (iii) an oxygen-glucose deprived (OGD) medium which was similar to (ii) and in which the glucose had been replaced with sucrose. Exposure of a slice to a hypoxic medium for 1.5-3.0 min led to a decrease in the PS or fepsps; the potentials recovered to control levels within 3-5 min. Repeat exposure, 45 min later, of the same slice to the same hypoxic medium for the same duration as the first exposure caused a reduction in the potentials again; there were no significant differences between the degree of reduction caused by the first or second exposure for all three types of hypoxic media (P>0.05; paired t-test). In some of the slices, two episodes of LTP were induced 25 and 35 min after the first hypoxic exposure; this caused inhibition of reduction in potentials caused by the second hypoxic insult which was given at 45 min after the first; the differences in reduction in potentials were highly significant for all the hypoxic media used (Peffects of LTP were not prevented by cyclothiazide or inhibitors of NO synthetase compounds that have been shown to be effective in blocking the effects of LTP on the actions of exogenously applied AMPA and NMDA, respectively. The neuroprotective effects of LTP were similar to those of propentofylline, a known neuroprotective

  2. Reversal of long-term potentiation-like plasticity processes after motor learning disrupts skill retention.

    Science.gov (United States)

    Cantarero, Gabriela; Lloyd, Ashley; Celnik, Pablo

    2013-07-31

    Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlusion of LTP-like plasticity after learning, indicative of how much LTP was used to learn, is essential for retention. Here we provide supporting evidence of it in humans. Induction of LTP-like plasticity can be abolished using a depotentiation protocol (DePo) consisting of brief continuous theta burst stimulation. We used transcranial magnetic stimulation to assess whether application of DePo over M1 after motor learning affected (1) occlusion of LTP-like plasticity and (2) retention of motor skill learning. We found that the magnitude of motor memory retention is proportional to the magnitude of occlusion of LTP-like plasticity. Moreover, DePo stimulation over M1, but not over a control site, reversed the occlusion of LTP-like plasticity induced by motor learning and disrupted skill retention relative to control subjects. Altogether, these results provide evidence of a link between occlusion of LTP-like plasticity and retention and that this measure could be used as a biomarker to predict retention. Importantly, attempts to reverse the occlusion of LTP-like plasticity after motor learning comes with the cost of reducing retention of motor learning.

  3. Enhanced hippocampal long-term potentiation and fear memory in Btbd9 mutant mice.

    Directory of Open Access Journals (Sweden)

    Mark P DeAndrade

    Full Text Available Polymorphisms in BTBD9 have recently been associated with higher risk of restless legs syndrome (RLS, a neurological disorder characterized by uncomfortable sensations in the legs at rest that are relieved by movement. The BTBD9 protein contains a BTB/POZ domain and a BACK domain, but its function is unknown. To elucidate its function and potential role in the pathophysiology of RLS, we generated a line of mutant Btbd9 mice derived from a commercial gene-trap embryonic stem cell clone. Btbd9 is the mouse homolog of the human BTBD9. Proteins that contain a BTB/POZ domain have been reported to be associated with synaptic transmission and plasticity. We found that Btbd9 is naturally expressed in the hippocampus of our mutant mice, a region critical for learning and memory. As electrophysiological characteristics of CA3-CA1 synapses of the hippocampus are well characterized, we performed electrophysiological recordings in this region. The mutant mice showed normal input-output relationship, a significant impairment in pre-synaptic activity, and an enhanced long-term potentiation. We further performed an analysis of fear memory and found the mutant mice had an enhanced cued and contextual fear memory. To elucidate a possible molecular basis for these enhancements, we analyzed proteins that have been associated with synaptic plasticity. We found an elevated level of dynamin 1, an enzyme associated with endocytosis, in the mutant mice. These results suggest the first identified function of Btbd9 as being involved in regulating synaptic plasticity and memory. Recent studies have suggested that enhanced synaptic plasticity, analogous to what we have observed, in other regions of the brain could enhance sensory perception similar to what is seen in RLS patients. Further analyses of the mutant mice will help shine light on the function of BTBD9 and its role in RLS.

  4. Enhanced hippocampal long-term potentiation and fear memory in Btbd9 mutant mice.

    Science.gov (United States)

    DeAndrade, Mark P; Zhang, Li; Doroodchi, Atbin; Yokoi, Fumiaki; Cheetham, Chad C; Chen, Huan-Xin; Roper, Steven N; Sweatt, J David; Li, Yuqing

    2012-01-01

    Polymorphisms in BTBD9 have recently been associated with higher risk of restless legs syndrome (RLS), a neurological disorder characterized by uncomfortable sensations in the legs at rest that are relieved by movement. The BTBD9 protein contains a BTB/POZ domain and a BACK domain, but its function is unknown. To elucidate its function and potential role in the pathophysiology of RLS, we generated a line of mutant Btbd9 mice derived from a commercial gene-trap embryonic stem cell clone. Btbd9 is the mouse homolog of the human BTBD9. Proteins that contain a BTB/POZ domain have been reported to be associated with synaptic transmission and plasticity. We found that Btbd9 is naturally expressed in the hippocampus of our mutant mice, a region critical for learning and memory. As electrophysiological characteristics of CA3-CA1 synapses of the hippocampus are well characterized, we performed electrophysiological recordings in this region. The mutant mice showed normal input-output relationship, a significant impairment in pre-synaptic activity, and an enhanced long-term potentiation. We further performed an analysis of fear memory and found the mutant mice had an enhanced cued and contextual fear memory. To elucidate a possible molecular basis for these enhancements, we analyzed proteins that have been associated with synaptic plasticity. We found an elevated level of dynamin 1, an enzyme associated with endocytosis, in the mutant mice. These results suggest the first identified function of Btbd9 as being involved in regulating synaptic plasticity and memory. Recent studies have suggested that enhanced synaptic plasticity, analogous to what we have observed, in other regions of the brain could enhance sensory perception similar to what is seen in RLS patients. Further analyses of the mutant mice will help shine light on the function of BTBD9 and its role in RLS.

  5. The potential benefits of a new poliovirus vaccine for long-term poliovirus risk management.

    Science.gov (United States)

    Duintjer Tebbens, Radboud J; Thompson, Kimberly M

    2016-12-01

    To estimate the incremental net benefits (INBs) of a hypothetical ideal vaccine with all of the advantages and no disadvantages of existing oral and inactivated poliovirus vaccines compared with current vaccines available for future outbreak response. INB estimates based on expected costs and polio cases from an existing global model of long-term poliovirus risk management. Excluding the development costs, an ideal poliovirus vaccine could offer expected INBs of US$1.6 billion. The ideal vaccine yields small benefits in most realizations of long-term risks, but great benefits in low-probability-high-consequence realizations. New poliovirus vaccines may offer valuable insurance against long-term poliovirus risks and new vaccine development efforts should continue as the world gathers more evidence about polio endgame risks.

  6. Correlating learning and memory improvements to long-term potentiation in patients with brain injury

    Institute of Scientific and Technical Information of China (English)

    Xingfu Peng; Qian Yu

    2008-01-01

    BACKGROUND:Brain injury patients often exhibit learning and memory functional deficits.Long-term potentiation(LTP)is a representative index for studying learning and memory cellular models; the LTP index correlates to neural plasticity. OBJECTIVE:This study was designed to investigate correlations of learning and memory functions to LTP in brain injury patients,and to summarize the research advancements in mechanisms underlying brain functional improvements after rehabilitation intervention. RETRIEVAL STRATEGY:Using the terms "brain injuries,rehabilitation,learning and memory,long-term potentiation",manuscripts that were published from 2000-2007 were retrieved from the PubMed database.At the same time,manuscripts published from 2000-2007 were also retrieved from the Database of Chinese Scientific and Technical Periodicals with the same terms in the Chinese language.A total of 64 manuscripts were obtained and primarily screened.Inclusion criteria:studies on learning and memory,as well as LTP in brain injury patients,and studies focused on the effects of rehabilitation intervention on the two indices; studies that were recently published or in high-impact journals.Exclusion criteria:repetitive studies.LITERATURE EVALUATION:The included manuscripts primarily focused on correlations between learning and memory and LTP,the effects of brain injury on learning and memory,as well as LTP,and the effects of rehabilitation intervention on learning and memory after brain injury.The included 39 manuscripts were clinical,basic experimental,or review studies. DATA SYNTHESIS:Learning and memory closely correlates to LTP.The neurobiological basis of learning and memory is central nervous system plasticity,which involves neural networks,neural circuits,and synaptic connections,in particular,synaptic plasticity.LTP is considered to be an ideal model for studying synaptic plasticity,and it is also a classic model for studying neural plasticity of learning and memory.Brain injury

  7. Conditioned taste aversion modifies persistently the subsequent induction of neocortical long-term potentiation in vivo.

    Science.gov (United States)

    Rodríguez-Durán, Luis F; Castillo, Diana V; Moguel-González, Minerva; Escobar, Martha L

    2011-05-01

    The ability of neurons to modify their synaptic strength in an activity-dependent manner has a crucial role in learning and memory processes. It has been proposed that homeostatic forms of plasticity might provide the global regulation necessary to maintain synaptic strength and plasticity within a functional dynamic range. Similarly, it is considered that the capacity of synapses to express plastic changes is itself subject to variation dependent on previous experience. In particular, training in several behavioral tasks modifies the possibility to induce long-term potentiation (LTP). Our previous studies in the insular cortex (IC) have shown that induction of LTP in the basolateral amygdaloid nucleus (Bla)-IC projection previous to conditioned taste aversion (CTA) training enhances the retention of this task. The aim of the present study was to analyze whether CTA training modifies the ability to induce subsequent LTP in the Bla-IC projection in vivo. Thus, CTA trained rats received high frequency stimulation in the Bla-IC projection in order to induce LTP 48, 72, 96 and 120 h after the aversion test. Our results show that CTA training prevents the subsequent induction of LTP in the Bla-IC projection, for at least 120 h after CTA training. We also showed that pharmacological inhibition of CTA consolidation with anisomycin (1 μl/side; 100 μg/μl) prevents the CTA effect on IC-LTP. These findings reveal that CTA training produces a persistent change in the ability to induce subsequent LTP in the Bla-IC projection in a protein-synthesis dependent manner, suggesting that changes in the ability to induce subsequent synaptic plasticity contribute to the formation and persistence of aversive memories. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Pharmacological Modulation of Long-Term Potentiation-Like Activity in the Dorsolateral Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    Bahar Salavati

    2018-04-01

    Full Text Available Background: Long-term potentiation (LTP depends on glutamatergic neurotransmission and is modulated by cholinergic, dopaminergic and GABAergic inputs. Paired associative stimulation (PAS is a neurostimulation paradigm that, when combined with electroencephalography (EEG, assesses LTP-like activity (PAS-induced LTP in the dorsolateral prefrontal cortex (DLPFC. Thus, we conducted a study to assess the role of cholinergic, dopaminergic, GABAergic and glutamatergic neurotransmission on PAS-induced LTP in the DLPFC. We hypothesized that increasing the dopaminergic tone with L-DOPA and the cholinergic tone with rivastigmine will enhance PAS-induced LTP, while increasing the GABAergic tone with baclofen and inhibiting glutamatergic neurotransmission with dextromethorphan will reduce it compared to placebo.Methods: In this randomized controlled, double-blind cross-over within-subject study, 12 healthy participants received five sessions of PAS to the DLPFC in a random order, each preceded by the administration of placebo or one of the four active drugs. PAS-induced LTP was assessed after each drug administration and compared to PAS-induced LTP after placebo.Results: As predicted, L-DOPA and rivastigmine resulted in enhanced PAS-induced LTP in the DLPFC and dextromethorphan inhibited it compared to placebo. In contrast, baclofen did not significantly suppress PAS-induced LTP compared to placebo.Conclusions: This study provides a novel approach to study DLPFC neuroplasticity and its modulation in patients with brain disorders that are associated with abnormalities in these neurochemical systems. This study was based on a single dose administration of each drug. Given that these drugs are typically administered chronically, future studies should assess the effects of chronic administration.

  9. Potential long-term storage of the predatory mite Phytoseiulus persimilis

    Science.gov (United States)

    Increasing the ability to store mass-reared natural enemies during periods or seasons of low demand is a critical need of the biocontrol industry. We tested the hypothesis that cryoprotectant or carbohydrate molecules can enhance long-term cold storage of a predatory mite Phytoseiulus persimilis At...

  10. Potentials of short term and long term cryopreserved sperm of the ...

    African Journals Online (AJOL)

    To service the growing demand for male African giant catfish (Clarias gariepinus) broodstock for aquaculture in Nigeria, and to conserve valuable genetic resources, we improved both short-term (in deep freezer at -35°C) and long-term cryopreservation (in liquid nitrogen at -296°C) of catfish sperm. Catfish sperm ...

  11. Long-term aerosol climatology over Indo-Gangetic Plain: Trend, prediction and potential source fields

    Science.gov (United States)

    Kumar, M.; Parmar, K. S.; Kumar, D. B.; Mhawish, A.; Broday, D. M.; Mall, R. K.; Banerjee, T.

    2018-05-01

    Long-term aerosol climatology is derived using Terra MODIS (Collection 6) enhanced Deep Blue (DB) AOD retrieval algorithm to investigate decadal trend (2006-2015) in columnar aerosol loading, future scenarios and potential source fields over the Indo-Gangetic Plain (IGP), South Asia. Satellite based aerosol climatology was analyzed in two contexts: for the entire IGP considering area weighted mean AOD and for nine individual stations located at upper (Karachi, Multan, Lahore), central (Delhi, Kanpur, Varanasi, Patna) and lower IGP (Kolkata, Dhaka). A comparatively high aerosol loading (AOD: 0.50 ± 0.25) was evident over IGP with a statistically insignificant increasing trend of 0.002 year-1. Analysis highlights the existing spatial and temporal gradients in aerosol loading with stations over central IGP like Varanasi (decadal mean AOD±SD; 0.67 ± 0.28) and Patna (0.65 ± 0.30) exhibit the highest AOD, followed by stations over lower IGP (Kolkata: 0.58 ± 0.21; Dhaka: 0.60 ± 0.24), with a statistically significant increasing trend (0.0174-0.0206 year-1). In contrast, stations over upper IGP reveal a comparatively low aerosol loading, having an insignificant increasing trend. Variation in AOD across IGP is found to be mainly influenced by seasonality and topography. A distinct "aerosol pool" region over eastern part of Ganges plain is identified, where meteorology, topography, and aerosol sources favor the persistence of airborne particulates. A strong seasonality in aerosol loading and types is also witnessed, with high AOD and dominance of fine particulates over central to lower IGP, especially during post-monsoon and winter. The time series analyses by autoregressive integrated moving average (ARIMA) indicate contrasting patterns in randomness of AOD over individual stations with better performance especially over central IGP. Concentration weighted trajectory analyses identify the crucial contributions of western dry regions and partial contributions from

  12. Base cation depletion and potential long-term acidification of Norwegian catchments

    International Nuclear Information System (INIS)

    Kirchner, J.W.; Lydersen, E.

    1995-01-01

    Long-term monitoring data from Norwegian catchments show that since the late 1970s, sulfate deposition and runoff sulfate concentrations have declined significantly. However, water quality has not significantly improved, because reductions in runoff sulfate have been matched by equal declines in calcium and magnesium concentrations. Long-term declines in runoff Ca and Mg are most pronounced at catchments subject to highly acidic deposition; the observed rates of decline are quantitatively consistent with depletion of exchangeable bases by accelerated leaching under high acid loading. Even though water quality has not recovered, reductions in acid deposition have been valuable because they have prevented significant acidification that would otherwise have occurred under constant acid deposition. Ongoing depletion of exchangeable bases from these catchments implies that continued deposition reductions will be needed to avoid further acidification and that recovery from acidification will be slow. 31 refs., 2 figs., 4 tabs

  13. The potential impact of urban growth simulation on the long-term planning of our cities

    CSIR Research Space (South Africa)

    Waldeck, L

    2012-10-01

    Full Text Available of urban growth simulation on the long-term planning of our cities 4th Biennial Conference Presented by: Dr Louis Waldeck Date: 10 October 2012 Slide 2 of 17 Why Urban Growth Simulation? ? Reduced carbon footprint ? Reduce resource consumption... of the population concentrated in cities and the opportunities to gain efficiencies, cities are the most important arena for intervention.? Maurice Strong Unabated urbanisation Quest for sustainable development What makes a city sustainable? Slide 3 of 17...

  14. Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions.

    Science.gov (United States)

    Ellingsen, Kari E; Yoccoz, Nigel G; Tveraa, Torkild; Hewitt, Judi E; Thrush, Simon F

    2017-10-30

    The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability of data. In Norway, the authorities require environmental monitoring of the impacts of the offshore petroleum industry on the Norwegian continental shelf, and in 1996, a large-scale regional environmental monitoring program was established. As a case study, we used a sub-set of data from this monitoring to explore concepts regarding best practices for long-term environmental monitoring. Specifically, we examined data from physical and chemical sediment samples and benthic macroinvertebrate assemblages from 11 stations from six sampling occasions during the period 1996-2011. Despite the established quality assessment and quality control protocols for this monitoring program, we identified several data challenges, such as missing values and outliers, discrepancies in variable and station names, changes in procedures without calibration, and different taxonomic resolution. Furthermore, we show that the use of different laboratories over time makes it difficult to draw conclusions with regard to some of the observed changes. We offer recommendations to facilitate comparison of data over time. We also present a new procedure to handle different taxonomic resolution, so valuable historical data is not discarded. These topics have a broader relevance and application than for our case study.

  15. A Protein Synthesis and Nitric Oxide-Dependent Presynaptic Enhancement in Persistent Forms of Long-Term Potentiation

    Science.gov (United States)

    Johnstone, Victoria P. A.; Raymond, Clarke R.

    2011-01-01

    Long-term potentiation (LTP) is an important process underlying learning and memory in the brain. At CA3-CA1 synapses in the hippocampus, three discrete forms of LTP (LTP1, 2, and 3) can be differentiated on the basis of maintenance and induction mechanisms. However, the relative roles of pre- and post-synaptic expression mechanisms in LTP1, 2,…

  16. Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn

    Science.gov (United States)

    Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emis-sions, and global warming potential (GWP) in irrigated systems, however,...

  17. Human sensory Long-Term Potentiation (LTP) predicts visual memory performance and is modulated by the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism

    OpenAIRE

    King, Rohan; Moreau, David; Russell, Bruce; Kirk, Ian; Wu, Carolyn; Antia, Ushtana; Lamb, Yvette; Spriggs, Meg; Thompson, Chris; Mckay, Nicole; Shelling, Andrew; Waldie, Karen; Teyler, Tim; Hamm, Jeff; Mcnair, Nicolas

    2018-01-01

    Background: Long-Term Potentiation (LTP) is recognised as a core neuronal process underlying long-term memory. However, a direct relationship between LTP and human memory performance is yet to be demonstrated. The first aim of the current study was thus to assess the relationship between LTP and human long-term memory performance. With this also comes an opportunity to explore factors thought to mediate the relationship between LTP and long-term memory, and to gain additional insight into var...

  18. A systematic review of potential long-term effects of sport-related concussion.

    Science.gov (United States)

    Manley, Geoff; Gardner, Andrew J; Schneider, Kathryn J; Guskiewicz, Kevin M; Bailes, Julian; Cantu, Robert C; Castellani, Rudolph J; Turner, Michael; Jordan, Barry D; Randolph, Christopher; Dvořák, Jiří; Hayden, K Alix; Tator, Charles H; McCrory, Paul; Iverson, Grant L

    2017-06-01

    Systematic review of possible long-term effects of sports-related concussion in retired athletes. Ten electronic databases. Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as > 10 years after the injury. Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. A systematic review of potential long-term effects of sport-related concussion

    Science.gov (United States)

    Gardner, Andrew J; Schneider, Kathryn J; Guskiewicz, Kevin M; Bailes, Julian; Cantu, Robert C; Castellani, Rudolph J; Turner, Michael; Jordan, Barry D; Randolph, Christopher; Dvořák, Jiří; Hayden, K. Alix; Tator, Charles H; McCrory, Paul; Iverson, Grant L

    2017-01-01

    Objective Systematic review of possible long-term effects of sports-related concussion in retired athletes. Data sources Ten electronic databases. Study selection Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as >10 years after the injury. Data extraction Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. Results Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. Conclusion Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports. PMID:28455362

  20. Spectral model for long-term computation of thermodynamics and potential evaporation in shallow wetlands

    Science.gov (United States)

    de la Fuente, Alberto; Meruane, Carolina

    2017-09-01

    Altiplanic wetlands are unique ecosystems located in the elevated plateaus of Chile, Argentina, Peru, and Bolivia. These ecosystems are under threat due to changes in land use, groundwater extractions, and climate change that will modify the water balance through changes in precipitation and evaporation rates. Long-term prediction of the fate of aquatic ecosystems imposes computational constraints that make finding a solution impossible in some cases. In this article, we present a spectral model for long-term simulations of the thermodynamics of shallow wetlands in the limit case when the water depth tends to zero. This spectral model solves for water and sediment temperature, as well as heat, momentum, and mass exchanged with the atmosphere. The parameters of the model (water depth, thermal properties of the sediments, and surface albedo) and the atmospheric downscaling were calibrated using the MODIS product of the land surface temperature. Moreover, the performance of the daily evaporation rates predicted by the model was evaluated against daily pan evaporation data measured between 1964 and 2012. The spectral model was able to correctly represent both seasonal fluctuation and climatic trends observed in daily evaporation rates. It is concluded that the spectral model presented in this article is a suitable tool for assessing the global climate change effects on shallow wetlands whose thermodynamics is forced by heat exchanges with the atmosphere and modulated by the heat-reservoir role of the sediments.

  1. Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training

    OpenAIRE

    Shields, Richard K.; Dudley-Javoroski, Shauna; Littmann, Andrew E.

    2006-01-01

    Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potent...

  2. Local establishment of repetitive long-term potentiation-induced synaptic enhancement in cultured hippocampal slices with divided input pathways.

    Science.gov (United States)

    Oe, Yuki; Tominaga-Yoshino, Keiko; Ogura, Akihiko

    2011-09-01

    Long-term potentiation (LTP) in the rodent hippocampus is a popular model for synaptic plasticity, which is considered the cellular basis for brain memory. Because most LTP analysis involves acutely prepared brain slices, however, the longevity of single LTP has not been well documented. Using stable hippocampal slice cultures for long-term examination, we previously found that single LTP disappeared within 1 day. In contrast, repeated induction of LTP led to the development of a distinct type of plasticity that lasted for more than 3 weeks and was accompanied by the formation of new synapses. Naming this novel plastic phenomenon repetitive LTP-induced synaptic enhancement (RISE), we proposed it as a model for the cellular processes involved in long-term memory formation. However, because in those experiments LTP was induced pharmacologically in the whole slice, it is not known whether RISE has input-pathway specificity, an essential property for memory. In this study, we divided the input pathway of CA1 pyramidal neurons by a knife cut and induced LTP three times, the third by tetanic stimulation in one of the divided pathways to express RISE specifically. Voltage-sensitive dye imaging and Golgi-staining performed 2 weeks after the three LTP inductions revealed both enhanced synaptic strength and increased dendritic spine density confined to the tetanized region. These results demonstrate that RISE is a feasible cellular model for long-term memory. Copyright © 2011 Wiley-Liss, Inc.

  3. Deliberating and communicating the potential of fusion power based on long-term foresight knowledge

    International Nuclear Information System (INIS)

    Laes, E.; Bombaerts, G.

    2006-01-01

    Aim This paper is based on research performed for EFDA under the SERF programme (Task TW5-TRE/FESO/A). The main aim of this contribution is to provide guidance (in terms of quality criteria) for setting up foresight exercises as a platform for discussion of the benefits and drawbacks of fusion with a broad range of stake holders. At the same time, we explore conditions that might enhance the resonance of such foresight exercises in the policy sphere. Method This paper starts from a fundamental paradox in foresight studies. On the one hand, foresight falls beyond the domain of 'traditional science', since the results of foresight exercises cannot be tested empirically against 'hard facts'. However, on the other hand, the organisations funding such exercises of course do this with the aim to improve their knowledge about the future, in view of making 'better decisions' or at least stimulating a discussion and/or creating awareness for the goals and problem definition(s) that the organisations have set for themselves. Therefore, the question is: '' How can we assess the quality of knowledge embedded in foresight exercises and its implications for policy making? ''. Starting from this central question, we first introduce a (probably somewhat unfamiliar) philosophical framework called 'constructivism'. Next, we give a constructivist reading of scientific foresight as a combined scientific-political practice and point out some of the main points of interest regarding the relationship between foresight knowledge and policy. We illustrate these points of interest with practical case-study examples. Finally, we draw upon our theoretical and case-study research to propose a methodology for developing long-term energy scenarios, and we give some practical recommendations on using long-term energy foresight exercises as a platform for communication with wider audiences. Achievements This paper proposes an architecture for integrating foresight in a complex policy setting based

  4. Deliberating and communicating the potential of fusion power based on long-term foresight knowledge

    International Nuclear Information System (INIS)

    Laes, Erik; Bombaerts, Gunter

    2007-01-01

    The main aim of this contribution is to provide guidance (in terms of quality criteria) for setting up foresight exercises as a platform for discussion and communication of the benefits and drawbacks of fusion with a broad range of stakeholders. At the same time, we explore conditions that might enhance the resonance of such foresight exercises in the policy sphere. In order to address this dual aim, we first introduce a philosophical framework called 'constructivism'. Next, we give a constructivist reading of scientific foresight as a combined scientific-political practice and point out some of the main points of interest regarding the relationship between foresight knowledge and policy. We illustrate these points of interest with practical case-study examples. Finally, we draw upon our theoretical and case-study research to propose some points of particular interest for the fusion community wishing to develop long-term energy scenarios

  5. Potentials for energy savings and long term energy demands for Croatian households sector

    DEFF Research Database (Denmark)

    Pukšec, Tomislav; Mathiesen, Brian Vad; Duic, Neven

    2011-01-01

    demand in the future, based on careful and rational energy planning. Different financial, legal and technological mechanisms can lead to significant savings in the households sector which also leads to lesser greenhouse gas emissions and lower Croatian dependence on foreign fossil fuels....... relevant. In order to plan future energy systems it is important to know future possibilities and needs regarding energy demand for different sectors. Through this paper long term energy demand projections for Croatian households sector will be shown with a special emphasis on different mechanisms, both...... financial, legal but also technological that will influence future energy demand scenarios. It is important to see how these mechanisms influence, positive or negative, on future energy demand and which mechanism would be most influential. Energy demand predictions in this paper are based upon bottom...

  6. Potentials for energy savings and long term energy demands for Croatian households sector

    DEFF Research Database (Denmark)

    Pukšec, Tomislav; Mathiesen, Brian Vad; Duic, Neven

    2013-01-01

    demand in the future, based on careful and rational energy planning. Different financial, legal and technological mechanisms can lead to significant savings in the households sector which also leads to lesser greenhouse gas emissions and lower Croatian dependence on foreign fossil fuels....... relevant. In order to plan future energy systems it is important to know future possibilities and needs regarding energy demand for different sectors. Through this paper long term energy demand projections for Croatian households sector will be shown with a special emphasis on different mechanisms, both...... financial, legal but also technological that will influence future energy demand scenarios. It is important to see how these mechanisms influence, positive or negative, on future energy demand and which mechanism would be most influential. Energy demand predictions in this paper are based upon bottom...

  7. Deliberating and communicating the potential of fusion power based on long-term foresight knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Laes, Erik [SCK-CEN - Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium)], E-mail: erik.laes@sckcen.be; Bombaerts, Gunter [SCK-CEN - Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); UGent (Ghent University) (Belgium)

    2007-10-15

    The main aim of this contribution is to provide guidance (in terms of quality criteria) for setting up foresight exercises as a platform for discussion and communication of the benefits and drawbacks of fusion with a broad range of stakeholders. At the same time, we explore conditions that might enhance the resonance of such foresight exercises in the policy sphere. In order to address this dual aim, we first introduce a philosophical framework called 'constructivism'. Next, we give a constructivist reading of scientific foresight as a combined scientific-political practice and point out some of the main points of interest regarding the relationship between foresight knowledge and policy. We illustrate these points of interest with practical case-study examples. Finally, we draw upon our theoretical and case-study research to propose some points of particular interest for the fusion community wishing to develop long-term energy scenarios.

  8. Potentials for energy savings and long term energy demand of Croatian households sector

    International Nuclear Information System (INIS)

    Pukšec, Tomislav; Vad Mathiesen, Brian; Duić, Neven

    2013-01-01

    Highlights: ► Long term energy demand of Croatian households sector has been modelled. ► Developed model can describe the whole households sector. ► Main modes include heating, cooling, electrical appliances, cooking and hot water. ► Different scenarios regarding future energy demand are presented and discussed. -- Abstract: Households represent one of the most interesting sectors, when analyzing Croatia’s energy balance. It makes up one of the largest energy consumers with around 75 PJ per year, which is almost 29% of Croatia’s final energy demand. Considering this consumption, implementing various mechanisms, which would lead to improvements in energy efficiency of this sector, seems relevant. In order to plan future energy systems, important would be to know future possibilities and needs regarding energy demand of different sectors. Through this paper, long term energy demand projections of Croatian households sector will be shown. Focus of the paper will be on various mechanisms influencing future energy demand scenarios. Important would be to quantify this influence, whether positive or negative, and see which mechanisms would be the most significant. Energy demand projections in this paper are based upon bottom-up approach model which combines and processes a large number of input data. The model will be compared to Croatian National Energy Strategy and certain differences and conclusions will be presented. One of the major conclusions shown in this paper is significant possibilities for energy efficiency improvements and lower energy demand in the future, based on careful and rational energy planning. Different financial, legal and technological mechanisms can lead to significant savings in the households sector which leads to lower GHG emissions and lower Croatian dependence on foreign fossil fuels.

  9. A comparative study of long-term energy demand and potential greenhouse gas emission control in Bangladesh

    International Nuclear Information System (INIS)

    Khalaquazzaman, Mohammad

    2005-02-01

    This report presents a comparative study of long-term energy demand and potential greenhouse gas emissions projections from energy demand and supply sectors in Bangladesh covering the period 2000 to 2020. The study was conducted employing the IAEA's tool ENPEP- BALANCE model. This study presents a reliable energy system plan with minimal carbon emission for the country. Primary energy demands distributed by energy carriers and electricity demand have been projected based on macro-economic growth scenarios constructed for national energy policy of 1996. The conservation of indigenous energy resources was emphasized to build a long-term secured energy supply system. The potential energy supply options including nuclear energy and prospective greenhouse gas mitigation options were analyzed

  10. Net sulfur mineralization potential in Swedish arable soils in relation to long-term treatment history and soil properties

    DEFF Research Database (Denmark)

    Boye, Kristin; Nilsson, S Ingvar; Eriksen, Jørgen

    2009-01-01

    accumulated net S mineralization (SAccMin) and a number of soil physical and chemical properties were determined. Treatments and soil differences in SAccMin, as well as correlations with soil variables, were tested with single and multivariate analyses. Long-term FYM application resulted in a significantly (p......The long-term treatment effect (since 1957-1966) of farmyard manure (FYM) application compared with crop residue incorporation was investigated in five soils (sandy loam to silty clay) with regards to the net sulfur (S) mineralization potential. An open incubation technique was used to determine...... = 0.012) higher net S mineralization potential, although total amounts of C, N, and S were not significantly (p soils within this treatment. The measured soil variables were not significantly correlated...

  11. Oral administration of fisetin promotes the induction of hippocampal long-term potentiation in vivo

    OpenAIRE

    Wen-bin He; Kazuho Abe; Tatsuhiro Akaishi

    2018-01-01

    To explore memory enhancing effect of the flavonoid fisetin, we investigated the effect of oral administration of flavonoids on the induction of long-term potentiation (LTP) at hippocampal CA1 synapses of anesthetized rats. Among four flavonoids (fisetin, quercetin, luteolin and myricetin) tested, only fisetin significantly facilitated the induction of hippocampal LTP. The effect of oral fisetin was abolished by intracerebroventricular injection of U0126, an agent that was previously found to...

  12. Long-term characterization of residential runoff and assessing potential surrogates of fecal indicator organisms.

    Science.gov (United States)

    Reano, Dane C; Haver, Darren L; Oki, Lorence R; Yates, Marylynn V

    2015-05-01

    Investigations into the microbiological impacts of urban runoff on receiving water bodies, especially during storm conditions, have yielded general paradigms that influence runoff abatement and control management strategies. To determine whether these trends are present in other runoff sources, the physical, chemical, and microbiological components of residential runoff from eight neighborhoods in Northern and Southern California were characterized over the course of five years. Sampling occurred regularly and during storm events, resulting in 833 data sets. Analysis of runoff data assisted in characterizing residential runoff, elucidating differences between dry and storm conditions, and identifying surrogates capable of assessing microbiological quality. Results indicate that although microbial loading increases during storm events similar to urban runoff, annual microbial loading in these study sites principally occurs during dry conditions (24% storm, 76% dry). Generated artificial neural network and multiple linear regression models assessed surrogate performance by accurately predicting Escherichia coli concentrations from validation data sets (R(2) = 0.74 and 0.77, respectively), but required input from other fecal indicator organism (FIO) variables to maintain performance (R(2) = 0.27 and 0.18, respectively, without FIO). This long-term analysis of residential runoff highlights characteristics distinct from urban runoff and establishes necessary variables for determining microbiological quality, thus better informing future management strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Hypoxia-Induced neonatal seizures diminish silent synapses and long-term potentiation in hippocampal CA1 neurons

    Science.gov (United States)

    Zhou, Chengwen; Bell, Jocelyn J. Lippman; Sun, Hongyu; Jensen, Frances E.

    2012-01-01

    Neonatal seizures can lead to epilepsy and long-term cognitive deficits in adulthood. Using a rodent model of the most common form of human neonatal seizures, hypoxia-induced seizures (HS), we aimed to determine whether these seizures modify long-term potentiation (LTP) and “silent” N-methyl-D-aspartate receptor (NMDAR)-only synapses in hippocampal CA1. At 48-72 hours (hrs) post-HS, electrophysiology and immunofluorescent confocal microscopy revealed a significant decrease in the incidence of silent synapses, and an increase in amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) at the synapses. Coincident with this decrease in silent synapses, there was an attenuation of LTP elicited by either tetanic stimulation of Schaffer collaterals or a pairing protocol, and persistent attenuation of LTP in slices removed in later adulthood after P10 HS. Furthermore, post-seizure treatment in vivo with the AMPAR antagonist 2,3-dihydroxy-6-nitro-7-sulfonyl-benzo[f]quinoxaline (NBQX) protected against the HS-induced depletion of silent synapses and preserved LTP. Thus, this study demonstrates a novel mechanism by which early-life seizures could impair synaptic plasticity, suggesting a potential target for therapeutic strategies to prevent long-term cognitive deficits. PMID:22171027

  14. PKMζ inhibition prevents the metaplastic change induced by conditioned taste aversion on insular cortex long-term potentiation in vivo.

    Science.gov (United States)

    Ángeles-Durán, Sandybel; Ramos-Languren, Laura E; Escobar, Martha L

    2012-01-01

    The activity history of a given neuron or pathway has been suggested to influence its future responses to synaptic inputs. In particular, training in several learning tasks produces a metaplastic change, that is, a change in the ability to induce subsequent synaptic plasticity. Experimental evidence shows that the maintenance of long term memory and long-term potentiation (LTP) requires the persistent action of the atypical protein kinase Cisoform, protein kinase M ζ (PKM ζ ). Recent work has demonstrated that the inactivation of PKM ζ in the insular cortex (IC) abolishes conditioned taste aversion (CTA) long term memory. Our previous studies in the IC have demonstrated that the induction of LTP in the basolateral amygdaloid nucleus (Bla)-IC projection previous to CTA training enhances the retention of this task. Moreover, recently, we have observed that CTA training blocks the subsequent induction of LTP in the Bla-IC projection. The aim of the present study was to investigate the participation of PKM ζon the CTA-dependent modification of the ability to induce subsequent LTP in the Bla-IC projection in vivo . Thus, we have delivered high-frequency stimulation in the Bla-IC projection in order to induce in vivo IC-LTP in the rats that underwent or did not have an impairment of CTA retention due to the intracortical administration of the selective PKM ζ pseudosubstrate inhibitory peptide, ZIP. Our results show that the microinfusion of ZIP into the IC of the behaving rats impairs long-term memory of CTA and prevents its effects on IC-LTP. These results indicate that PKM ζ is a key component of the cellular mechanisms necessary for the persistence of lasting memory traces as well as for those underlying metaplastic changes in neocortex, contributing to the persistence of aversive memories.

  15. Alterations in synaptic curvature in the dentate gyrus following induction of long-term potentiation, long-term depression, and treatment with the N-methyl-D-aspartate receptor antagonist CPP

    Czech Academy of Sciences Publication Activity Database

    Medvedev, N. I.; Popov, V. I.; Dallerac, G.; Davies, H.A.; Laroche, S.; Kraev, I. V.; Rodríguez Arellano, Jose Julio; Doyere, V.; Stewart, M.G.

    2010-01-01

    Roč. 171, č. 2 (2010), s. 390-397 ISSN 0306-4522 Institutional research plan: CEZ:AV0Z50390703 Keywords : D synaptic ultrastructure * hippocampus * long term potentiation and depression Subject RIV: FH - Neurology Impact factor: 3.215, year: 2010

  16. HIPPOCAMPAL ADULT NEUROGENESIS: ITS REGULATION AND POTENTIAL ROLE IN SPATIAL LEARNING AND MEMORY

    Science.gov (United States)

    Lieberwirth, Claudia; Pan, Yongliang; Liu, Yan; Zhang, Zhibin; Wang, Zuoxin

    2016-01-01

    Adult neurogenesis, defined here as progenitor cell division generating functionally integrated neurons in the adult brain, occurs within the hippocampus of numerous mammalian species including humans. The present review details various endogenous (e.g., neurotransmitters) and environmental (e.g., physical exercise) factors that have been shown to influence hippocampal adult neurogenesis. In addition, the potential involvement of adult-generated neurons in naturally-occurring spatial learning behavior is discussed by summarizing the literature focusing on traditional animal models (e.g., rats and mice), non-traditional animal models (e.g., tree shrews), as well as natural populations (e.g., chickadees and Siberian chipmunk). PMID:27174001

  17. Long-term effect of set potential on biocathodes in microbial fuel cells: electrochemical and phylogenetic characterization.

    Science.gov (United States)

    Xia, Xue; Sun, Yanmei; Liang, Peng; Huang, Xia

    2012-09-01

    The long-term effect of set potential on oxygen reducing biocathodes was investigated in terms of electrochemical and biological characteristics. Three biocathodes were poised at 200, 60 and -100 mV vs. saturated calomel electrode (SCE) for 110 days, including the first 17 days for startup. Electrochemical analyses showed that 60 mV was the optimum potential during long-term operation. The performance of all the biocathodes kept increasing after startup, suggesting a period longer than startup time needed to make potential regulation more effective. The inherent characteristics without oxygen transfer limitation were studied. Different from short-term regulation, the amounts of biomass were similar while the specific electrochemical activity was significantly influenced by potential. Moreover, potential showed a strong selection for cathode bacteria. Clones 98% similar with an uncultured Bacteroidetes bacterium clone CG84 accounted for 75% to 80% of the sequences on the biocathodes that showed higher electrochemical activity (60 and -100 mV). Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Hyaluronan preserves the proliferation and differentiation potentials of long-term cultured murine adipose-derived stromal cells

    International Nuclear Information System (INIS)

    Chen, P.-Y.; Huang, Lynn L.H.; Hsieh, H.-J.

    2007-01-01

    For long-term culture, murine adipose-derived stromal cells (mADSCs) at latter passages demonstrated a marked decline in proliferative activity, exhibited senescent morphology and reduced differentiation potentials, particularly osteogenesis. To extend the lifespan of mADSCs, two culture conditions containing hyaluronan (HA) was compared in our study, one as a culture medium supplement (SHA), and the other where HA was pre-coated on culture surface (CHA). mADSCs cultivated with SHA exhibited a prolonged lifespan, reduced cellular senescence, and enhanced osteogenic potential compared to regular culture condition (control). Upon CHA treatment, mADSCs tended to form cell aggregates with gradual growth profiles, while their differentiation activities remained similar to SHA groups. After transferring mADSCs from CHA to control surface, they were shown to have an extended lifespan and an increase of osteogenic potential. Our results suggested that HA can be useful for preserving the proliferation and differentiation potentials of long-term cultured mADSCs

  19. Ischemic long-term-potentiation (iLTP: perspectives to set the threshold of neural plasticity toward therapy

    Directory of Open Access Journals (Sweden)

    Maximilian Lenz

    2015-01-01

    Full Text Available The precise role of neural plasticity under pathological conditions remains not well understood. It appears to be well accepted, however, that changes in the ability of neurons to express plasticity accompany neurological diseases. Here, we discuss recent experimental evidence, which suggests that synaptic plasticity induced by a pathological stimulus, i.e., ischemic long-term-potentiation (iLTP of excitatory synapses, could play an important role for post-stroke recovery by influencing the post-lesional reorganization of surviving neuronal networks.

  20. Oral administration of fisetin promotes the induction of hippocampal long-term potentiation in vivo

    Directory of Open Access Journals (Sweden)

    Wen-bin He

    2018-01-01

    Full Text Available To explore memory enhancing effect of the flavonoid fisetin, we investigated the effect of oral administration of flavonoids on the induction of long-term potentiation (LTP at hippocampal CA1 synapses of anesthetized rats. Among four flavonoids (fisetin, quercetin, luteolin and myricetin tested, only fisetin significantly facilitated the induction of hippocampal LTP. The effect of oral fisetin was abolished by intracerebroventricular injection of U0126, an agent that was previously found to inhibit its effect in hippocampal slices in vitro. These results suggest that orally administered fisetin crosses the blood–brain barrier and promotes synaptic functions in the hippocampus.

  1. Elevated NMDA receptor levels and enhanced postsynaptic long-term potentiation induced by prenatal exposure to valproic acid

    DEFF Research Database (Denmark)

    Rinaldi, Tania; Kulangara, Karina; Antoniello, Katia

    2007-01-01

    as the commonly linked kinase calcium/calmodulin-dependent protein kinase II. Synaptic plasticity experiments between pairs of pyramidal neurons revealed an augmented postsynaptic form of long-term potentiation. These results indicate that VPA significantly enhances NMDA receptor-mediated transmission and causes......Valproic acid (VPA) is a powerful teratogen causing birth defects in humans, including autism spectrum disorder (ASD), if exposure occurs during the first trimester of embryogenesis. Learning and memory alterations are common symptoms of ASD, but underlying molecular and synaptic alterations remain...

  2. Layer 2/3 synapses in monocular and binocular regions of tree shrew visual cortex express mAChR-dependent long-term depression and long-term potentiation.

    Science.gov (United States)

    McCoy, Portia; Norton, Thomas T; McMahon, Lori L

    2008-07-01

    Acetylcholine is an important modulator of synaptic efficacy and is required for learning and memory tasks involving the visual cortex. In rodent visual cortex, activation of muscarinic acetylcholine receptors (mAChRs) induces a persistent long-term depression (LTD) of transmission at synapses recorded in layer 2/3 of acute slices. Although the rodent studies expand our knowledge of how the cholinergic system modulates synaptic function underlying learning and memory, they are not easily extrapolated to more complex visual systems. Here we used tree shrews for their similarities to primates, including a visual cortex with separate, defined regions of monocular and binocular innervation, to determine whether mAChR activation induces long-term plasticity. We find that the cholinergic agonist carbachol (CCh) not only induces long-term plasticity, but the direction of the plasticity depends on the subregion. In the monocular region, CCh application induces LTD of the postsynaptic potential recorded in layer 2/3 that requires activation of m3 mAChRs and a signaling cascade that includes activation of extracellular signal-regulated kinase (ERK) 1/2. In contrast, layer 2/3 postsynaptic potentials recorded in the binocular region express long-term potentiation (LTP) following CCh application that requires activation of m1 mAChRs and phospholipase C. Our results show that activation of mAChRs induces long-term plasticity at excitatory synapses in tree shrew visual cortex. However, depending on the ocular inputs to that region, variation exists as to the direction of plasticity, as well as to the specific mAChR and signaling mechanisms that are required.

  3. Assessment of the potential for long-term toxicological effects of the Exxon Valdez oil spill on birds and mammals

    International Nuclear Information System (INIS)

    Hartung, R.

    1995-01-01

    This paper assesses the potential for direct long-term toxicological effects of exposures to oils in birds and mammals by tracing exposures and effects form the initial cute phases through the sub-chronic to the eventual long-term exposures. The immediate effects of oil spills are physical, the oil acting on the plumage of birds or the fur of mammals. This causes a loss of entrained air and a concomitant reduction in buoyancy and thermal insulation. Animals that escape the immediate impacts may be isolated from their food supply and often ingest large amounts of oil while attempting to clean themselves. At the comparatively high dose levels involved, these exposures can result in toxicologically significant responses in many organ systems. In the course of an oil pollution incident, the amounts of biologically available oils decrease steadily, and simultaneously the composition of the oils shifts towards those components that have low volatility, and that resist photo- and bio-degradation. As this occurs, the primary pathways of exposure change from direct intakes to indirect routes involving the food supply. Although laboratory studies often report finding some adverse effects, the dose rates employed in many of these studies are extremely high when compared with those that are potentially available to animals in the wild, and very few actually use weathered oils. An assessment of the toxicological literature and of the available empirical data on the Exxon Valdez oil spill leads to the conclusion that long-term sub-lethal toxic effects of crude oils on wildlife in such marine spills appear to be very unlikely. 111 refs., 4 figs., 1 tab

  4. Analysis of the potential impact of capillarity on long-term geochemical processes in sulphidic waste-rock dumps

    International Nuclear Information System (INIS)

    Pedretti, Daniele; Lassin, Arnault; Beckie, Roger D.

    2015-01-01

    Highlights: • Capillarity may affect geochemical reactions generating acid-rock drainage. • We studied its impact in a simplified, synthetic WRD. • Capillarity mainly affects the formation of secondary minerals. • It can strongly control long-term formation of gypsum and in turn sulfate release. • Capillarity can be also important for the analysis of calcite passivation. - Abstract: Assessing long-term production of acid rock drainage (ARD) from waste-rock dumps (WRDs) requires a careful analysis of the processes controlling acid-generating geochemical reactions under unsaturated conditions. In this work, we focus on the potential control of capillarity on these reactions, as previous studies showed that capillarity affects the activity of water and solutes in the unsaturated zone through the pore water pressure. We used capillarity-corrected thermodynamic databases and compared calculated speciation and solubility results with those from databases that do not account for capillarity. We developed a simple dynamic model with reduced geochemical components to analyze in detail the effect of capillarity. Results indicate that under low pH conditions simulations with capillarity-controlled reactions generate relatively larger dissolved sulfate concentrations from the WRDs over longer time scales, when compared against simulations without capillarity control. This occurs because capillarity strongly controls the formation of secondary sulfate-bearing minerals such as gypsum. When sufficient oxygen and carbon dioxide partial pressures are maintained within WRDs (such as in well-ventilated systems) and calcite content is insufficient to buffer acidity, the amount of secondary gypsum was calculated to be much larger in capillarity-corrected models. No appreciable effects of capillarity were observed under conditions where gypsum was not generated. Model results are also insensitive to temperature changes in typical climatic ranges. These results indicate some of

  5. Regional prediction of long-term landfill gas to energy potential.

    Science.gov (United States)

    Amini, Hamid R; Reinhart, Debra R

    2011-01-01

    Quantifying landfill gas to energy (LFGTE) potential as a source of renewable energy is difficult due to the challenges involved in modeling landfill gas (LFG) generation. In this paper a methodology is presented to estimate LFGTE potential on a regional scale over a 25-year timeframe with consideration of modeling uncertainties. The methodology was demonstrated for the US state of Florida, as a case study, and showed that Florida could increase the annual LFGTE production by more than threefold by 2035 through installation of LFGTE facilities at all landfills. The estimated electricity production potential from Florida LFG is equivalent to removing some 70 million vehicles from highways or replacing over 800 million barrels of oil consumption during the 2010-2035 timeframe. Diverting food waste could significantly reduce fugitive LFG emissions, while having minimal effect on the LFGTE potential; whereas, achieving high diversion goals through increased recycling will result in reduced uncollected LFG and significant loss of energy production potential which may be offset by energy savings from material recovery and reuse. Estimates showed that the power density for Florida LFGTE production could reach as high as 10 Wm(-2) with optimized landfill operation and energy production practices. The environmental benefits from increased lifetime LFG collection efficiencies magnify the value of LFGTE projects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Role of platelet-activating factor in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Francescangeli, E; Goracci, G; Pettorossi, V E

    1998-06-01

    In rat brain stem slices, we investigated the role of platelet activating factor (PAF) in long-term potentiation (LTP) induced in the ventral part of the medial vestibular nuclei (MVN) by high-frequency stimulation (HFS) of the primary vestibular afferent. The synaptosomal PAF receptor antagonist, BN-52021 was administered before and after HFS. BN-52021 did not modify the vestibular potentials under basal conditions, but it reduced the magnitude of potentiation induced by HFS, which completely developed after the drug wash-out. The same effect was obtained by using CV-62091, a more potent PAF antagonist at microsomal binding sites, but with concentrations higher than those of BN-52021. By contrast both BN-52021 and CV-6209 had no effect on the potentiation once induced. This demonstrates that PAF is involved in the induction but not in the maintenance of vestibular long-term effect through activation of synaptosomal PAF receptors. In addition, we analyzed the effect of the PAF analogue, 1-O-hexadecyl-2-O- (methylcarbamyl)-sn-glycero-3-phosphocoline (MC-PAF) and the inactive PAF metabolite, 1-O-hexadecyl-sn-glycero-3-phosphocoline (Lyso-PAF) on vestibular responses. Our results show that MC-PAF, but not Lyso-PAF induced potentiation. This potentiation was prevented by D,L-2-amino 5-phosphonopentanoic acid, suggesting an involvement of N-methyl-D-aspartate receptors. Furthermore, under BN-52021 and CV-6209, the MC-PAF potentiation was reduced or abolished. The dose-effect curve of MC-PAF showed a shift to the right greater under BN-52021 than under CV-6209, confirming the main dependence of MC-PAF potentiation on the activation of synaptosomal PAF receptors. Our results suggest that PAF can be released in the MVN after the activation of postsynaptic mechanisms triggering LTP, and it may act as a retrograde messenger which activates the presynaptic mechanisms facilitating synaptic plasticity.

  7. Assessment of the Potential Occurrence of Dry Period in the Long Term for Pahang State, Malaysia

    Directory of Open Access Journals (Sweden)

    Othman Ahmad Saifuddin

    2018-01-01

    Full Text Available The interference of climate circulation and continuous rising of surface temperature every year has caused the atmosphere composition change which gives serious impact to water resource management. Pahang is among of the affected states by El Nino that hit Malaysia in recent years which led to water depletion at several water plants. Based on the current situation, this study focuses on 1 simulate the average rain pattern using statistical downscaling; 2 identify the severity index and dry duration occurrence in the catchment area. Predicting potential changes in the climate events is important to evaluate the level of climate change in the critical region. Therefore, the integration of Statistical Downscaling Model (SDSM and Standard Precipitation Index (SPI have been conducted to study the potential occurrence of the dry period due to climate change for year 2020s and year 2050s. The results reveal that the dry condition is high during the mid-year. The lowest SPI value is estimated to reach -2.2 which can be classified as extreme. The potential dry period is expected to increase 2.5% and 3.3% in 2020 and 2050, respectively.

  8. Long-term detection of Parkinsonian tremor activity from subthalamic nucleus local field potentials.

    Science.gov (United States)

    Houston, Brady; Blumenfeld, Zack; Quinn, Emma; Bronte-Stewart, Helen; Chizeck, Howard

    2015-01-01

    Current deep brain stimulation paradigms deliver continuous stimulation to deep brain structures to ameliorate the symptoms of Parkinson's disease. This continuous stimulation has undesirable side effects and decreases the lifespan of the unit's battery, necessitating earlier replacement. A closed-loop deep brain stimulator that uses brain signals to determine when to deliver stimulation based on the occurrence of symptoms could potentially address these drawbacks of current technology. Attempts to detect Parkinsonian tremor using brain signals recorded during the implantation procedure have been successful. However, the ability of these methods to accurately detect tremor over extended periods of time is unknown. Here we use local field potentials recorded during a deep brain stimulation clinical follow-up visit 1 month after initial programming to build a tremor detection algorithm and use this algorithm to detect tremor in subsequent visits up to 8 months later. Using this method, we detected the occurrence of tremor with accuracies between 68-93%. These results demonstrate the potential of tremor detection methods for efficacious closed-loop deep brain stimulation over extended periods of time.

  9. Complex modulation by stress of the effect of seizures on long term potentiation in mouse hippocampal slices.

    Science.gov (United States)

    Maggio, Nicola; Shavit Stein, Efrat; Segal, Menahem

    2017-08-01

    Stress has a profound effect on ability to express neuronal plasticity, learning, and memory. Likewise, epileptic seizures lead to massive changes in brain connectivity, and in ability to undergo long term changes in reactivity to afferent stimulation. In this study, we analyzed possible long lasting interactions between a stressful experience and reactivity to pilocarpine, on the ability to produce long term potentiation (LTP) in a mouse hippocampus. Pilocarpine lowers paired pulse potentiation as well as LTP in CA1 region of the mouse hippocampal slice. When stress experience precedes exposure to pilocarpine, it protects the brain from the lasting effect of pilocarpine. When stress follows pilocarpine, it exacerbates the effect of the drug, to produce a long lasting reduction in LTP. These changes are accompanied by a parallel change in blood corticosterone level. A single exposure to selective mineralo- or gluco-corticosterone (MR and GR, respectively) agonists and antagonists can mimic the stress effects, indicating that GR's underlie the lasting detrimental effects of stress whereas MRs are instrumental in counteracting the effects of stress. These studies open a new avenue of understanding of the interactive effects of stress and epileptic seizures on brain plasticity. © 2017 Wiley Periodicals, Inc.

  10. A single episode of high intensity sound inhibits long-term potentiation in the hippocampus of rats.

    Science.gov (United States)

    de Deus, J L; Cunha, A O S; Terzian, A L; Resstel, L B; Elias, L L K; Antunes-Rodrigues, J; Almeida, S S; Leão, R M

    2017-10-26

    Exposure to loud sounds has become increasingly common. The most common consequences of loud sound exposure are deafness and tinnitus, but emotional and cognitive problems are also associated with loud sound exposure. Loud sounds can activate the hipothalamic-pituitary-adrenal axis resulting in the secretion of corticosterone, which affects hippocampal synaptic plasticity. Previously we have shown that long-term exposure to short episodes of high intensity sound inhibited hippocampal long-term potentiation (LTP) without affecting spatial learning and memory. Here we aimed to study the impact of short term loud sound exposure on hippocampal synaptic plasticity and function. We found that a single minute of 110 dB sound inhibits hippocampal Schaffer-CA1 LTP for 24 hours. This effect did not occur with an 80-dB sound exposure, was not correlated with corticosterone secretion and was also observed in the perforant-dentate gyrus synapse. We found that despite the deficit in the LTP these animals presented normal spatial learning and memory and fear conditioning. We conclude that a single episode of high-intensity sound impairs hippocampal LTP, without impairing memory and learning. Our results show that the hippocampus is very responsive to loud sounds which can have a potential, but not yet identified, impact on its function.

  11. D-Serine rescues the deficits of hippocampal long-term potentiation and learning and memory induced by sodium fluoroacetate.

    Science.gov (United States)

    Han, Huili; Peng, Yan; Dong, Zhifang

    2015-06-01

    It is well known that bidirectional glia-neuron interactions play important roles in the neurophysiological and neuropathological processes. It is reported that impairing glial functions with sodium fluoroacetate (FAC) impaired hippocampal long-term depression (LTD) and spatial memory retrieval. However, it remains unknown whether FAC impairs hippocampal long-term potentiation (LTP) and learning and/or memory, and if so, whether pharmacological treatment with exogenous d-serine can recuse the impairment. Here, we reported that systemic administration of FAC (3mg/kg, i.p.) before training resulted in dramatic impairments of spatial learning and memory in water maze and fear memory in contextual fear conditioning. Furthermore, the behavioral deficits were accompanied by impaired LTP induction in the hippocampal CA1 area of brain slices. More importantly, exogenous d-serine treatment succeeded in recusing the deficits of hippocampal LTP and learning and memory induced by FAC. Together, these results suggest that astrocytic d-serine may be essential for hippocampal synaptic plasticity and memory, and that alteration of its levels may be relevant to the induction and potentially treatment of psychiatric and neurological disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Chronic treatment with ginsenoside Rg1 promotes memory and hippocampal long-term potentiation in middle-aged mice.

    Science.gov (United States)

    Zhu, G; Wang, Y; Li, J; Wang, J

    2015-04-30

    Ginseng serves as a potential candidate for the treatment of aging-related memory decline or memory loss. However, the related mechanism is not fully understood. In this study, we applied an intraperitoneal injection of ginsenoside Rg1, an active compound from ginseng in middle-aged mice and detected memory improvement and the underlying mechanisms. Our results showed that a period of 30-day administration of ginsenoside Rg1 enhanced long-term memory in the middle-aged animals. Consistent with the memory improvement, ginsenoside Rg1 administration facilitated weak theta-burst stimulation (TBS)-induced long-term potentiation (LTP) in acute hippocampal slices from middle-aged animals. Ginsenoside Rg1 administration increased the dendritic apical spine numbers and area in the CA1 region. In addition, ginsenoside Rg1 administration up-regulated the expression of hippocampal p-AKT, brain-derived neurotrophic factor (BDNF), proBDNF and glutamate receptor 1 (GluR1), but not p-ERK. Interestingly, the phosphatase and tensin homolog deleted on chromosome ten (PTEN) inhibitor (bpV) mimicked the ginsenoside Rg1 effects, including increasing p-AKT expression, promoting hippocampal basal synaptic transmission, LTP and memory. Taken together, our data suggest that ginsenoside Rg1 treatment improves memory in middle-aged mice possibly through regulating the PI3K/AKT pathway, altering apical spines and facilitating hippocampal LTP. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Possible Long Term Effects of Chemical Warfare Using Visual Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Abbas Riazi

    2014-09-01

    Full Text Available Some studies have already addressed the effects of occupational organic solvent exposure on the visually evoked potentials (VEPs. Visual system is an important target for Sulphur Mustard (SM toxicity. A number of Iranian victims of Sulphur Mustard (SM agent were apprehensive about the delay effect of SM on their vision and a possible delay effect of SM on their visual cortex. This investigation was performed on 34 individuals with a history of chemical exposure and a control group of 15 normal people. The Toennies electro-diagnosis device was used and its signals were saved as the latencies. The mean of N75, N140 and P100 of victims of chemical warfare (VCWs and control group indicated no significant results (P>0.05. The VCWs did not show any visual symptoms and there was no clear deficit in their VEPs.

  14. Long-term cyclicities in Phanerozoic sea-level sedimentary record and their potential drivers

    Science.gov (United States)

    Boulila, Slah; Laskar, Jacques; Haq, Bilal U.; Galbrun, Bruno; Hara, Nathan

    2018-06-01

    Cyclic sedimentation has varied at several timescales and this variability has been geologically well documented at Milankovitch timescales, controlled in part by climatically (insolation) driven sea-level changes. At the longer (tens of Myr) timescales connection between astronomical parameters and sedimentation via cyclic solar-system motions within the Milky Way has also been proposed, but this hypothesis remains controversial because of the lack of long geological records. In addition, the absence of a meaningful physical mechanism that could explain the connection between climate and astronomy at these longer timescales led to the more plausible explanation of plate motions as the main driver of climate and sedimentation through changes in ocean and continent mass distribution on Earth. Here we statistically show a prominent and persistent 36 Myr sedimentary cyclicity superimposed on two megacycles ( 250 Myr) in a relatively well-constrained sea-level (SL) record of the past 542 Myr (Phanerozoic eon). We also show two other significant 9.3 and 91 Myr periodicities, but with lower amplitudes. The 9.3 Myr cyclicity was previously attributed to long-period Milankovitch band based on the Cenozoic record. However, the 91 Myr cyclicity has never been observed before in the geologic record. The 250 Myr cyclicity was attributed to the Wilson tectonic (supercontinent) cycle. The 36 Myr periodicity, also detected for the first time in SL record, has previously been ascribed either to tectonics or to astronomical cyclicity. Given the possible link between amplitudes of the 36 and 250 Myr cyclicities in SL record and the potential that these periodicities fall into the frequency band of solar system motions, we suggest an astronomical origin, and model these periodicities as originating from the path of the solar system in the Milky Way as vertical and radial periods that modulate the flux of cosmic rays on Earth. Our finding of the 36 Myr SL cyclicity lends credibility

  15. GluA2-dependent AMPA receptor endocytosis and the decay of early and late long-term potentiation: possible mechanisms for forgetting of short- and long-term memories.

    Science.gov (United States)

    Hardt, Oliver; Nader, Karim; Wang, Yu-Tian

    2014-01-05

    The molecular processes involved in establishing long-term potentiation (LTP) have been characterized well, but the decay of early and late LTP (E-LTP and L-LTP) is poorly understood. We review recent advances in describing the mechanisms involved in maintaining LTP and homeostatic plasticity. We discuss how these phenomena could relate to processes that might underpin the loss of synaptic potentiation over time, and how they might contribute to the forgetting of short-term and long-term memories. We propose that homeostatic downscaling mediates the loss of E-LTP, and that metaplastic parameters determine the decay rate of L-LTP, while both processes require the activity-dependent removal of postsynaptic GluA2-containing AMPA receptors.

  16. Stimulus uncertainty enhances long-term potentiation-like plasticity in human motor cortex.

    Science.gov (United States)

    Sale, Martin V; Nydam, Abbey S; Mattingley, Jason B

    2017-03-01

    Plasticity can be induced in human cortex using paired associative stimulation (PAS), which repeatedly and predictably pairs a peripheral electrical stimulus with transcranial magnetic stimulation (TMS) to the contralateral motor region. Many studies have reported small or inconsistent effects of PAS. Given that uncertain stimuli can promote learning, the predictable nature of the stimulation in conventional PAS paradigms might serve to attenuate plasticity induction. Here, we introduced stimulus uncertainty into the PAS paradigm to investigate if it can boost plasticity induction. Across two experimental sessions, participants (n = 28) received a modified PAS paradigm consisting of a random combination of 90 paired stimuli and 90 unpaired (TMS-only) stimuli. Prior to each of these stimuli, participants also received an auditory cue which either reliably predicted whether the upcoming stimulus was paired or unpaired (no uncertainty condition) or did not predict the upcoming stimulus (maximum uncertainty condition). Motor evoked potentials (MEPs) evoked from abductor pollicis brevis (APB) muscle quantified cortical excitability before and after PAS. MEP amplitude increased significantly 15 min following PAS in the maximum uncertainty condition. There was no reliable change in MEP amplitude in the no uncertainty condition, nor between post-PAS MEP amplitudes across the two conditions. These results suggest that stimulus uncertainty may provide a novel means to enhance plasticity induction with the PAS paradigm in human motor cortex. To provide further support to the notion that stimulus uncertainty and prediction error promote plasticity, future studies should further explore the time course of these changes, and investigate what aspects of stimulus uncertainty are critical in boosting plasticity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The global economic long-term potential of modern biomass in a climate-constrained world

    Science.gov (United States)

    Klein, David; Humpenöder, Florian; Bauer, Nico; Dietrich, Jan Philipp; Popp, Alexander; Bodirsky, Benjamin Leon; Bonsch, Markus; Lotze-Campen, Hermann

    2014-07-01

    Low-stabilization scenarios consistent with the 2 °C target project large-scale deployment of purpose-grown lignocellulosic biomass. In case a GHG price regime integrates emissions from energy conversion and from land-use/land-use change, the strong demand for bioenergy and the pricing of terrestrial emissions are likely to coincide. We explore the global potential of purpose-grown lignocellulosic biomass and ask the question how the supply prices of biomass depend on prices for greenhouse gas (GHG) emissions from the land-use sector. Using the spatially explicit global land-use optimization model MAgPIE, we construct bioenergy supply curves for ten world regions and a global aggregate in two scenarios, with and without a GHG tax. We find that the implementation of GHG taxes is crucial for the slope of the supply function and the GHG emissions from the land-use sector. Global supply prices start at 5 GJ-1 and increase almost linearly, doubling at 150 EJ (in 2055 and 2095). The GHG tax increases bioenergy prices by 5 GJ-1 in 2055 and by 10 GJ-1 in 2095, since it effectively stops deforestation and thus excludes large amounts of high-productivity land. Prices additionally increase due to costs for N2O emissions from fertilizer use. The GHG tax decreases global land-use change emissions by one-third. However, the carbon emissions due to bioenergy production increase by more than 50% from conversion of land that is not under emission control. Average yields required to produce 240 EJ in 2095 are roughly 600 GJ ha-1 yr-1 with and without tax.

  18. The global economic long-term potential of modern biomass in a climate-constrained world

    International Nuclear Information System (INIS)

    Klein, David; Humpenöder, Florian; Bauer, Nico; Dietrich, Jan Philipp; Popp, Alexander; Leon Bodirsky, Benjamin; Bonsch, Markus; Lotze-Campen, Hermann

    2014-01-01

    Low-stabilization scenarios consistent with the 2 °C target project large-scale deployment of purpose-grown lignocellulosic biomass. In case a GHG price regime integrates emissions from energy conversion and from land-use/land-use change, the strong demand for bioenergy and the pricing of terrestrial emissions are likely to coincide. We explore the global potential of purpose-grown lignocellulosic biomass and ask the question how the supply prices of biomass depend on prices for greenhouse gas (GHG) emissions from the land-use sector. Using the spatially explicit global land-use optimization model MAgPIE, we construct bioenergy supply curves for ten world regions and a global aggregate in two scenarios, with and without a GHG tax. We find that the implementation of GHG taxes is crucial for the slope of the supply function and the GHG emissions from the land-use sector. Global supply prices start at $5 GJ −1 and increase almost linearly, doubling at 150 EJ (in 2055 and 2095). The GHG tax increases bioenergy prices by $5 GJ −1 in 2055 and by $10 GJ −1 in 2095, since it effectively stops deforestation and thus excludes large amounts of high-productivity land. Prices additionally increase due to costs for N 2 O emissions from fertilizer use. The GHG tax decreases global land-use change emissions by one-third. However, the carbon emissions due to bioenergy production increase by more than 50% from conversion of land that is not under emission control. Average yields required to produce 240 EJ in 2095 are roughly 600 GJ ha −1 yr −1 with and without tax. (letter)

  19. Ginsenoside Rg1 ameliorates hippocampal long-term potentiation and memory in an Alzheimer's disease model.

    Science.gov (United States)

    Li, Fengling; Wu, Xiqing; Li, Jing; Niu, Qingliang

    2016-06-01

    The complex etiopathogenesis of Alzheimer's disease (AD) has limited progression in the identification of effective therapeutic agents. Amyloid precursor protein (APP) and presenilin‑1 (PS1) are always overexpressed in AD, and are considered to be the initiators of the formation of β‑amyloid plaques and the symptoms of AD. In the present study, a transgenic AD model, constructed via the overexpression of APP and PS1, was used to verify the protective effects of ginsenoside Rg1 on memory performance and synaptic plasticity. AD mice (6‑month‑old) were treated via intraperitoneal injection of 0.1‑10 mg/kg ginsenoside Rg1. Long‑term memory, synaptic plasticity, and the levels of AD‑associated and synaptic plasticity‑associated proteins were measured following treatment. Memory was measured using a fear conditioning task and protein expression levels were investigated using western blotting. All the data was analyzed by one-way analysis of variance or t‑test. Following 30 days of consecutive treatment, memory in the AD mouse model was ameliorated in the 10 mg/kg ginsenoside Rg1 treatment group. As demonstrated by biochemical experiments, ginsenoside Rg1 treatment reduced the accumulations of β‑amyloid 1‑42 and phosphorylated (p)‑Tau in the AD model. Additionally, brain-derived neurotrophic factor (BDNF) and p‑TrkB synaptic plasticity‑associated proteins were upregulated following ginsenoside Rg1 application. Correspondingly, long‑term potentiation (LTP) was restored following ginsenoside Rg1 application in the AD mice model. Taken together, ginsenoside Rg1 repaired hippocampal LTP and memory, likely through facilitating the clearance of AD‑associated proteins and through activation of the BDNF‑TrkB pathway. Therefore, ginsenoside Rg1 may be a candidate drug for the treatment of AD.

  20. The Greenville Fault: preliminary estimates of its long-term creep rate and seismic potential

    Science.gov (United States)

    Lienkaemper, James J.; Barry, Robert G.; Smith, Forrest E.; Mello, Joseph D.; McFarland, Forrest S.

    2013-01-01

    Once assumed locked, we show that the northern third of the Greenville fault (GF) creeps at 2 mm/yr, based on 47 yr of trilateration net data. This northern GF creep rate equals its 11-ka slip rate, suggesting a low strain accumulation rate. In 1980, the GF, easternmost strand of the San Andreas fault system east of San Francisco Bay, produced a Mw5.8 earthquake with a 6-km surface rupture and dextral slip growing to ≥2 cm on cracks over a few weeks. Trilateration shows a 10-cm post-1980 transient slip ending in 1984. Analysis of 2000-2012 crustal velocities on continuous global positioning system stations, allows creep rates of ~2 mm/yr on the northern GF, 0-1 mm/yr on the central GF, and ~0 mm/yr on its southern third. Modeled depth ranges of creep along the GF allow 5-25% aseismic release. Greater locking in the southern two thirds of the GF is consistent with paleoseismic evidence there for large late Holocene ruptures. Because the GF lacks large (>1 km) discontinuities likely to arrest higher (~1 m) slip ruptures, we expect full-length (54-km) ruptures to occur that include the northern creeping zone. We estimate sufficient strain accumulation on the entire GF to produce Mw6.9 earthquakes with a mean recurrence of ~575 yr. While the creeping 16-km northern part has the potential to produce a Mw6.2 event in 240 yr, it may rupture in both moderate (1980) and large events. These two-dimensional-model estimates of creep rate along the southern GF need verification with small aperture surveys.

  1. Acute inhibition of estradiol synthesis impacts vestibulo-ocular reflex adaptation and cerebellar long-term potentiation in male rats.

    Science.gov (United States)

    Dieni, Cristina V; Ferraresi, Aldo; Sullivan, Jacqueline A; Grassi, Sivarosa; Pettorossi, Vito E; Panichi, Roberto

    2018-03-01

    The vestibulo-ocular reflex (VOR) adaptation is an ideal model for investigating how the neurosteroid 17 beta-estradiol (E2) contributes to the modification of behavior by regulating synaptic activities. We hypothesized that E2 impacts VOR adaptation by affecting cerebellar synaptic plasticity at the parallel fiber-Purkinje cell (PF) synapse. To verify this hypothesis, we investigated the acute effect of blocking E2 synthesis on gain increases and decreases in adaptation of the VOR in male rats using an oral dose (2.5 mg/kg) of the aromatase inhibitor letrozole. We also assessed the effect of letrozole on synaptic plasticity at the PF synapse in vitro, using cerebellar slices from male rats. We found that letrozole acutely impaired both gain increases and decreases adaptation of the VOR without altering basal ocular-motor performance. Moreover, letrozole prevented long-term potentiation at the PF synapse (PF-LTP) without affecting long-term depression (PF-LTD). Thus, in male rats neurosteroid E2 has a relevant impact on VOR adaptation and affects exclusively PF-LTP. These findings suggest that E2 might regulate changes in VOR adaptation by acting locally on cerebellar and extra-cerebellar synaptic plasticity sites.

  2. Decellularized allogeneic heart valves demonstrate self-regeneration potential after a long-term preclinical evaluation.

    Directory of Open Access Journals (Sweden)

    Laura Iop

    Full Text Available Tissue-engineered heart valves are proposed as novel viable replacements granting longer durability and growth potential. However, they require extensive in vitro cell-conditioning in bioreactor before implantation. Here, the propensity of non-preconditioned decellularized heart valves to spontaneous in body self-regeneration was investigated in a large animal model. Decellularized porcine aortic valves were evaluated for right ventricular outflow tract (RVOT reconstruction in Vietnamese Pigs (n = 11 with 6 (n = 5 and 15 (n = 6 follow-up months. Repositioned native valves (n = 2 for each time were considered as control. Tissue and cell components from explanted valves were investigated by histology, immunohistochemistry, electron microscopy, and gene expression. Most substitutes constantly demonstrated in vivo adequate hemodynamic performances and ex vivo progressive repopulation during the 15 implantation months without signs of calcifications, fibrosis and/or thrombosis, as revealed by histological, immunohistochemical, ultrastructural, metabolic and transcriptomic profiles. Colonizing cells displayed native-like phenotypes and actively synthesized novel extracellular matrix elements, as collagen and elastin fibers. New mature blood vessels, i.e. capillaries and vasa vasorum, were identified in repopulated valves especially in the medial and adventitial tunicae of regenerated arterial walls. Such findings correlated to the up-regulated vascular gene transcription. Neoinnervation hallmarks were appreciated at histological and ultrastructural levels. Macrophage populations with reparative M2 phenotype were highly represented in repopulated valves. Indeed, no aspects of adverse/immune reaction were revealed in immunohistochemical and transcriptomic patterns. Among differentiated elements, several cells were identified expressing typical stem cell markers of embryonic, hematopoietic, neural and mesenchymal lineages in significantly

  3. Synaptic long-term potentiation realized in Pavlov's dog model based on a NiOx-based memristor

    Science.gov (United States)

    Hu, S. G.; Liu, Y.; Liu, Z.; Chen, T. P.; Yu, Q.; Deng, L. J.; Yin, Y.; Hosaka, Sumio

    2014-12-01

    Synaptic Long-Term Potentiation (LTP), which is a long-lasting enhancement in signal transmission between neurons, is widely considered as the major cellular mechanism during learning and memorization. In this work, a NiOx-based memristor is found to be able to emulate the synaptic LTP. Electrical conductance of the memristor is increased by electrical pulse stimulation and then spontaneously decays towards its initial state, which resembles the synaptic LTP. The lasting time of the LTP in the memristor can be estimated with the relaxation equation, which well describes the conductance decay behavior. The LTP effect of the memristor has a dependence on the stimulation parameters, including pulse height, width, interval, and number of pulses. An artificial network consisting of three neurons and two synapses is constructed to demonstrate the associative learning and LTP behavior in extinction of association in Pavlov's dog experiment.

  4. Oral administration of fisetin promotes the induction of hippocampal long-term potentiation in vivo.

    Science.gov (United States)

    He, Wen-Bin; Abe, Kazuho; Akaishi, Tatsuhiro

    2018-01-01

    To explore memory enhancing effect of the flavonoid fisetin, we investigated the effect of oral administration of flavonoids on the induction of long-term potentiation (LTP) at hippocampal CA1 synapses of anesthetized rats. Among four flavonoids (fisetin, quercetin, luteolin and myricetin) tested, only fisetin significantly facilitated the induction of hippocampal LTP. The effect of oral fisetin was abolished by intracerebroventricular injection of U0126, an agent that was previously found to inhibit its effect in hippocampal slices in vitro. These results suggest that orally administered fisetin crosses the blood-brain barrier and promotes synaptic functions in the hippocampus. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  5. Amyloid-β Peptide Is Needed for cGMP-Induced Long-Term Potentiation and Memory.

    Science.gov (United States)

    Palmeri, Agostino; Ricciarelli, Roberta; Gulisano, Walter; Rivera, Daniela; Rebosio, Claudia; Calcagno, Elisa; Tropea, Maria Rosaria; Conti, Silvia; Das, Utpal; Roy, Subhojit; Pronzato, Maria Adelaide; Arancio, Ottavio; Fedele, Ernesto; Puzzo, Daniela

    2017-07-19

    High levels of amyloid-β peptide (Aβ) have been related to Alzheimer's disease pathogenesis. However, in the healthy brain, low physiologically relevant concentrations of Aβ are necessary for long-term potentiation (LTP) and memory. Because cGMP plays a key role in these processes, here we investigated whether the cyclic nucleotide cGMP influences Aβ levels and function during LTP and memory. We demonstrate that the increase of cGMP levels by the phosphodiesterase-5 inhibitors sildenafil and vardenafil induces a parallel release of Aβ due to a change in the approximation of amyloid precursor protein (APP) and the β-site APP cleaving enzyme 1. Moreover, electrophysiological and behavioral studies performed on animals of both sexes showed that blocking Aβ function, by using anti-murine Aβ antibodies or APP knock-out mice, prevents the cGMP-dependent enhancement of LTP and memory. Our data suggest that cGMP positively regulates Aβ levels in the healthy brain which, in turn, boosts synaptic plasticity and memory. SIGNIFICANCE STATEMENT Amyloid-β (Aβ) is a key pathogenetic factor in Alzheimer's disease. However, low concentrations of endogenous Aβ, mimicking levels of the peptide in the healthy brain, enhance hippocampal long-term potentiation (LTP) and memory. Because the second messenger cGMP exerts a central role in LTP mechanisms, here we studied whether cGMP affects Aβ levels and function during LTP. We show that cGMP enhances Aβ production by increasing the APP/BACE-1 convergence in endolysosomal compartments. Moreover, the cGMP-induced enhancement of LTP and memory was disrupted by blockade of Aβ, suggesting that the physiological effect of the cyclic nucleotide on LTP and memory is dependent upon Aβ. Copyright © 2017 the authors 0270-6474/17/376926-12$15.00/0.

  6. Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn.

    Science.gov (United States)

    Jin, Virginia L; Schmer, Marty R; Stewart, Catherine E; Sindelar, Aaron J; Varvel, Gary E; Wienhold, Brian J

    2017-07-01

    Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emissions, and global warming potential (GWP) in irrigated systems, however, remain relatively unknown. Here, residue and tillage management effects were quantified by measuring soil nitrous oxide (N 2 O) and methane (CH 4 ) fluxes and SOC changes (ΔSOC) at a long-term, irrigated continuous corn (Zea mays L.) system in eastern Nebraska, United States. Management treatments began in 2002, and measured treatments included no or high stover removal (0 or 6.8 Mg DM ha -1  yr -1 , respectively) under no-till (NT) or conventional disk tillage (CT) with full irrigation (n = 4). Soil N 2 O and CH 4 fluxes were measured for five crop-years (2011-2015), and ΔSOC was determined on an equivalent mass basis to ~30 cm soil depth. Both area- and yield-scaled soil N 2 O emissions were greater with stover retention compared to removal and for CT compared to NT, with no interaction between stover and tillage practices. Methane comprised <1% of total emissions, with NT being CH 4 neutral and CT a CH 4 source. Surface SOC decreased with stover removal and with CT after 14 years of management. When ΔSOC, soil GHG emissions, and agronomic energy usage were used to calculate system GWP, all management systems were net GHG sources. Conservation practices (NT, stover retention) each decreased system GWP compared to conventional practices (CT, stover removal), but pairing conservation practices conferred no additional mitigation benefit. Although cropping system, management equipment/timing/history, soil type, location, weather, and the depth to which ΔSOC is measured affect the GWP outcomes of irrigated systems at large, this long-term irrigated study provides valuable empirical evidence of how management decisions can impact soil GHG emissions and surface

  7. NMDA receptor-mediated long term modulation of electrically evoked field potentials in the rat medial vestibular nuclei.

    Science.gov (United States)

    Capocchi, G; Della Torre, G; Grassi, S; Pettorossi, V E; Zampolini, M

    1992-01-01

    The effect of high frequency stimulation (HFS) of the primary vestibular afferents on field potentials recorded in the ipsilateral Medial Vestibular Nuclei (MVN) was studied. Our results show that potentiation and depression can be induced in different portions of MVN, which are distinguishable by their anatomical organization. HFS induces potentiation of the monosynaptic component in the ventral portion of the MVN, whereas it provokes depression of the polysynaptic component in the dorsal portion of the same nucleus. The induction of both potentiation and depression was blocked under AP5 perfusion, thus demonstrating that NMDA receptor activation mediates both phenomena. Furthermore, the finding that the field potentials were not modified during perfusion with DL-AP5, as previously reported, supports the hypothesis that NMDA receptors are not involved in the normal synaptic transmission from the primary vestibular afferent fibres, but are only activated following hyperstimulation of this afferent system. Our results suggest that the mechanisms of long term modification of synaptic efficacy observed in MVN may underlie the plasticity phenomena occurring in vestibular nuclei.

  8. Spatial, contextual and working memory are not affected by the absence of mossy fiber long-term potentiation and depression

    NARCIS (Netherlands)

    Hensbroek, R.A.; Kamal, A.; Baars, A.M.; Verhage, M.; Spruijt, B.M.

    2003-01-01

    The mossy fibers of the hippocampus display NMDA-receptor independent long-term plasticity. A number of studies addressed the role of mossy fiber long-term plasticity in memory, but have provided contrasting results. Here, we have exploited a genetic model, the rab3A null-mutant, which is

  9. Potential of thorium-based fuel cycle for PWR core to reduce plutonium and long-term toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Hyung Kook; Kim, Taek Kyum; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-01-01

    The cross section libraries and calculation methods of the participants were inter-compared through the first stage benchmark calculation. The multiplication factor of unit cell benchmark are in good agreement, but there is significant discrepancies of 2.3 to 3.5 %k at BOC and at EOC between the calculated infinite multiplication factors of each participants for the assembly benchmark. Our results with HELIOS show a reasonable agreement with the others except the MTC value at EOC. To verify the potential of the thorium-based fuel to consume the plutonium and to reduce the radioactivity from the spent fuel, the conceptual core with ThO{sub 2}-PuO{sub 2} or MOX fuel were constructed. The composition and quantity of plutonium isotopes and the radioactivity level of spent fuel for conceptual cores were analyzed, and the neutronic characteristics of conceptual cores were also calculated. The nuclear characteristics for ThO{sub 2}-PuO{sub 2} thorium fueled core was similar to MOX fueled core, mainly due to the same seed fuel material, plutonium. For the capability of plutonium consumption, ThO{sub 2}-PuO{sub 2} thorium fuel can consume plutonium 2.1-2.4 times MOX fuel. The fraction of fissile plutonium in the spent ThO{sub 2}-PuO{sub 2} thorium fuel is more favorable in view of plutonium consumption and non-proliferation than MOX fuel. The radioactivity of spent ThO{sub 2}-PuO{sub 2} thorium and MOX fuel batches were calculated. Since plutonium isotopes are dominant for the long-term radioactivity, ThO{sub 2}-PuO{sub 2} thorium has almost the same level of radioactivity as in MOX fuel for a long-term perspective. (author). 22 figs., 11 tabs.

  10. Enhanced decomposition of stable soil organic carbon and microbial catabolic potentials by long-term field warming.

    Science.gov (United States)

    Feng, Wenting; Liang, Junyi; Hale, Lauren E; Jung, Chang Gyo; Chen, Ji; Zhou, Jizhong; Xu, Minggang; Yuan, Mengting; Wu, Liyou; Bracho, Rosvel; Pegoraro, Elaine; Schuur, Edward A G; Luo, Yiqi

    2017-11-01

    Quantifying soil organic carbon (SOC) decomposition under warming is critical to predict carbon-climate feedbacks. According to the substrate regulating principle, SOC decomposition would decrease as labile SOC declines under field warming, but observations of SOC decomposition under warming do not always support this prediction. This discrepancy could result from varying changes in SOC components and soil microbial communities under warming. This study aimed to determine the decomposition of SOC components with different turnover times after subjected to long-term field warming and/or root exclusion to limit C input, and to test whether SOC decomposition is driven by substrate lability under warming. Taking advantage of a 12-year field warming experiment in a prairie, we assessed the decomposition of SOC components by incubating soils from control and warmed plots, with and without root exclusion for 3 years. We assayed SOC decomposition from these incubations by combining inverse modeling and microbial functional genes during decomposition with a metagenomic technique (GeoChip). The decomposition of SOC components with turnover times of years and decades, which contributed to 95% of total cumulative CO 2 respiration, was greater in soils from warmed plots. But the decomposition of labile SOC was similar in warmed plots compared to the control. The diversity of C-degradation microbial genes generally declined with time during the incubation in all treatments, suggesting shifts of microbial functional groups as substrate composition was changing. Compared to the control, soils from warmed plots showed significant increase in the signal intensities of microbial genes involved in degrading complex organic compounds, implying enhanced potential abilities of microbial catabolism. These are likely responsible for accelerated decomposition of SOC components with slow turnover rates. Overall, the shifted microbial community induced by long-term warming accelerates the

  11. Mechanisms and potential treatments for declining olfactory function and neurogenesis in the ageing brain

    OpenAIRE

    Broad, K. D.

    2017-01-01

    The role of olfactory function in maintaining quality of life and as a potential surrogate marker of neurogenic activity in the elderly brain is an underappreciated topic. The olfactory system is complex and is unusual in that its function is maintained by neurogenesis at multiple sites throughout the lifetime of an organism, which in humans may be over 80 years in length. Declines in olfactory function are common with advancing age and this is associated with reductions in the qu...

  12. Long-term Water Table Monitoring of Rio Grande Riparian Ecosystems for Restoration Potential Amid Hydroclimatic Challenges

    Science.gov (United States)

    Thibault, James R.; Cleverly, James R.; Dahm, Clifford N.

    2017-12-01

    Hydrological processes drive the ecological functioning and sustainability of cottonwood-dominated riparian ecosystems in the arid southwestern USA. Snowmelt runoff elevates groundwater levels and inundates floodplains, which promotes cottonwood germination. Once established, these phreatophytes rely on accessible water tables (WTs). In New Mexico's Middle Rio Grande corridor diminished flooding and deepening WTs threaten native riparian communities. We monitored surface flows and riparian WTs for up to 14 years, which revealed that WTs and surface flows, including peak snowmelt discharge, respond to basin climate conditions and resource management. WT hydrographs influence the composition of riparian communities and can be used to assess if potential restoration sites meet native vegetation tolerances for WT depths, rates of recession, and variability throughout their life stages. WTs were highly variable in some sites, which can preclude native vegetation less adapted to deep drawdowns during extended droughts. Rates of WT recession varied between sites and should be assessed in regard to recruitment potential. Locations with relatively shallow WTs and limited variability are likely to be more viable for successful restoration. Suitable sites have diminished greatly as the once meandering Rio Grande has been constrained and depleted. Increasing demands on water and the presence of invasive vegetation better adapted to the altered hydrologic regime further impact native riparian communities. Long-term monitoring over a range of sites and hydroclimatic extremes reveals attributes that can be evaluated for restoration potential.

  13. Long-Term Expansion, Enhanced Chondrogenic Potential, and Suppression of Endochondral Ossification of Adult Human MSCs via WNT Signaling Modulation

    Directory of Open Access Journals (Sweden)

    Roberto Narcisi

    2015-03-01

    Full Text Available Mesenchymal stem cells (MSCs are a potential source of chondrogenic cells for the treatment of cartilage disorders, but loss of chondrogenic potential during in vitro expansion and the propensity of cartilage to undergo hypertrophic maturation impede their therapeutic application. Here we report that the signaling protein WNT3A, in combination with FGF2, supports long-term expansion of human bone marrow-derived MSCs. The cells retained their chondrogenic potential and other phenotypic and functional properties of multipotent MSCs, which were gradually lost in the absence of WNT3A. Moreover, we discovered that endogenous WNT signals are the main drivers of the hypertrophic maturation that follows chondrogenic differentiation. Inhibition of WNT signals during differentiation prevented calcification and maintained cartilage properties following implantation in a mouse model. By maintaining potency during expansion and preventing hypertrophic maturation following differentiation, the modulation of WNT signaling removes two major obstacles that impede the clinical application of MSCs in cartilage repair.

  14. Long-term potentiation in the rat medial vestibular nuclei depends on locally synthesized 17beta-estradiol.

    Science.gov (United States)

    Grassi, Silvarosa; Frondaroli, Adele; Dieni, Cristina; Scarduzio, Mariangela; Pettorossi, Vito E

    2009-08-26

    In male rat brainstem slices, we investigated the involvement of locally synthesized 17beta-estradiol (E(2)) in the induction in the medial vestibular nucleus (MVN) of long-term potentiation (LTP) by high-frequency stimulation (HFS) of the primary vestibular afferents. We demonstrated that the blockade of aromatase by letrozole or of E(2) receptors (ERalpha and ERbeta) by ICI 182,780 prevented the HFS-induced LTP of the N1 wave of the evoked field potential (FP) without affecting baseline responses. Only prolonged afferent activation could induce low LTP. In contrast, HFS applied under a combined blockade of GABA(A) receptors and aromatase or ERs was still able to induce LTP, but it was significantly lower and slower. These findings demonstrate that E(2) does not have a tonic influence on the activity of the MVN neurons and provide the first evidence of the crucial role played by local synthesis of E(2) in inducing LTP. We suggest that the synthesis of E(2) occurs after aromatase activation during HFS and facilitates the development of vestibular synaptic plasticity by influencing glutamate and GABA transmission.

  15. X11beta rescues memory and long-term potentiation deficits in Alzheimer's disease APPswe Tg2576 mice.

    LENUS (Irish Health Repository)

    Mitchell, Jacqueline C

    2009-12-01

    Increased production and deposition of amyloid beta-protein (Abeta) are believed to be key pathogenic events in Alzheimer\\'s disease. As such, routes for lowering cerebral Abeta levels represent potential therapeutic targets for Alzheimer\\'s disease. X11beta is a neuronal adaptor protein that binds to the intracellular domain of the amyloid precursor protein (APP). Overexpression of X11beta inhibits Abeta production in a number of experimental systems. However, whether these changes to APP processing and Abeta production induced by X11beta overexpression also induce beneficial effects to memory and synaptic plasticity are not known. We report here that X11beta-mediated reduction in cerebral Abeta is associated with normalization of both cognition and in vivo long-term potentiation in aged APPswe Tg2576 transgenic mice that model the amyloid pathology of Alzheimer\\'s disease. Overexpression of X11beta itself has no detectable adverse effects upon mouse behaviour. These findings support the notion that modulation of X11beta function represents a therapeutic target for Abeta-mediated neuronal dysfunction in Alzheimer\\'s disease.

  16. Recent Advances on the Role of Neurogenesis in the Adult Brain: Therapeutic Potential in Parkinson's and Alzheimer's Diseases.

    Science.gov (United States)

    Radad, Khaled; Moldzio, Rudolf; Al-Shraim, Mubarak; Kranner, Barbara; Krewenka, Christopher; Rausch, Wolf-Dieter

    2017-01-01

    Generation of nascent functional neurons from neural stem cells in the adult brain has recently become largely accepted by the neuroscience community. In adult mammals including humans, the process of neurogenesis has been well documented in two brain regions; the subventricular zone of the lateral ventricles and the subgranular zone in the dentate gyrus of the hippocampus. Some evidence has indicated neurogenesis in other regions of the adult mammalian brain such as the neocortex, cerebellum, striatum, amygdala and hypothalamus. These discoveries question a long standing dogma on nervous system regeneration and provide medical science with potential new strategies to harness the process of neurogenesis for treating neurological disabilities and neurodegenerative diseases. In this current review, we address the most recent advances on the role of neurogenesis in the adult brain and therapeutic potential in the two most common neurodegenerative disorders, Parkinson's and Alzheimer's diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. A neuroligin-1-derived peptide stimulates phosphorylation of the NMDA receptor NR1 subunit and rescues MK-801-induced decrease in long-term potentiation and memory impairment

    DEFF Research Database (Denmark)

    Korshunova, Irina; Gjørlund, Michelle D; Jacobsen, Sylwia Owczarek

    2015-01-01

    neurolide-1 effects on short- and long-term social and spatial memory in social recognition, Morris water-maze, and Y-maze tests. We found that subcutaneous neurolide-1 administration, restored hippocampal LTP compromised by NMDA receptor inhibitor MK-801. It counteracted MK-801-induced memory deficit...... in the water-maze and Y-maze tests after long-term treatment (24 h and 1-2 h before the test), but not after short-term exposure (1-2 h). Long-term exposure to neurolide-1 also facilitated social recognition memory. In addition, neurolide-1-induced phosphorylation of the NMDA receptor NR1 subunit on a site...... receptor phosphorylation after treatment with NL1 or a mimetic peptide, neurolide-1, was quantified by immunoblotting. Subsequently, we investigated effects of neurolide-1 on long-term potentiation (LTP) induction in hippocampal slices compromised by NMDA receptor inhibitor MK-801. Finally, we investigated...

  18. Effects of inhaled anesthetic isoflurane on long-term potentiation of CA3 pyramidal cell afferents in vivo

    Directory of Open Access Journals (Sweden)

    Ballesteros KA

    2012-11-01

    Full Text Available Kristen A Ballesteros,1 Angela Sikorski,2 James E Orfila,3 Joe L Martinez Jr41Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA; 2Texas A&M University Texarkana, Texarkana, TX, USA; 3University of Colorado in Denver, Denver, CO, USA; 4University of Illinois in Chicago, Chicago, IL, USAAbstract: Isoflurane is a preferred anesthetic, due to its properties that allow a precise concentration to be delivered continually during in vivo experimentation. The major mechanism of action of isoflurane is modulation of the γ-amino butyric acid (GABAA receptor-chloride channel, mediating inhibitory synaptic transmission. Animal studies have shown that isoflurane does not cause cell death, but it does inhibit cell growth and causes long-term hippocampal learning deficits. As there are no studies characterizing the effects of isoflurane on electrophysiological aspects of long-term potentiation (LTP in the hippocampus, it is important to determine whether isoflurane alters the characteristic responses of hippocampal afferents to cornu ammonis region 3 (CA3. We investigated the effects of isoflurane on adult male rats during in vivo induction of LTP, using the mossy fiber pathway, the lateral perforant pathway, the medial perforant pathway, and the commissural CA3 (cCA3 to CA3, with intracranial administration of Ringer’s solution, naloxone, RS-aminoindan-1, 5-dicarboxylic acid (AIDA, or 3-[(R-2-carboxypiperazin-4-yl]-propo-2-enyl-1-phosphonic acid (CPP. Then, we compared these responses to published electrophysiological data, using sodium pentobarbital as an anesthetic, under similar experimental conditions. Our results showed that LTP was exhibited in animals anesthetized with isoflurane under vehicle conditions. With the exception of AIDA in the lateral perforant pathway, the defining characteristics of the four pathways appeared to remain intact, except for the observation that LTP was markedly reduced in animals

  19. Stress enhances fear by forming new synapses with greater capacity for long-term potentiation in the amygdala.

    Science.gov (United States)

    Suvrathan, Aparna; Bennur, Sharath; Ghosh, Supriya; Tomar, Anupratap; Anilkumar, Shobha; Chattarji, Sumantra

    2014-01-05

    Prolonged and severe stress leads to cognitive deficits, but facilitates emotional behaviour. Little is known about the synaptic basis for this contrast. Here, we report that in rats subjected to chronic immobilization stress, long-term potentiation (LTP) and NMDA receptor (NMDAR)-mediated synaptic responses are enhanced in principal neurons of the lateral amygdala, a brain area involved in fear memory formation. This is accompanied by electrophysiological and morphological changes consistent with the formation of 'silent synapses', containing only NMDARs. In parallel, chronic stress also reduces synaptic inhibition. Together, these synaptic changes would enable amygdalar neurons to undergo further experience-dependent modifications, leading to stronger fear memories. Consistent with this prediction, stressed animals exhibit enhanced conditioned fear. Hence, stress may leave its mark in the amygdala by generating new synapses with greater capacity for plasticity, thereby creating an ideal neuronal substrate for affective disorders. These findings also highlight the unique features of stress-induced plasticity in the amygdala that are strikingly different from the stress-induced impairment of structure and function in the hippocampus.

  20. Matrix metalloproteinases regulate the formation of dendritic spine head protrusions during chemically induced long-term potentiation.

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Szepesi

    Full Text Available Dendritic spines are are small membranous protrusions that extend from neuronal dendrites and harbor the majority of excitatory synapses. Increasing evidence has shown that matrix metalloproteinases (MMPs, a family of extracellularly acting and Zn(2+-dependent endopeptidases, are able to rapidly modulate dendritic spine morphology. Spine head protrusions (SHPs are filopodia-like processes that extend from the dendritic spine head, representing a form of postsynaptic structural remodeling in response to altered neuronal activity. Herein, we show that chemically induced long-term potentiation (cLTP in dissociated hippocampal cultures upregulates MMP-9 activity that controls the formation of SHPs. Blocking of MMPs activity or microtubule dynamics abolishes the emergence of SHPs. In addition, autoactive recombinant MMP-9, promotes the formation of SHPs in organotypic hippocampal slices. Furthermore, spines with SHPs gained postsynaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA receptors upon cLTP and the synaptic delivery of AMPA receptors was controlled by MMPs. The present results strongly imply that MMP-9 is functionally involved in the formation of SHPs and the control of postsynaptic receptor distribution upon cLTP.

  1. Enhanced Stress Response in 5-HT1AR Overexpressing Mice: Altered HPA Function and Hippocampal Long-Term Potentiation.

    Science.gov (United States)

    Pilar-Cuéllar, Fuencisla; Vidal, Rebeca; Díaz, Álvaro; Garro-Martínez, Emilio; Linge, Raquel; Castro, Elena; Haberzettl, Robert; Fink, Heidrun; Bert, Bettina; Brosda, Jan; Romero, Beatriz; Crespo-Facorro, Benedicto; Pazos, Ángel

    2017-11-15

    Postsynaptic 5-HT 1A receptors (5-HT 1A R) play an important role in anxiety and stress, although their contribution is still controversial. Previous studies report that mice overexpressing postsynaptic 5-HT 1A Rs show no changes in basal anxiety, though the influence of stress conditions has not been addressed yet. In this study, we used this animal model to evaluate the role of 5-HT 1A Rs in anxiety response after pre-exposure to an acute stressor. Under basal conditions, 5-HT 1A R overexpressing animals presented high corticosterone levels and a lower mineralocorticoid/glucocorticoid receptor ratio. After pre-exposure to a single stressor, they showed a high anxiety-like response, associated with a blunted increase in corticosterone levels and higher c-Fos activation in the prefrontal cortex. Moreover, these mice also presented a lack of downregulation of hippocampal long-term potentiation after stress exposure. Therefore, higher postsynaptic 5-HT 1A R activation might predispose to a high anxious phenotype and an impaired stress coping behavior.

  2. Enhanced deficits in long-term potentiation in the adult dentate gyrus with 2nd trimester ethanol consumption.

    Directory of Open Access Journals (Sweden)

    Jennifer L Helfer

    Full Text Available Ethanol exposure during pregnancy can cause structural and functional changes in the brain that can impair cognitive capacity. The hippocampal formation, an area of the brain strongly linked with learning and memory, is particularly vulnerable to the teratogenic effects of ethanol. In the present experiments we sought to determine if the functional effects of developmental ethanol exposure could be linked to ethanol exposure during any single trimester-equivalent. Ethanol exposure during the 1(st or 3(rd trimester-equivalent produced only minor changes in synaptic plasticity in adult offspring. In contrast, ethanol exposure during the 2(nd trimester equivalent resulted in a pronounced decrease in long-term potentiation, indicating that the timing of exposure influences the severity of the deficit. Together, the results from these experiments demonstrate long-lasting alterations in synaptic plasticity as the result of developmental ethanol exposure and dependent on the timing of exposure. Furthermore, these results allude to neural circuit malfunction within the hippocampal formation, perhaps relating to the learning and memory deficits observed in individuals with fetal alcohol spectrum disorders.

  3. NMDA receptor expression and C terminus structure in the rotifer Brachionus plicatilis and long-term potentiation across the Metazoa.

    Science.gov (United States)

    Kenny, Nathan J; Dearden, Peter K

    2013-12-01

    The C termini of N-methyl-D-aspartate (NMDA) receptor NR2 subunits are thought to play a major role in the molecular establishment of memory across the Bilateria, via the phenomenon known as long-term potentiation (LTP). Despite their long history of use as models in the study of memory, the expression and structure of the NR2 subunit in the Lophotrochozoa has remained uncategorized. Here, we report the phylogenic relationships of NR subunits across the Bilateria, and the cloning and in situ analysis of expression of NMDA NR1 and NR2 subunits in the monogont rotifer Brachionus plicatilis. RNA in situ hybridization suggests expression of NMDA receptor subunits in B. plicatilis is neural, consistent with expression observed in other species, and ours is the first report confirming NR2 expression in the lophotrochozoan clade. However, the single NR2 subunit identified in B. plicatilis was found to lack the long C terminal domain found in vertebrates, which is believed to modulate LTP. Further investigation revealed that mollusc and annelid NR2 subunits possess long intracellular C terminal domains. As data from molluscs (and particularly Aplysia californica) are the basis for much of our understanding of LTP, understanding how these diverse lophotrochozoan C termini function in vivo will have many implications for how we consider the evolution of the molecular control of learning and memory across the Metazoa as a whole and interpret the results of experiments into this vital component of cognition.

  4. Widespread promoter methylation of synaptic plasticity genes in long-term potentiation in the adult brain in vivo.

    Science.gov (United States)

    Maag, Jesper L V; Kaczorowski, Dominik C; Panja, Debabrata; Peters, Timothy J; Bramham, Clive R; Wibrand, Karin; Dinger, Marcel E

    2017-03-23

    DNA methylation is a key modulator of gene expression in mammalian development and cellular differentiation, including neurons. To date, the role of DNA modifications in long-term potentiation (LTP) has not been explored. To investigate the occurrence of DNA methylation changes in LTP, we undertook the first detailed study to describe the methylation status of all known LTP-associated genes during LTP induction in the dentate gyrus of live rats. Using a methylated DNA immunoprecipitation (MeDIP)-array, together with previously published matched RNA-seq and public histone modification data, we discover widespread changes in methylation status of LTP-genes. We further show that the expression of many LTP-genes is correlated with their methylation status. We show that these correlated genes are enriched for RNA-processing, active histone marks, and specific transcription factors. These data reveal that the synaptic activity-evoked methylation changes correlates with pre-existing activation of the chromatin landscape. Finally, we show that methylation of Brain-derived neurotrophic factor (Bdnf) CpG-islands correlates with isoform switching from transcripts containing exon IV to exon I. Together, these data provide the first evidence of widespread regulation of methylation status in LTP-associated genes.

  5. A computational simulation of long-term synaptic potentiation inducing protocol processes with model of CA3 hippocampal microcircuit.

    Science.gov (United States)

    Świetlik, D; Białowąs, J; Kusiak, A; Cichońska, D

    2018-01-01

    An experimental study of computational model of the CA3 region presents cog-nitive and behavioural functions the hippocampus. The main property of the CA3 region is plastic recurrent connectivity, where the connections allow it to behave as an auto-associative memory. The computer simulations showed that CA3 model performs efficient long-term synaptic potentiation (LTP) induction and high rate of sub-millisecond coincidence detection. Average frequency of the CA3 pyramidal cells model was substantially higher in simulations with LTP induction protocol than without the LTP. The entropy of pyramidal cells with LTP seemed to be significantly higher than without LTP induction protocol (p = 0.0001). There was depression of entropy, which was caused by an increase of forgetting coefficient in pyramidal cells simulations without LTP (R = -0.88, p = 0.0008), whereas such correlation did not appear in LTP simulation (p = 0.4458). Our model of CA3 hippocampal formation microcircuit biologically inspired lets you understand neurophysiologic data. (Folia Morphol 2018; 77, 2: 210-220).

  6. The taurine transporter substrate guanidinoethyl sulfonate mimics the action of taurine on long-term synaptic potentiation.

    Science.gov (United States)

    Suárez, Luz M; Muñoz, María-Dolores; González, José C; Bustamante, Julián; Del Río, Rafael Martín; Solís, José M

    2016-11-01

    Taurine is especially abundant in rodent brain where it appears to be involved in osmoregulation and synaptic plasticity mechanisms. The demonstration of a physiological role for taurine has been hampered by the difficulty in modifying taurine levels in most tissues, including the brain. We used an experimental strategy to reduce taurine levels, involving treatment with guanidinoethyl sulfonate (GES), a structural analogue of taurine that, among other properties, acts as a competitive inhibitor of taurine transport. GES delivered in the drinking water of rats for 1 month effectively reduced taurine levels in brain structures (hippocampus, cerebellum and cortex) and outside the brain (heart, muscle, kidney, liver and plasma) by between 50 and 80 %, depending on the tissue. This partial taurine depletion did not affect either basal synaptic transmission or the late phase of long-term potentiation (late-LTP) in hippocampal slices. In vivo microdialysis studies in the hippocampus revealed that GES treatment reduced extracellular taurine levels and the magnitude of taurine released in response to the application of either N-methyl-D-aspartate (NMDA) or a hypoosmotic solution, without affecting release mechanisms. Finally, we demonstrated in hippocampal slices that a brief GES application can mimic taurine action on the conversion of a decremental LTP into a perdurable late-LTP, concluding that GES might replace taurine function in some mechanisms such as those implicated in synaptic plasticity.

  7. Potentiation of glucocorticoid release does not modify the long-term effects of a single exposure to immobilization stress.

    Science.gov (United States)

    Dal-Zotto, Silvina; Martí, Octavi; Delgado, Raúl; Armario, Antonio

    2004-12-01

    Previous work has shown that a single exposure of rats to a severe stressor (immobilization, IMO) results, days to weeks later, in a reduced response (desensitization) of the hypothalamic-pituitary-adrenal (HPA) axis to a second exposure to the same stressor. In the present work, we studied the influence of both length of exposure to IMO and circulating levels of corticosterone on the first day on the degree of desensitization of two sets of physiological variables: HPA hormones and food intake. Rats were given SC saline or ACTH administration and then exposed to IMO for 0, 1 or 20 min. Seven days later, all rats were exposed to 20 min IMO. HPA response was followed on both experimental days by repeated blood sampling and food intake was measured on a 24-h basis. Both ACTH administration and IMO activates the HPA axis and IMO reduced food intake for several days. A single previous experience with IMO enhanced the post-IMO return of HPA hormones to basal levels on day 8 and reduced the degree of anorexia. The protective effect of previous IMO on food intake was independent of, whereas that on HPA activation was positively related to, the length of exposure on day 1. Concomitant ACTH administration on day 1 did not modify the observed effects. Long-term protective effects of a single exposure to IMO are observed even with a brief exposure, but they are not potentiated by increasing corticosterone levels during the first exposure.

  8. Methylprednisolone as a memory enhancer in rats: Effects on aversive memory, long-term potentiation and calcium influx.

    Science.gov (United States)

    de Vargas, Liane da Silva; Gonçalves, Rithiele; Lara, Marcus Vinícius S; Costa-Ferro, Zaquer S M; Salamoni, Simone Denise; Domingues, Michelle Flores; Piovesan, Angela Regina; de Assis, Dênis Reis; Vinade, Lucia; Corrado, Alexandre P; Alves-Do-Prado, Wilson; Correia-de-Sá, Paulo; da Costa, Jaderson Costa; Izquierdo, Ivan; Dal Belo, Cháriston A; Mello-Carpes, Pâmela B

    2017-09-01

    It is well recognized that stress or glucocorticoids hormones treatment can modulate memory performance in both directions, either impairing or enhancing it. Despite the high number of studies aiming at explaining the effects of glucocorticoids on memory, this has not yet been completely elucidated. Here, we demonstrate that a low daily dose of methylprednisolone (MP, 5mg/kg, i.p.) administered for 10-days favors aversive memory persistence in adult rats, without any effect on the exploring behavior, locomotor activity, anxiety levels and pain perception. Enhanced performance on the inhibitory avoidance task was correlated with long-term potentiation (LTP), a phenomenon that was strengthen in hippocampal slices of rats injected with MP (5mg/kg) during 10days. Additionally, in vitro incubation with MP (30-300µM) concentration-dependently increased intracellular [Ca 2+ ] i in cultured hippocampal neurons depolarized by KCl (35mM). In conclusion, a low daily dose of MP for 10days may promote aversive memory persistence in rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Translating long-term potentiation from animals to humans: a novel method for noninvasive assessment of cortical plasticity.

    Science.gov (United States)

    Clapp, Wesley C; Hamm, Jeff P; Kirk, Ian J; Teyler, Timothy J

    2012-03-15

    Long-term potentiation (LTP) is a synaptic mechanism underlying learning and memory that has been studied extensively in laboratory animals. The study of LTP recently has been extended into humans with repetitive sensory stimulation to induce cortical LTP. In this review article, we will discuss past results from our group demonstrating that repetitive sensory stimulation (visual or auditory) induces LTP within the sensory cortex (visual/auditory, respectively) and can be measured noninvasively with electroencephalography or functional magnetic resonance imaging. We will discuss a number of studies that indicate that this form of LTP shares several characteristics with the synaptic LTP described in animals: it is frequency dependent, long-lasting (> 1 hour), input-specific, depotentiates with low-frequency stimulation, and is blocked by N-methyl-D-aspartate receptor blockers in rats. In this review, we also present new data with regard to the behavioral significance of human sensory LTP. These advances will permit enquiry into the functional significance of LTP that has been hindered by the absence of a human model. The ability to elicit LTP with a natural sensory stimulus noninvasively will provide a model system allowing the detailed examination of synaptic plasticity in normal subjects and might have future clinical applications in the diagnosis and assessment of neuropsychiatric and neurocognitive disorders. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  10. Midazolam inhibits hippocampal long-term potentiation and learning through dual central and peripheral benzodiazepine receptor activation and neurosteroidogenesis.

    Science.gov (United States)

    Tokuda, Kazuhiro; O'Dell, Kazuko A; Izumi, Yukitoshi; Zorumski, Charles F

    2010-12-15

    Benzodiazepines (BDZs) enhance GABA(A) receptor inhibition by direct actions on central BDZ receptors (CBRs). Although some BDZs also bind mitochondrial receptors [translocator protein (18 kDa) (TSPO)] and promote the synthesis of GABA-enhancing neurosteroids, the role of neurosteroids in the clinical effects of BDZs is unknown. In rat hippocampal slices, we compared midazolam, an anesthetic BDZ, with clonazepam, an anticonvulsant/anxiolytic BDZ that activates CBRs selectively. Midazolam, but not clonazepam, increased neurosteroid levels in CA1 pyramidal neurons without changing TSPO immunostaining. Midazolam, but not clonazepam, also augmented a form of spike inhibition after stimulation adjacent to the pyramidal cell layer and inhibited induction of long-term potentiation. These effects were prevented by finasteride, an inhibitor of neurosteroid synthesis, or 17PA [17-phenyl-(3α,5α)-androst-16-en-3-ol], a blocker of neurosteroid effects on GABA(A) receptors. Moreover, the synaptic effects were mimicked by a combination of clonazepam with FGIN (2-[2-(4-fluorophenyl)-1H-indol-3-yl]-N,N-dihexylacetamide), a selective TSPO agonist, or a combination of clonazepam with exogenous allopregnanolone. Consistent with these in vitro results, finasteride abolished the effects of midazolam on contextual fear learning when administrated 1 d before midazolam injection. Thus, dual activation of CBRs and TSPO appears to result in unique actions of clinically important BDZs. Furthermore, endogenous neurosteroids are shown to be important regulators of pyramidal neuron function and synaptic plasticity.

  11. In-Situ Strain Analysis of Potential Habitat Composites Exposed to a Simulated Long-Term Lunar Radiation Exposure

    Science.gov (United States)

    Rojdev, Kristina; O'Rourke, Mary Jane; Hill, Charles; Nutt, Steven; Atwell, William

    2010-01-01

    NASA is studying the effects of long-term space radiation on potential multifunctional composite materials for habitats to better determine their characteristics in the harsh space environment. Two composite materials were selected for the study and were placed in a test stand that simulated the stresses of a pressure vessel wall on the material. The samples in the test stand were exposed to radiation at either a fast dose rate or a slow dose rate, and their strain and temperature was recorded during the exposure. It was found that during a fast dose rate exposure the materials saw a decreased strain with time, or a shrinking of the materials. Given previous radiation studies of polymers, this is believed to be a result of crosslinking occurring in the matrix material. However, with a slow dose rate, the materials saw an increase in strain with time, or a stretching of the materials. This result is consistent with scission or degradation of the matrix occurring, possibly due to oxidative degradation.

  12. Impaired induction of long-term potentiation-like plasticity in patients with high-functioning autism and Asperger syndrome.

    Science.gov (United States)

    Jung, Nikolai H; Janzarik, Wibke G; Delvendahl, Igor; Münchau, Alexander; Biscaldi, Monica; Mainberger, Florian; Bäumer, Tobias; Rauh, Reinhold; Mall, Volker

    2013-01-01

    We aimed to investigate the induction of long-term potentiation (LTP)-like plasticity by paired associative stimulation (PAS) in patients with high-functioning autism and Asperger syndrome (HFA/AS). PAS with an interstimulus interval between electrical and transcranial magnetic stimulation of 25 ms (PAS(25)) was performed in patients with HFA/AS (n=9; eight males, one female; mean age 17 y 11 mo, SD 4 y 5 mo) and in typically developing age-matched volunteers (n=9; five males, four females; mean age 22 y 4 mo, SD 5 y 2 mo). The amplitude of motor-evoked potentials was measured before PAS(25), immediately after stimulation, and 30 minutes and 60 minutes later. A PAS protocol adapted to individual N20 latency (PAS(N20+2)) was performed in six additional patients with HFA/AS. Short-interval intracortical inhibition was measured using paired-pulse stimulation. In contrast to the typically developing participants, the patients with HFA/AS did not show a significant increase in motor-evoked potentials after PAS(25). This finding could also be demonstrated after adaptation for N20 latency. Short-interval intracortical inhibition of patients with HFA/AS was normal compared with the comparison group and did not correlate with PAS effect. Our results show a significant impairment of LTP-like plasticity induced by PAS in individuals with HFA/AS compared with typically developing participants. This finding is in accordance with results from animal studies as well as human studies. Impaired LTP-like plasticity in patients with HFA/AS points towards reduced excitatory synaptic connectivity and deficits in sensory-motor integration in these patients. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

  13. Long-term potentiation of synaptic response and intrinsic excitability in neurons of the rat medial vestibular nuclei.

    Science.gov (United States)

    Pettorossi, V E; Dieni, C V; Scarduzio, M; Grassi, S

    2011-07-28

    Using intracellular recordings, we investigated the effects of high frequency stimulation (HFS) of the primary vestibular afferents on the evoked excitatory postsynaptic potential (EPSP) and intrinsic excitability (IE) of type-A and type-B neurons of the medial vestibular nucleus (MVN), in male rat brainstem slices. HFS induces long-term potentiation (LTP) of both EPSP and IE, which may occur in combination or separately. Synaptic LTP is characterized by an increase in the amplitude, slope and decay time constant of EPSP and IE-LTP through enhancements of spontaneous and evoked neuron firing and of input resistance (Rin). Moreover, IE-LTP is associated with a decrease in action potential afterhyperpolarization (AHP) amplitude and an increase in interspike slope steepness (ISS). The more frequent effects of HFS are EPSP-LTP in type-B neurons and IE-LTP in type-A neurons. In addition, the development of EPSP-LTP is fast in type-B neurons but slow in type-A, whereas IE-LTP develops slowly in both types. We have demonstrated that activation of N-methyl-d aspartate receptors (NMDARs) is only required for EPSP-LTP induction, whereas metabotropic glutamate receptors type-1 (mGluR1) are necessary for IE-LTP induction as well as the full development and maintenance of EPSP-LTP. Taken together, these findings demonstrate that brief and intense activation of vestibular afferent input to the MVN neurons may provoke synaptic LTP and/or IE-LTP that, induced in combination or separately, may assure the different selectivity of the MVN neuron response enhancement to the afferent signals. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Effects of a human milk oligosaccharide, 2'-fucosyllactose, on hippocampal long-term potentiation and learning capabilities in rodents.

    Science.gov (United States)

    Vázquez, Enrique; Barranco, Alejandro; Ramírez, Maria; Gruart, Agnes; Delgado-García, José M; Martínez-Lara, Esther; Blanco, Santos; Martín, María Jesús; Castanys, Esther; Buck, Rachael; Prieto, Pedro; Rueda, Ricardo

    2015-05-01

    Human milk oligosaccharides (HMOs) are unique with regard to their diversity, quantity and complexity, particularly in comparison to bovine milk oligosaccharides. HMOs are associated with functional development during early life, mainly related to immunity and intestinal health. Whether HMOs elicit a positive effect on cognitive capabilities of lactating infants remains an open question. This study evaluated the role of the most abundant HMO, 2'-fucosyllactose (2'-FL), in synaptic plasticity and learning capabilities in rodents. Mice and rats were prepared for the chronic recording of field excitatory postsynaptic potentials evoked at the hippocampal CA3-CA1 synapse. Following chronic oral administration of 2'-FL, both species showed improvements in input/output curves and in long-term potentiation (LTP) evoked experimentally in alert behaving animals. This effect on LTP was related to better performance of animals in various types of learning behavioral tests. Mice were tested for spatial learning, working memory and operant conditioning using the IntelliCage system, while rats were submitted to a fixed-ratio schedule in the Skinner box. In both cases, 2'-FL-treated animals performed significantly better than controls. In addition, chronic administration of 2'-FL increased the expression of different molecules involved in the storage of newly acquired memories, such as the postsynaptic density protein 95, phosphorylated calcium/calmodulin-dependent kinase II and brain-derived neurotrophic factor in cortical and subcortical structures. Taken together, the data show that dietary 2'-FL affects cognitive domains and improves learning and memory in rodents. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Differences in kainate receptor involvement in hippocampal mossy fibre long-term potentiation depending on slice orientation.

    Science.gov (United States)

    Sherwood, John L; Amici, Mascia; Dargan, Sheila L; Culley, Georgia R; Fitzjohn, Stephen M; Jane, David E; Collingridge, Graham L; Lodge, David; Bortolotto, Zuner A

    2012-09-01

    Long-term potentiation (LTP) is a well-established experimental model used to investigate the synaptic basis of learning and memory. LTP at mossy fibre - CA3 synapses in the hippocampus is unusual because it is normally N-methyl-d-aspartate (NMDA) receptor-independent. Instead it seems that the trigger for mossy fibre LTP involves kainate receptors (KARs). Although it is generally accepted that pre-synaptic KARs play an essential role in frequency facilitation and LTP, their subunit composition remains a matter of significant controversy. We have reported previously that both frequency facilitation and LTP can be blocked by selective antagonism of GluK1 (formerly GluR5/Glu(K5))-containing KARs, but other groups have failed to reproduce this effect. Moreover, data from receptor knockout and mRNA expression studies argue against a major role of GluK1, supporting a more central role for GluK2 (formerly GluR6/Glu(K6)). A potential reason underlying the controversy in the pharmacological experiments may reside in differences in the preparations used. Here we show differences in pharmacological sensitivity of synaptic plasticity at mossy fibre - CA3 synapses depend critically on slice orientation. In transverse slices, LTP of fEPSPs was invariably resistant to GluK1-selective antagonists whereas in parasagittal slices LTP was consistently blocked by GluK1-selective antagonists. In addition, there were pronounced differences in the magnitude of frequency facilitation and the sensitivity to the mGlu2/3 receptor agonist DCG-IV. Using anterograde labelling of granule cells we show that slices of both orientations possess intact mossy fibres and both large and small presynaptic boutons. Transverse slices have denser fibre tracts but a smaller proportion of giant mossy fibre boutons. These results further demonstrate a considerable heterogeneity in the functional properties of the mossy fibre projection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. The effects of lindane and long-term potentiation (LTP) on pyramidal cell excitability in the rat hippocampal slice.

    Science.gov (United States)

    Albertson, T E; Walby, W F; Stark, L G; Joy, R M

    1997-01-01

    An in vitro orthodromic stimulation technique was used to examine the effects of lindane and long-term potentiation (LTP) inducing stimuli, alone or in combination, on the excitatory afferent terminal of CA1 pyramidal cells and on recurrent collateral evoked inhibition using the rat hippocampal slice model. Hippocampal slices of 400 microns thickness were perfused with oxygenated artificial cerebrospinal fluid. Stimulation of Schaffer collateral/commissural fibers produced extracellular excitatory postsynaptic potential (EPSP) and/or populations spike (PS) responses recorded from electrodes in the CA1 region. A paired-pulse technique was used to measure gamma-aminobutyric acid (GABAA)-mediated recurrent inhibition before and after treatments. After both lindane and LTP, larger PS amplitudes for a given stimulus intensity were seen. The resulting leftward shift in the curve of the PS amplitude versus stimulus intensity was larger after LTP than after 25 microM lindane. Both lindane and LTP treatments reduced PS thresholds and reduced or eliminated recurrent inhibition as measured by paired-pulse stimulation at the 15 msec interval. The reduction of recurrent inhibition after both treatments was more pronounced at lower stimulus intensities. When LTP stimuli were applied after lindane exposure a further large shift to the left was seen in the PS amplitude versus stimulus intensity curve. A smaller shift to the left was seen in the PS amplitude versus stimulus intensity curve only at the higher stimuli when lindane exposure occurred after LTP. Only at low stimulus intensities were further argumentations seen in PS amplitudes when the LTP stimuli was followed by a second LTP stimuli. Previous exposure to 25 microM lindane stimuli does not block the development of a further robust LTP in this in vitro model.

  17. The ethanol metabolite acetaldehyde inhibits the induction of long-term potentiation in the rat dentate gyrus in vivo

    Science.gov (United States)

    Abe, Kazuho; Yamaguchi, Shinichi; Sugiura, Minoru; Saito, Hiroshi

    1999-01-01

    Ethanol has been reported to inhibit the induction of long-term potentiation (LTP) in the hippocampus. However, the correlation between the effects of ethanol in vivo and in vitro remained unclear. In addition, previous works have little considered the possibility that the effect of ethanol is mediated by its metabolites. To solve these problems, we investigated the effects of ethanol and acetaldehyde, the first metabolite in the metabolism of ethanol, on the induction of LTP at medial perforant path-granule cell synapses in the dentate gyrus of anaesthetized rats in vivo.Oral administration of 1 g kg−1 ethanol significantly inhibited the induction of LTP, confirming the effectiveness of ethanol in vivo.A lower dose of ethanol (0.5 g kg−1) failed to inhibit the induction of LTP in intact rats, but significantly inhibited LTP in rats treated with disulfiram, an inhibitor of aldehyde dehydrogenase, demonstrating that LTP is inhibited by acetaldehyde accumulation following ethanol administration.Intravenous injection of acetaldehyde (0.06 g kg−1) significantly inhibited the induction of LTP.The inhibitory effect of acetaldehyde on LTP induction was also observed when it was injected into the cerebroventricules, suggesting that acetaldehyde has a direct effect on the brain. The intracerebroventricular dose of acetaldehyde effective in inhibiting LTP induction (0.1–0.15 mg brain−1) was approximately 10 fold lower than that of ethanol (1.0–1.5 mg brain−1).It is possible that acetaldehyde is partly responsible for memory impairments induced by ethanol intoxication. PMID:10482910

  18. Exposure to Kynurenic Acid during Adolescence Increases Sign-Tracking and Impairs Long-Term Potentiation in Adulthood.

    Science.gov (United States)

    DeAngeli, Nicole E; Todd, Travis P; Chang, Stephen E; Yeh, Hermes H; Yeh, Pamela W; Bucci, David J

    2014-01-01

    Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and α7 nicotinic acetylcholine receptors, both of which are critically involved in neurodevelopment, plasticity, and behavior. In Experiment 1, rats were treated throughout adolescence with L-kynurenine (L-KYN), the precursor of KYNA. As adults, the rats were tested drug-free in an autoshaping procedure in which a lever was paired with food. Rats treated with L-KYN during adolescence exhibited increased sign-tracking behavior (lever pressing) when they were tested as adults. Sign-tracking is thought to reflect the lever acquiring incentive salience (motivational value) as a result of its pairing with reward. Thus, KYNA exposure may increase the incentive salience of cues associated with reward, perhaps contributing to an increase in sensitivity to drug-related cues in persons with schizophrenia. In Experiment 2, we tested the effects of exposure to KYNA during adolescence on hippocampal long-term potentiation (LTP). Rats treated with L-KYN exhibited no LTP after a burst of high-frequency stimulation that was sufficient to produce robust LTP in vehicle-treated rats. This finding represents the first demonstrated consequence of elevated KYNA concentration during development and provides insight into the basis for cognitive and behavioral deficits that result from exposure to KYNA during adolescence.

  19. Priming stimulation of basal but not lateral amygdala affects long-term potentiation in the rat dentate gyrus in vivo.

    Science.gov (United States)

    Li, Z; Richter-Levin, G

    2013-08-29

    The amygdaloid complex, or amygdala, has been implicated in assigning emotional significance to sensory information and producing appropriate behavioral responses to external stimuli. The lateral and basal nuclei (lateral and basal amygdala), which are termed together as basolateral amygdala, play a critical role in emotional and motivational learning and memory. It has been established that the basolateral amygdala activation by behavioral manipulations or direct electrical stimulation can modulate hippocampal long-term potentiation (LTP), a putative cellular mechanism of memory. However, the specific functional role of each subnucleus in the modulation of hippocampal LTP has not been studied yet, even though studies have shown cytoarchitectural differences between the basal and lateral amygdala and differences in the connections of each one of them to other brain areas. In this study we have tested the effects of lateral or basal amygdala pre-stimulation on hippocampal dentate gyrus LTP, induced by theta burst stimulation of the perforant path, in anesthetized rats. We found that while priming stimulation of the lateral amygdala did not affect LTP of the dentate gyrus, priming stimulation of the basal amygdala enhanced the LTP response when the priming stimulation was relatively weak, but impaired it when it was relatively strong. These results show that the basal and lateral nuclei of the amygdala, which have been already shown to differ in their anatomy and connectivity, may also have different functional roles. These findings raise the possibility that the lateral and basal amygdala differentially modulate memory processes in the hippocampus under emotional and motivational situations. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Harmful potential toxic elements in greenhouse soils under long-term cultivation in Almería (Spain)

    Science.gov (United States)

    Joaquin Ramos-Miras, Jose; Rodríguez Martín, Jose Antonio; Boluda, Rafael; Bech, Jaume; Gil, Carlos

    2014-05-01

    Heavy metals (HM) are considered highly significant environmental contaminants and are the object of many scientific research works into the soil environment. Activities like agriculture or industry can increase the concentration of these contaminants in soils and waters, which can affect the food chain. Intensification of certain agricultural practices, constant and excessive use of fertilizers and phytosanitary products, and using machinery, increase the HM content in agricultural soils. Many studies have dealt with HM accumulation over time. Despite these works, the influence of long periods of time on these contents, the dynamics and evolution of these elements in agricultural soils, especially soils used for intensive farming purposes under greenhouse conditions, remain unknown to a certain extent. The western Almería region (Spain) is a very important area from both the socio-economic and agricultural viewpoints. A common practice in greenhouse agriculture is the addition of agrochemicals to soils and crops to improve nutrient supply or crop protection and disease control. Such intense agricultural activity has a strong impact, which may have negative repercussions on both these greenhouse soils and the environment. A research has been carried out to determine the total and available levels of six harmful potentially toxic elements (Cd, Cu, Pb, Ni, Zn and Co), and to assess long-term variations in the greenhouse soils of western Almeria. The results indicate that managing soils in the greenhouse preparation stage determines major changes in total and available HM contents. Furthermore, Cd, Cu and Pb enrichment in soil was observed depending on the element and years of growth.

  1. Inhibition of long-term potentiation in the schaffer-CA1 pathway by repetitive high-intensity sound stimulation.

    Science.gov (United States)

    Cunha, A O S; de Oliveira, J A C; Almeida, S S; Garcia-Cairasco, N; Leão, R M

    2015-12-03

    High-intensity sound can induce seizures in susceptible animals. After repeated acoustic stimuli changes in behavioural seizure repertoire and epileptic EEG activity might be seen in recruited limbic and forebrain structures, a phenomenon known as audiogenic kindling. It is postulated that audiogenic kindling can produce synaptic plasticity events leading to the spread of epileptogenic activity to the limbic system. In order to test this hypothesis, we investigated if long-term potentiation (LTP) of hippocampal Schaffer-CA1 synapses and spatial navigation memory are altered by a repeated high-intensity sound stimulation (HISS) protocol, consisting of one-minute 120 dB broadband noise applied twice a day for 10 days, in normal Wistar rats and in audiogenic seizure-prone rats (Wistar Audiogenic Rats - WARs). After HISS all WARs exhibited midbrain seizures and 50% of these animals developed limbic recruitment, while only 26% of Wistar rats presented midbrain seizures and none of them had limbic recruitment. In naïve animals, LTP in hippocampal CA1 neurons was induced by 50- or 100-Hz high-frequency stimulation of Schaffer fibres in slices from both Wistar and WAR animals similarly. Surprisingly, HISS suppressed LTP in CA1 neurons in slices from Wistar rats that did not present any seizure, and inhibited LTP in slices from Wistar rats with only midbrain seizures. However HISS had no effect on LTP in CA1 neurons from slices of WARs. Interestingly HISS did not alter spatial navigation and memory in both strains. These findings show that repeated high-intensity sound stimulation prevent LTP of Schaffer-CA1 synapses from Wistar rats, without affecting spatial memory. This effect was not seen in hippocampi from audiogenic seizure-prone WARs. In WARs the link between auditory stimulation and hippocampal LTP seems to be disrupted which could be relevant for the susceptibility to seizures in this strain. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Exposure to Kynurenic Acid during Adolescence Increases Sign-Tracking and Impairs Long-Term Potentiation in Adulthood

    Science.gov (United States)

    DeAngeli, Nicole E.; Todd, Travis P.; Chang, Stephen E.; Yeh, Hermes H.; Yeh, Pamela W.; Bucci, David J.

    2015-01-01

    Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and α7 nicotinic acetylcholine receptors, both of which are critically involved in neurodevelopment, plasticity, and behavior. In Experiment 1, rats were treated throughout adolescence with L-kynurenine (L-KYN), the precursor of KYNA. As adults, the rats were tested drug-free in an autoshaping procedure in which a lever was paired with food. Rats treated with L-KYN during adolescence exhibited increased sign-tracking behavior (lever pressing) when they were tested as adults. Sign-tracking is thought to reflect the lever acquiring incentive salience (motivational value) as a result of its pairing with reward. Thus, KYNA exposure may increase the incentive salience of cues associated with reward, perhaps contributing to an increase in sensitivity to drug-related cues in persons with schizophrenia. In Experiment 2, we tested the effects of exposure to KYNA during adolescence on hippocampal long-term potentiation (LTP). Rats treated with L-KYN exhibited no LTP after a burst of high-frequency stimulation that was sufficient to produce robust LTP in vehicle-treated rats. This finding represents the first demonstrated consequence of elevated KYNA concentration during development and provides insight into the basis for cognitive and behavioral deficits that result from exposure to KYNA during adolescence

  3. Long-term data from a small mammal community reveal loss of diversity and potential effects of local climate change.

    Science.gov (United States)

    Santoro, Simone; Sanchez-Suarez, Cristina; Rouco, Carlos; Palomo, L Javier; Fernández, M Carmen; Kufner, Maura B; Moreno, Sacramento

    2017-10-01

    Climate change affects distribution and persistence of species. However, forecasting species' responses to these changes requires long-term data series that are often lacking in ecological studies. We used 15 years of small mammal trapping data collected between 1978 and 2015 in 3 areas at Doñana National Park (southwest Spain) to (i) describe changes in species composition and (ii) test the association between local climate conditions and size of small mammal populations. Overall, 5 species were captured: wood mouse Apodemus sylvaticus , algerian mouse Mus spretus , greater white-toothed shrew Crocidura russula , garden dormouse Eliomys quercinus , and black rat Rattus rattus . The temporal pattern in the proportion of captures of each species suggests that the small mammal diversity declined with time. Although the larger species (e.g., E. quercinus ), better adapted to colder climate, have disappeared from our trapping records, M. spretus , a small species inhabiting southwest Europe and the Mediterranean coast of Africa, currently is almost the only trapped species. We used 2-level hierarchical models to separate changes in abundance from changes in probability of capture using records of A. sylvaticus in all 3 areas and of M. spretus in 1. We found that heavy rainfall and low temperatures were positively related to abundance of A. sylvaticus , and that the number of extremely hot days was negatively related to abundance of M. spretus . Despite other mechanisms are likely to be involved, our findings support the importance of climate for the distribution and persistence of these species and raise conservation concerns about potential cascading effects in the Doñana ecosystem.

  4. Preventive effect of theanine intake on stress-induced impairments of hippocamapal long-term potentiation and recognition memory.

    Science.gov (United States)

    Tamano, Haruna; Fukura, Kotaro; Suzuki, Miki; Sakamoto, Kazuhiro; Yokogoshi, Hidehiko; Takeda, Atsushi

    2013-06-01

    Theanine, γ-glutamylethylamide, is one of the major amino acid components in green tea. On the basis of the preventive effect of theanine intake after birth on mild stress-induced attenuation of hippocamapal CA1 long-term potentiation (LTP), the present study evaluated the effect of theanine intake after weaning on stress-induced impairments of LTP and recognition memory. Young rats were fed water containing 0.3% theanine for 3 weeks after weaning and subjected to water immersion stress for 30min, which was more severe than tail suspension stress for 30s used previously. Serum corticosterone levels were lower in theanine-administered rats than in the control rats even after exposure to stress. CA1 LTP induced by a 100-Hz tetanus for 1s was inhibited in the presence of 2-amino-5-phosphonovalerate (APV), an N-methyl-d-aspartate (NMDA) receptor antagonist, in hippocampal slices from the control rats and was attenuated by water immersion stress. In contrast, CA1 LTP was not significantly inhibited in the presence of APV in hippocampal slices from theanine-administered rats and was not attenuated by the stress. Furthermore, object recognition memory was impaired in the control rats, but not in theanine-administered rats. The present study indicates the preventive effect of theanine intake after weaning on stress-induced impairments of hippocampal LTP and recognition memory. It is likely that the modification of corticosterone secretion after theanine intake is involved in the preventive effect. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Exposure to Kynurenic Acid during Adolescence Increases Sign-tracking and Impairs Long-term Potentiation in Adulthood

    Directory of Open Access Journals (Sweden)

    Nicole eDeAngeli

    2015-01-01

    Full Text Available Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently there are few treatments for persons with a dual-diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA, a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and α7 nicotinic acetylcholine receptors, both of which are critically involved in neurodevelopment, plasticity, and behavior. In Experiment 1, rats were treated throughout adolescence with l-kynurenine (L-KYN, the precursor of KYNA. As adults, the rats were tested drug-free in an autoshaping procedure in which a lever was paired with food. Rats treated with L-KYN during adolescence exhibited increased sign-tracking behavior (lever pressing when they were tested as adults. Sign-tracking is thought to reflect the lever acquiring incentive salience (motivational value as a result of its pairing with reward. Thus, KYNA exposure may increase the incentive salience of cues associated with reward, perhaps contributing to an increase in sensitivity to drug-related cues in persons with schizophrenia. In Experiment 2, we tested the effects of exposure to KYNA during adolescence on hippocampal long-term potentiation (LTP. Rats treated with L-KYN exhibited no LTP after a burst of high frequency stimulation that was sufficient to produce robust LTP in vehicle-treated rats. This finding represents the first demonstrated consequence of elevated KYNA concentration during development and provides insight into the basis for cognitive and behavioral deficits that result from exposure to KYNA during

  6. Daily acclimation handling does not affect hippocampal long-term potentiation or cause chronic sleep deprivation in mice.

    Science.gov (United States)

    Vecsey, Christopher G; Wimmer, Mathieu E J; Havekes, Robbert; Park, Alan J; Perron, Isaac J; Meerlo, Peter; Abel, Ted

    2013-04-01

    Gentle handling is commonly used to perform brief sleep deprivation in rodents. It was recently reported that daily acclimation handling, which is often used before behavioral assays, causes alterations in sleep, stress, and levels of N-methyl-D-aspartate receptor subunits prior to the actual period of sleep deprivation. It was therefore suggested that acclimation handling could mediate some of the observed effects of subsequent sleep deprivation. Here, we examine whether acclimation handling, performed as in our sleep deprivation studies, alters sleep/wake behavior, stress, or forms of hippocampal synaptic plasticity that are impaired by sleep deprivation. Adult C57BL/6J mice were either handled daily for 6 days or were left undisturbed in their home cages. On the day after the 6(th) day of handling, long-term potentiation (LTP) was induced in hippocampal slices with spaced four-train stimulation, which we previously demonstrated to be impaired by brief sleep deprivation. Basal synaptic properties were also assessed. In three other sets of animals, activity monitoring, polysomnography, and stress hormone measurements were performed during the 6 days of handling. Daily gentle handling alone does not alter LTP, rest/activity patterns, or sleep/wake architecture. Handling initially induces a minimal stress response, but by the 6(th) day, stress hormone levels are unaltered by handling. It is possible to handle mice daily to accustom them to the researcher without causing alterations in sleep, stress, or synaptic plasticity in the hippocampus. Therefore, effects of acclimation handling cannot explain the impairments in signaling mechanisms, synaptic plasticity, and memory that result from brief sleep deprivation.

  7. Social Isolation During Adolescence Strengthens Retention of Fear Memories and Facilitates Induction of Late-Phase Long-Term Potentiation.

    Science.gov (United States)

    Liu, Ji-Hong; You, Qiang-Long; Wei, Mei-Dan; Wang, Qian; Luo, Zheng-Yi; Lin, Song; Huang, Lang; Li, Shu-Ji; Li, Xiao-Wen; Gao, Tian-Ming

    2015-12-01

    Social isolation during the vulnerable period of adolescence produces emotional dysregulation that often manifests as abnormal behavior in adulthood. The enduring consequence of isolation might be caused by a weakened ability to forget unpleasant memories. However, it remains unclear whether isolation affects unpleasant memories. To address this, we used a model of associative learning to induce the fear memories and evaluated the influence of isolation mice during adolescence on the subsequent retention of fear memories and its underlying cellular mechanisms. Following adolescent social isolation, we found that mice decreased their social interaction time and had an increase in anxiety-related behavior. Interestingly, when we assessed memory retention, we found that isolated mice were unable to forget aversive memories when tested 4 weeks after the original event. Consistent with this, we observed that a single train of high-frequency stimulation (HFS) enabled a late-phase long-term potentiation (L-LTP) in the hippocampal CA1 region of isolated mice, whereas only an early-phase LTP was observed with the same stimulation in the control mice. Social isolation during adolescence also increased brain-derived neurotrophic factor (BDNF) expression in the hippocampus, and application of a tropomyosin-related kinase B (TrkB) receptor inhibitor ameliorated the facilitated L-LTP seen after isolation. Together, our results suggest that adolescent isolation may result in mental disorders during adulthood and that this may stem from an inability to forget the unpleasant memories via BDNF-mediated synaptic plasticity. These findings may give us a new strategy to prevent mental disorders caused by persistent unpleasant memories.

  8. Prior Activation of Inositol 1,4,5-Trisphosphate Receptors Suppresses the Subsequent Induction of Long-Term Potentiation in Hippocampal CA1 Neurons

    Science.gov (United States)

    Fujii, Satoshi; Yamazaki, Yoshihiko; Goto, Jun-Ichi; Fujiwara, Hiroki; Mikoshiba, Katsuhiko

    2016-01-01

    We investigated the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) activated by preconditioning low-frequency afferent stimulation (LFS) in the subsequent induction of long-term potentiation (LTP) in CA1 neurons in hippocampal slices from mature guinea pigs. Induction of LTP in the field excitatory postsynaptic potential or the population…

  9. Long-Term Effects of Child Corporal Punishment on Depressive Symptoms in Young Adults: Potential Moderators and Mediators

    Science.gov (United States)

    Turner, Heather A.; Muller, Paul A.

    2004-01-01

    Based on a sample of 649 students from 3 New England colleges, this study examined the long-term effects of childhood corporal punishment on symptoms of depression and considered factors that may moderate or mediate the association. Similar to national studies, approximately 40% of the sample reported experiencing some level of corporal punishment…

  10. US Department of Energy Approach to Probabilistic Evaluation of Long-Term Safety for a Potential Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Dr. R. Dyer; Dr. R. Andrews; Dr. A. Van Luik

    2005-01-01

    Regulatory requirements being addressed in the US geological repository program for spent nuclear fuel and high-level waste disposal specify probabilistically defined mean-value dose limits. These dose limits reflect acceptable levels of risk. The probabilistic approach mandated by regulation calculates a ''risk of a dose,'' a risk of a potential given dose value at a specific time in the future to a hypothetical person. The mean value of the time-dependent performance measure needs to remain below an acceptable level defined by regulation. Because there are uncertain parameters that are important to system performance, the regulation mandates an analysis focused on the mean value of the performance measure, but that also explores the ''full range of defensible and reasonable parameter distributions''...System performance evaluations should not be unduly influenced by...''extreme physical situations and parameter values''. Challenges in this approach lie in defending the scientific basis for the models selected, and the data and distributions sampled. A significant challenge lies in showing that uncertainties are properly identified and evaluated. A single-value parameter has no uncertainty, and where used such values need to be supported by scientific information showing the selected value is appropriate. Uncertainties are inherent in data, but are also introduced by creating parameter distributions from data sets, selecting models from among alternative models, abstracting models for use in probabilistic analysis, and in selecting the range of initiating event probabilities for unlikely events. The goal of the assessment currently in progress is to evaluate the level of risk inherent in moving ahead to the next phase of repository development: construction. During the construction phase, more will be learned to inform a new long-term risk evaluation to support moving to the next phase: accepting waste. Therefore, though there was sufficient confidence of safety

  11. Ramifications of a potential gap in passive microwave data for the long-term sea ice climate record

    Science.gov (United States)

    Meier, W.; Stewart, J. S.

    2017-12-01

    will also discuss potential contingency plans, such as using operational sea ice charts, to fill any gaps. This would allow the record to continue, but the consistency of the time series will be degraded because the ice charts use human analysis and differing sources, amounts and quality of input data, which makes them sub-optimal for long-term climate records.

  12. Potential of the solid-Earth response for limiting long-term West Antarctic Ice Sheet retreat

    Science.gov (United States)

    Konrad, Hannes; Sasgen, Ingo; Pollard, David; Klemann, Volker

    2016-04-01

    for asthenosphere viscosities of 3x10^20 Pa s or higher. References Gomez, N., Pollard, D., Mitrovica, J. X., Huybers, P., & Clark, P. U. (2012). Evolution of a coupled marine ice sheet-sea level model. J. Geophys. Res. 117(F1). Konrad, H., Sasgen, I., Pollard, D. & Klemann, V. (2015). Potential of the solid-Earth response for limiting long-term West Antarctic Ice Sheet retreat in a warming climate. Earth Planet. Sci. Lett. 432, 2015.

  13. Long-term potentiation and memory processes in the psychological works of Sigmund Freud and in the formation of neuropsychiatric symptoms.

    Science.gov (United States)

    Centonze, D; Siracusano, A; Calabresi, P; Bernardi, G

    2005-01-01

    Far from disproving the model of mind functioning proposed by psychoanalysis, the recent advances in neuropsychiatrical research confirmed the crucial ideas of Sigmund Freud. The hypothesis that the origin of mental illnesses lies in the impossibility for a subject to erase the long-term effects of a remote adverse event is in tune with the view that several psychiatric disturbances reflect the activation of aberrant unconscious memory processes. Freud's insights did not stop here, but went on to describe in an extremely precise manner the neural mechanisms of memory formation almost a century before the description of long-term synaptic potentiation.

  14. DEVELOPMENTAL LEAD (PB) EXPOSURE REDUCES THE ABILITY OF THE NNDA ANTAGONIST MK801 TO SUPPRESS LONG-TERM POTENTIATION (LTP) IN THE RAT DENTATE GYRUS, IN VIVO

    Science.gov (United States)

    Chronic developmental lead (Pb) exposure increases the threshold and enhances decay of long-term potentiation (LTP) in the dentate gyrus of the hippocampal formation. MK-801 and other antagonists of the N-methyl-D-aspartate (NMDA) glutamate receptor subtype impair induction of LT...

  15. A juvenile form of postsynaptic hippocampal long-term potentiation in mice deficient for the AMPA receptor subunit GluR-A

    NARCIS (Netherlands)

    Jensen, V.; Kaiser, K.M.M.; Borchardt, T.; Adelmann, G.; Rozov, A.; Burnashev, N.; Brix, C.; Frotscher, M.; Anderson, P.; Hvalby, O.; Sakmann, B.; Seeburg, P.H.; Sprengel, R.

    2003-01-01

    In adult mice, long-term potentiation (LTP) of synaptic transmission at CA3-to-CA1 synapses induced by tetanic stimulation requires L-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors containing GluR-A subunits. Here, we report a GluR-A-independent form of LTP, which is comparable in

  16. Using OpenTarget to Generate Potential Countermeasures for Long-Term Space Exposure from Data Available on GeneLab

    Science.gov (United States)

    Beheshti, Afshin

    2018-01-01

    GeneLab as a general tool for the scientific community; Utilizing GeneLab datasets to generate hypothesis and determining potential biological targets against health risks due to long-term space missions; How can OpenTarget be used to discover novel drugs to test as countermeasures that can be utilized by astronauts.

  17. Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

    Science.gov (United States)

    Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; Flather, Curtis H; VanDerWal, Jeremy; Akçakaya, H Resit; Thogmartin, Wayne E; Albright, Thomas P; Vavrus, Stephen J; Heglund, Patricia J

    2016-12-01

    Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate

  18. The impact of cocaine on adult hippocampal neurogenesis: Potential neurobiological mechanisms and contributions to maladaptive cognition in cocaine addiction disorder.

    Science.gov (United States)

    Castilla-Ortega, Estela; Ladrón de Guevara-Miranda, David; Serrano, Antonia; Pavón, Francisco J; Suárez, Juan; Rodríguez de Fonseca, Fernando; Santín, Luis J

    2017-10-01

    After discovering that addictive drugs alter adult neurogenesis, the potential role of adult-born hippocampal neurons in drug addiction has become a promising research field, in which cocaine is the most frequently investigated drug. Although a substantial amount of pre-clinical evidence has accumulated, additional studies are required to reveal the mechanisms by which cocaine modulates adult hippocampal neurogenesis (AHN) and determine whether these adult-born neurons have a role in cocaine-related behaviors, such as cocaine-mediated cognitive symptoms. First, this review will summarize the cocaine-induced alterations in a number of neurobiological factors (neurotransmitters, neurotrophins, glucocorticoids, inflammatory mediators) that likely regulate both hippocampal-dependent learning and adult hippocampal neurogenesis after cocaine exposure. A separate section will provide a detailed review of the available literature that challenges the common view that cocaine reduces adult hippocampal neurogenesis. In fact, cocaine has a short-term anti-proliferative role, but the young adult-born neurons are apparently spared, or even enhanced, following certain cocaine protocols. Thus, we will try to reconcile this evidence with the hippocampal-dependent cognitive symptoms that are typically observed in cocaine addicts, and we will propose new directions for future studies to test the relevant hypothesis. Based on the evidence presented here, the regulation of adult hippocampal neurogenesis might be one of the many mechanisms by which cocaine sculpts hippocampus-dependent learning. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Predictive Potential of Preoperative Nutritional Status in Long-Term Outcome Projections for Patients with Gastric Cancer.

    Science.gov (United States)

    Sakurai, Katsunobu; Ohira, Masaichi; Tamura, Tatsuro; Toyokawa, Takahiro; Amano, Ryosuke; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Maeda, Kiyoshi; Hirakawa, Kosei

    2016-02-01

    Preoperative nutritional status not only correlates with the incidence of postoperative complications but also may be indicative of long-term outcomes for patients with cancer. The impact of preoperative nutritional status on outcomes for patients undergoing gastrectomy for gastric cancer (GC) was investigated. The study reviewed 594 patients treated for GC by gastrectomy at the authors' hospital between January, 2004 and December, 2010. Onodera's prognostic nutritional index (PNI) was invoked, using an optimal cut point to group patients as having high (PNI > 45; n = 449) or low (PNI ≤ 45; n = 145) nutritional status. Clinicopathologic features, perioperative results, and long-term outcomes, including cause of death, were compared. Multivariate analysis of 5-year overall survival (OS) and disease-specific survival (DSS) indicated that low PNI was independently associated with unfavorable outcomes for patients with GC. In subgroup analysis, the 5-year OS and DSS rates for patients with GC at stages 1 and 2 were significantly worse in the low PNI group than in the high PNI group. Although wound and extrasurgical field infections also tended to be more frequent in the low PNI group, postoperative intraabdominal infections did not differ significantly by group. Preoperative PNI may have merit as a gauge of prognosis for patients with GC at stages 1 and 2, but PNI and postoperative morbidity showed no correlation in this setting.

  20. Forever Young(er: Potential Age-defying Effects of Long-term Meditation on Gray Matter Atrophy

    Directory of Open Access Journals (Sweden)

    Eileen eLuders

    2015-01-01

    Full Text Available While overall life expectancy has been increasing, the human brain still begins deteriorating after the first two decades of life and continues degrading further with increasing age. Thus, techniques that diminish the negative impact of aging on the brain are desirable. Existing research, although scarce, suggests meditation to be an attractive candidate in the quest for an accessible and inexpensive, efficacious remedy. Here, we examined the link between age and cerebral gray matter re-analyzing a large sample (n=100 of long-term meditators and control subjects aged between 24 and 77 years. When correlating global and local gray matter with age, we detected negative correlations within both controls and meditators, suggesting a decline over time. However, the slopes of the regression lines were steeper and the correlation coefficients were stronger in controls than in meditators. Moreover, the age-affected brain regions were much more extended in controls than in meditators, with significant group-by-age interactions in numerous clusters throughout the brain. Altogether, these findings seem to suggest less age-related gray matter atrophy in long-term meditation practitioners.

  1. Forever Young(er): potential age-defying effects of long-term meditation on gray matter atrophy

    Science.gov (United States)

    Luders, Eileen; Cherbuin, Nicolas; Kurth, Florian

    2015-01-01

    While overall life expectancy has been increasing, the human brain still begins deteriorating after the first two decades of life and continues degrading further with increasing age. Thus, techniques that diminish the negative impact of aging on the brain are desirable. Existing research, although scarce, suggests meditation to be an attractive candidate in the quest for an accessible and inexpensive, efficacious remedy. Here, we examined the link between age and cerebral gray matter re-analyzing a large sample (n = 100) of long-term meditators and control subjects aged between 24 and 77 years. When correlating global and local gray matter with age, we detected negative correlations within both controls and meditators, suggesting a decline over time. However, the slopes of the regression lines were steeper and the correlation coefficients were stronger in controls than in meditators. Moreover, the age-affected brain regions were much more extended in controls than in meditators, with significant group-by-age interactions in numerous clusters throughout the brain. Altogether, these findings seem to suggest less age-related gray matter atrophy in long-term meditation practitioners. PMID:25653628

  2. The effect of extensive reading and paired-associate learning on long-term vocabulary retention: an event-related potential study.

    Science.gov (United States)

    Chun, Eunjin; Choi, Sungmook; Kim, Junsoo

    2012-07-19

    We investigated the relative efficacy of extensive reading (ER) and paired-associate learning (PAL) in the ability of second language (L2) learners to retain new vocabulary words. To that end, we combined behavioral measures (i.e., vocabulary tests) and an event-related potential (ERP) investigation with a focus on the N400 ERP component to track short- and long-term vocabulary retention as a consequence of the two different approaches. Behavioral results indicated that both ER and PAL led to substantial short-term retention of the target words. In contrast, on a long-term basis, ER was more effective than PAL to a considerable degree as indicated by a large-size effect (d=1.35). Evidence from the N400 effects (d=1.70) observed in the parietal electrode group (P3, Pz, P4) provided further support for the superior effects of ER over PAL on long-term vocabulary retention. The converging evidence challenges the assumptions of some L2 researchers and makes a significant contribution to the literature of vocabulary acquisition, because it provides the first ERP evidence that ER is more conducive to long-term vocabulary retention than PAL. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. Platelet-activating factor and group I metabotropic glutamate receptors interact for full development and maintenance of long-term potentiation in the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Francescangeli, E; Goracci, G; Pettorossi, V E

    1999-01-01

    In rat brainstem slices, we investigated the interaction between platelet-activating factor and group I metabotropic glutamate receptors in mediating long-term potentiation within the medial vestibular nuclei. We analysed the N1 field potential wave evoked in the ventral portion of the medial vestibular nuclei by primary vestibular afferent stimulation. The group I metabotropic glutamate receptor antagonist, (R,S)-1-aminoindan-1,5-dicarboxylic acid, prevented long-term potentiation induced by a platelet-activating factor analogue [1-O-hexadecyl-2-O-(methylcarbamyl)-sn-glycero-3-phosphocholine], as well as the full development of potentiation, induced by high-frequency stimulation under the blocking agent for synaptosomal platelet-activating factor receptors (ginkolide B), at drug washout. However, potentiation directly induced by the group I glutamate metabotropic receptor agonist, (R,S)-3,5-dihydroxyphenylglycine, was reduced by ginkolide B. These findings suggest that platelet-activating factor, whether exogenous or released following potentiation induction, exerts its effect through presynaptic group I metabotropic glutamate receptors, mediating the increase of glutamate release. In addition, we found that this mechanism, which led to full potentiation through presynaptic group I metabotropic glutamate receptor activation, was inactivated soon after application of potentiation-inducing stimulus. In fact, the long-lasting block of the platelet-activating factor and metabotropic glutamate receptors prevented the full potentiation development and the induced potentiation progressively declined to null. Moreover, ginkolide B, given when high-frequency-dependent potentiation was established, only reduced it within 5 min after potentiation induction. We conclude that to fully develop vestibular long-term potentiation requires presynaptic events. Platelet-activating factor, released after the activation of postsynaptic mechanisms which induce potentiation, is necessary

  4. Brevican-deficient mice display impaired hippocampal CA1 long-term potentiation but show no obvious deficits in learning and memory

    DEFF Research Database (Denmark)

    Brakebusch, Cord; Seidenbecher, Constanze I; Asztely, Fredrik

    2002-01-01

    to be less prominent in mutant than in wild-type mice. Brevican-deficient mice showed significant deficits in the maintenance of hippocampal long-term potentiation (LTP). However, no obvious impairment of excitatory and inhibitory synaptic transmission was found, suggesting a complex cause for the LTP defect....... Detailed behavioral analysis revealed no statistically significant deficits in learning and memory. These data indicate that brevican is not crucial for brain development but has restricted structural and functional roles....

  5. Blue light potentiates neurogenesis induced by retinoic acid-loaded responsive nanoparticles.

    Science.gov (United States)

    Santos, Tiago; Ferreira, Raquel; Quartin, Emanuel; Boto, Carlos; Saraiva, Cláudia; Bragança, José; Peça, João; Rodrigues, Cecília; Ferreira, Lino; Bernardino, Liliana

    2017-09-01

    Neurogenic niches constitute a powerful endogenous source of new neurons that can be used for brain repair strategies. Neuronal differentiation of these cells can be regulated by molecules such as retinoic acid (RA) or by mild levels of reactive oxygen species (ROS) that are also known to upregulate RA receptor alpha (RARα) levels. Data showed that neural stem cells from the subventricular zone (SVZ) exposed to blue light (405nm laser) transiently induced NADPH oxidase-dependent ROS, resulting in β-catenin activation and neuronal differentiation, and increased RARα levels. Additionally, the same blue light stimulation was capable of triggering the release of RA from light-responsive nanoparticles (LR-NP). The synergy between blue light and LR-NP led to amplified neurogenesis both in vitro and in vivo, while offering a temporal and spatial control of RA release. In conclusion, this combinatory treatment offers great advantages to potentiate neuronal differentiation, and provides an innovative and efficient application for brain regenerative therapies. Controlling the differentiation of stem cells would support the development of promising brain regenerative therapies. Blue light transiently increased reactive oxygen species, resulting in neuronal differentiation and increased retinoic acid receptor (RARα) levels. Additionally, the same blue light stimulation was capable of triggering the release of RA from light-responsive nanoparticles (LR-NP). The synergy between blue light and LR-NP led to amplified neurogenesis, while offering a temporal and spatial control of RA release. In this sense, our approach relying on the modulation of endogenous stem cells for the generation of new neurons may support the development of novel clinical therapies. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. Long-term collections

    CERN Multimedia

    Collectes à long terme

    2007-01-01

    The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.

  7. p-Coumaric acid enhances long-term potentiation and recovers scopolamine-induced learning and memory impairments.

    Science.gov (United States)

    Kim, Hyun-Bum; Lee, Seok; Hwang, Eun-Sang; Maeng, Sungho; Park, Ji-Ho

    2017-10-21

    Due to the improvement of medical level, life expectancy increased. But the increased incidence of cognitive disorders is an emerging social problem. Current drugs for dementia treatment can only delay the progress rather than cure. p-Coumaric acid is a phenylpropanoic acid derived from aromatic amino acids and known as a precursor for flavonoids such as resveratrol and naringenin. It was shown to reduce oxidative stress, inhibit genotoxicity and exert neuroprotection. Based on these findings, we evaluated whether p-coumaric acid can protect scopolamine induced learning and memory impairment by measuring LTP in organotypic hippocampal slice and cognitive behaviors in rats. p-Coumaric acid dose-dependently increased the total activity of fEPSP after high frequency stimulation and attenuated scopolamine-induced blockade of fEPSP in the hippocampal CA1 area. In addition, while scopolamine shortened the step-through latency in the passive avoidance test and prolonged the latency as well as reduced the latency in the target quadrant in the Morris water maze test, co-treatment of p-coumaric acid improved avoidance memory and long-term retention of spatial memory in behavioral tests. Since p-coumaric acid improved electrophysiological and cognitive functional deterioration by scopolamine, it may have regulatory effects on central cholinergic synapses and is expected to improve cognitive problems caused by abnormality of the cholinergic nervous system. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Neurogenesis and Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Philippe Taupin

    2006-01-01

    Full Text Available Alzheimer’s disease (AD is a neurodegenerative disease, characterized in the brain by amyloid plaque deposits and neurofibrillary tangles. It is the most common form of dementia among older people. There is at present no cure for AD, and current treatments consist mainly in drug therapy. Potential therapies for AD involve gene and cellular therapy. The recent confirmation that neurogenesis occurs in the adult brain and neural stem cells (NSCs reside in the adult central nervous system (CNS provide new opportunities for cellular therapy in the CNS, particularly for AD, and to better understand brain physiopathology. Hence, researchers have aimed at characterizing neurogenesis in patients with AD. Studies show that neurogenesis is increased in these patients, and in animal models of AD. The effect of drugs used to treat AD on neurogenesis is currently being investigated, to identify whether neurogenesis contributes to their therapeutic activities.

  9. Neurogenesis and Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Philippe Taupin

    2006-01-01

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disease, characterized in the brain by amyloid plaque deposits and neurofibrillary tangles. It is the most common form of dementia among older people. There is at present no cure for AD, and current treatments consist mainly in drug therapy. Potential therapies for AD involve gene and cellular therapy. The recent confirmation that neurogenesis occurs in the adult brain and neural stem cells (NSCs reside in the adult central nervous system (CNS provide new opportunities for cellular therapy in the CNS, particularly for AD, and to better understand brain physiopathology. Hence, researchers have aimed at characterizing neurogenesis in patients with AD. Studies show that neurogenesis is increased in these patients, and in animal models of AD. The effect of drugs used to treat AD on neurogenesis is currently being investigated, to identify whether neurogenesis contributes to their therapeutic activities.

  10. Gene expression profile in long-term non progressor HIV infected patients: in search of potential resistance factors.

    Science.gov (United States)

    Luque, Maria Carolina; Santos, Camila C; Mairena, Eliane C; Wilkinson, Peter; Boucher, Genèvieve; Segurado, Aluisio C; Fonseca, Luiz A; Sabino, Ester; Kalil, Jorge E; Cunha-Neto, Edecio

    2014-11-01

    Long-term non-progressors (LTNP) represent a minority (1-5%) of HIV-infected individuals characterized by documented infection for more than 7-10 years, a stable CD4+ T cell count over 500/mm(3) and low viremia in the absence of antiretroviral treatment. Protective factors described so far such as the CCR5delta32 deletion, protective HLA alleles, or defective viruses fail to fully explain the partial protection phenotype. The existence of additional host resistance mechanisms in LTNP patients was investigated here using a whole human genome microarray study comparing gene expression profiles of unstimulated peripheral blood mononuclear cells from LTNP patients, HIV-1 infected patients under antiretroviral therapy with CD4+ T cell levels above 500/mm(3) (ST), as well as healthy individuals. Genes that were up- or downregulated exclusively in LTNP, ST or in both groups in comparison to controls were identified and classified in functional categories using Ingenuity Pathway Analysis. ST and LTNP patient groups revealed distinct genetic profiles, regarding gene number in each category and up- or downregulation of specific genes, which could have a bearing on the outcome of each group. We selected some relevant genes to validate the differential expression using quantitative real-time qRT-PCR. Among others, we found several genes related to the canonical Wnt/beta-catenin signaling pathway. Our results identify new possible host genes and molecules that could be involved in the mechanisms leading to the slower progression to AIDS and sustained CD4+ T cell counts that is peculiar to LTNP patients. Copyright © 2014. Published by Elsevier Ltd.

  11. Long term energy demand projection and potential for energy savings of Croatian tourism–catering trade sector

    International Nuclear Information System (INIS)

    Irsag, Bojan; Pukšec, Tomislav; Duić, Neven

    2012-01-01

    Today, tourism represents one of the backbones of Croatian economy and one of the main factors of its growth. Combined with catering trade sector, tourism represents a significant energy consumer that has the tendencies of future growth. Since services sector, which tourism–catering trade sector is a part of, is not yet well described regarding future energy balances it would be very interesting to see how could possible future growth in tourism influence energy consumption of the services sector in Croatia. Through this paper long term energy demand projections of tourism–catering trade sector were studied with special emphasis on future growth of tourism in Croatia as well as different mechanisms that might lead to certain energy savings. Bottom-up approach was chosen as the most suitable one since it allows better quantification of different measures, technological or legal, that would influence future energy demand. Downside of this approach is extensive input data that is required to analyse and model future energy demand which is roughly divided into heating/cooling section and all other consumption. Results show that additional energy savings in the tourism–catering trade sector are possible if careful and rational demand side planning is in place. -- Highlights: ► Future energy demand of Croatian touristm–catering trade sector has been modelled. ► Model is roughly divided into two basic modes (heating/cooling and all other consumption). ► Different factors influencing future energy demand were implemented into the model. ► Possibilities for energy efficiency improvements have been presented.

  12. Drivers, trends, and potential impacts of long-term coastal reclamation in China from 1985 to 2010

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Bo; Wu, Wenting; Yang, Zhaoqing; Zhou, Yunxuan

    2016-03-01

    Driven by rapid economic development, population growth, and urbanization, China has experienced severe coastal land reclamation over the last decades, which resulted in significant loss of coastal wetland and wildlife habitat, and degradation of marine ecosystems. This study used advanced remote-sensing techniques to analyze the spatial and temporal distributions of coastal reclamation in China and investigated the relationships between coastal land reclamation and coastal economy, population growth, and urbanization. Analysis of long-term Landsat images time series from 1985 to 2010 in 5-year intervals, in combination with remotely sensed image techniques, indicated a sharp increasing trend of land reclamation after 2005, which accounted for over 35% of China’s total reclamation during the 25-year period since 1985. High-intensity coastal reclamation in China was mainly driven by the booming economy associated with urbanization and industrial development in the coastal region. Analysis indicated that coastal land reclamation is closely correlated with the GDP per capita in China. Study results of Landsat images showed that 754,697 ha of coastal wetlands have been reclaimed across all coastal provinces and metropolises from 1985 to 2010, at an annual rate of 5.9%. Coastal areas within the three major economic zones (Bohai Bay, Yangtze River Delta, and Pearl River Delta) were found to generally have higher reclamation rates. For example, the built-up area in Shanghai, which is located in the Yangtze River Delta, increased more than five times from 1985 to 2010. Approximately 35% of the reclamation occurred in Bohai Bay, in which the CRI between 2005 and 2010 was three times higher than the average CRI over the 25-year period.

  13. Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.

    Science.gov (United States)

    Scarduzio, Mariangela; Panichi, Roberto; Pettorossi, Vito Enrico; Grassi, Silvarosa

    2013-01-01

    Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs) and androgens (ARs). We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN). Long-term depression (LTD) and long-term potentiation (LTP) caused by different patterns of high frequency stimulation (HFS) of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase) and E2 (P450-aromatase) from testosterone (T). We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids.

  14. Long-term exposure to estrogen enhances chemotherapeutic efficacy potentially through epigenetic mechanism in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Yu-Wei Chang

    Full Text Available Chemotherapy is the most common clinical option for treatment of breast cancer. However, the efficacy of chemotherapy depends on the age of breast cancer patients. Breast tissues are estrogen responsive and the levels of ovarian estrogen vary among the breast cancer patients primarily between pre- and post-menopausal age. Whether this age-dependent variation in estrogen levels influences the chemotherapeutic efficacy in breast cancer patients is not known. Therefore, the objective of this study was to evaluate the effects of natural estrogen 17 beta-estradiol (E2 on the efficacy of chemotherapeutic drugs in breast cancer cells. Estrogen responsive MCF-7 and T47D breast cancer cells were long-term exposed to 100 pg/ml estrogen, and using these cells the efficacy of chemotherapeutic drugs doxorubicin and cisplatin were determined. The result of cell viability and cell cycle analysis revealed increased sensitivities of doxorubicin and cisplatin in estrogen-exposed MCF-7 and T47D cells as compared to their respective control cells. Gene expression analysis of cell cycle, anti-apoptosis, DNA repair, and drug transporter genes further confirmed the increased efficacy of chemotherapeutic drugs in estrogen-exposed cells at molecular level. To further understand the role of epigenetic mechanism in enhanced chemotherapeutic efficacy by estrogen, cells were pre-treated with epigenetic drugs, 5-aza-2-deoxycytidine and Trichostatin A prior to doxorubicin and cisplatin treatments. The 5-aza-2 deoxycytidine pre-treatment significantly decreased the estrogen-induced efficacy of doxorubicin and cisplatin, suggesting the role of estrogen-induced hypermethylation in enhanced sensitivity of these drugs in estrogen-exposed cells. In summary, the results of this study revealed that sensitivity to chemotherapy depends on the levels of estrogen in breast cancer cells. Findings of this study will have clinical implications in selecting the chemotherapy strategies for

  15. Wnt Signaling Is Required for Long-Term Memory Formation

    Directory of Open Access Journals (Sweden)

    Ying Tan

    2013-09-01

    Full Text Available Wnt signaling regulates synaptic plasticity and neurogenesis in the adult nervous system, suggesting a potential role in behavioral processes. Here, we probed the requirement for Wnt signaling during olfactory memory formation in Drosophila using an inducible RNAi approach. Interfering with β-catenin expression in adult mushroom body neurons specifically impaired long-term memory (LTM without altering short-term memory. The impairment was reversible, being rescued by expression of a wild-type β-catenin transgene, and correlated with disruption of a cellular LTM trace. Inhibition of wingless, a Wnt ligand, and arrow, a Wnt coreceptor, also impaired LTM. Wingless expression in wild-type flies was transiently elevated in the brain after LTM conditioning. Thus, inhibiting three key components of the Wnt signaling pathway in adult mushroom bodies impairs LTM, indicating that this pathway mechanistically underlies this specific form of memory.

  16. Low-fat, high-carbohydrate parenteral nutrition (PN) may potentially reverse liver disease in long-term PN-dependent infants

    DEFF Research Database (Denmark)

    Jakobsen, Marianne Skytte; Jørgensen, Marianne Hørby; Husby, Steffen

    2015-01-01

    INTRODUCTION: Parenteral nutrition-associated cholestasis (PNAC) is a complication of long-term parenteral nutrition (PN). Removal of lipids may reverse PNAC but compromises the energy to ensure infant growth. The purpose of this study was to test whether a low-fat, high-carbohydrate PN regimen......, which prevents and reverses PNAC in adults, could do the same in infants. This regimen could potentially avoid the problem of diminished energy input after removing nutritional lipids. METHODS: Infants developing PNAC over a 2-year period were started on a low-fat PN regimen with calories primarily from...

  17. Long-Term Collections

    CERN Multimedia

    Comité des collectes à long terme

    2011-01-01

    It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.

  18. Leptin attenuates the detrimental effects of β-amyloid on spatial memory and hippocampal later-phase long term potentiation in rats.

    Science.gov (United States)

    Tong, Jia-Qing; Zhang, Jun; Hao, Ming; Yang, Ju; Han, Yu-Fei; Liu, Xiao-Jie; Shi, Hui; Wu, Mei-Na; Liu, Qing-Song; Qi, Jin-Shun

    2015-07-01

    β-Amyloid (Aβ) is the main component of amyloid plaques developed in the brain of patients with Alzheimer's disease (AD). The increasing burden of Aβ in the cortex and hippocampus is closely correlated with memory loss and cognition deficits in AD. Recently, leptin, a 16kD peptide derived mainly from white adipocyte tissue, has been appreciated for its neuroprotective function, although less is known about the effects of leptin on spatial memory and synaptic plasticity. The present study investigated the neuroprotective effects of leptin against Aβ-induced deficits in spatial memory and in vivo hippocampal late-phase long-term potentiation (L-LTP) in rats. Y maze spontaneous alternation was used to assess short term working memory, and the Morris water maze task was used to assess long term reference memory. Hippocampal field potential recordings were performed to observe changes in L-LTP. We found that chronically intracerebroventricular injection of leptin (1μg) effectively alleviated Aβ1-42 (20μg)-induced spatial memory impairments of Y maze spontaneous alternation and Morris water maze. In addition, chronic administration of leptin also reversed Aβ1-42-induced suppression of in vivo hippocampal L-LTP in rats. Together, these results suggest that chronic leptin treatments reversed Aβ-induced deficits in learning and memory and the maintenance of L-LTP. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat.

    Science.gov (United States)

    Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

    2015-01-01

    Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD) and depotentiation (DP) by low frequency stimulation (LFS, 15 min-1 Hz) and of long-term potentiation (LTP) by high frequency stimulation (HFS, 1 s-100 Hz), medium (MFS, 1 s-50 Hz), or weak (WFS, 1 s-25 Hz) frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T) into DHT (5α-reductase) and T into E2 (P450-aromatase). We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects.

  20. Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat

    Directory of Open Access Journals (Sweden)

    Michela eDi Mauro

    2015-10-01

    Full Text Available Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17b-estradiol (E2 and 5a-dihydrotestosterone (DHT neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD and depotentiation (DP by low frequency stimulation (LFS, 15 min-1 Hz and of long-term potentiation (LTP by high (HFS, 1 s-100 Hz, medium (MFS, 1 s-50 Hz, or weak (WFS, 1 s-25 Hz frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T into DHT (5a-reductase and T into E2 (P450-aromatase. We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects.

  1. Japan's long-term energy outlook to 2050: Estimation for the potential of massive CO2 mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, Ryoichi

    2010-09-15

    This paper analyzes Japan's energy outlook and CO2 emissions to 2050. Scenario analysis reveals that Japan's CO2 emissions in 2050 could be potentially reduced by 58% from the emissions in 2005. For achieving this massive mitigation, it is required to reduce primary energy supply per GDP by 60% in 2050 from the 2005 level and to expand the share of non-fossil fuel in total supply to 50% by 2050. Concerning power generation mix, nuclear will account for 60%, renewable for 30% in 2050. For massive CO2 abatement, Japan should tackle technological and economic challenges for large-scale deployment of advanced technologies.

  2. Long Term Sugarcane Crop Residue Retention Offers Limited Potential to Reduce Nitrogen Fertilizer Rates in Australian Wet Tropical Environments.

    Science.gov (United States)

    Meier, Elizabeth A; Thorburn, Peter J

    2016-01-01

    The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues ('trash'). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a 'trash blanket' in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer

  3. Long term sugarcane crop residue retention offers limited potential to reduce nitrogen fertilizer rates in Australian wet tropical environments

    Directory of Open Access Journals (Sweden)

    Elizabeth Anne Meier

    2016-07-01

    Full Text Available The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1 reduce emissions (e.g. those that reduce nitrous oxide (N2O emissions by avoiding excess nitrogen (N fertilizer application, and (2 increase soil organic carbon (SOC stocks (e.g. by retaining instead of burning crop residues. Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues (‘trash’. Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a ‘trash blanket’ in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location  soil  fertilizer  trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 yr after trash blanketing commenced. After this period, there was potential to

  4. Virtual Models of Long-Term Care

    Science.gov (United States)

    Phenice, Lillian A.; Griffore, Robert J.

    2012-01-01

    Nursing homes, assisted living facilities and home-care organizations, use web sites to describe their services to potential consumers. This virtual ethnographic study developed models representing how potential consumers may understand this information using data from web sites of 69 long-term-care providers. The content of long-term-care web…

  5. Long-term use of biosolids as organic fertilizers in agricultural soils: potentially toxic elements occurrence and mobility.

    Science.gov (United States)

    Marguí, E; Iglesias, M; Camps, F; Sala, L; Hidalgo, M

    2016-03-01

    The presence of potentially toxic elements (PTEs) may hinder a more widespread application of biosolids in agriculture. At present, the European Directive 86/278/CEE limit the total concentrations of seven metals (Cu, Cr, Ni, Pb, Zn, Cd and Hg) in agricultural soils and in sewage sludges used as fertilizers but it has not taken into consideration the potential impacts of other emerging micropollutants that may be present in the biosolids as well as their mobility. The aim of this study was to evaluate the accumulation and mobility of 13 elements (including regulated metals and other inorganic species) in agricultural soils repeatedly amended with biosolids for 15 years. Firstly, three digestions programs using different acid mixtures were tested to evaluate the most accurate and efficient method for analysis of soil and sludge. Results demonstrated that sewage sludge application increased concentrations of Pb and Hg in soil, but values did not exceed the quality standard established by legislation. In addition, other elements (As, Co, Sb, Ag, Se and Mn) that at present are not regulated by the Spanish and European directives were identified in the sewage sludge, and significant differences were found between Ag content in soils amended with biosolids in comparison with control soils. This fact can be related to the increasing use of silver nanoparticles in consumer products due to their antibacterial properties. Results from the leaching tests show up that, in general, the mobility degree for both regulated and non-regulated elements in soils amended with biosolids was quite low (<10 %).

  6. A greener Greenland? Climatic potential and long-term constraints on future expansions of trees and shrubs

    Science.gov (United States)

    Normand, Signe; Randin, Christophe; Ohlemüller, Ralf; Bay, Christian; Høye, Toke T.; Kjær, Erik D.; Körner, Christian; Lischke, Heike; Maiorano, Luigi; Paulsen, Jens; Pearman, Peter B.; Psomas, Achilleas; Treier, Urs A.; Zimmermann, Niklaus E.; Svenning, Jens-Christian

    2013-01-01

    Warming-induced expansion of trees and shrubs into tundra vegetation will strongly impact Arctic ecosystems. Today, a small subset of the boreal woody flora found during certain Plio-Pleistocene warm periods inhabits Greenland. Whether the twenty-first century warming will induce a re-colonization of a rich woody flora depends on the roles of climate and migration limitations in shaping species ranges. Using potential treeline and climatic niche modelling, we project shifts in areas climatically suitable for tree growth and 56 Greenlandic, North American and European tree and shrub species from the Last Glacial Maximum through the present and into the future. In combination with observed tree plantings, our modelling highlights that a majority of the non-native species find climatically suitable conditions in certain parts of Greenland today, even in areas harbouring no native trees. Analyses of analogous climates indicate that these conditions are widespread outside Greenland, thus increasing the likelihood of woody invasions. Nonetheless, we find a substantial migration lag for Greenland's current and future woody flora. In conclusion, the projected climatic scope for future expansions is strongly limited by dispersal, soil development and other disequilibrium dynamics, with plantings and unintentional seed dispersal by humans having potentially large impacts on spread rates. PMID:23836785

  7. Long-Term Waste Package Degradation Studies at the Yucca Mountain Potential High-Level Nuclear Waste Repository

    International Nuclear Information System (INIS)

    Mon, K. G.; Bullard, B. E.; Longsine, D. E.; Mehta, S.; Lee, J. H.; Monib, A. M.

    2002-01-01

    The Site Recommendation (SR) process for the potential repository for spent nuclear fuel (SNF) and high-level nuclear waste (HLW) at Yucca Mountain, Nevada is underway. Fulfillment of the requirements for substantially complete containment of the radioactive waste emplaced in the potential repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere will rely on a robust waste container design, among other EBS components. Part of the SR process involves sensitivity studies aimed at elucidating which model parameters contribute most to the drip shield and waste package degradation characteristics. The model parameters identified included (a) general corrosion rate model parameters (temperature-dependence and uncertainty treatment), and (b) stress corrosion cracking (SCC) model parameters (uncertainty treatment of stress and stress intensity factor profiles in the Alloy 22 waste package outer barrier closure weld regions, the SCC initiation stress threshold, and the fraction of manufacturing flaws oriented favorably for through-wall penetration by SCC). These model parameters were reevaluated and new distributions were generated. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters and models used

  8. Ryanodine receptors contribute to the induction of nociceptive input-evoked long-term potentiation in the rat spinal cord slice

    Directory of Open Access Journals (Sweden)

    Zhao Zhi-Qi

    2010-01-01

    Full Text Available Abstract Background Our previous study demonstrated that nitric oxide (NO contributes to long-term potentiation (LTP of C-fiber-evoked field potentials by tetanic stimulation of the sciatic nerve in the spinal cord in vivo. Ryanodine receptor (RyR is a downstream target for NO. The present study further explored the role of RyR in synaptic plasticity of the spinal pain pathway. Results By means of field potential recordings in the adult male rat in vivo, we showed that RyR antagonist reduced LTP of C-fiber-evoked responses in the spinal dorsal horn by tetanic stimulation of the sciatic nerve. Using spinal cord slice preparations and field potential recordings from superficial dorsal horn, high frequency stimulation of Lissauer's tract (LT stably induced LTP of field excitatory postsynaptic potentials (fEPSPs. Perfusion of RyR antagonists blocked the induction of LT stimulation-evoked spinal LTP, while Ins(1,4,5P3 receptor (IP3R antagonist had no significant effect on LTP induction. Moreover, activation of RyRs by caffeine without high frequency stimulation induced a long-term potentiation in the presence of bicuculline methiodide and strychnine. Further, in patch-clamp recordings from superficial dorsal horn neurons, activation of RyRs resulted in a large increase in the frequency of miniature EPSCs (mEPSCs. Immunohistochemical study showed that RyRs were expressed in the dorsal root ganglion (DRG neurons. Likewise, calcium imaging in small DRG neurons illustrated that activation of RyRs elevated [Ca2+]i in small DRG neurons. Conclusions These data indicate that activation of presynaptic RyRs play a crucial role in the induction of LTP in the spinal pain pathway, probably through enhancement of transmitter release.

  9. Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.

    Directory of Open Access Journals (Sweden)

    Mariangela Scarduzio

    Full Text Available Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs and androgens (ARs. We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2 and 5α-dihydrotestosterone (DHT on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN. Long-term depression (LTD and long-term potentiation (LTP caused by different patterns of high frequency stimulation (HFS of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase and E2 (P450-aromatase from testosterone (T. We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids.

  10. Comparative assessment of different energy sources and their potential role in long-term sustainable energy mix

    International Nuclear Information System (INIS)

    Kagramanian, V.S.

    2001-01-01

    In the debate on sustainable energy future, the role of nuclear power is a contentious issue. Many, who are outside of the nuclear community, do not even consider nuclear, because of public concerns on nuclear safety, radioactive waste and non-proliferation issues. For example, the United Nations Development Program, in its document Energy After Rio does not suggest a specific role for nuclear power except in the most doubtful of terms. On the contrary, most nuclear organisations and related industries see nuclear power as the only mature carbon-free electricity generating option that can be deployed even on a much larger scale than today. This paper analyses the potential role of nuclear power in the context of the global sustainable energy future. The fundamental features of sustainable energy development are examined in terms of the following compatibility constraints: Demand driven compatibility; Natural resource compatibility; Environmental compatibility; Geopolitical compatibility; and Economic compatibility

  11. Life History theory hypotheses on child growth: Potential implications for short and long-term child growth, development and health.

    Science.gov (United States)

    Said-Mohamed, Rihlat; Pettifor, John M; Norris, Shane A

    2018-01-01

    Life history theory integrates ecological, physiological, and molecular layers within an evolutionary framework to understand organisms' strategies to optimize survival and reproduction. Two life history hypotheses and their implications for child growth, development, and health (illustrated in the South African context) are reviewed here. One hypothesis suggests that there is an energy trade-off between linear growth and brain growth. Undernutrition in infancy and childhood may trigger adaptive physiological mechanisms prioritizing the brain at the expense of body growth. Another hypothesis is that the period from conception to infancy is a critical window of developmental plasticity of linear growth, the duration of which may vary between and within populations. The transition from infancy to childhood may mark the end of a critical window of opportunity for improving child growth. Both hypotheses emphasize the developmental plasticity of linear growth and the potential determinants of growth variability (including the role of parent-offspring conflict in maternal resources allocation). Implications of these hypotheses in populations with high burdens of undernutrition and infections are discussed. In South Africa, HIV/AIDS during pregnancy (associated with adverse birth outcomes, short duration of breastfeeding, and social consequences) may lead to a shortened window of developmental plasticity of growth. Furthermore, undernutrition and infectious diseases in children living in South Africa, a country undergoing a rapid nutrition transition, may have adverse consequences on individuals' cognitive abilities and risks of cardio-metabolic diseases. Studies are needed to identify physiological mechanisms underlying energy allocation between biological functions and their potential impacts on health. © 2017 Wiley Periodicals, Inc.

  12. Long-term change of potential evapotranspiration over Southwest China and teleconnections with large-scale climate anomalies

    Science.gov (United States)

    Liu, B.; Chen, X.; Li, Y.; Chen, Z.

    2017-12-01

    bstract: Potential evapotranspiration (PET) is a sensitive factor for atmospheric and ecological systems over Southwest China which is characterized by intensive karst geomorphology and fragile environment. Based on daily meteorological data of 94 stations during 1961-2013, the spatiotemporal characteristics of PET are analyzed. The changing characteristics of local meteorological factors and large-scale climatic features are also investigated to explain the potential reasons for changing PET. Study results are as follows: (1) The high-value center of PET with a mean value of 1097 mm/a locates in the south mainly resulted from the regional climatic features of higher air temperature (TEM), sunshine duration (SSD) and lower relative humidity (RHU); and the low-value center of PET with a mean value of 831 mm/a is in the northeast primarily attributed to higher RHU and weaker SSD. (2) Annual PET decreases at -10.04 mm decade-1 before the year 2000 but increases at 50.65 mm decade-1 thereafter; and the dominant factors of PET change are SSD, RHU and wind speed (WIN), with the relative contributions of 33.29%, 25.42% and 22.16%, respectively. (3) The abrupt change of PET in 2000 is strongly dominated by large-scale climatic anomalies. The strengthened 850hPa geostrophic wind (0.51 ms-1 decade-1), weakened total cloud cover (-2.25 % decade-1) and 500hPa water vapor flux (-2.85 % decade-1) have provided advantageous dynamic, thermal and dry conditions for PET over Southwest China since the 21st century.

  13. Long-term trajectories of lower extremity function in older adults: estimating gender differences while accounting for potential mortality bias.

    Science.gov (United States)

    Botoseneanu, Anda; Allore, Heather G; Gahbauer, Evelyne A; Gill, Thomas M

    2013-07-01

    Gender-specific trajectories of lower extremity function (LEF) and the potential for bias in LEF estimation due to differences in survival have been understudied. We evaluated longitudinal data from 690 initially nondisabled adults age 70 or older from the Precipitating Events Project. LEF was assessed every 18 months for 12 years using a modified Short Physical Performance Battery (mSPPB). Hierarchical linear models with adjustments for length-of-survival estimated the intraindividual trajectory of LEF and differences in trajectory intercept and slope between men and women. LEF declined following a nonlinear trajectory. In the full sample, and among participants with high (mSPPB 10-12) and intermediate (mSPPB 7-9) baseline LEF, the rate-of-decline in mSPPB was slower in women than in men, with no gender differences in baseline mSPPB scores. Among participants with low baseline LEF (mSPPB ≤6), men had a higher starting mSPPB score, whereas women experienced a deceleration in the rate-of-decline over time. In all groups, participants who survived longer had higher starting mSPPB scores and slower rates-of-decline compared with those who died sooner. Over the course of 12 years, older women preserve LEF better than men. Nonadjustment for differences in survival results in overestimating the level and underestimating the rate-of-decline in LEF over time.

  14. Paired-Associative Stimulation-Induced Long-term Potentiation-Like Motor Cortex Plasticity in Healthy Adolescents

    Directory of Open Access Journals (Sweden)

    Jonathan C. Lee

    2017-05-01

    Full Text Available ObjectiveThe objective of this study was to evaluate the feasibility of using paired-associative stimulation (PAS to study excitatory and inhibitory plasticity in adolescents while examining variables that may moderate plasticity (such as sex and environment.MethodsWe recruited 34 healthy adolescents (aged 13–19, 13 males, 21 females. To evaluate excitatory plasticity, we compared mean motor-evoked potentials (MEPs elicited by single-pulse transcranial magnetic stimulation (TMS before and after PAS at 0, 15, and 30 min. To evaluate inhibitory plasticity, we evaluated the cortical silent period (CSP elicited by single-pulse TMS in the contracted hand before and after PAS at 0, 15, and 30 min.ResultsAll participants completed PAS procedures. No adverse events occurred. PAS was well tolerated. PAS-induced significant increases in the ratio of post-PAS MEP to pre-PAS MEP amplitudes (p < 0.01 at all post-PAS intervals. Neither socioeconomic status nor sex was associated with post-PAS MEP changes. PAS induced significant CSP lengthening in males but not females.ConclusionPAS is a feasible, safe, and well-tolerated index of adolescent motor cortical plasticity. Gender may influence PAS-induced changes in cortical inhibition. PAS is safe and well tolerated by healthy adolescents and may be a novel tool with which to study adolescent neuroplasticity.

  15. Juvenile flatfish in the northern Baltic Sea - long-term decline and potential links to habitat characteristics

    Science.gov (United States)

    Jokinen, Henri; Wennhage, Håkan; Ollus, Victoria; Aro, Eero; Norkko, Alf

    2016-01-01

    Flatfish in the northern Baltic Sea are facing multiple environmental pressures due to on-going large-scale ecosystem changes linked to eutrophication and climate change. Shallow juvenile habitats of flatfishes are expected to be especially susceptible to these environmental pressures. Using previously unpublished historical and present-state data on juvenile flatfish in nursery areas along the Finnish coast we demonstrate a drastic (up to 40 ×) decline in 1-Y-O flounder densities since the 1980s and a particularly low current occurrence of both flounders and turbots in several known juvenile habitats. As a consequence of ongoing coastal eutrophication vegetation coverage and filamentous algae have generally increased in shallow areas. We examined the predicted negative effect of vegetation/algae by exploring quantitative relationships between juvenile flatfish (flounder and turbot) occurrence and vegetation/algae among other environmental factors in shallow juvenile habitats. Despite sparse occurrence of juveniles we found a significant negative relationship between flatfish abundance and vegetation cover, implicating eutrophication as a potential major driver affecting the value of juvenile habitat. Shallow littoral habitats play a particularly central role for flatfish due to the spatial concentration of fish in these areas during the critical juvenile stage. Despite their importance, these areas have been relatively poorly studied in the northern Baltic Sea, which makes it difficult to quantify overall changes in environmental conditions and to relate these changes to flatfish recruitment. The low present-state flatfish densities recorded preclude strong inferences of the role of habitat quality to be drawn. Our study does, however, provide a baseline for future assessment. Based on existing evidence, we cannot thus establish any bottlenecks but hypothesize that the current low occurrence of juvenile flatfish, and the population decline of flounder on the

  16. Studies on nuclear fusion energy potential based on a long-term world energy and environment model

    International Nuclear Information System (INIS)

    Tokimatsu, K.; Fujino, J.; Asaoka, Y.

    2001-01-01

    This study investigates introduction conditions and potential of nuclear fusion energy as energy supply and CO 2 mitigation technologies in the 21st century. Time horizon of the 21st century, 10 regionally allocated world energy/environment model (Linearized Dynamic New Earth 21) is used for this study. Following nuclear fusion technological data are taken into consideration: cost of electricity (COE) in nuclear fusion introduction year, annual COE reduction rates, regional introduction year, and maximum regional plant capacity constraints by maximum plant construction speed. We made simulation under a constraint of atmospheric CO 2 concentration of 550 parts per million by volume (ppmv) targeted at year 2100, assuming that sequestration technologies and unknown innovative technologies for CO 2 reduction are available. The results indicate that under the 550ppm scenario with nuclear fusion within maximum construction speed, 66mill/kWh is required for introducing nuclear fusion in 2050, 92 mill/kWh in 2060, and 106 mill/kWh in 2070. Therefore, tokamak type nuclear fusion reactors of present several reactor cost estimates are expected to be introduced between 2060 and 2070, and electricity generation fraction by nuclear fusion will go around 20% in 2100 if nuclear fusion energy growth is limited only by the maximum construction speed. CO 2 reduction by nuclear fusion introduced in 2050 from business-as-usual (BAU) scenario without nuclear fusion is about 20% of total reduction amount in 2100. In conclusion, nuclear fusion energy is revealed to be one of the candidates of energy supply technologies and CO 2 mitigation technologies. Cost competitiveness and removal of capacity constraint factors are desired for use of nuclear fusion energy in a large scale. (author)

  17. Potential for long-term transfer of dissolved organic carbon from riparian zones to streams in boreal catchments.

    Science.gov (United States)

    Ledesma, José L J; Grabs, Thomas; Bishop, Kevin H; Schiff, Sherry L; Köhler, Stephan J

    2015-08-01

    Boreal regions store most of the global terrestrial carbon, which can be transferred as dissolved organic carbon (DOC) to inland waters with implications for both aquatic ecology and carbon budgets. Headwater riparian zones (RZ) are important sources of DOC, and often just a narrow 'dominant source layer' (DSL) within the riparian profile is responsible for most of the DOC export. Two important questions arise: how long boreal RZ could sustain lateral DOC fluxes as the sole source of exported carbon and how its hydromorphological variability influences this role. We estimate theoretical turnover times by comparing carbon pools and lateral exports in the DSL of 13 riparian profiles distributed over a 69 km(2) catchment in northern Sweden. The thickness of the DSL was 36 ± 18 (average ± SD) cm. Thus, only about one-third of the 1-m-deep riparian profile contributed 90% of the lateral DOC flux. The 13 RZ exported 8.7 ± 6.5 g C m(-2) year(-1) , covering the whole range of boreal stream DOC exports. The variation could be explained by local hydromorphological characteristics including RZ width (R(2) = 0.90). The estimated theoretical turnover times were hundreds to a few thousands of years, that is there is a potential long-lasting supply of DOC. Estimates of net ecosystem production in the RZ suggest that lateral fluxes, including both organic and inorganic C, could be maintained without drawing down the riparian pools. This was supported by measurements of stream DO(14) C that indicated modern carbon as the predominant fraction exported, including streams disturbed by ditching. The transfer of DOC into boreal inland waters from new and old carbon sources has a major influence on surface water quality and global carbon balances. This study highlights the importance of local variations in RZ hydromorphology and DSL extent for future DOC fluxes under a changing climate. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  18. 5-HT4-receptors modulate induction of long-term depression but not potentiation at hippocampal output synapses in acute rat brain slices.

    Directory of Open Access Journals (Sweden)

    Matthias Wawra

    Full Text Available The subiculum is the principal target of CA1 pyramidal cells and mediates hippocampal output to various cortical and subcortical regions of the brain. The majority of subicular pyramidal cells are burst-spiking neurons. Previous studies indicated that high frequency stimulation in subicular burst-spiking cells causes presynaptic NMDA-receptor dependent long-term potentiation (LTP whereas low frequency stimulation induces postsynaptic NMDA-receptor-dependent long-term depression (LTD. In the present study, we investigate the effect of 5-hydroxytryptamine type 4 (5-HT4 receptor activation and blockade on both forms of synaptic plasticity in burst-spiking cells. We demonstrate that neither activation nor block of 5-HT4 receptors modulate the induction or expression of LTP. In contrast, activation of 5-HT4 receptors facilitates expression of LTD, and block of the 5-HT4 receptor prevents induction of short-term depression and LTD. As 5-HT4 receptors are positively coupled to adenylate cyclase 1 (AC1, 5-HT4 receptors might modulate PKA activity through AC1. Since LTD is blocked in the presence of 5-HT4 receptor antagonists, our data are consistent with 5-HT4 receptor activation by ambient serotonin or intrinsically active 5-HT4 receptors. Our findings provide new insight into aminergic modulation of hippocampal output.

  19. Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system

    Science.gov (United States)

    Tozzi, Alessandro; de Iure, Antonio; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Giampà, Carmela; Di Mauro, Michela; Mazzocchetti, Petra; Costa, Cinzia; Di Filippo, Massimiliano; Grassi, Silvarosa; Pettorossi, Vito Enrico; Calabresi, Paolo

    2015-01-01

    17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic interneurons (ChIs). Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson’s disease. PMID:26074768

  20. Chelation of hippocampal zinc enhances long-term potentiation and synaptic tagging/capture in CA1 pyramidal neurons of aged rats: implications to aging and memory.

    Science.gov (United States)

    Shetty, Mahesh Shivarama; Sharma, Mahima; Sajikumar, Sreedharan

    2017-02-01

    Aging is associated with decline in cognitive functions, prominently in the memory consolidation and association capabilities. Hippocampus plays a crucial role in the formation and maintenance of long-term associative memories, and a significant body of evidence shows that impairments in hippocampal function correlate with aging-related memory loss. A number of studies have implicated alterations in hippocampal synaptic plasticity, such as long-term potentiation (LTP), in age-related cognitive decline although exact mechanisms underlying are not completely clear. Zinc deficiency and the resultant adverse effects on cognition have been well studied. However, the role of excess of zinc in synaptic plasticity, especially in aging, is not addressed well. Here, we have investigated the hippocampal zinc levels and the impairments in synaptic plasticity, such as LTP and synaptic tagging and capture (STC), in the CA1 region of acute hippocampal slices from 82- to 84-week-old male Wistar rats. We report increased zinc levels in the hippocampus of aged rats and also deficits in the tetani-induced and dopaminergic agonist-induced late-LTP and STC. The observed deficits in synaptic plasticity were restored upon chelation of zinc using a cell-permeable chelator. These data suggest that functional plasticity and associativity can be successfully established in aged neural networks by chelating zinc with cell-permeable chelating agents. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  1. Persistent changes in ability to express long-term potentiation/depression in the rat hippocampus after juvenile/adult stress.

    Science.gov (United States)

    Maggio, Nicola; Segal, Menahem

    2011-04-15

    The ventral hippocampus (VH) was recently shown to express lower magnitude long-term potentiation (LTP) compared with the dorsal hippocampus (DH). Exposure to acute stress reversed this difference, and VH slices from stressed rats expressed larger LTP than that produced in the DH, which was reduced by stress. Stressful experience in adolescence has been shown to produce long-lasting effects on animal behavior and on ability to express LTP/long-term depression (LTD) of reactivity to afferent stimulation in the adult. We are interested in possible interactions between juvenile and adult stress in their effects of adult plasticity. We studied the effects of a composite juvenile (28-30 days) stress, followed by a reminder stressful experience in the young adult (60 days) rat, on the ability to produce LTP and LTD in CA1 region of slices of the VH and DH. Juvenile or adult stress produced a transient decrease in ability to express LTP in DH and a parallel increase in LTP in VH. Stress in the young adult after juvenile stress produced a striking prolongation of the DH/VH disparity with respect to the ability to express both LTP and LTD into the adulthood of the rat. These results have important implications for the impact of juvenile stress on adult neuronal plasticity and on the understanding the functions of the different sectors of the hippocampus. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system.

    Science.gov (United States)

    Tozzi, Alessandro; de Iure, Antonio; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Giampà, Carmela; Di Mauro, Michela; Mazzocchetti, Petra; Costa, Cinzia; Di Filippo, Massimiliano; Grassi, Silvarosa; Pettorossi, Vito Enrico; Calabresi, Paolo

    2015-01-01

    17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic interneurons (ChIs). Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson's disease.

  3. Endogenous 17ß-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system

    Directory of Open Access Journals (Sweden)

    Alessandro eTozzi

    2015-05-01

    Full Text Available 17β-estradiol (E2, a neurosteroid synthesized by P450-aromatase (ARO, modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs and dopamine (DA receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP in both medium spiny neurons (MSNs and cholinergic interneurons (ChIs. Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson's disease.

  4. The effects of prolonged administration of norepinephrine reuptake inhibitors on long-term potentiation in dentate gyrus, and on tests of spatial and object recognition memory in rats.

    Science.gov (United States)

    Walling, Susan G; Milway, J Stephen; Ingram, Matthew; Lau, Catherine; Morrison, Gillian; Martin, Gerard M

    2016-02-01

    Phasic norepinephrine (NE) release events are involved in arousal, novelty detection and in plasticity processes underlying learning and memory in mammalian systems. Although the effects of phasic NE release events on plasticity and memory are prevalently documented, it is less understood what effects chronic NE reuptake inhibition and sustained increases in noradrenergic tone, might have on plasticity and cognitive processes in rodent models of learning and memory. This study investigates the effects of chronic NE reuptake inhibition on hippocampal plasticity and memory in rats. Rats were administered NE reuptake inhibitors (NRIs) desipramine (DMI; 0, 3, or 7.5mg/kg/day) or nortriptyline (NTP; 0, 10 or 20mg/kg/day) in drinking water. Long-term potentiation (LTP; 200 Hz) of the perforant path-dentate gyrus evoked potential was examined in urethane anesthetized rats after 30-32 days of DMI treatment. Short- (4-h) and long-term (24-h) spatial memory was tested in separate rats administered 0 or 7.5mg/kg/day DMI (25-30 days) using a two-trial spatial memory test. Additionally, the effects of chronically administered DMI and NTP were tested in rats using a two-trial, Object Recognition Test (ORT) at 2- and 24-h after 45 and 60 days of drug administration. Rats administered 3 or 7.5mg/kg/day DMI had attenuated LTP of the EPSP slope but not the population spike at the perforant path-dentate gyrus synapse. Short- and long-term memory for objects is differentially disrupted in rats after prolonged administration of DMI and NTP. Rats that were administered 7.5mg/kg/day DMI showed decreased memory for a two-trial spatial task when tested at 4-h. In the novel ORT, rats receiving 0 or 7.5mg/kg/day DMI showed a preference for the arm containing a Novel object when tested at both 2- and 24-h demonstrating both short- and long-term memory retention of the Familiar object. Rats that received either dose of NTP or 3mg/kg/day DMI showed impaired memory at 2-h, however this

  5. Calcitonin gene-related peptide erases the fear memory and facilitates long-term potentiation in the central nucleus of the amygdala in rats.

    Science.gov (United States)

    Wu, Xin; Zhang, Jie-Ting; Liu, Jue; Yang, Si; Chen, Tao; Chen, Jian-Guo; Wang, Fang

    2015-11-01

    Calcitonin gene-related peptide (CGRP) is a 37 amino acid neuropeptide, which plays a critical role in the central nervous system. CGRP binds to G protein-coupled receptors, including CGRP1, which couples positively to adenylyl cyclase (AC) and protein kinase A (PKA) activation. CGRP and CGRP1 receptors are enriched in central nucleus of the amygdala (CeA), the main part of the amygdala, which regulates conditioned fear memories. Here, we reported the importance of CGRP and CGRP1 receptor for synaptic plasticity in the CeA and the extinction of fear memory in rats. Our electrophysiological and behavioral in vitro and in vivo results showed exogenous application of CGRP induced an immediate and lasting long-term potentiation in the basolateral nucleus of amygdala-CeA pathway, but not in the lateral nucleus of amygdala-CeA pathway, while bilateral intra-CeA infusion CGRP (0, 5, 13 and 21 μM/side) dose dependently enhanced fear memory extinction. The effects were blocked by CGRP1 receptor antagonist (CGRP8-37 ), N-methyl-d-aspartate receptors antagonist MK801 and PKA inhibitor H89. These results demonstrate that CGRP can lead to long-term potentiation of basolateral nucleus of amygdala-CeA pathway through a PKA-dependent postsynaptic mechanism that involved N-methyl-d-aspartate receptors and enhance the extinction of fear memory in rats. Together, the results strongly support a pivotal role of CGRP in the synaptic plasticity of CeA and extinction of fear memory. Calcitonin gene-related peptide (CGRP) plays an essential role in synaptic plasticity in the amygdala and fear memory. We found that CGRP-induced chemical long-term potentiation (LTP) in a dose-dependent way in the BLA-CeA (basolateral and central nucleus of amygdala, respectively) pathway and enhanced fear memory extinction in rats through a protein kinase A (PKA)-dependent postsynaptic mechanism that involved NMDA receptors. These results support a pivotal role of CGRP in amygdala. © 2015 International

  6. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

    2014-05-09

    Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cells Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway.

  7. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    International Nuclear Information System (INIS)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin

    2014-01-01

    Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cells Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway

  8. Two organizational effects of pubertal testosterone in male rats: transient social memory and a shift away from long-term potentiation following a tetanus in hippocampal CA1.

    Science.gov (United States)

    Hebbard, Pamela C; King, Rebecca R; Malsbury, Charles W; Harley, Carolyn W

    2003-08-01

    The organizational role of pubertal androgen receptor (AR) activation in synaptic plasticity in hippocampal CA1 and in social memory was assessed. Earlier data suggest pubertal testosterone reduces adult hippocampal synaptic plasticity. Four groups were created following gonadectomy at the onset of puberty: rats given testosterone; rats given testosterone but with the AR antagonist flutamide, present during puberty; rats given testosterone at the end of puberty; and rats given cholesterol at the end of puberty. A tetanus normally inducing long-term potentiation (LTP) was used to stimulate CA1 in the urethane-anesthetized adults during the dark phase of their cycle. Social memory was assessed prior to electrophysiology. Social memory for a juvenile rat at 120 min was seen only in rats not exposed to AR activation during puberty. Pubertal AR activation may induce the reduced social memory of male rats. Early CA1 LTP occurred following tetanus in rats with no pubertal testosterone. Short-term potentiation occurred in rats exposed to pubertal testosterone. Unexpectedly, rats with pubertal AR activation developed long-term depression (LTD). The same pattern was seen in normal male rats. Lack of LTP during the dark phase is consistent with other data on circadian modulation of CA1 LTP. No correlations were seen among social memory scores and CA1 plasticity measures. These data argue for two organizational effects of pubertal testosterone: (1) CA1 synaptic plasticity shifts away from potentiation toward depression; (2) social memory is reduced. Enduring effects of pubertal androgen on limbic circuits may contribute to reorganized behaviors in the postpubertal period.

  9. The effects of CCK-8S on spatial memory and long-term potentiation at CA1 during induction of stress in rats

    Directory of Open Access Journals (Sweden)

    Malihe Sadeghi

    2017-12-01

    Full Text Available Objective(s: Cholecystokinin (CCK has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Materials and Methods: Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days. Cholecystokinin sulfated octapeptide (CCK-8S was injected (1.6 µg/kg, IP before each session of stress induction. Spatial memory was evaluated by Morris water maze test. Long term potentiation (LTP in Schaffer collateral-CA1 synapses was assessed (by 100 Hz tetanization in order to investigate synaptic plasticity. Results: Stress impaired spatial memory significantly (P

  10. Effect of Prenatal Protein Malnutrition on Long-Term Potentiation and BDNF Protein Expression in the Rat Entorhinal Cortex after Neocortical and Hippocampal Tetanization

    Directory of Open Access Journals (Sweden)

    Alejandro Hernández

    2008-01-01

    Full Text Available Reduction of the protein content from 25 to 8% casein in the diet of pregnant rats results in impaired neocortical long-term potentiation (LTP of the offspring together with lower visuospatial memory performance. The present study was aimed to investigate whether this type of maternal malnutrition could result in modification of plastic capabilities of the entorhinal cortex (EC in the adult progeny. Unlike normal eutrophic controls, 55–60-day-old prenatally malnourished rats were unable to develop LTP in the medial EC to tetanizing stimulation delivered to either the ipsilateral occipital cortex or the CA1 hippocampal region. Tetanizing stimulation of CA1 also failed to increase the concentration of brain-derived neurotrophic factor (BDNF in the EC of malnourished rats. Impaired capacity of the EC of prenatally malnourished rats to develop LTP and to increase BDNF levels during adulthood may be an important factor contributing to deficits in learning performance having adult prenatally malnourished animals.

  11. Effect of prenatal protein malnutrition on long-term potentiation and BDNF protein expression in the rat entorhinal cortex after neocortical and hippocampal tetanization.

    Science.gov (United States)

    Hernández, Alejandro; Burgos, Héctor; Mondaca, Mauricio; Barra, Rafael; Núñez, Héctor; Pérez, Hernán; Soto-Moyano, Rubén; Sierralta, Walter; Fernández, Victor; Olivares, Ricardo; Valladares, Luis

    2008-01-01

    Reduction of the protein content from 25 to 8% casein in the diet of pregnant rats results in impaired neocortical long-term potentiation (LTP) of the offspring together with lower visuospatial memory performance. The present study was aimed to investigate whether this type of maternal malnutrition could result in modification of plastic capabilities of the entorhinal cortex (EC) in the adult progeny. Unlike normal eutrophic controls, 55-60-day-old prenatally malnourished rats were unable to develop LTP in the medial EC to tetanizing stimulation delivered to either the ipsilateral occipital cortex or the CA1 hippocampal region. Tetanizing stimulation of CA1 also failed to increase the concentration of brain-derived neurotrophic factor (BDNF) in the EC of malnourished rats. Impaired capacity of the EC of prenatally malnourished rats to develop LTP and to increase BDNF levels during adulthood may be an important factor contributing to deficits in learning performance having adult prenatally malnourished animals.

  12. Improvement in Memory and Brain Long-term Potentiation Deficits Due to Permanent Hypoperfusion/Ischemia by Grape Seed Extract in Rats

    Directory of Open Access Journals (Sweden)

    Alireza Sarkaki

    2013-09-01

    Full Text Available   Objective(s: Cerebral hypoperfusion/ischemia (CHI is a neurological disease where impaired hippocampus electrical activity and cognition caused by a serial pathophysiological events. This study aimed to evaluate the effects of chronic oral administration of grape seed extract (GSE on passive avoidance memory and long-term potentiation (LTP after permanent bilateral common carotid arteries occlusion (2CCAO in male adult rats.   Materials and Methods: Thirty-two adult male Wistar rats were randomly divided into: 1 Sham+Veh, 2 Isch+Veh, 3 Sham+GSE, 4 Isch+GSE. In order to make 2CCAO as an animal model of CHI, carotid arteries were ligatured and then cut bilaterally. To evaluation of passive avoidance memory, step-down latency (STL was measured and LTP was recorded from hippocampal dentate gyrus (DG after high frequency stimulation (HFS in all rats. Results: We found that memory was significantly impaired in rats after CHI (P

  13. Long-Term Collections

    CERN Multimedia

    Staff Association

    2016-01-01

    45 years helping in developing countries! CERN personnel have been helping the least fortunate people on the planet since 1971. How? With the Long-Term Collections! Dear Colleagues, The Staff Association’s Long-Term Collections (LTC) Committee is delighted to share this important milestone in the life of our Laboratory with you. Indeed, whilst the name of CERN is known worldwide for scientific discoveries, it also shines in the many humanitarian projects which have been supported by the LTC since 1971. Several schools and clinics, far and wide, carry its logo... Over the past 45 years, 74 projects have been supported (9 of which are still ongoing). This all came from a group of colleagues who wanted to share a little of what life offered them here at CERN, in this haven of mutual understanding, peace and security, with those who were less fortunate elsewhere. Thus, the LTC were born... Since then, we have worked as a team to maintain the dream of these visionaries, with the help of regular donat...

  14. Long-Term Collection

    CERN Multimedia

    Staff Association

    2016-01-01

    Dear Colleagues, As previously announced in Echo (No. 254), your delegates took action to draw attention to the projects of the Long-Term Collections (LTC), the humanitarian body of the CERN Staff Association. On Tuesday, 11 October, at noon, small Z-Cards were widely distributed at the entrances of CERN restaurants and we thank you all for your interest. We hope to have achieved an important part of our goal, which was to inform you, convince you and find new supporters among you. We will find out in the next few days! An exhibition of the LTC was also set up in the Main Building for the entire week. The Staff Association wants to celebrate the occasion of the Long-Term Collection’s 45th anniversary at CERN because, ever since 1971, CERN personnel have showed great support in helping the least fortunate people on the planet in a variety of ways according to their needs. On a regular basis, joint fundraising appeals are made with the Directorate to help the victims of natural disasters around th...

  15. Collectes à long terme

    CERN Multimedia

    Collectes à long terme

    2014-01-01

    En cette fin d’année 2014 qui approche à grands pas, le Comité des Collectes à Long Terme remercie chaleureusement ses fidèles donatrices et donateurs réguliers pour leurs contributions à nos actions en faveur des plus démunis de notre planète. C’est très important, pour notre Comité, de pouvoir compter sur l’appui assidu que vous nous apportez. Depuis plus de 40 ans maintenant, le modèle des CLT est basé principalement sur des actions à long terme (soit une aide pendant 4-5 ans par projet, mais plus parfois selon les circonstances), et sa planification demande une grande régularité de ses soutiens financiers. Grand MERCI à vous ! D’autres dons nous parviennent au cours de l’année, et ils sont aussi les bienvenus. En particulier, nous tenons à remercier...

  16. Effects of Joint Attention on Long-Term Memory in 9-Month-Old Infants: An Event-Related Potentials Study

    Science.gov (United States)

    Kopp, Franziska; Lindenberger, Ulman

    2011-01-01

    Joint attention develops during the first year of life but little is known about its effects on long-term memory. We investigated whether joint attention modulates long-term memory in 9-month-old infants. Infants were familiarized with visually presented objects in either of two conditions that differed in the degree of joint attention (high…

  17. The Screening of Genes Sensitive to Long-Term, Low-Level Microwave Exposure and Bioinformatic Analysis of Potential Correlations to Learning and Memory

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ya Li; LI Ying Xian; MA Hong Bo; LI Dong; LI Hai Liang; JIANG Rui; KAN Guang Han; YANG Zhen Zhong; HUANG Zeng Xin

    2015-01-01

    Objective To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Methods Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. Results The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memory. Conclusion Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases.

  18. The Screening of Genes Sensitive to Long-Term, Low-Level Microwave Exposure and Bioinformatic Analysis of Potential Correlations to Learning and Memory.

    Science.gov (United States)

    Zhao, Ya Li; Li, Ying Xian; Ma, Hong Bo; Li, Dong; Li, Hai Liang; Jiang, Rui; Kan, Guang Han; Yang, Zhen Zhong; Huang, Zeng Xin

    2015-08-01

    To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memorye. Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  19. Introduction: Long term prediction

    International Nuclear Information System (INIS)

    Beranger, G.

    2003-01-01

    Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance

  20. Long-Term Symbolic Learning

    National Research Council Canada - National Science Library

    Kennedy, William G; Trafton, J. G

    2007-01-01

    What are the characteristics of long-term learning? We investigated the characteristics of long-term, symbolic learning using the Soar and ACT-R cognitive architectures running cognitive models of two simple tasks...

  1. Hippocampal network activity is transiently altered by induction of long-term potentiation in the dentate gyrus of freely behaving rats

    Directory of Open Access Journals (Sweden)

    Arthur Bikbaev

    2007-12-01

    Full Text Available A role for oscillatory activity in hippocampal neuronal networks has been proposed in sensory encoding, cognitive functions and synaptic plasticity. In the hippocampus, theta (5–10 Hz and gamma (30–100 Hz oscillations may provide a mechanism for temporal encoding of information, and the basis for formation and retrieval of memory traces. Long-term potentiation (LTP of synaptic transmission, a candidate cellular model of synaptic information storage, is typically induced by high-frequency tetanisation (HFT of afferent pathways. Taking into account the role of oscillatory activity in the processing of information, dynamic changes may occur in hippocampal network activity in the period during HFT and/or soon after it. These changes in rhythmic activity may determine or, at least, contribute to successful potentiation and, in general, to formation of memory. We have found that short-term potentiation (STP and LTP as well LTPfailure are characterised with different profiles of changes in theta and gamma frequencies. Potentiation of synaptic transmission was associated with a significant increase in the relative theta power and mean amplitude of theta cycles in the period encompassing 300 seconds after HFT. Where LTP or STP, but not failure of potentiation, occurred, this facilitation of theta was accompanied by transient increases in gamma power and in the mean amplitude of gamma oscillations within a single theta cycle. Our data support that specific, correlated changes in these parameters are associated with successful synaptic potentiation. These findings suggest that changes in theta-gamma activity associated with induction of LTP may enable synaptic information storage in the hippocampus.

  2. LONG TERM COLLECTIONS

    CERN Multimedia

    STAFF ASSOCIATION

    2010-01-01

    ACKNOWLEDGMENTS The Long-Term Collections (CLT) committee would like to warmly thank its faithful donors who, year after year, support our actions all over the world. Without you, all this would not be possible. We would like to thank, in particular, the CERN Firemen’s Association who donated 5000 CHF in the spring thanks to the sale of their traditional calendar, and the generosity of the CERN community. A huge thank you to the firemen for their devotion to our cause. And thank you to all those who have opened their door, their heart, and their purses! Similarly, we warmly thank the CERN Yoga Club once again for its wonderful donation of 2000 CHF we recently received. We would also like to tell you that all our projects are running well. Just to remind you, we are currently supporting the activities of the «Réflexe-Partage» Association in Mali; the training centre of «Education et Développement» in Abomey, Benin; and the orphanage and ...

  3. Synaptic characteristics with strong analog potentiation, depression, and short-term to long-term memory transition in a Pt/CeO2/Pt crossbar array structure

    Science.gov (United States)

    Kim, Hyung Jun; Park, Daehoon; Yang, Paul; Beom, Keonwon; Kim, Min Ju; Shin, Chansun; Kang, Chi Jung; Yoon, Tae-Sik

    2018-06-01

    A crossbar array of Pt/CeO2/Pt memristors exhibited the synaptic characteristics such as analog, reversible, and strong resistance change with a ratio of ∼103, corresponding to wide dynamic range of synaptic weight modulation as potentiation and depression with respect to the voltage polarity. In addition, it presented timing-dependent responses such as paired-pulse facilitation and the short-term to long-term memory transition by increasing amplitude, width, and repetition number of voltage pulse and reducing the interval time between pulses. The memory loss with a time was fitted with a stretched exponential relaxation model, revealing the relation of memory stability with the input stimuli strength. The resistance change was further enhanced but its stability got worse as increasing measurement temperature, indicating that the resistance was changed as a result of voltage- and temperature-dependent electrical charging and discharging to alter the energy barrier for charge transport. These detailed synaptic characteristics demonstrated the potential of crossbar array of Pt/CeO2/Pt memristors as artificial synapses in highly connected neuron-synapse network.

  4. 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

    Proechimys are small terrestrial rodents from Amazon rainforest. Each animal species is adapted to a specific environment in which the animal evolved therefore without comparative approaches unique characteristics of distinct species cannot be fully recognized. Laboratory rodents are exceedingly inbred strains dissociated from their native habitats and their fundamental ecological aspects are abstracted. Thus, the employment of exotic non-model species can be informative and complement conventional animal models. With the aim of promoting comparative studies between the exotic wildlife populations in the laboratory and traditional rodent model, we surveyed a type of synaptic plasticity intimately related to memory encoding in animals. Using theta-burst paradigm, in vitro long-term potentiation (LTP) in the CA1 subfield of hippocampal slices was assessed in the Amazon rodents Proechimys and Wistar rats. Memory, learning and anxiety were investigated through the plus-maze discriminative avoidance task (PM-DAT) and object recognition test. In PM-DAT, both animal species were submitted to two test sessions (3-h and 24-h) after the conditioning training. Proechimys exhibited higher anxiety-like behavior in the training session but during test sessions both species exhibited similar patterns of anxiety-related behavior. After 3-h of the training, Proechimys and Wistar spent significantly less time in the aversive enclosed arm than in the non-aversive arm. But, at 24-h after training, Wistar rats remained less time in the aversive closed arm in comparison with the non-aversive one, while Proechimys rodents spent the same amount of time in both enclosed arms. In the object recognition test, both species were evaluated at 24-h after the acquisition session and similar findings than those of the PM-DAT (24-h) were obtained, suggesting that long-term memory duration did not persist for 24-h in the Amazon rodent. Field excitatory post-synaptic potentials recordings revealed

  5. Long-term Potentiation Decay and Poor Long-lasting Memory Process in the Wild Rodents Proechimys from Brazil’s Amazon Rainforest

    Directory of Open Access Journals (Sweden)

    Marcia J. Guimarães Marques

    2018-01-01

    Full Text Available Proechimys are small terrestrial rodents from Amazon rainforest. Each animal species is adapted to a specific environment in which the animal evolved therefore without comparative approaches unique characteristics of distinct species cannot be fully recognized. Laboratory rodents are exceedingly inbred strains dissociated from their native habitats and their fundamental ecological aspects are abstracted. Thus, the employment of exotic non-model species can be informative and complement conventional animal models. With the aim of promoting comparative studies between the exotic wildlife populations in the laboratory and traditional rodent model, we surveyed a type of synaptic plasticity intimately related to memory encoding in animals. Using theta-burst paradigm, in vitro long-term potentiation (LTP in the CA1 subfield of hippocampal slices was assessed in the Amazon rodents Proechimys and Wistar rats. Memory, learning and anxiety were investigated through the plus-maze discriminative avoidance task (PM-DAT and object recognition test. In PM-DAT, both animal species were submitted to two test sessions (3-h and 24-h after the conditioning training. Proechimys exhibited higher anxiety-like behavior in the training session but during test sessions both species exhibited similar patterns of anxiety-related behavior. After 3-h of the training, Proechimys and Wistar spent significantly less time in the aversive enclosed arm than in the non-aversive arm. But, at 24-h after training, Wistar rats remained less time in the aversive closed arm in comparison with the non-aversive one, while Proechimys rodents spent the same amount of time in both enclosed arms. In the object recognition test, both species were evaluated at 24-h after the acquisition session and similar findings than those of the PM-DAT (24-h were obtained, suggesting that long-term memory duration did not persist for 24-h in the Amazon rodent. Field excitatory post-synaptic potentials

  6. 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

    Proechimys are small terrestrial rodents from Amazon rainforest. Each animal species is adapted to a specific environment in which the animal evolved therefore without comparative approaches unique characteristics of distinct species cannot be fully recognized. Laboratory rodents are exceedingly inbred strains dissociated from their native habitats and their fundamental ecological aspects are abstracted. Thus, the employment of exotic non-model species can be informative and complement conventional animal models. With the aim of promoting comparative studies between the exotic wildlife populations in the laboratory and traditional rodent model, we surveyed a type of synaptic plasticity intimately related to memory encoding in animals. Using theta-burst paradigm, in vitro long-term potentiation (LTP) in the CA1 subfield of hippocampal slices was assessed in the Amazon rodents Proechimys and Wistar rats. Memory, learning and anxiety were investigated through the plus-maze discriminative avoidance task (PM-DAT) and object recognition test. In PM-DAT, both animal species were submitted to two test sessions (3-h and 24-h) after the conditioning training. Proechimys exhibited higher anxiety-like behavior in the training session but during test sessions both species exhibited similar patterns of anxiety-related behavior. After 3-h of the training, Proechimys and Wistar spent significantly less time in the aversive enclosed arm than in the non-aversive arm. But, at 24-h after training, Wistar rats remained less time in the aversive closed arm in comparison with the non-aversive one, while Proechimys rodents spent the same amount of time in both enclosed arms. In the object recognition test, both species were evaluated at 24-h after the acquisition session and similar findings than those of the PM-DAT (24-h) were obtained, suggesting that long-term memory duration did not persist for 24-h in the Amazon rodent. Field excitatory post-synaptic potentials recordings revealed

  7. Sustained increase of spontaneous input and spike transfer in the CA3-CA1 pathway following long term potentiation in vivo

    Directory of Open Access Journals (Sweden)

    Oscar eHerreras

    2012-10-01

    Full Text Available Long term potentiation (LTP is commonly used to study synaptic plasticity but the associated changes in the spontaneous activity of individual neurons or the computational properties of neural networks in vivo remain largely unclear. The multisynaptic origin of spontaneous spikes makes difficult estimating the impact of a particular potentiated input. Accordingly, we adopted an approach that isolates pathway-specific postsynaptic activity from raw local field potentials (LFPs in the rat hippocampus in order to study the effects of LTP on ongoing spike transfer between cell pairs in the CA3-CA1 pathway. CA1 Schaffer-specific LFPs elicited by spontaneous clustered firing of CA3 pyramidal cells involved a regular succession of elementary micro-field-EPSPs (gamma-frequency that fired spikes in CA1 units. LTP increased the amplitude but not the frequency of these ongoing excitatory quanta. Also, the proportion of Schaffer-driven spikes in both CA1 pyramidal cells and interneurons increased in a cell-specific manner only in previously connected CA3-CA1 cell pairs, i.e., when the CA3 pyramidal cell had shown pre-LTP significant correlation with firing of a CA1 unit and potentiated spike-triggered average of Schaffer LFPs following LTP. Moreover, LTP produced subtle reorganization of presynaptic CA3 cell assemblies. These findings show effective enhancement of pathway specific ongoing activity which leads to increased spike transfer in potentiated segments of a network. These indicate that plastic phenomena induced by external protocols may intensify spontaneous information flow across specific channels as proposed in transsynaptic propagation of plasticity and synfire chain hypotheses that may be the substrate for different types of memory involving multiple brain structures.

  8. Evaluating long term forecasts

    Energy Technology Data Exchange (ETDEWEB)

    Lady, George M. [Department of Economics, College of Liberal Arts, Temple University, Philadelphia, PA 19122 (United States)

    2010-03-15

    The U.S. Department of Energy's Energy Information Administration (EIA), and its predecessor organizations, has published projections of U.S. energy production, consumption, distribution and prices annually for over 30 years. A natural issue to raise in evaluating the projections is an assessment of their accuracy compared to eventual outcomes. A related issue is the determination of the sources of 'error' in the projections that are due to differences between the actual versus realized values of the associated assumptions. One way to do this would be to run the computer-based model from which the projections are derived at the time the projected values are realized, using actual rather than assumed values for model assumptions; and, compare these results to the original projections. For long term forecasts, this approach would require that the model's software and hardware configuration be archived and available for many years, possibly decades, into the future. Such archival creates many practical problems; and, in general, it is not being done. This paper reports on an alternative approach for evaluating the projections. In the alternative approach, the model is run many times for cases in which important assumptions are changed individually and in combinations. A database is assembled from the solutions and a regression analysis is conducted for each important projected variable with the associated assumptions chosen as exogenous variables. When actual data are eventually available, the regression results are then used to estimate the sources of the differences in the projections of the endogenous variables compared to their eventual outcomes. The results presented here are for residential and commercial sector natural gas and electricity consumption. (author)

  9. Quantifying the benefit of wellbore leakage potential estimates for prioritizing long-term MVA well sampling at a CO2 storage site.

    Science.gov (United States)

    Azzolina, Nicholas A; Small, Mitchell J; Nakles, David V; Glazewski, Kyle A; Peck, Wesley D; Gorecki, Charles D; Bromhal, Grant S; Dilmore, Robert M

    2015-01-20

    This work uses probabilistic methods to simulate a hypothetical geologic CO2 storage site in a depleted oil and gas field, where the large number of legacy wells would make it cost-prohibitive to sample all wells for all measurements as part of the postinjection site care. Deep well leakage potential scores were assigned to the wells using a random subsample of 100 wells from a detailed study of 826 legacy wells that penetrate the basal Cambrian formation on the U.S. side of the U.S./Canadian border. Analytical solutions and Monte Carlo simulations were used to quantify the statistical power of selecting a leaking well. Power curves were developed as a function of (1) the number of leaking wells within the Area of Review; (2) the sampling design (random or judgmental, choosing first the wells with the highest deep leakage potential scores); (3) the number of wells included in the monitoring sampling plan; and (4) the relationship between a well’s leakage potential score and its relative probability of leakage. Cases where the deep well leakage potential scores are fully or partially informative of the relative leakage probability are compared to a noninformative base case in which leakage is equiprobable across all wells in the Area of Review. The results show that accurate prior knowledge about the probability of well leakage adds measurable value to the ability to detect a leaking well during the monitoring program, and that the loss in detection ability due to imperfect knowledge of the leakage probability can be quantified. This work underscores the importance of a data-driven, risk-based monitoring program that incorporates uncertainty quantification into long-term monitoring sampling plans at geologic CO2 storage sites.

  10. Different contributions of platelet-activating factor and nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Pettorossi, V E; Grassi, S

    2001-01-01

    In rat brainstem slices, we investigated the differential role of nitric oxide (NO) and platelet-activating factor (PAF) in long-term potentiation (LTP) induced in the ventral portion of the medial vestibular nuclei (MVN) by high-frequency stimulation (HFS) of the primary vestibular afferents. The NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) and the PAF receptor antagonist ginkgolide B (BN-52021) were administered before and after induction of potentiation. The effect of carboxy-PTIO was to completely prevent LTP. By contrast, BN-52021 only reduced the amplitude of HFS potentiation, which could develop fully at the drug washout or decline to zero, becoming a short-term phenomenon, in the case of long-lasting PAF receptor block. Both drugs, when given after HFS, had no effect on the already established potentiation, but whilst BN-52021 showed an influence within 5 min of the LTP induction, carboxy-PTIO did not affect the response once HFS was delivered. Moreover, we showed that the NO donor, sodium nitroprusside, and methylcarbamyl PAF (mc-PAF) induced LTP which was associated with an increase in glutamate release as shown by reduction in the paired-pulse facilitation ratio. The mc-PAF LTP was prevented by the NO scavenger, while NO LTP was only reduced by BN-52021. We suggest that NO and PAF are implicated as retrograde messengers in two different phases of vestibular LTP: NO in the induction phase; and PAF in the full expression phase.

  11. Modulation of Long-term Potentiation of Cortico-amygdala Synaptic Responses and Auditory Fear Memory by Dietary Polyunsaturated Fatty Acid

    Directory of Open Access Journals (Sweden)

    Daisuke Yamada

    2016-08-01

    Full Text Available Converging evidence suggests that an imbalance of ω3 to ω6 polyunsaturated fatty acid (PUFA in the brain is involved in mental illnesses such as anxiety disorders. However, the underlying mechanism is unknown. We previously reported that the dietary ratio of ω3 to ω6 PUFA alters this ratio in the brain, and influences contextual fear memory. In addition to behavioral change, enhancement of cannabinoid CB1 receptor-mediated short-term synaptic plasticity and facilitation of the agonist sensitivity of CB1 receptors have been observed in excitatory synaptic responses in the basolateral nucleus of the amygdala. However, it is not known whether long-term synaptic plasticity in the amygdala is influenced by the dietary ratio of ω3 to ω6 PUFA. In the present study, we examined long-term potentiation (LTP of optogenetically–evoked excitatory synaptic responses in synapses between the terminal of the projection from the auditory cortex and the pyramidal cells in the lateral nucleus of the amygdala. We found that LTP in this pathway was attenuated in mice fed a diet with a high ω3 to ω6 PUFA ratio (0.97, compared with mice fed a diet with a low ω3 to ω6 PUFA ratio (0.14. Furthermore, mice in the former condition showed reduced fear responses in an auditory fear conditioning test, compared with mice in the latter condition. In both electrophysiological and behavioral experiments, the effect of a diet with a high ω3 to ω6 PUFA ratio was completely blocked by treatment with a CB1 receptor antagonist. Furthermore, a significant reduction was observed in cholesterol content, but not in the level of an endogenous CB1 receptor agonist, 2-arachidonoylglycerol, in brain samples containing the amygdala. These results suggest that the balance of ω3 to ω6 PUFA has an impact on fear memory and cortico-amygdala synaptic plasticity, both in a CB1 receptor–dependent manner.

  12. Forebrain-specific knockout of B-raf kinase leads to deficits in hippocampal long-term potentiation, learning, and memory.

    Science.gov (United States)

    Chen, Adele P; Ohno, Masuo; Giese, K Peter; Kühn, Ralf; Chen, Rachel L; Silva, Alcino J

    2006-01-01

    Raf kinases are downstream effectors of Ras and upstream activators of the MEK-ERK cascade. Ras and MEK-ERK signaling play roles in learning and memory (L&M) and neural plasticity, but the roles of Raf kinases in L&M and plasticity are unclear. Among Raf isoforms, B-raf is preferentially expressed in the brain. To determine whether B-raf has a role in synaptic plasticity and L&M, we used the Cre-LoxP gene targeting system to derive forebrain excitatory neuron B-raf knockout mice. This conditional knockout resulted in deficits in ERK activation and hippocampal long-term potentiation (LTP) and impairments in hippocampus-dependent L&M, including spatial learning and contextual discrimination. Despite the widespread expression of B-raf, this mutation did not disrupt other forms of L&M, such as cued fear conditioning and conditioned taste aversion. Our findings demonstrate that B-raf plays a role in hippocampal ERK activation, synaptic plasticity, and L&M.

  13. Characterization of stress-induced suppression of long-term potentiation in the hippocampal CA1 field of freely moving rats.

    Science.gov (United States)

    Hirata, Riki; Togashi, Hiroko; Matsumoto, Machiko; Yamaguchi, Taku; Izumi, Takeshi; Yoshioka, Mitsuhiro

    2008-08-21

    Several lines of evidence have shown that exposure to stress impairs long-term potentiation (LTP) in the CA1 field of the hippocampus, but the detailed mechanisms for this effect remain to be clarified. The present study elucidated the synaptic mechanism of stress-induced LTP suppression in conscious, freely moving rats using electrophysiological approaches. Open field stress (i.e., novel environment stress) and elevated platform stress (i.e., uncontrollable stress) were employed. Basal synaptic transmission was significantly reduced during exposure to elevated platform stress but not during exposure to open field stress. LTP induction was blocked by elevated platform stress but not influenced by open field stress. Significant increases in serum corticosterone levels were observed in the elevated platform stress group compared with the open field stress group. Furthermore, LTP suppression induced by elevated platform stress was prevented by pretreatment with an anxiolytic drug diazepam (1 mg/kg, i.p.). These results suggest that stress-induced LTP suppression depends on the relative intensity of the stressor. The inhibitory synaptic response induced by an intense psychological stress, such as elevated platform stress, may be attributable to LTP impairment in the CA1 field of the hippocampus.

  14. Expression of p53 Target Genes in the Early Phase of Long-Term Potentiation in the Rat Hippocampal CA1 Area

    Directory of Open Access Journals (Sweden)

    Vladimir O. Pustylnyak

    2015-01-01

    Full Text Available Gene expression plays an important role in the mechanisms of long-term potentiation (LTP, which is a widely accepted experimental model of synaptic plasticity. We have studied the expression of at least 50 genes that are transcriptionally regulated by p53, as well as other genes that are related to p53-dependent processes, in the early phase of LTP. Within 30 min after Schaffer collaterals (SC tetanization, increases in the mRNA and protein levels of Bax, which are upregulated by p53, and a decrease in the mRNA and protein levels of Bcl2, which are downregulated by p53, were observed. The inhibition of Mdm2 by nutlin-3 increased the basal p53 protein level and rescued its tetanization-induced depletion, which suggested the involvement of Mdm2 in the control over p53 during LTP. Furthermore, nutlin-3 caused an increase in the basal expression of Bax and a decrease in the basal expression of Bcl2, whereas tetanization-induced changes in their expression were occluded. These results support the hypothesis that p53 may be involved in transcriptional regulation during the early phase of LTP. We hope that the presented data may aid in the understanding of the contribution of p53 and related genes in the processes that are associated with synaptic plasticity.

  15. Estradiol-induced increase in the magnitude of long-term potentiation is prevented by blocking NR2B-containing receptors.

    Science.gov (United States)

    Smith, Caroline C; McMahon, Lori L

    2006-08-16

    Estradiol, through activation of genomic estrogen receptors, induces changes in synaptic morphology and function in hippocampus, a brain region important for memory acquisition. Specifically, this hormone increases CA1 pyramidal cell dendritic spine density, NMDA receptor (NMDAR)-mediated transmission, and the magnitude of long-term potentiation (LTP) at CA3-CA1 synapses. We recently reported that the estradiol-induced increase in LTP magnitude occurs only when there is a simultaneous increase in the fractional contribution of NMDAR-mediated transmission relative to AMPA receptor transmission, suggesting a direct role for the increase in NMDAR transmission to the heightened LTP magnitude. Estradiol has been shown to increase expression of the NMDAR subunit NR2B, but whether this translates into an increase in function of NR2B-containing receptors remains to be determined. Here we show that not only is the estradiol-induced increase in NMDAR transmission mediated by NR2B-containing receptors, but blocking these receptors using RO25-6981 [R-(R,S)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidine propranol] (0.5 microM), an NR2B selective antagonist, prevents the estradiol-induced increase in LTP magnitude. Thus, our data show a causal link between the estradiol-induced increase in transmission mediated by NR2B-containing NMDARs and the increase in LTP magnitude.

  16. The effects of CCK-8S on spatial memory and long-term potentiation at CA1 during induction of stress in rats.

    Science.gov (United States)

    Sadeghi, Malihe; Reisi, Parham; Radahmadi, Maryam

    2017-12-01

    Cholecystokinin (CCK) has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days. Cholecystokinin sulfated octapeptide (CCK-8S) was injected (1.6 µg/kg, IP) before each session of stress induction. Spatial memory was evaluated by Morris water maze test. Long-term potentiation (LTP) in Schaffer collateral-CA1 synapses was assessed (by 100 Hz tetanization) in order to investigate synaptic plasticity. Stress impaired spatial memory significantly ( P stress group. With respect to the control group, both fEPSP amplitude and slope were significantly ( P stress group. However, there were no differences between responses of the control-CCK and Stress-CCK groups compared to the control group. The present results suggest that high levels of CCK-8S during induction of stress can modulate the destructive effects of stress on hippocampal synaptic plasticity and memory. Therefore, the mediatory effects of CCK in stress are likely as compensatory responses.

  17. Dietary 2'-Fucosyllactose Enhances Operant Conditioning and Long-Term Potentiation via Gut-Brain Communication through the Vagus Nerve in Rodents.

    Directory of Open Access Journals (Sweden)

    Enrique Vazquez

    Full Text Available 2´-fucosyllactose (2´-FL is an abundant human milk oligosaccharide (HMO in human milk with diverse biological effects. We recently reported ingested 2´-FL stimulates central nervous system (CNS function, such as hippocampal long term potentiation (LTP and learning and memory in rats. Conceivably the effect of 2´-FL on CNS function may be via the gut-brain axis (GBA, specifically the vagus nerve, and L-fucose (Fuc may play a role. This study had two aims: (1 determine if the effect of ingested 2´-FL on the modulation of CNS function is dependent on the integrity of the molecule; and (2 confirm if oral 2´-FL modified hippocampal LTP and associative learning related skills in rats submitted to bilateral subdiaphragmatic vagotomy. Results showed that 2´-FL but not Fuc enhanced LTP, and vagotomy inhibited the effects of oral 2´-FL on LTP and associative learning related paradigms. Taken together, the data show that dietary 2´-FL but not its Fuc moiety affects cognitive domains and improves learning and memory in rats. This effect is dependent on vagus nerve integrity, suggesting GBA plays a role in 2´-FL-mediated cognitive benefits.

  18. Levothyroxine rescues the lead-induced hypothyroidism and impairment of long-term potentiation in hippocampal CA1 region of the developmental rats

    International Nuclear Information System (INIS)

    Wu Chuanyun; Liu Bing; Wang Huili; Ruan Diyun

    2011-01-01

    Lead (Pb) exposure during development has been associated with impaired long-term potentiation (LTP). Hypothyroidism happening upon subjects with occupational exposure to Pb is suggestive of an adverse effect of Pb on thyroid homeostasis, leading to the hypothesis that Pb exposure may alter thyroid hormone homeostasis. Hippocampus is one of the targets of Pb exposure, and is sensitive to and dependent on thyroid hormones, leading us to explore whether levothyroxine (L-T 4 ) administration could alter the thyroid disequilibrium and impairment of LTP in rat hippocampus caused by Pb exposure. Our results show that Pb exposure caused a decrease in triiodothyronine (T 3 ) and tetraiodothyronine (T 4 ) levels accompanied by a dramatic decrease of TSH and application of L-T 4 restored these changes to about control levels. Hippocampal and blood Pb concentration were significantly reduced following L-T 4 treatment. L-T 4 treatment rescued the impairment of LTP induced by the Pb exposure. These results suggest that Pb exposure may lead to thyroid dysfunction and induce hypothyroidism and provide a direct electrophysiological proof that L-T 4 relieves chronic Pb exposure-induced impairment of synaptic plasticity. - Highlights: → Lead may interfere with thyroid hormone homeostasis and induce hypothyroidism. → Levothyroxine decreases the hippocampal and blood Pb concentration. → Levothyroxine amends the T 3 , T 4 and TSH levels in blood. → Levothyroxine rescues the impaired LTP in CA1.

  19. Adolescent mice show anxiety- and aggressive-like behavior and the reduction of long-term potentiation in mossy fiber-CA3 synapses after neonatal maternal separation.

    Science.gov (United States)

    Shin, S Y; Han, S H; Woo, R-S; Jang, S H; Min, S S

    2016-03-01

    Exposure to maternal separation (MS) during early life is an identified risk factor for emotional disorders such as anxiety and depression later in life. This study investigated the effects of neonatal MS on the behavior and long-term potentiation (LTP) as well as basic synaptic transmission at hippocampal CA3-CA1 and mossy fiber (MF)-CA3 synapses in adolescent mice for 19days. When mice were adolescents, we measured depression, learning, memory, anxious and aggressive behavior using the forced swimming test (FST), Y-maze, Morris water maze (MWM), elevated plus maze (EPM), three consecutive days of the open field test, the social interaction test, the tube-dominance test and the resident-intruder test. The results showed that there was no difference in FST, Y-maze, and MWM performance. However, MS mice showed more anxiety-like behavior in the EPM test and aggressive-like behavior in the tube-dominance and resident-intruder tests. In addition, the magnitude of LTP and release probability in the MF-CA3 synapses was reduced in the MS group but not in the CA3-CA1 synapse. Our results indicate that early life stress due to MS may induce anxiety- and aggressive-like behavior during adolescence, and these effects are associated with synaptic plasticity at the hippocampal MF-CA3 synapses. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Right hemicolectomy for mesenteric phlebosclerosis potentially caused by long-term use of herbal medicine: A case report and literature review.

    Science.gov (United States)

    Hoshino, Nobuaki; Hasegawa, Suguru; Hida, Koya; Kawada, Kenji; Sakai, Yoshiharu

    2016-01-01

    Mesenteric phlebosclerosis is a rare ischemic disease affecting the colon. Systemic disease and herbal medicine have been pointed out as possible causes, and the disease is characterized by calcifications involved the mesocolic veins. Patients who do not respond to conservative therapy require surgical treatment. In surgical intervention, an adequate extent of colonic resection is important. We present a case of an 87-year-old woman with mesenteric phlebosclerosis who had consumed herbal medicine for 40 years. She suffered from ileus caused by mesenteric phlebosclerosis, and the symptoms did not improve with conservative therapy. Right hemicolectomy was performed since the disease was localized in the right colon. Long-term use of herbal medicine was considered the potential cause of mesenteric phlebosclerosis. The postoperative course was mostly uneventful. The patient stopped using herbal medicine and had no signs of recurrence 2 years after surgery. The greatest concern in surgery for mesenteric phleboscrerosis is to detect the affected area, which should be removed. Characteristic findings in computed tomography and intraoperative findings can help to determine the optimal extent of colonic resection. Mesenteric phlebosclerosis caused by herbal medicines occurs as localized disease in the right colon compared with mesenteric phlebosclerosis caused by other pathogenesis. Limited colonic resection is usually indicated for mesenteric phlebosclerosis caused by herbal medicine. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Underlying Mechanisms of Cooperativity, Input Specificity, and Associativity of Long-Term Potentiation Through a Positive Feedback of Local Protein Synthesis

    Directory of Open Access Journals (Sweden)

    Lijie Hao

    2018-05-01

    Full Text Available Long-term potentiation (LTP is a specific form of activity-dependent synaptic plasticity that is a leading mechanism of learning and memory in mammals. The properties of cooperativity, input specificity, and associativity are essential for LTP; however, the underlying mechanisms are unclear. Here, based on experimentally observed phenomena, we introduce a computational model of synaptic plasticity in a pyramidal cell to explore the mechanisms responsible for the cooperativity, input specificity, and associativity of LTP. The model is based on molecular processes involved in synaptic plasticity and integrates gene expression involved in the regulation of neuronal activity. In the model, we introduce a local positive feedback loop of protein synthesis at each synapse, which is essential for bimodal response and synapse specificity. Bifurcation analysis of the local positive feedback loop of brain-derived neurotrophic factor (BDNF signaling illustrates the existence of bistability, which is the basis of LTP induction. The local bifurcation diagram provides guidance for the realization of LTP, and the projection of whole system trajectories onto the two-parameter bifurcation diagram confirms the predictions obtained from bifurcation analysis. Moreover, model analysis shows that pre- and postsynaptic components are required to achieve the three properties of LTP. This study provides insights into the mechanisms underlying the cooperativity, input specificity, and associativity of LTP, and the further construction of neural networks for learning and memory.

  2. Dopamine D1-like receptor in lateral habenula nucleus affects contextual fear memory and long-term potentiation in hippocampal CA1 in rats.

    Science.gov (United States)

    Chan, Jiangping; Guan, Xin; Ni, Yiling; Luo, Lilu; Yang, Liqiang; Zhang, Pengyue; Zhang, Jichuan; Chen, Yanmei

    2017-03-15

    The Lateral Habenula (LHb) plays an important role in emotion and cognition. Recent experiments suggest that LHb has functional interaction with the hippocampus and plays an important role in spatial learning. LHb is reciprocally connected with midbrain monoaminergic brain areas such as the ventral tegmental area (VTA). However, the role of dopamine type 1 receptor (D1R) in LHb in learning and memory is not clear yet. In the present study, D1R agonist or antagonist were administered bilaterally into the LHb in rats. We found that both D1R agonist and antagonist impaired the acquisition of contextual fear memory in rats. D1R agonist or antagonist also impaired long term potentiation (LTP) in hippocampal CA3-CA1 synapses in freely moving rats and attenuated learning induced phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) subunit 1 (GluA1) at Ser831 and Ser845 in hippocampus. Taken together, our results suggested that dysfunction of D1R in LHb affected the function of hippocampus. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Cystathionine-β-synthase-derived hydrogen sulfide is required for amygdalar long-term potentiation and cued fear memory in rats.

    Science.gov (United States)

    Chen, Hai-Bo; Wu, Wen-Ning; Wang, Wei; Gu, Xun-Hu; Yu, Bin; Wei, Bo; Yang, Yuan-Jian

    2017-04-01

    Hydrogen sulfide (H 2 S) is an endogenous gaseous molecule that functions as a neuromodulator in the brain. We previously reported that H 2 S regulated amygdalar synaptic plasticity and cued fear memory in rats. However, whether endogenous H 2 S is required for amygdalar long-term potentiation (LTP) induction and cued fear memory formation remains unclear. Here, we show that cystathionine-β-synthase (CBS), the predominant H 2 S-producing enzyme in the brain, was highly expressed in the amygdala of rats. Suppressing CBS activity by inhibitor prevented activity-triggered generation of H 2 S in the lateral amygdala (LA) region. Incubating brain slices with CBS inhibitor significantly prevented the induction of NMDA receptors (NMDARs)-dependent LTP in the thalamo-LA pathway, and intra-LA infusion of CBS inhibitor impaired cued fear memory in rats. Notably, treatment with H 2 S donor, but not CBS activator, significantly reversed the impairments of LTP and fear memory caused by CBS inhibition. Mechanismly, inhibition of CBS activity led to a reduction in NMDAR-mediated synaptic response in the thalamo-LA pathway, and treatment with H 2 S donor restored the function of NMDARs. Collectively, these results indicate that CBS-derived H 2 S is required for amygdalar synaptic plasticity and cued fear memory in rats, and the effects of endogenous H 2 S might involve the regulation of NMDAR function. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Methodological Aspects of the Potential Use of Dendrochronological Techniques When Analyzing the Long-Term Impact of Tourism on Protected Areas.

    Science.gov (United States)

    Ciapała, Szymon; Adamski, Paweł

    2015-01-01

    Intensification of pedestrian tourism causes damage to trees near tourist tracks, and likewise changes the soil structure. As a result, one may expect that annual amount of trees growing near tracks is significantly lower than deeper in the forest. However, during the study of the long-term impact of tourism on the environment (determined from tree increment dynamics), some methodological problems may occur. It is particularly important in protected areas where law and administrative regulations related to nature conservation force research to be conducted using small samples. In this paper we have analyzed the data collected in the Polish part of the Tatra National Park in the two study plots divided into two zones each: the area directly under the influence of the tourist's trampling and the control group. The aim of such analyses was to present the potential effects of the factors which may affect the results of dendrochronological analysis: (i) small size of samples that affects their representativeness, (ii) spatial differences in the rates of the process, as a result of spatial variability of environmental factors and (iii) temporal differences in the rates of the process. This study confirms that the factors mentioned above could significantly influence the results and should be taken into consideration during the analysis.

  5. Methodological Aspects of the Potential Use of Dendrochronological Techniques When Analyzing the Long-Term Impact of Tourism on Protected Areas.

    Directory of Open Access Journals (Sweden)

    Szymon Ciapała

    Full Text Available Intensification of pedestrian tourism causes damage to trees near tourist tracks, and likewise changes the soil structure. As a result, one may expect that annual amount of trees growing near tracks is significantly lower than deeper in the forest. However, during the study of the long-term impact of tourism on the environment (determined from tree increment dynamics, some methodological problems may occur. It is particularly important in protected areas where law and administrative regulations related to nature conservation force research to be conducted using small samples. In this paper we have analyzed the data collected in the Polish part of the Tatra National Park in the two study plots divided into two zones each: the area directly under the influence of the tourist's trampling and the control group. The aim of such analyses was to present the potential effects of the factors which may affect the results of dendrochronological analysis: (i small size of samples that affects their representativeness, (ii spatial differences in the rates of the process, as a result of spatial variability of environmental factors and (iii temporal differences in the rates of the process. This study confirms that the factors mentioned above could significantly influence the results and should be taken into consideration during the analysis.

  6. Age-Dependent Long-Term Potentiation Deficits in the Prefrontal Cortex of the Fmr1 Knockout Mouse Model of Fragile X Syndrome.

    Science.gov (United States)

    Martin, Henry G S; Lassalle, Olivier; Brown, Jonathan T; Manzoni, Olivier J

    2016-05-01

    The most common inherited monogenetic cause of intellectual disability is Fragile X syndrome (FXS). The clinical symptoms of FXS evolve with age during adulthood; however, neurophysiological data exploring this phenomenon are limited. The Fmr1 knockout (Fmr1KO) mouse models FXS, but studies in these mice of prefrontal cortex (PFC) function are underrepresented, and aging linked data are absent. We studied synaptic physiology and activity-dependent synaptic plasticity in the medial PFC of Fmr1KO mice from 2 to 12 months. In young adult Fmr1KO mice, NMDA receptor (NMDAR)-mediated long-term potentiation (LTP) is intact; however, in 12-month-old mice this LTP is impaired. In parallel, there was an increase in the AMPAR/NMDAR ratio and a concomitant decrease of synaptic NMDAR currents in 12-month-old Fmr1KO mice. We found that acute pharmacological blockade of mGlu5 receptor in 12-month-old Fmr1KO mice restored a normal AMPAR/NMDAR ratio and LTP. Taken together, the data reveal an age-dependent deficit in LTP in Fmr1KO mice, which may correlate to some of the complex age-related deficits in FXS. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Inhibitory effects of caffeine on hippocampal neurogenesis and function.

    Science.gov (United States)

    Han, Myoung-Eun; Park, Kyu-Hyun; Baek, Sun-Yong; Kim, Bong-Seon; Kim, Jae-Bong; Kim, Hak-Jin; Oh, Sae-Ock

    2007-05-18

    Caffeine is one of the most extensively consumed psychostimulants in the world. However, compared to short-term effects of caffeine, the long-term effects of caffeine consumption on learning and memory are poorly characterized. The present study found that long-term consumption of low dose caffeine (0.3 g/L) slowed hippocampus-dependent learning and impaired long-term memory. Caffeine consumption for 4 weeks also significantly reduced hippocampal neurogenesis compared to controls. From these results, we concluded that long-term consumption of caffeine could inhibit hippocampus-dependent learning and memory partially through inhibition of hippocampal neurogenesis.

  8. Long-term biodosimetry Redux

    International Nuclear Information System (INIS)

    Simon, Steven L.; Bouville, Andre

    2016-01-01

    This paper revisits and reiterates the needs, purposes and requirements of bio-dosimetric assays for long-term dose and health risk assessments. While the most crucial need for bio-dosimetric assays is to guide medical response for radiation accidents, the value of such techniques for improving our understanding of radiation health risk by supporting epidemiological (long-term health risk) studies is significant. As new cohorts of exposed persons are identified and new health risk studies are undertaken with the hopes that studying the exposed will result in a deeper understanding of radiation risk, the value of reliable dose reconstruction is underscored. The ultimate application of biodosimetry in long-term health risk studies would be to completely replace model-based dose reconstruction-a complex suite of methods for retrospectively estimating dose that is commonly fraught with large uncertainties due to the absence of important exposure-related information, as well as imperfect models. While biodosimetry could potentially supplant model-based doses, there are numerous limitations of presently available techniques that constrain their widespread application in health risk research, including limited ability to assess doses received far in the past, high cost, great inter-individual variability, invasiveness, higher than preferred detection limits and the inability to assess internal dose (for the most part). These limitations prevent the extensive application of biodosimetry to large cohorts and should be considered a challenge to researchers to develop new and more flexible techniques that meet the demands of long-term health risk research. Events in recent years, e.g. the Fukushima reactor accident and the increased threat of nuclear terrorism, underscore that any event that results in significant radiation exposures of a group of people will also produce a much larger population, exposed at lower levels, but that likewise needs (or demands) an exposure

  9. Neurotoxicity of developmental hypothyroxinemia and hypothyroidism in rats: Impairments of long-term potentiation are mediated by phosphatidylinositol 3-kinase signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi; Wei, Wei; Wang, Yuan; Dong, Jing; Song, Binbin; Min, Hui [Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang (China); Teng, Weiping, E-mail: twpendocrine@yahoo.com.cn [Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Hospital of China Medical University, Shenyang (China); Chen, Jie, E-mail: chenjie@mail.cmu.edu.cn [Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang (China)

    2013-09-01

    Neurotoxicity of iodine deficiency-induced hypothyroidism during developmental period results in serious impairments of brain function, such as learning and memory. These impairments are largely irreversible, and the underlying mechanisms remain unclear. In addition to hypothyroidism, iodine deficiency may cause hypothyroxinemia, a relatively subtle form of thyroid hormone deficiency. Neurotoxicity of developmental hypothyroxinemia also potentially impairs learning and memory. However, more direct evidence of the associations between developmental hypothyroxinemia and impairments of learning and memory should be provided, and the underlying mechanisms remain to be elucidated. Thus, in the present study, we investigated the effects of developmental hypothyroxinemia and hypothyroidism on long-term potentiation (LTP), a widely accepted cellular model of learning and memory, in the hippocampal CA1 region. The activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway – a pathway closely associated with synaptic plasticity and learning and memory – was also investigated. Wistar rats were treated with iodine deficient diet or methimazole (MMZ) to induce developmental hypothyroxinemia or hypothyroidism. The results showed that developmental hypothyroxinemia caused by mild iodine deficiency and developmental hypothyroidism caused by severe iodine deficiency or MMZ significantly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Decreased activation of the PI3K signaling pathway was also observed in rats subjected to developmental hypothyroxinemia or hypothyroidism. Our results may support the hypothesis that neurotoxicity of both developmental hypothyroxinemia and hypothyroidism causes damages to learning and memory. Our results also suggest that decreased activation of the PI3K signaling pathway may contribute to impairments of LTP caused by neurotoxicity of both developmental hypothyroxinemia and

  10. Neurotoxicity of developmental hypothyroxinemia and hypothyroidism in rats: Impairments of long-term potentiation are mediated by phosphatidylinositol 3-kinase signaling pathway

    International Nuclear Information System (INIS)

    Wang, Yi; Wei, Wei; Wang, Yuan; Dong, Jing; Song, Binbin; Min, Hui; Teng, Weiping; Chen, Jie

    2013-01-01

    Neurotoxicity of iodine deficiency-induced hypothyroidism during developmental period results in serious impairments of brain function, such as learning and memory. These impairments are largely irreversible, and the underlying mechanisms remain unclear. In addition to hypothyroidism, iodine deficiency may cause hypothyroxinemia, a relatively subtle form of thyroid hormone deficiency. Neurotoxicity of developmental hypothyroxinemia also potentially impairs learning and memory. However, more direct evidence of the associations between developmental hypothyroxinemia and impairments of learning and memory should be provided, and the underlying mechanisms remain to be elucidated. Thus, in the present study, we investigated the effects of developmental hypothyroxinemia and hypothyroidism on long-term potentiation (LTP), a widely accepted cellular model of learning and memory, in the hippocampal CA1 region. The activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway – a pathway closely associated with synaptic plasticity and learning and memory – was also investigated. Wistar rats were treated with iodine deficient diet or methimazole (MMZ) to induce developmental hypothyroxinemia or hypothyroidism. The results showed that developmental hypothyroxinemia caused by mild iodine deficiency and developmental hypothyroidism caused by severe iodine deficiency or MMZ significantly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Decreased activation of the PI3K signaling pathway was also observed in rats subjected to developmental hypothyroxinemia or hypothyroidism. Our results may support the hypothesis that neurotoxicity of both developmental hypothyroxinemia and hypothyroidism causes damages to learning and memory. Our results also suggest that decreased activation of the PI3K signaling pathway may contribute to impairments of LTP caused by neurotoxicity of both developmental hypothyroxinemia and

  11. α1-Adrenoceptors in the hippocampal dentate gyrus involved in learning-dependent long-term potentiation during active-avoidance learning in rats.

    Science.gov (United States)

    Lv, Jing; Zhan, Su-Yang; Li, Guang-Xie; Wang, Dan; Li, Ying-Shun; Jin, Qing-Hua

    2016-11-09

    The hippocampus is the key structure for learning and memory in mammals and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. The influences of norepinephrine (NE) on the modulation of learning and memory, as well as LTP, through β-adrenoceptors are well documented, whereas the role of α1-adrenoceptors in learning-dependent LTP is not yet clear. In the present study, we measured extracellular concentrations of NE in the hippocampal dentate gyrus (DG) region using an in-vivo brain microdialysis and high-performance liquid chromatography techniques during the acquisition and extinction of active-avoidance behavior in freely moving conscious rats. Next, the effects of prazosin (an antagonist of α1-adrenoceptor) and phenylephrine (an agonist of the α1-adrenoceptor) on amplitudes of field excitatory postsynaptic potential were measured in the DG region during the active-avoidance behavior. Our results showed that the extracellular concentration of NE in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to the baseline level following extinction training. A local microinjection of prazosin into the DG significantly accelerated the acquisition of the active-avoidance behavior, whereas a local microinjection of phenylephrine retarded the acquisition of the active-avoidance behavior. Furthermore, in all groups, the changes in field excitatory postsynaptic potential amplitude were accompanied by corresponding changes in active-avoidance behavior. Our results suggest that NE activation of α1-adrenoceptors in the hippocampal DG inhibits active-avoidance learning by modulation of synaptic efficiency in rats.

  12. Nano-CuO impairs spatial cognition associated with inhibiting hippocampal long-term potentiation via affecting glutamatergic neurotransmission in rats.

    Science.gov (United States)

    Li, Xiaoliang; Sun, Wei; An, Lei

    2018-06-01

    Manufactured metal nanoparticles and their applications are continuously expanding because of their unique characteristics while their increasing use may predispose to potential health problems. Several studies have reported the adverse effects of copper oxide nanoparticles (nano-CuO) relative to ecotoxicity and cell toxicity, whereas little is known about the neurotoxicity of nano-CuO. The present study aimed to examine its effects on spatial cognition, hippocampal function, and the possible mechanisms. Male Wistar rats were used to establish an animal model, and nano-CuO was administered at a dose of 0.5 mg/kg/day for 2 weeks. The Morris water maze (MWM) test was employed to evaluate learning and memory. The long-term potentiation (LTP) from Schaffer collaterals to the hippocampal CA1 region, and the effects of nano-CuO on synases were recorded in the hippocampal CA1 neurons of rats. MWM test showed that learning and memory abilities were impaired significantly by nano-CuO ( p nano-CuO-treated groups compared with the control group ( p nano-CuO markedly depressed the frequencies of both spontaneous excitatory postsynaptic currents (sEPSCs) and miniature EPSCs (mEPSCs), indicating an effect of nano-CuO on inhibiting the release frequency of glutamate presynapticly ( p nano-CuO-treated animals, which suggested that the effect of nano-CuO modulates postsynaptic receptor kinetics ( p nano-CuO impaired glutamate transmission presynapticly and postsynapticly, which may contribute importantly to diminished LTP and other induced cognitive deficits.

  13. Hydrocarbon degradation potential and plant growth-promoting activity of culturable endophytic bacteria of Lotus corniculatus and Oenothera biennis from a long-term polluted site.

    Science.gov (United States)

    Pawlik, Małgorzata; Cania, Barbara; Thijs, Sofie; Vangronsveld, Jaco; Piotrowska-Seget, Zofia

    2017-08-01

    Many endophytic bacteria exert beneficial effects on their host, but still little is known about the bacteria associated with plants growing in areas heavily polluted by hydrocarbons. The aim of the study was characterization of culturable hydrocarbon-degrading endophytic bacteria associated with Lotus corniculatus L. and Oenothera biennis L. collected in long-term petroleum hydrocarbon-polluted site using culture-dependent and molecular approaches. A total of 26 hydrocarbon-degrading endophytes from these plants were isolated. Phylogenetic analyses classified the isolates into the phyla Proteobacteria and Actinobacteria. The majority of strains belonged to the genera Rhizobium, Pseudomonas, Stenotrophomonas, and Rhodococcus. More than 90% of the isolates could grow on medium with diesel oil, approximately 20% could use n-hexadecane as a sole carbon and energy source. PCR analysis revealed that 40% of the isolates possessed the P450 gene encoding for cytochrome P450-type alkane hydroxylase (CYP153). In in vitro tests, all endophytic strains demonstrated a wide range of plant growth-promoting traits such as production of indole-3-acetic acid, hydrogen cyanide, siderophores, and phosphate solubilization. More than 40% of the bacteria carried the gene encoding for the 1-aminocyclopropane-1-carboxylic acid deaminase (acdS). Our study shows that the diversity of endophytic bacterial communities in tested plants was different. The results revealed also that the investigated plants were colonized by endophytic bacteria possessing plant growth-promoting features and a clear potential to degrade hydrocarbons. The properties of isolated endophytes indicate that they have the high potential to improve phytoremediation of petroleum hydrocarbon-polluted soils.

  14. Assessment of risk associated with long-term corrosion of alloy 22 and Ti-7 in the potential yucca mountain high-level nuclear waste repository

    International Nuclear Information System (INIS)

    Ahn, T.M.; Pensado, O.; Dunn, D.

    2004-01-01

    Full text of publication follows: The potential high-level nuclear waste (HLW) repository at Yucca Mountain (YM) may rely on the robustness of the outer container of the waste package (WP) as one of many barriers for waste isolation. The container is proposed to be constructed of Alloy 22, a Ni-Cr-Mo alloy known to be resistant to localized corrosion and stress corrosion cracking. Additionally, drip shields (DS) will be emplaced above the WP to minimize the groundwater contact, in the form of seepage, with the WP. The candidate alloy to construct the drip shields is a titanium based alloy (Ti-7) with some small amounts of Pd and is also known for resistance to localized corrosion. To enhance confidence of long-term WP and DS lifetimes, it is necessary to assess the conditions under which loss of passivity or localized degradation processes could occur. The accelerated degradation processes may include uniform passivity breakdown, localized corrosion, and stress corrosion cracking. This paper evaluates how such processes may occur under the long-term YM repository conditions. In the uniform passivity breakdown, three potential concerns are evaluated. The first is anodic sulphur segregation at the interface between the passive film and the bare metal. This paper models the cyclic behavior of free transient fast dissolution (induced by sulfur segregation) and re-passivation. The second is the potential accumulation of corrosion products on the WP surface, which may act as cathode of large surface area leading to fast corrosion. The effective ratio of the corrosion product area to the bare metal area is evaluated. The third is the ion selectivity in the corrosion products to alter the aqueous chemistry, which may accelerate or inhibit the corrosion. Thermodynamics of ionic sorption in the corrosion products is reviewed. In the localized corrosion, the groundwater chemistry on the WP surface is evaluated at the temperatures of the WP above 100 deg. C during the early

  15. Long Term Financing of Infrastructure

    OpenAIRE

    Sinha, Sidharth

    2014-01-01

    Infrastructure projects, given their long life, require long term financing. The main sources of long term financings are insurance and pension funds who seek long term investments with low credit risk. However, in India household financial savings are mainly invested in bank deposits. Insurance and pension funds account for only a small percentage of household financial savings. In addition most infrastructure projects do not qualify for investment by insurance and pension funds because of t...

  16. Temporal Variation in Honey Production by the Stingless Bee Melipona subnitida (Hymenoptera: Apidae): Long-Term Management Reveals its Potential as a Commercial Species in Northeastern Brazil.

    Science.gov (United States)

    Koffler, Sheina; Menezes, Cristiano; Menezes, Paulo Roberto; Kleinert, Astrid de Matos Peixoto; Imperatriz-Fonseca, Vera Lucia; Pope, Nathaniel; Jaffé, Rodolfo

    2015-06-01

    Even though stingless beekeeping has a great potential as a sustainable development tool, the activity remains essentially informal, technical knowledge is scarce, and management practices lack the sophistication and standardization found in apiculture. Here, we contributed to the further development of stingless beekeeping by investigating the long-term impact of management and climate on honey production and colony survival in the stingless bee Melipona subnitida Ducke (1910). We analyzed a 10-yr record of 155 M. subnitida colonies kept by a commercial honey producer of northeastern Brazil. This constitutes the longest and most accurate record available for a stingless bee. We modeled honey production in relation to time (years), age, management practices (colony division and food supplementation), and climatic factors (temperature and precipitation), and used a model selection approach to identify which factors best explained honey production. We also modeled colony mortality in relation to climatic factors. Although the amount of honey produced by each colony decreased over time, we found that the probability of producing honey increased over the years. Colony divisions decreased honey production, but did not affect honey presence, while supplementary feeding positively affected honey production. In warmer years, the probability of producing honey decreased and the amount of honey produced was lower. In years with lower precipitation, fewer colonies produced honey. In contrast, colony mortality was not affected by climatic factors, and some colonies lived up to nine years, enduring extreme climatic conditions. Our findings provide useful guidelines to improve management and honey production in stingless bees. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Signaling through cGMP-dependent protein kinase I in the amygdala is critical for auditory-cued fear memory and long-term potentiation.

    Science.gov (United States)

    Paul, Cindy; Schöberl, Florian; Weinmeister, Pascal; Micale, Vincenzo; Wotjak, Carsten T; Hofmann, Franz; Kleppisch, Thomas

    2008-12-24

    Long-term potentiation (LTP) of inputs relaying sensory information from cortical and thalamic neurons to principal neurons in the lateral amygdala (LA) is thought to serve as a cellular mechanism for associative fear learning. Nitric oxide (NO), a messenger molecule widely implicated in synaptic plasticity and behavior, has been shown to enhance LTP in the LA as well as consolidation of associative fear memory. Additional evidence suggests that NO-induced enhancement of LTP and amygdala-dependent learning requires signaling through soluble guanylyl cyclase (sGC) and cGMP-dependent protein kinase (cGK). Mammals possess two genes for cGK: the prkg1 gene gives rise to the cGK type I isoforms, cGKIalpha and cGKIbeta, and the prkg2 gene encodes the cGK type II. Reportedly, both cGKI and cGKII are expressed in the amygdala, and cGKII is involved in controlling anxiety-like behavior. Because selective pharmacological tools for individual cGK isoforms are lacking, we used different knock-out mouse models to examine the function of cGKI and cGKII for LTP in the LA and pavlovian fear conditioning. We found robust expression of the cGKI specifically in the LA with cGKIbeta as the prevailing isoform. We further show a marked reduction of LTP at both thalamic and cortical inputs to the LA and a selective impairment of auditory-cued fear memory in cGKI-deficient mutants. In contrast, cGKII null mutants lack these phenotypes. Our data suggest a function of cGKI, likely the beta isoform, in the LA, supporting synaptic plasticity and consolidation of fear memory.

  18. Influx of extracellular Zn(2+) into the hippocampal CA1 neurons is required for cognitive performance via long-term potentiation.

    Science.gov (United States)

    Takeda, A; Suzuki, M; Tempaku, M; Ohashi, K; Tamano, H

    2015-09-24

    Physiological significance of synaptic Zn(2+) signaling was examined in the CA1 of young rats. In vivo CA1 long-term potentiation (LTP) was induced using a recording electrode attached to a microdialysis probe and the recording region was locally perfused with artificial cerebrospinal fluid (ACSF) via the microdialysis probe. In vivo CA1 LTP was inhibited under perfusion with CaEDTA and ZnAF-2DA, extracellular and intracellular Zn(2+) chelators, respectively, suggesting that the influx of extracellular Zn(2+) is required for in vivo CA1 LTP induction. The increase in intracellular Zn(2+) was chelated with intracellular ZnAF-2 in the CA1 1h after local injection of ZnAF-2DA into the CA1, suggesting that intracellular Zn(2+) signaling induced during learning is blocked with intracellular ZnAF-2 when the learning was performed 1h after ZnAF-2DA injection. Object recognition was affected when training of object recognition test was performed 1h after ZnAF-2DA injection. These data suggest that intracellular Zn(2+) signaling in the CA1 is required for object recognition memory via LTP. Surprisingly, in vivo CA1 LTP was affected under perfusion with 0.1-1μM ZnCl2, unlike the previous data that in vitro CA1 LTP was enhanced in the presence of 1-5μM ZnCl2. The influx of extracellular Zn(2+) into CA1 pyramidal cells has bidirectional action in CA1 LTP. The present study indicates that the degree of extracellular Zn(2+) influx into CA1 neurons is critical for LTP and cognitive performance. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Erection capability is potentiated by long-term sildenafil treatment: role of blood flow-induced endothelial nitric-oxide synthase phosphorylation.

    Science.gov (United States)

    Musicki, Biljana; Champion, Hunter C; Becker, Robyn E; Liu, Tongyun; Kramer, Melissa F; Burnett, Arthur L

    2005-07-01

    Despite demonstrated clinical efficacy of sildenafil for the temporary treatment of erectile dysfunction, the possibility that sildenafil used long-term durably augments erectile ability remains unclear. We investigated whether continuous long-term administration of sildenafil at clinically relevant levels to aged rats "primes" the penis for improved erectile ability and involves nitric oxide (NO) or RhoA/Rho-kinase signaling pathways. In aged, but not young rats, sildenafil prolonged erection and increased the protein expressions of phosphorylated endothelial NO synthase (eNOS) at serine-1177 and phosphorylated Akt at serine-473 in penes. Only in the young rat penis, protein expressions of phosphodiesterase-5 and phosphomyosin phosphatase target subunit 1, a marker of Rho-kinase activity, were increased by sildenafil. Sildenafil inhibited phosphodiesterase-5 activity in penes of young and aged rats coincident with assayed free plasma levels of the drug equivalent to clinically therapeutic measurements. We conclude that erectile ability can be enhanced under preconditions of erectile impairment by long-term inhibition of phosphodiesterase-5 and that the effect is mediated by Akt-dependent eNOS phosphorylation. The lack of erectile ability enhancement in young rats by long-term phosphodiesterase-5 inhibition may relate to restrained NO signaling by phosphodiesterase-5 up-regulation, lack of incremental Akt and eNOS phosphorylation, and heightened Rho-kinase signaling in the penis.

  20. An assessment of the potentials of nuclear power and carbon capture and storage in the long-term global warming mitigation options based on Asian Modeling Exercise scenarios

    International Nuclear Information System (INIS)

    Mori, Shunsuke

    2012-01-01

    This paper presents an evaluation of global warming mitigation options based on scenarios from the Asian Modeling Exercise. Using an extended version of the integrated assessment model MARIA-23 (Multiregional Approach for Resource and Industry Allocation), we analyze nuclear fuel recycling options, carbon capture and storage technologies (CCS), and biomass utilization. To assess the potential implications of decreased social acceptance of nuclear power in the wake of the Fukushima nuclear accident, additional scenarios including a nuclear power expansion limitation, are analyzed. We also evaluate MARIA-23 model simulation estimates of long-term contributions and interrelationships among nuclear power, biomass, and CCS. Finally, potential costs of nuclear limitation under carbon control policies are assessed. The simulation results in this paper suggest the following: (1) under the reference scenario, global GDP losses in climate limitation scenarios range from 1.3% per year to 3.9% per year in 2060, rising to between 3.5% per year and 4.5% per year in 2100; (2) the use of nuclear fuel reprocessing technologies increase rapidly in all carbon control policy scenarios; (3) under a scenario where the price of CO 2 is $30 and nuclear power expansion is strictly limited, GDP losses increase significantly—from 4.5% per year to 6.4% per year by 2100; (4) nuclear power and CCS are substitute mitigation technologies. With nuclear power technology available CCS deployment reaches approximately 15,000 Mt-CO 2 per year by 2010; without a nuclear power option, CCS deployment rises to more than 80,000 Mt-CO 2 per year; and (5) biomass utilization cannot fully compensate for limitations to nuclear power expansion in policy scenarios. In addition to examining the role of these three technologies on global scales, we report results for several major Asian regions, namely Japan, China, and India. China tends to deploy nuclear power (if available) in response to rapidly growing

  1. Use of Bayesian networks classifiers for long-term mean wind turbine energy output estimation at a potential wind energy conversion site

    Energy Technology Data Exchange (ETDEWEB)

    Carta, Jose A. [Department of Mechanical Engineering, University of Las Palmas de Gran Canaria, Campus de Tafira s/n, 35017 Las Palmas de Gran Canaria, Canary Islands (Spain); Velazquez, Sergio [Department of Electronics and Automatics Engineering, University of Las Palmas de Gran Canaria, Campus de Tafira s/n, 35017 Las Palmas de Gran Canaria, Canary Islands (Spain); Matias, J.M. [Department of Statistics, University of Vigo, Lagoas Marcosende, 36200 Vigo (Spain)

    2011-02-15

    Due to the interannual variability of wind speed a feasibility analysis for the installation of a Wind Energy Conversion System at a particular site requires estimation of the long-term mean wind turbine energy output. A method is proposed in this paper which, based on probabilistic Bayesian networks (BNs), enables estimation of the long-term mean wind speed histogram for a site where few measurements of the wind resource are available. For this purpose, the proposed method allows the use of multiple reference stations with a long history of wind speed and wind direction measurements. That is to say, the model that is proposed in this paper is able to involve and make use of regional information about the wind resource. With the estimated long-term wind speed histogram and the power curve of a wind turbine it is possible to use the method of bins to determine the long-term mean energy output for that wind turbine. The intelligent system employed, the knowledgebase of which is a joint probability function of all the model variables, uses efficient calculation techniques for conditional probabilities to perform the reasoning. This enables automatic model learning and inference to be performed efficiently based on the available evidence. The proposed model is applied in this paper to wind speeds and wind directions recorded at four weather stations located in the Canary Islands (Spain). Ten years of mean hourly wind speed and direction data are available for these stations. One of the conclusions reached is that the BN with three reference stations gave fewer errors between the real and estimated long-term mean wind turbine energy output than when using two measure-correlate-predict algorithms which were evaluated and which use a linear regression between the candidate station and one reference station. (author)

  2. Use of Bayesian networks classifiers for long-term mean wind turbine energy output estimation at a potential wind energy conversion site

    International Nuclear Information System (INIS)

    Carta, Jose A.; Velazquez, Sergio; Matias, J.M.

    2011-01-01

    Due to the interannual variability of wind speed a feasibility analysis for the installation of a Wind Energy Conversion System at a particular site requires estimation of the long-term mean wind turbine energy output. A method is proposed in this paper which, based on probabilistic Bayesian networks (BNs), enables estimation of the long-term mean wind speed histogram for a site where few measurements of the wind resource are available. For this purpose, the proposed method allows the use of multiple reference stations with a long history of wind speed and wind direction measurements. That is to say, the model that is proposed in this paper is able to involve and make use of regional information about the wind resource. With the estimated long-term wind speed histogram and the power curve of a wind turbine it is possible to use the method of bins to determine the long-term mean energy output for that wind turbine. The intelligent system employed, the knowledgebase of which is a joint probability function of all the model variables, uses efficient calculation techniques for conditional probabilities to perform the reasoning. This enables automatic model learning and inference to be performed efficiently based on the available evidence. The proposed model is applied in this paper to wind speeds and wind directions recorded at four weather stations located in the Canary Islands (Spain). Ten years of mean hourly wind speed and direction data are available for these stations. One of the conclusions reached is that the BN with three reference stations gave fewer errors between the real and estimated long-term mean wind turbine energy output than when using two measure-correlate-predict algorithms which were evaluated and which use a linear regression between the candidate station and one reference station.

  3. Long-term urethral catheterisation.

    Science.gov (United States)

    Turner, Bruce; Dickens, Nicola

    This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

  4. Involvement of N-methyl-D-aspartate receptor subunits in zinc-mediated modification of CA1 long-term potentiation in the developing hippocampus.

    Science.gov (United States)

    Takeda, Atsushi; Itagaki, Kosuke; Ando, Masaki; Oku, Naoto

    2012-03-01

    Zinc is an endogenous N-methyl-D-aspartate (NMDA) receptor blocker. It is possible that zinc-mediated modification of hippocampal CA1 long-term potentiation (LTP) is linked to the expression of NMDA receptor subunits, which varies with postnatal development. In the present study, the effect of ZnCl(2) and CaEDTA, a membrane-impermeable zinc chelator, on CA1 LTP induction was examined in hippocampal slices from immature (3-week-old) and young (6-week-old) rats. Tetanus (10-100 Hz, 1 sec)-induced CA1 LTP was more greatly enhanced in 3-week-old rats. CA1 LTP was inhibited in the presence of 2-amino-5-phosphonovalerate (APV), an NMDA receptor antagonist, and CaEDTA in 3-week-old rats, as in the case of 6-week-old rats reported previously. In 3-week-old rats, on the other hand, 5 μM ZnCl(2) attenuated NMDA receptor-mediated EPSPs more than in 6-week-old rats and significantly attenuated CA1 LTP. Moreover, 5 μM ZnCl(2) significantly attenuated CA1 LTP in the presence of (2R,4S)-4-(3-phosphonopropyl)-2-piperidinecarboxylic acid (PPPA), an NR2A antagonist, in 3-week-old rats, but not that in the presence of ifenprodil, an NR2B antagonist, suggesting that zinc-mediated attenuation of CA1 LTP is associated with the preferential expression of NR2B subunit in 3-week-old rats. In 6-week-old rats, however, 5 μM ZnCl(2) significantly potentiated CA1 LTP and also CA1 LTP in the presence of PPPA. The present study demonstrates that endogenous zinc may participate in the induction of CA1 LTP. It is likely that the changes in expression of NMDA receptor subunits are involved in the zinc-mediated modification of CA1 LTP in the developing hippocampus. Copyright © 2011 Wiley Periodicals, Inc.

  5. Long term radiotoxicity

    International Nuclear Information System (INIS)

    Slessarev, I.

    2001-01-01

    A major issue to secure the development of nuclear energy in future is the radioactive waste minimization, both inside the fuel cycle and in a deep geological storage. The aim of this paper is to establish the physical principles which provide an inherent minimization of the radioactive wastes. A new concept is introduced to characterize the radiotoxicity associated to various nuclei families in equilibrium state. The analysis shows the potential of evolutionary nuclear systems, mostly based on known technologies and the potential of more futuristic systems, like accelerator-driven systems and Th-fuel cycle. Several groups of the toxicity sources are object of the studies: Actinides as a part of the nuclear fuel which is remaining unusable after irradiation in nuclear power plants; long-lived fission products as the inevitable result of nuclear energy production; Lanthanides as an important part of fission products which separation from Actinides is technologically difficult because of similar chemical properties

  6. Long-term Relationships

    DEFF Research Database (Denmark)

    Hémous, David; Olsen, Morten

    2017-01-01

    In the 1980s the Japanese “keiretsu” system of interconnected business groups was praised as a model to emulate, but since then Japan has often been criticized for being less innovative than the United States. In this paper we connect the two views and argue that tight business relationships can...... suppliers and start cooperation immediately with new suppliers. We first consider broad innovations: every period, one supplier has the opportunity to create a higher quality input that can be used by all producers. Since relationships are harder to break in the cooperative equilibrium the market size...... for potential innovators is smaller and the rate of innovation might be lower than in the noncooperative equilibrium. We contrast this with a setting with relationship-specific innovations that we show are encouraged by the establishment of relational contracts. We illustrate the predictions of the model using...

  7. Modulation of long-term potentiation-like cortical plasticity in the healthy brain with low frequency-pulsed electromagnetic fields.

    Science.gov (United States)

    Premi, Enrico; Benussi, Alberto; La Gatta, Antonio; Visconti, Stefano; Costa, Angelo; Gilberti, Nicola; Cantoni, Valentina; Padovani, Alessandro; Borroni, Barbara; Magoni, Mauro

    2018-06-13

    Non-depolarizing magnetic fields, like low frequency-pulsed electromagnetic fields (LF-PEMFs) have shown the ability to modulate living structures, principally by influencing synaptic activity and ion channels on cellular membranes. Recently, the CTU Mega 20 device was presented as a molecular accelerator, using energy up to 200 J and providing high-power (2 Tesla) pulsating fields with a water-repulsive (diamagnetic) action and tissue biostimulation. We tested the hypothesis that LF-PEMFs could modulate long-term corticospinal excitability in healthy brains by applying CTU Mega 20 ® . Ten healthy subjects without known neurological and/or psychiatric diseases entered the study. A randomized double-blind sham-controlled crossover design was employed, recording TMS parameters (amplitude variation of the motor evoked potential as index of cortical excitability perturbations of the motor system) before (pre) and after (post + 0, + 15, + 30 min) a single CTU Mega 20 session on the corresponding primary right-hand motor area, using a real (magnetic field = 2 Tesla; intensity = 90 J; impulse frequency = 7 Hz; duration = 15 min) or sham device. A two-way repeated measures ANOVA with TIME (pre, post + 0, + 15, + 30 min) and TREATMENT (real vs. sham stimulation) as within-subjects factor was applied. A significant TIME × TREATMENT interaction was found (p < 0.001). Post hoc comparisons showed a significant effect of TIME, with significant differences at + 0, + 15 and + 30 min compared to baseline after real stimulation (all p < 0.05) but not after sham stimulation (all p < 0.05) and significant effects of TREATMENT, with significant differences at + 0, + 15 and + 30 min for real stimulation compared to sham stimulation (all p < 0.005). No significant depolarizing effects were detected throughout the (real) stimulation. Our proof-of-concept study in healthy subjects supports the idea that non-ionizing LF

  8. The E3 Ligase APC/C-Cdh1 Is Required for Associative Fear Memory and Long-Term Potentiation in the Amygdala of Adult Mice

    Science.gov (United States)

    Pick, Joseph E.; Malumbres, Marcos; Klann, Eric

    2013-01-01

    The anaphase promoting complex/cyclosome (APC/C) is an E3 ligase regulated by Cdh1. Beyond its role in controlling cell cycle progression, APC/C-Cdh1 has been detected in neurons and plays a role in long-lasting synaptic plasticity and long-term memory. Herein, we further examined the role of Cdh1 in synaptic plasticity and memory by generating…

  9. Effects of joint attention on long-term memory in 9-month-old infants: an event-related potentials study.

    Science.gov (United States)

    Kopp, Franziska; Lindenberger, Ulman

    2011-07-01

    Joint attention develops during the first year of life but little is known about its effects on long-term memory. We investigated whether joint attention modulates long-term memory in 9-month-old infants. Infants were familiarized with visually presented objects in either of two conditions that differed in the degree of joint attention (high versus low). EEG indicators in response to old and novel objects were probed directly after the familiarization phase (immediate recognition), and following a 1-week delay (delayed recognition). In immediate recognition, the amplitude of positive slow-wave activity was modulated by joint attention. In the delayed recognition, the amplitude of the Pb component differentiated between high and low joint attention. In addition, the positive slow-wave amplitude during immediate and delayed recognition correlated with the frequency of infants' looks to the experimenter during familiarization. Under both high- and low-joint-attention conditions, the processing of unfamiliar objects was associated with an enhanced Nc component. Our results show that the degree of joint attention modulates EEG during immediate and delayed recognition. We conclude that joint attention affects long-term memory processing in 9-month-old infants by enhancing the relevance of attended items. © 2010 Blackwell Publishing Ltd.

  10. SOX9 as a Predictor for Neurogenesis Potentiality of Amniotic Fluid Stem Cells

    Science.gov (United States)

    Wei, Pei-Cih; Chao, Angel; Peng, Hsiu-Huei; Chao, An-Shine; Chang, Yao-Lung; Chang, Shuenn-Dyh; Wang, Hsin-Shih; Chang, Yu-Jen; Tsai, Ming-Song; Sieber, Martin; Chen, Hua-Chien; Chen, Shu-Jen; Lee, Yun-Shien

    2014-01-01

    Preclinical studies of amniotic fluid-derived cell therapy have been successful in the research of neurodegenerative diseases, peripheral nerve injury, spinal cord injury, and brain ischemia. Transplantation of human amniotic fluid stem cells (AFSCs) into rat brain ventricles has shown improvement in symptoms of Parkinson's disease and also highlighted the minimal immune rejection risk of AFSCs, even between species. Although AFSCs appeared to be a promising resource for cell-based regenerative therapy, AFSCs contain a heterogeneous pool of distinct cell types, rendering each preparation of AFSCs unique. Identification of predictive markers for neuron-prone AFSCs is necessary before such stem cell-based therapeutics can become a reality. In an attempt to identify markers of AFSCs to predict their ability for neurogenesis, we performed a two-phase study. In the discovery phase of 23 AFSCs, we tested ZNF521/Zfp521, OCT6, SOX1, SOX2, SOX3, and SOX9 as predictive markers of AFSCs for neural differentiation. In the validation phase, the efficacy of these predictive markers was tested in independent sets of 18 AFSCs and 14 dental pulp stem cells (DPSCs). We found that high expression of SOX9 in AFSCs is associated with good neurogenetic ability, and these positive correlations were confirmed in independent sets of AFSCs and DPSCs. Furthermore, knockdown of SOX9 in AFSCs inhibited their neuronal differentiation. In conclusion, the discovery of SOX9 as a predictive marker for neuron-prone AFSCs could expedite the selection of useful clones for regenerative medicine, in particular, in neurological diseases and injuries. PMID:25154783

  11. Long term complications of diabetes

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000327.htm Long-term complications of diabetes To use the sharing features on this page, ... other tests. All these may help you keep complications of diabetes away. You will need to check your blood ...

  12. Optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) film and its potential for a long-term solar ultraviolet dosimeter

    International Nuclear Information System (INIS)

    Lester, R A; Parisi, A V; Kimlin, M G; Sabburg, J

    2003-01-01

    The optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) film have been characterized in order to develop an alternative method for UV dosimetry with a focus on long-term human exposure measurements. The dynamic range of PPO film was found to extend to 2 MJ m -2 of broadband UV exposure independently of film thickness, providing an exposure range of roughly four summer days at subtropical latitudes. The sensitivity of the film to UV exposure was positively related to film thickness in the 20-40 μm range. Films of 40 μm thickness proved to be the most suitable for long-term human UV exposure measurements. The temperature independence of the response of 40 μm PPO film was established from 1.5 deg. C to 50 deg. C within a dosimeter response uncertainty of 6.5%. Dose-rate independence was also demonstrated within 8% of the mean dosimeter response. The spectral response approximates the CIE erythemal action spectrum between 300 and 340 nm, with a peak response at 305 nm. A large deviation from this action spectrum was observed at shorter wavelengths. Investigation of the angular response in both the azimuth and altitude planes showed a cosine error of less than 6.2% between 0 deg. and 40 deg., and did not exceed 13.3% at any angle greater than 40 deg. These results indicate that PPO film satisfies the requirements for use as a UV dosimeter, and may be employed in long-term human exposure measurements

  13. Orexin 1 and orexin 2 receptor antagonism in the basolateral amygdala modulate long-term potentiation of the population spike in the perforant path-dentate gyrus-evoked field potential in rats.

    Science.gov (United States)

    Ardeshiri, Motahareh Rouhi; Hosseinmardi, Narges; Akbari, Esmaeil

    2018-03-01

    Involvement of amygdalo-hippocampal substructures in patients with narcolepsy due to deficiencies in the orexinergic system, and the presence of hippocampus-dependent memory impairments in this disorder, have led us to investigate the effects of orexin 1 and 2 receptor antagonism in the basolateral amygdala (BLA) on long-term potentiation (LTP) of dentate gyrus (DG) granular cells. We used a 200-Hz high-frequency stimulation protocol in anesthetized rats. We studied the long-term synaptic plasticity of perforant path-dentate gyrus granule cells following the inactivation of orexin receptors before and after tetanic stimulation. LTP of the DG population spike was attenuated in the presence of orexin 1 and 2 receptor antagonism (treatment with SB-334867-A and TCS-OX2-29, respectively) in the BLA when compared to that observed following treatment with dimethyl sulfoxide (DMSO). However, the population excitatory post-synaptic potentials were not affected. Moreover, when orexin 1 and 2 receptors in the BLA were blocked after LTP induction, there were no differences between the DMSO and treatment groups. Our findings suggest that the orexinergic system of the BLA plays a modulatory role in the regulation of hippocampal plasticity in rats. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Long-term corrosion studies

    International Nuclear Information System (INIS)

    Gdowski, G.

    1998-01-01

    The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application

  15. [Long-term psychiatric hospitalizations].

    Science.gov (United States)

    Plancke, L; Amariei, A

    2017-02-01

    Long-term hospitalizations in psychiatry raise the question of desocialisation of the patients and the inherent costs. Individual indicators were extracted from a medical administrative database containing full-time psychiatric hospitalizations for the period 2011-2013 of people over 16 years old living in the French region of Nord-Pas-de-Calais. We calculated the proportion of people who had experienced a hospitalization with a duration of 292 days or more during the study period. A bivariate analysis was conducted, then ecological data (level of health-care offer, the deprivation index and the size of the municipalities of residence) were included into a multilevel regression model in order to identify the factors significantly related to variability of long-term hospitalization rates. Among hospitalized individuals in psychiatry, 2.6% had had at least one hospitalization of 292 days or more during the observation period; the number of days in long-term hospitalization represented 22.5% of the total of days of full-time hospitalization in psychiatry. The bivariate analysis revealed that seniority in the psychiatric system was strongly correlated with long hospitalization rates. In the multivariate analysis, the individual indicators the most related to an increased risk of long-term hospitalization were: total lack of autonomy (OR=9.0; 95% CI: 6.7-12.2; P<001); diagnoses of psychological development disorders (OR=9.7; CI95%: 4.5-20.6; P<.001); mental retardation (OR=4.5; CI95%: 2.5-8.2; P<.001): schizophrenia (OR=3.0; CI95%: 1.7-5.2; P<.001); compulsory hospitalization (OR=1.7; CI95%: 1.4-2.1; P<.001); having experienced therapeutic isolation (OR=1.8; CI95%: 1.5-2.1; P<.001). Variations of long-term hospitalization rates depending on the type of establishment were very high, but the density of hospital beds or intensity of ambulatory activity services were not significantly linked to long-term hospitalization. The inhabitants of small urban units had

  16. Long term storage techniques for 85Kr

    International Nuclear Information System (INIS)

    Foster, B.A.; Pence, D.T.; Staples, B.A.

    1975-01-01

    As new nuclear fuel reprocessing plants go on stream, the collection of fission product 85 Kr will be required to avoid potential local release problems and long-term atmospheric buildup. Storage of the collected 85 Kr for a period of at least 100 years will be necessary to allow approximately 99.9 percent decay before it is released. A program designed to develop and evaluate proposed methods for long-term storage of 85 Kr is discussed, and the results of a preliminary evaluation of three methods, high pressure steel cylinders, zeolite encapsulation, and clathrate inclusion are presented. (U.S.)

  17. Short-Term Success versus Long-Term Failure: A Simulation-Based Approach for Understanding the Potential of Zambia’s Fertilizer Subsidy Program in Enhancing Maize Availability

    Directory of Open Access Journals (Sweden)

    Andreas Gerber

    2016-10-01

    Full Text Available In Sub-Saharan Africa, food-related policies such as fertilizer subsidy programs (FSPs have undergone a revival and triggered a controversy about their impact. In this article I applied a simulation-based approach to examine the FSPs’ short- and long-term potential for increasing maize availability in Zambia. The study revealed that FSPs are an effective policy measure to enhance maize availability in the short-term. However, in the long-term, the food system becomes dependent on the government’s annual expenses. The dependency occurs because FSPs fail to build up adequate stock levels of soil organic matter (SOM, which is an important source of resilience and productivity, and thus represents a long-term leverage point in Zambia’s maize production system. For this reason, alternative policies that combine increasing productivity and building up SOM stock levels were analyzed. They were found to be a viable means for enhancing long-term maize availability. The study concludes that gradually reducing investments in FSPs while simultaneously promoting farming practices that build up SOM stock levels is a promising strategy to enhance maize availability sustainably.

  18. Activation of the Akt/mTOR signaling pathway: A potential response to long-term neuronal loss in the hippocampus after sepsis

    Directory of Open Access Journals (Sweden)

    Jia-nan Guo

    2017-01-01

    Full Text Available Survivors of sepsis may suffer chronic cognitive impairment as a long-term sequela. However, the precise mechanisms of cognitive dysfunction after sepsis are not well understood. We employed the cecal ligation-and-puncture-induced septic mouse model. We observed elevated phosphorylation of Akt, mammalian target of rapamycin (mTOR and p70S6K on days 14 and 60, progressive neuronal loss in the cornu ammonis 1 region, and abnormal neuronal morphology in the hippocampus in the sepsis mouse model. These findings indicate that changes in neuronal morphology and number in the hippocampus after sepsis were associated with strong activation of the Akt/mTOR signaling pathway, and may reflect a “self-rescuing” feedback response to neuronal loss after sepsis.

  19. Exploring futures from an energy perspective. A natural capital accounting model study into the long-term economic development potential of the Netherlands

    International Nuclear Information System (INIS)

    Noorman, K.J.

    1995-01-01

    The need to quantify economic activity in physical flows has been stressed several times elsewhere. To relate economic development with 'physical reality', in this thesis Resource Accounting (or Natural Capital Accounting) has been adopted as a method. This physical perspective on sustainable development has been made operational by designing an ECCO (Enhancement of Capital Creation Options) model for the Netherlands using energy as a physical numeraire. The purpose of the model is to investigate the long-term physical aspects of contemporary and future (economic or political) strategies to move the economy towards a more sustainable state and to explore the dynamics of such a process. Chapter 2 deals with the physical nature of economic processes and the fundamental role of thermodynamics in an economic system. Chapter 3 discusses the application of the ECCO paradigm within the context of Natural Capital Accounting methodology. Furthermore, the main structure of an ECCO model is presented. Chapter 4 elaborates on the Dutch model. Historical trends in direct energy use and the methodology of I-O analysis as well as the results of I-O analysis are presented in chapter 5. A method has been developed to estimate the primary energy captured in capital stocks in the diverse ECCO sectors. This method as well as the results, derived from applying this method, are presented in chapter 6. In chapter 7 the application of ECCO as a tool for assessing long term physical consequences of different development strategies is discussed. With respect to reducing the throughput of matter and energy, this study concentrates on energy conservation to reduce the demand for primary energy and the transition to a more sustainable energy supply sector by introducing renewable energy sources. figs., tabs., appendices, refs

  20. Potential long-term effects of a mind-body intervention for women with major depressive disorder: sustained mental health improvements with a pilot yoga intervention.

    Science.gov (United States)

    Kinser, Patricia Anne; Elswick, R K; Kornstein, Susan

    2014-12-01

    Despite pharmacologic and psychotherapeutic advances over the past decades, many individuals with major depressive disorder (MDD) experience recurrent depressive episodes and persistent depressive symptoms despite treatment with the usual care. Yoga is a mind-body therapeutic modality that has received attention in both the lay and research literature as a possible adjunctive therapy for depression. Although promising, recent findings about the positive mental health effects of yoga are limited because few studies have used standardized outcome measures and none of them have involved long-term follow-up beyond a few months after the intervention period. The goal of our research study was to evaluate the feasibility, acceptability, and effects of a yoga intervention for women with MDD using standardized outcome measures and a long follow-up period (1year after the intervention). The key finding is that previous yoga practice has long-term positive effects, as revealed in both qualitative reports of participants' experiences and in the quantitative data about depression and rumination scores over time. Although generalizability of the study findings is limited because of a very small sample size at the 1-year follow-up assessment, the trends in the data suggest that exposure to yoga may convey a sustained positive effect on depression, ruminations, stress, anxiety, and health-related quality of life. Whether an individual continues with yoga practice, simple exposure to a yoga intervention appears to provide sustained benefits to the individual. This is important because it is rare that any intervention, pharmacologic or non-pharmacologic, for depression conveys such sustained effects for individuals with MDD, particularly after the treatment is discontinued. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Factors affecting nursing staff use of a communication tool to reduce potentially preventable acute care transfers in long-term care.

    Science.gov (United States)

    Ballard, Stephanie A; Peretti, Matteo; Lungu, Ovidiu; Voyer, Philippe; Tabamo, Fruan; Alfonso, Linda; Cetin-Sahin, Deniz; Johnson, Sarasa M A; Wilchesky, Machelle

    Although specialized communication tools can effectively reduce acute care transfers, few studies have assessed the factors that may influence the use of such tools by nursing staff at the individual level. We evaluated the associations between years of experience, tool-related training, nursing attitudes, and intensity of use of a communication tool developed to reduce transfers in a long-term care facility. We employed a mixed methods design using data from medical charts, electronic records, and semi-structured interviews. Experienced nurses used the tool significantly less than inexperienced nurses, and training had a significant positive impact on tool use. Nurses found the purpose of the tool to be confusing. No significant differences in attitude were observed based on years of experience or intensity of use. Project findings indicate that focused efforts to enrich training may increase intervention adherence. Experienced nurses in particular should be made aware of the benefits of utilizing communication tools. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Multiple myeloma patients in long-term complete response after autologous stem cell transplantation express a particular immune signature with potential prognostic implication.

    Science.gov (United States)

    Arteche-López, A; Kreutzman, A; Alegre, A; Sanz Martín, P; Aguado, B; González-Pardo, M; Espiño, M; Villar, L M; García Belmonte, D; de la Cámara, R; Muñoz-Calleja, C

    2017-06-01

    The proportion of multiple myeloma patients in long-term complete response (LTCR-MM) for more than 6 years after autologous stem cell transplantation (ASCT) is small. To evaluate whether this LTCR is associated with a particular immune signature, peripheral blood samples from 13 LTCR-MM after ASCT and healthy blood donors (HBD) were analysed. Subpopulations of T-cells (naïve, effector, central memory and regulatory), B-cells (naïve, marginal zone-like, class-switched memory, transitional and plasmablasts) and NK-cells expressing inhibitory and activating receptors were quantified by multiparametric flow cytometry (MFC). Heavy/light chains (HLC) were quantified by nephelometry. The percentage of CD4 + T-cells was lower in patients, whereas an increment in the percentage of CD4 + and CD8 + effector memory T-cells was associated with the LTCR. Regulatory T-cells and NK-cells were similar in both groups but a particular redistribution of inhibitory and activating receptors in NK-cells were found in patients. Regarding B-cells, an increase in naïve cells and a corresponding reduction in marginal zone-like and class-switched memory B-cells was observed. The HLC values were normal. Our results suggest that LTCR-MM patients express a particular immune signature, which probably reflects a 'high quality' immune reconstitution that could exert a competent anti-tumor immunological surveillance along with a recovery of the humoral immunity.

  3. Unilateral lesion of dorsal hippocampus in adult rats impairs contralateral long-term potentiation in vivo and spatial memory in the early postoperative phase.

    Science.gov (United States)

    Li, Hongjie; Wu, Xiaoyan; Bai, Yanrui; Huang, Yan; He, Wenting; Dong, Zhifang

    2012-05-01

    It is well documented that bilateral hippocampal lesions or unilateral hippocampal lesion at birth causes impairment of contralateral LTP and long-term memory. However, effects of unilateral hippocampal lesion in adults on contralateral in vivo LTP and memory are not clear. We here examined the influence of unilateral electrolytic dorsal hippocampal lesion in adult rats on contralateral LTP in vivo and spatial memory during different postoperative phases. We found that acute unilateral hippocampal lesion had no effect on contralateral LTP. However, contralateral LTP was impaired at 1 week after lesion, and was restored to the control level at postoperative week 4. Similarly, spatial memory was also impaired at postoperative week 1, and was restored at postoperative week 4. In addition, the rats at postoperative week 1 showed stronger spatial exploratory behavior in a novel open-field environment. The sham operation had no effects on contralateral LTP, spatial memory and exploration at either postoperative week 1 or week 4. These results suggest that unilateral dorsal hippocampal lesion in adult rats causes transient contralateral LTP impairment and spatial memory deficit. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. A single amino acid difference between the intracellular domains of amyloid precursor protein and amyloid-like precursor protein 2 enables induction of synaptic depression and block of long-term potentiation.

    Science.gov (United States)

    Trillaud-Doppia, Emilie; Paradis-Isler, Nicolas; Boehm, Jannic

    2016-07-01

    Alzheimer disease (AD) is initially characterized as a disease of the synapse that affects synaptic transmission and synaptic plasticity. While amyloid-beta and tau have been traditionally implicated in causing AD, recent studies suggest that other factors, such as the intracellular domain of the amyloid-precursor protein (APP-ICD), can also play a role in the development of AD. Here, we show that the expression of APP-ICD induces synaptic depression, while the intracellular domain of its homolog amyloid-like precursor protein 2 (APLP2-ICD) does not. We are able to show that this effect by APP-ICD is due to a single alanine vs. proline difference between APP-ICD and APLP2-ICD. The alanine in APP-ICD and the proline in APLP2-ICD lie directly behind a conserved caspase cleavage site. Inhibition of caspase cleavage of APP-ICD prevents the induction of synaptic depression. Finally, we show that the expression of APP-ICD increases and facilitates long-term depression and blocks induction of long-term potentiation. The block in long-term potentiation can be overcome by mutating the aforementioned alanine in APP-ICD to the proline of APLP2. Based on our results, we propose the emergence of a new APP critical domain for the regulation of synaptic plasticity and in consequence for the development of AD. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Nuclear Energy, Long Term Requirements

    International Nuclear Information System (INIS)

    Knapp, V.

    2006-01-01

    There are serious warnings about depletion of oil and gas and even more serious warnings about dangers of climate change caused by emission of carbon dioxide. Should developed countries be called to replace CO2 emitting energy sources as soon as possible, and the time available may not be longer then few decades, can nuclear energy answer the call and what are the requirements? Assuming optimistic contribution of renewable energy sources, can nuclear energy expand to several times present level in order to replace large part of fossil fuels use? Paper considers intermediate and long-term requirements. Future of nuclear power depends on satisfactory answers on several questions. First group of questions are those important for near and intermediate future. They deal with economics and safety of nuclear power stations in the first place. On the same time scale a generally accepted concept for radioactive waste disposal is also required. All these issues are in the focus of present research and development. Safer and more economical reactors are targets of international efforts in Generation IV and INPRO projects, but aiming further ahead these innovative projects are also addressing issues such as waste reduction and proliferation resistance. However, even assuming successful technical development of these projects, and there is no reason to doubt it, long term and large-scale nuclear power use is thereby not yet secured. If nuclear power is to play an essential role in the long-term future energy production and in reduction of CO2 emission, than several additional questions must be replied. These questions will deal with long-term nuclear fuel sufficiency, with necessary contribution of nuclear power in sectors of transport and industrial processes and with nuclear proliferation safety. This last issue is more political then technical, thus sometimes neglected by nuclear engineers, yet it will have essential role for the long-term prospects of nuclear power. The

  6. Potential long-term effects of MDMA on the basal ganglia-thalamocortical circuit: a proton MR spectroscopy and diffusion-tensor imaging study.

    Science.gov (United States)

    Liu, Hua-Shan; Chou, Ming-Chung; Chung, Hsiao-Wen; Cho, Nai-Yu; Chiang, Shih-Wei; Wang, Chao-Ying; Kao, Hung-Wen; Huang, Guo-Shu; Chen, Cheng-Yu

    2011-08-01

    To investigate the effects of 3,4-methylenedioxymethamphetamine (MDMA, commonly known as "ecstasy") on the alterations of brain metabolites and anatomic tissue integrity related to the function of the basal ganglia-thalamocortical circuit by using proton magnetic resonance (MR) spectroscopy and diffusion-tensor MR imaging. This study was approved by a local institutional review board, and written informed consent was obtained from all subjects. Thirty-one long-term (>1 year) MDMA users and 33 healthy subjects were enrolled. Proton MR spectroscopy from the middle frontal cortex and bilateral basal ganglia and whole-brain diffusion-tensor MR imaging were performed with a 3.0-T system. Absolute concentrations of metabolites were computed, and diffusion-tensor data were registered to the International Consortium for Brain Mapping template to facilitate voxel-based group comparison. The mean myo-inositol level in the basal ganglia of MDMA users (left: 4.55 mmol/L ± 2.01 [standard deviation], right: 4.48 mmol/L ± 1.33) was significantly higher than that in control subjects (left: 3.25 mmol/L ± 1.30, right: 3.31 mmol/L ± 1.19) (P 50 voxels). Increased myo-inositol and Cho concentrations in the basal ganglia of MDMA users are suggestive of glial response to degenerating serotonergic functions. The abnormal metabolic changes in the basal ganglia may consequently affect the inhibitory effect of the basal ganglia to the thalamus, as suggested by the increased FA in the thalamus and abnormal changes in water diffusion in the corresponding basal ganglia-thalamocortical circuit. © RSNA, 2011.

  7. Analysing long term discursive processes

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    which extend beyond the single interaction, for instance negotiations or planning processes, seems to have played a less important role, with studies such as Iedema 2001 and Wodak 2000 as exceptions. These long term processes, however, are central to the constitution and workings of organizations......What do timescales - the notion that processes take place or can be viewed within a shorter or longer temporal range (Lemke 2005) - mean for the analysis of discourse? What are the methodological consequences of analyzing discourse at different timescales? It may be argued that discourse analysis...... in general has favored either the analysis of short term processes such as interviews, discussions, and lessons, or the analysis of non-processual entities such as (multimodal) texts, arguments, discursive repertoires, and discourses (in a Foucaultian sense). In contrast, analysis of long term processes...

  8. Comparing long term energy scenarios

    International Nuclear Information System (INIS)

    Cumo, M.; Simbolotti, G.

    2001-01-01

    Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems [it

  9. Long term radioactive waste management

    International Nuclear Information System (INIS)

    Lavie, J.M.

    1984-01-01

    In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France [fr

  10. Long term adequacy of uranium resources

    International Nuclear Information System (INIS)

    Steyn, J.

    1990-01-01

    This paper examines the adequacy of world economic uranium resources to meet requirements in the very long term, that is until at least 2025 and beyond. It does so by analysing current requirements forecasts, existing and potential production centre supply capability schedules and national resource estimates. It takes into account lead times from resource discovery to production and production rate limitations. The institutional and political issues surrounding the question of adequacy are reviewed. (author)

  11. Medium and Long-term Opportunities and Risks of the Biotechnological Production of Bulk Chemicals from Renewable Resources. The Potential of White Biotechnology. The BREW Project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Patel, M.; Crank, M.; Dornburg, V.; Hermann, B.; Roes, L. [Department of Science, Technology and Society NWS, Utrecht University, Utrecht (Netherlands); Huesing, B. [Fraunhofer Institute for Systems and Innovation Research FhG-ISl, Karlsruhe (Germany); Overbeek, L. [Plant Research International PRI, Wageningen (Netherlands); Terragni, F.; Recchia, E. [CERISS, Centro per I' Educazione, la Ricerca, I' lnformazione su Scienza e Society, Milan (Italy)

    2006-09-15

    This study investigates the medium and long-term opportunities and risks of the biotechnological production of organic chemicals. The objective is to gain better understanding of the techno-economic and the societal viability of White Biotechnology in the coming decades. The key research questions are which products could be made with White Biotechnology, whether these products can contribute to savings of energy use and greenhouse gas (GHG) emissions, under which conditions the products become economically viable, which risks may originate from the use of genetically modified organisms (GMO) in fermentation and what the public perception is. The main purpose of Chapter 2 is to provide an overview of emerging key White Biotechnology products and to explain which chemicals could be produced on their basis. For a selection of these products, detailed environmental and economic assessments are conducted in Chapter 3 (in specific terms, i.e. per tonne of product). Chapter 3 discusses also the so-called Generic Approach which is the methodology we developed and applied to assess future processes and processes, for which very little information is available. In Chapter 4, three scenario projections are developed for Europe (EU-25), thereby assuming benign, moderate and disadvantageous conditions for bio-based chemicals. The purpose of this chapter is hence to understand to which extent restructuring of the chemical sector might occur under which conditions. In Chapter 5, the risks related to the use of White Biotechnology are addressed. The main purpose of this chapter is to give insight into the main risk components influencing the overall risk and of the knowledge gaps. Both conventional risks (e.g., human toxicity and accidents) and risks related to generic modification (e.g., horizontal gene transfer) are analyzed. Since the public perception may play an important role for the implementation of White Biotechnology on a large scale, these issues are discussed in

  12. Potential Long-Term Records of Surface Albedo at Fine Spatiotemporal Resolution from Landsat/Sentinle-2A Surface Reflectance and MODIS/VIIRS BRDF

    Science.gov (United States)

    Li, Z.; Schaaf, C.; Shuai, Y.; Liu, Y.; Sun, Q.; Erb, A.; Wang, Z.

    2016-12-01

    The land surface albedo products at fine spatial resolutions are generated by coupling surface reflectance (SR) from Landsat (30 m) or Sentinel-2A (20 m) with concurrent surface anisotropy information (the Bidirectional Reflectance Distribution Function - BRDF) at coarser spatial resolutions from sequential multi-angular observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) or its successor, the Visible Infrared Imaging Radiometer Suite (VIIRS). We assess the comparability of four types of fine-resolution albedo products (black-sky and white-sky albedos over the shortwave broad band) generated by coupling, (1) Landsat-8 Optical Land Imager (OLI) SR with MODIS BRDF; (2) OLI SR with VIIRS BRDF; (3) Sentinel-2A MultiSpectral Instrument (MSI) SR with MODIS BRDF; and (4) MSI SR with VIIRS BRDF. We evaluate the accuracy of these four types of fine-resolution albedo products using ground tower measurements of surface albedo over six SURFace RADiation Network (SURFRAD) sites in the United States. For comparison with the ground measurements, we estimate the actual (blue-sky) albedo values at the six sites by using the satellite-based retrievals of black-sky and white-sky albedos and taking into account the proportion of direct and diffuse solar radiation from the ground measurements at the sites. The coupling of the OLI and MSI SR with MODIS BRDF has already been shown to provide accurate fine-resolution albedo values. With demonstration of a high agreement in BRDF products from MODIS and VIIRS, we expect to see consistency between all four types of fine-resolution albedo products. This assurance of consistency between the couplings of both OLI and MSI with both MODIS and VIIRS guarantees the production of long-term records of surface albedo at fine spatial resolutions and an increased temporal resolution. Such products will be critical in studying land surface changes and associated surface energy balance over the dynamic and heterogeneous landscapes

  13. Neurogenesis and The Effect of Antidepressants

    Directory of Open Access Journals (Sweden)

    Philippe Taupin

    2006-01-01

    Full Text Available The recent evidence that neurogenesis occurs throughout adulthood and neural stem cells (NSCs reside in the adult central nervous system (CNS suggests that the CNS has the potential for self-repair. Beside this potential, the function of newly generated neuronal cells in the adult brain remains the focus of intense research. The hippocampus of patients with depression show signs of atrophy and neuronal loss. This suggests that adult neurogenesis may contribute to the biology of depression. The observations that antidepressants, like fluoxetine, increase neurogenesis in the dentate gyrus (DG and neurogenesis is required for the behavioral effect of antidepressants, lead to a new theory for depression and the design of new strategies and drugs for the treatment of depression. However, the role of adult neurogenesis in the etiology of depression remains the source of controversies and debates.

  14. Neurogenesis and the Effect of Antidepressants

    Directory of Open Access Journals (Sweden)

    Philippe Taupin

    2006-01-01

    Full Text Available The recent evidence that neurogenesis occurs throughout adulthood and neural stem cells (NSCs reside in the adult central nervous system (CNS suggests that the CNS has the potential for self-repair. Beside this potential, the function of newly generated neuronal cells in the adult brain remains the focus of intense research. The hippocampus of patients with depression show signs of atrophy and neuronal loss. This suggests that adult neurogenesis may contribute to the biology of depression. The observations that antidepressants, like fluoxetine, increase neurogenesis in the dentate gyrus (DG and neurogenesis is required for the behavioral effect of antidepressants, lead to a new theory for depression and the design of new strategies and drugs for the treatment of depression. However, the role of adult neurogenesis in the etiology of depression remains the source of controversies and debates.

  15. The endogenous regenerative capacity of the damaged newborn brain: boosting neurogenesis with mesenchymal stem cell treatment.

    Science.gov (United States)

    Donega, Vanessa; van Velthoven, Cindy T J; Nijboer, Cora H; Kavelaars, Annemieke; Heijnen, Cobi J

    2013-05-01

    Neurogenesis continues throughout adulthood. The neurogenic capacity of the brain increases after injury by, e.g., hypoxia-ischemia. However, it is well known that in many cases brain damage does not resolve spontaneously, indicating that the endogenous regenerative capacity of the brain is insufficient. Neonatal encephalopathy leads to high mortality rates and long-term neurologic deficits in babies worldwide. Therefore, there is an urgent need to develop more efficient therapeutic strategies. The latest findings indicate that stem cells represent a novel therapeutic possibility to improve outcome in models of neonatal encephalopathy. Transplanted stem cells secrete factors that stimulate and maintain neurogenesis, thereby increasing cell proliferation, neuronal differentiation, and functional integration. Understanding the molecular and cellular mechanisms underlying neurogenesis after an insult is crucial for developing tools to enhance the neurogenic capacity of the brain. The aim of this review is to discuss the endogenous capacity of the neonatal brain to regenerate after a cerebral ischemic insult. We present an overview of the molecular and cellular mechanisms underlying endogenous regenerative processes during development as well as after a cerebral ischemic insult. Furthermore, we will consider the potential to use stem cell transplantation as a means to boost endogenous neurogenesis and restore brain function.

  16. Long term stability of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Kundur, P; Gao, B [Powertech Labs. Inc., Surrey, BC (Canada)

    1994-12-31

    Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

  17. IMPAIRMENT IN SHORT-TERM BUT ENHANCED LONG-TERM SYNAPTIC POTENTIATION AND ERK ACTIVATION IN ADULT HIPPOCAMPAL AREA CA1 FOLLOWING DEVELOPMENTAL HYPOTHYROIDISM.

    Science.gov (United States)

    The EPA must evaluate the risk of exposure of the developing brain to chemicals with the potential to disrupt thyroid hormone homeostasis. The existing literature identifies morphological and neurochemical indices of severe neonatal hypothyroidism in the early postnatal period i...

  18. Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site

    International Nuclear Information System (INIS)

    Meike, A.; Bourcier, W.L.; Alai, M.

    1995-09-01

    The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel's extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey

  19. Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.; Bourcier, W.L.; Alai, M. [and others

    1995-09-01

    The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel`s extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey.

  20. Short- and long-term effects on fuels, forest structure, and wildfire potential from prescribed fire and resource benefit fire in southwestern forests, USA

    Science.gov (United States)

    Molly E. Hunter; Jose M. Iniguez; Leigh B. Lentile

    2011-01-01

    Prescribed and resource benefit fires are used to manage fuels in fire-prone landscapes in the Southwest. These practices, however, typically occur under different conditions, potentially leading to differences in fire behavior and effects. The objectives of this study were to investigate the effects of recent prescribed fires, resource benefit fires, and repeated...

  1. Long-term agricultural land-cover change and potential for cropland expansion in the former Virgin Lands area of Kazakhstan

    DEFF Research Database (Denmark)

    Kraemer, Roland; Prishchepov, Alexander; Müller, Daniel

    2015-01-01

    of Northern Kazakhstan. Further, we assessed the potential of currently idle cropland for re-cultivation. We reconstructed the cropland extent before and after the Virgin Lands Campaign using archival maps, and we mapped the agricultural land cover in the late Soviet and post-Soviet period using multi...... until 1990, as well as cropland contraction after 1990, occurred mainly in areas that were less favorable for agriculture. Cropland re-cultivation after 2000 was occurring on lands with relatively favorable agro-environmental conditions in comparison to remaining idle croplands, albeit with much lower...... agro-environmental endowment compared to stable croplands from 1990 to 2010. In sum, we found that cropland production potentials of the currently uncultivated areas are much lower than commonly believed, and further cropland expansion is only possible at the expense of marginal lands. Our results...

  2. A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository

    Directory of Open Access Journals (Sweden)

    Jordan Daoudi

    2017-06-01

    Full Text Available We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl− selective electrodes, one Ag2S/Ag-based reference or S2− selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors.

  3. A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository.

    Science.gov (United States)

    Daoudi, Jordan; Betelu, Stephanie; Tzedakis, Theodore; Bertrand, Johan; Ignatiadis, Ioannis

    2017-06-13

    We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl - selective electrodes, one Ag₂S/Ag-based reference or S 2- selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors.

  4. Navigating Long-Term Care

    Directory of Open Access Journals (Sweden)

    James D. Holt MD

    2017-03-01

    Full Text Available Americans over age 65 constitute a larger percentage of the population each year: from 14% in 2010 (40 million elderly to possibly 20% in 2030 (70 million elderly. In 2015, an estimated 66 million people provided care to the ill, disabled, and elderly in the United States. In 2000, according to the Centers for Disease Control and Prevention (CDC, 15 million Americans used some form of long-term care: adult day care, home health, nursing home, or hospice. In all, 13% of people over 85 years old, compared with 1% of those ages 65 to 74, live in nursing homes in the United States. Transitions of care, among these various levels of care, are common: Nursing home to hospital transfer, one of the best-studied transitions, occurs in more than 25% of nursing home residents per year. This article follows one patient through several levels of care.

  5. Polyaromatic hydrocarbon (PAH) degradation potential of a new acid tolerant, diazotrophic P-solubilizing and heavy metal resistant bacterium Cupriavidus sp. MTS-7 isolated from long-term mixed contaminated soil.

    Science.gov (United States)

    Kuppusamy, Saranya; Thavamani, Palanisami; Megharaj, Mallavarapu; Lee, Yong Bok; Naidu, Ravi

    2016-11-01

    An isolate of Cupriavidus (strain MTS-7) was identified from a long-term PAHs and heavy metals mixed contaminated soil with the potential to biodegrade both LMW and HMW PAHs with added unique traits of acid and alkali tolerance, heavy metal tolerance, self-nutrient assimilation by N fixation and P solubilization. This strain completely degraded the model 3 (150 mg L(-1) Phe), 4 (150 mg L(-1) Pyr) and 5 (50 mg L(-1) BaP) ring PAHs in 4, 20 and 30 days, respectively. It could mineralize 90-100% of PAHs (200 mg L(-1) of Phe and Pyr) within 15 days across pH ranging from 5 to 8 and even in the presence of toxic metal contaminations. During biodegradation, the minimum inhibitory concentrations were 5 (Cu(2+)) and 3 (Cd(2+), Pb(2+), Zn(2+)) mg L(-1) of the potentially bioavailable metal ions and over 17 mg L(-1) metal levels was lethal for the microbe. Further, it could fix 217-274 μg mL(-1) of N and solubilize 79-135 μg mL(-1) of P while PAHs degradation. MTS-7 as a superior candidate could be thus used in the enhanced bioaugmentation and/or phytoremediation of long-term mixed contaminated sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Contribution to the study of diffusion as related to the leaching of glasses: application to the potential risk of long-term storage

    International Nuclear Information System (INIS)

    Imbert, J.C.; Pacaud, F.

    Leaching of glasses made from radioactive wastes of very high activity was studied. Leaching agents used were water for temperatures below 100 0 C; molten nitrates for temperatures higher than 100 0 C; solutions of various pH or charged with either sodium chloride or cesium; and dry or wet air. From the quantities of entrained radioactive elements, overall apparent diffusion coefficients were determined for fission products with long periods such as cerium, cesium, ruthenium, and strontium. Diffusion activation energies were also determined. These results are applied to the calculation of the potential risk of storage for vitrified fission products

  7. Assessing the Quality and Potential Efficacy of Commercial Extracts of Rhodiola rosea L. by Analyzing the Salidroside and Rosavin Content and the Electrophysiological Activity in Hippocampal Long-Term Potentiation, a Synaptic Model of Memory

    Directory of Open Access Journals (Sweden)

    Wilfried Dimpfel

    2018-05-01

    Full Text Available Rhodiola rosea L. roots and rhizome extracts are active ingredients in adaptogenic herbal medicinal products (HMP and dietary supplements for temporary relief of symptoms of stress, such as fatigue and weakness. R. rosea extract has a stimulating effect on the CNS, suggesting potential benefits on cognitive functions, memory, learning, and attention. The reproducible efficacy and quality of preparations of the underground parts of R. rosea depend on the highly variable content of the active markers, salidroside and rosavin, which affect the quality of HMP and dietary supplements. However, it is not clear which analytical markers are important for assessing the efficacy of R. rosea preparations intended for use in aging-induced mild cognitive disorders, such as attenuated memory, attention, and learning. Furthermore, the activity of various commercial R. rosea extracts has not been correlated with their content. Here, the biological activities of salidroside, rosavin, and seven commercial extracts of underground parts of R. rosea were assessed using a synaptic model of memory: long-term potentiation (LTP of synaptic transmission in hippocampus slices. A high degree of variation in the content of all active markers was observed. One extract from China lacked rosavin, and there was even variation in the extracts from the Altai geographic region. In vitro, rosavin, salidroside and all tested R. rosea extracts potentiated electric stimulation of an intra-hippocampal electric circuit, which resulted in higher responses of the pyramidal cells in isolated hippocampus slices. Rosavin was more active at higher concentrations than salidroside; while, salidroside was more effective at lower concentrations. The highest content of both active markers was found in the extracts that were active at the lowest concentrations tested; while, some extracts contained some other compounds that presumably reduced the efficacy due to antagonistic interactions

  8. The behavior during water-mineral interaction of britholite, an analogue of an apatite structured potential long-term actinide host phase

    Energy Technology Data Exchange (ETDEWEB)

    Chairat, C.; Oelkers, E.H.; Schott, J.; Harouiya, N.; Lartigue, J-E.; Guy, C.; Audubert, F

    2004-07-01

    Neodymium britholite (Ca{sub 9}Nd(PO{sub 4}){sub 5}SiO{sub 2}F{sub 2}) dissolution rates have been studied because it is an analogue for potential actinide waste hosts; it is believed that the behavior of Nd is representative of that of the actinide elements. Steady-state dissolution rates of britholite were measured in closed and open system reactors as a function of aqueous solution composition at 25 to 90 deg C. Measured britholite dissolution rates based on Ca, P, and F release are found to be close to corresponding apatite dissolution rates; these rates at 25 deg C decrease from 10-8 to 10-11 mol/m{sup 2}/s with increasing pH from 4 to 12. Measured Nd release rates are far slower than those of these other elements; Nd concentrations in solution appear to be in equilibrium with NdPO{sub 4}, which limits aqueous Nd concentrations to less than 10-12 mol/kg at near neutral conditions. By analogy, it appears likely that aqueous actinide release from analogous waste hosts will be similarly limited by the precipitation of sparingly soluble AcPO{sub 4} phases. (authors)

  9. Long-Term Memory Performance in Adult ADHD.

    Science.gov (United States)

    Skodzik, Timo; Holling, Heinz; Pedersen, Anya

    2017-02-01

    Memory problems are a frequently reported symptom in adult ADHD, and it is well-documented that adults with ADHD perform poorly on long-term memory tests. However, the cause of this effect is still controversial. The present meta-analysis examined underlying mechanisms that may lead to long-term memory impairments in adult ADHD. We performed separate meta-analyses of measures of memory acquisition and long-term memory using both verbal and visual memory tests. In addition, the influence of potential moderator variables was examined. Adults with ADHD performed significantly worse than controls on verbal but not on visual long-term memory and memory acquisition subtests. The long-term memory deficit was strongly statistically related to the memory acquisition deficit. In contrast, no retrieval problems were observable. Our results suggest that memory deficits in adult ADHD reflect a learning deficit induced at the stage of encoding. Implications for clinical and research settings are presented.

  10. Japan's Long-term Energy Demand and Supply Scenario to 2050 - Estimation for the Potential of Massive CO2 Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, Ryoichi; Marnay, Chris; Stadler, Michael; Lai, Judy; Borgeson, Sam; Coffey, Brian; Azevedo, Ines Lima

    2009-09-01

    In this analysis, the authors projected Japan's energy demand/supply and energy-related CO{sub 2} emissions to 2050. Their analysis of various scenarios indicated that Japan's CO{sub 2} emissions in 2050 could be potentially reduced by 26-58% from the current level (FY 2005). These results suggest that Japan could set a CO{sub 2} emission reduction target for 2050 at between 30% and 60%. In order to reduce CO{sub 2} emissions by 60% in 2050 from the present level, Japan will have to strongly promote energy conservation at the same pace as an annual rate of 1.9% after the oil crises (to cut primary energy demand per GDP (TPES/GDP) in 2050 by 60% from 2005) and expand the share of non-fossil energy sources in total primary energy supply in 2050 to 50% (to reduce CO{sub 2} emissions per primary energy demand (CO{sub 2}/TPES) in 2050 by 40% from 2005). Concerning power generation mix in 2050, nuclear power will account for 60%, solar and other renewable energy sources for 20%, hydro power for 10% and fossil-fired generation for 10%, indicating substantial shift away from fossil fuel in electric power supply. Among the mitigation measures in the case of reducing CO{sub 2} emissions by 60% in 2050, energy conservation will make the greatest contribution to the emission reduction, being followed by solar power, nuclear power and other renewable energy sources. In order to realize this massive CO{sub 2} abatement, however, Japan will have to overcome technological and economic challenges including the large-scale deployment of nuclear power and renewable technologies.

  11. Long-term variations of the riverine input of potentially toxic dissolved elements and the impacts on their distribution in Jiaozhou Bay, China.

    Science.gov (United States)

    Wang, Changyou; Guo, Jinqiang; Liang, Shengkang; Wang, Yunfei; Yang, Yanqun; Wang, Xiulin

    2018-03-01

    The concentrations of the potentially toxic dissolved elements (PTEs) As, Hg, Cr, Pb, Cd, and Cu in the main rivers into Jiaozhou Bay (JZB) during 1981-2006 were measured, and the impact of the fluvial PTE fluxes on their distributions in the bay was investigated. The overall average concentration in the rivers into JZB ranged from 8.8 to 39.6 μg L -1 for As, 10.1 to 632.6 ng L -1 for Hg, 4.1 to 3003.6 μg L -1 for Cr, 8.5 to 141.9 μg L -1 for Pb, 1.1 to 34.2 μg L -1 for Cd, and 13.2 to 1042.8 μg L -1 for Cu. The interannual average concentration variations of the PTEs in these rivers were enormous, with maximum differences of 41-21,680 times, while their relative seasonal changes were far smaller with maximum differences of 3-12 times. The total annual fluvial fluxes for As, Hg, and Cr into JZB exhibited the inverse "U" pattern, while those for Pb and Cd showed the "N" pattern. As a whole, the total annual Cu flux presented a growing tendency from 1998 to 2006. In general, the changing trends of the PTE concentrations in JZB were similar to those of their annual fluxes from the rivers, indicating a great impact of their fluvial fluxes on their distributions in JZB. The annual concentration of Cd in the bay almost remained constant and differed from the fluvial flux of Cd. The diversified pattern of the environmental Kuznets curve (EKC) represented China's approach to industrialization as "improving while developing."

  12. Studies of breakeven prices and electricity supply potentials of nuclear fusion by a long-term world energy and environment model

    International Nuclear Information System (INIS)

    Tokimatsu, K.; Asaoka, Y.; Okano, K.; Yoshida, T.; Hiwatari, R.; Konishi, S.; Nishio, S.; Fujino, J.; Ogawa, Y.; Yamaji, K.

    2002-01-01

    In response to social demand, this paper investigates the breakeven price (BP) and potential electricity supply of nuclear fusion energy in the 21st century by means of a world energy and environment model. We set the following objectives in this paper: (i) to reveal the economics of the introduction conditions of nuclear fusion; (ii) to know when tokamak-type nuclear fusion reactors are expected to be introduced cost-effectively into future energy systems; (iii) to estimate the share in 2100 of electricity produced by the presently designed reactors that could be economically selected in the year. The model can give in detail the energy and environment technologies and price-induced energy saving, and can illustrate optimal energy supply structures by minimizing the costs of total discounted energy systems at a discount rate of 5%. The following parameters of nuclear fusion were considered: cost of electricity (COE) in the nuclear fusion introduction year, annual COE reduction rates, regional introduction year, and regional nuclear fusion capacity projection. The investigations are carried out for three nuclear fusion projections one of which includes tritium breeding constraints, four future CO 2 concentration constraints, and technological assumptions on fossil fuels, nuclear fission, CO 2 sequestration, and anonymous innovative technologies. It is concluded that: (1) the BPs are from 65 to 125 mill kW -1 h -1 depending on the introduction year of nuclear fusion under the 550 ppmv CO 2 concentration constraints; those of a business-as-usual (BAU) case are from 51 to 68 mill kW -1 h -1 . Uncertainties resulting from the CO 2 concentration constraints and the technological options influenced the BPs by plus/minus some 10-30 mill kW -1 h -1 , (2) tokamak-type nuclear fusion reactors (as presently designed, with a COE range around 70-130 mill kW -1 h -1 ) would be favourably introduced into energy systems after 2060 based on the economic criteria under the 450 and

  13. Studies of breakeven prices and electricity supply potentials of nuclear fusion by a long-term world energy and environment model

    Science.gov (United States)

    Tokimatsu, K.; Asaoka, Y.; Konishi, S.; Fujino, J.; Ogawa, Y.; Okano, K.; Nishio, S.; Yoshida, T.; Hiwatari, R.; Yamaji, K.

    2002-11-01

    In response to social demand, this paper investigates the breakeven price (BP) and potential electricity supply of nuclear fusion energy in the 21st century by means of a world energy and environment model. We set the following objectives in this paper: (i) to reveal the economics of the introduction conditions of nuclear fusion; (ii) to know when tokamak-type nuclear fusion reactors are expected to be introduced cost-effectively into future energy systems; (iii) to estimate the share in 2100 of electricity produced by the presently designed reactors that could be economically selected in the year. The model can give in detail the energy and environment technologies and price-induced energy saving, and can illustrate optimal energy supply structures by minimizing the costs of total discounted energy systems at a discount rate of 5%. The following parameters of nuclear fusion were considered: cost of electricity (COE) in the nuclear fusion introduction year, annual COE reduction rates, regional introduction year, and regional nuclear fusion capacity projection. The investigations are carried out for three nuclear fusion projections one of which includes tritium breeding constraints, four future CO2 concentration constraints, and technological assumptions on fossil fuels, nuclear fission, CO2 sequestration, and anonymous innovative technologies. It is concluded that: (1) the BPs are from 65 to 125 mill kW-1 h-1 depending on the introduction year of nuclear fusion under the 550 ppmv CO2 concentration constraints; those of a business-as-usual (BAU) case are from 51 to 68 mill kW-1h-1. Uncertainties resulting from the CO2 concentration constraints and the technological options influenced the BPs by plus/minus some 10 30 mill kW-1h-1, (2) tokamak-type nuclear fusion reactors (as presently designed, with a COE range around 70 130 mill kW-1h-1) would be favourably introduced into energy systems after 2060 based on the economic criteria under the 450 and 550 ppmv CO2

  14. Long term study of mechanical

    Directory of Open Access Journals (Sweden)

    Ahmed M. Diab

    2016-06-01

    Full Text Available In this study, properties of limestone cement concrete containing different replacement levels of limestone powder were examined. It includes 0%, 5%, 10%, 15%, 20% and 25% of limestone powder as a partial replacement of cement. Silica fume was added incorporated with limestone powder in some mixes to enhance the concrete properties. Compressive strength, splitting tensile strength and modulus of elasticity were determined. Also, durability of limestone cement concrete with different C3A contents was examined. The weight loss, length change and cube compressive strength loss were measured for concrete attacked by 5% sodium sulfate using an accelerated test up to 525 days age. The corrosion resistance was measured through accelerated corrosion test using first crack time, cracking width and steel reinforcement weight loss. Consequently, for short and long term, the use of limestone up to 10% had not a significant reduction in concrete properties. It is not recommended to use blended limestone cement in case of sulfate attack. The use of limestone cement containing up to 25% limestone has insignificant effect on corrosion resistance before cracking.

  15. Long-term competence restoration.

    Science.gov (United States)

    Morris, Douglas R; DeYoung, Nathaniel J

    2014-01-01

    While the United States Supreme Court's Jackson v. Indiana decision and most state statutes mandate determinations of incompetent defendants' restoration probabilities, courts and forensic clinicians continue to lack empirical evidence to guide these determinations and do not yet have a consensus regarding whether and under what circumstances incompetent defendants are restorable. The evidence base concerning the restoration likelihood of those defendants who fail initial restoration efforts is even further diminished and has largely gone unstudied. In this study, we examined the disposition of a cohort of defendants who underwent long-term competence restoration efforts (greater than six months) and identified factors related to whether these defendants were able to attain restoration and adjudicative success. Approximately two-thirds (n = 52) of the 81 individuals undergoing extended restoration efforts were eventually deemed restored to competence. Lengths of hospitalization until successful restoration are presented with implications for the reasonable length of time that restoration efforts should persist. Older individuals were less likely to be restored and successfully adjudicated, and individuals with more severe charges and greater factual legal understanding were more likely to be restored and adjudicated. The significance of these findings for courts and forensic clinicians is discussed.

  16. Uranium ... long-term confidence

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Half way through 1983 the outlook for the world's uranium producers was far from bright if one takes a short term view. The readily accessible facts present a gloomy picture. The spot prices of uranium over the past few years decreased from a high of $42-$43/lb to a low of $17 in 1982. It now hovers between $23 and $24. the contract prices negotiated between producers and consumers are not so accessible but they do not reflect the spot price. The reasons why contractual uranium prices do not follow the usual dictates of supply and demand are related to the position in which uranium and associated power industries find themselves. There is public reaction with strong emotional overtones as well as much reduced expectations about the electric power needs of the world. Furthermore the supply of uranium is not guaranteed despite present over production. However the people in the industry, taking the medium- and long-term view, are not despondent

  17. General practitioners' views on (long-term) prescription and use of problematic and potentially inappropriate medication for oldest-old patients-A qualitative interview study with GPs (CIM-TRIAD study).

    Science.gov (United States)

    Pohontsch, Nadine Janis; Heser, Kathrin; Löffler, Antje; Haenisch, Britta; Parker, Debora; Luck, Tobias; Riedel-Heller, Steffi G; Maier, Wolfgang; Jessen, Frank; Scherer, Martin

    2017-02-17

    Potentially inappropriate medication (PIM) is defined as medication with uncertain therapeutic effects and/or potential adverse drug reactions outweighing the clinical benefits. The prescription rate of PIM for oldest-old patients is high despite the existence of lists of PIM (e.g. the PRISCUS list) and efforts to raise awareness. This study aims at identifying general practitioners' views on PIM and aspects affecting the (long-term) use of PIM. As part of the CIM-TRIAD study, we conducted semi-structured, qualitative interviews with 47 general practitioners, discussing 25 patients with and 22 without PIM (according to the PRISCUS list). The interview guideline included generic and patient-specific questions. Interviews were digitally recorded and transcribed verbatim. We content analyzed the interviews using deductive and inductive category development. The majority of the general practitioners were not aware of the PRISCUS list. Agents deemed potentially inappropriate from the general practitioners' point of view and the PRISCUS list are not completely superimposable. General practitioners named their criteria to identify appropriate medication for elderly patients (e.g. renal function, cognitive state) and emphasized the importance of monitoring. We identified prescription- (e.g. benzodiazepines on alternative private prescription), medication- (e.g. subjective perception that PIM has no alternative), general practitioner- (e.g. general practitioner relies on specialists), patient- (e.g. "demanding high-user", positive subjective benefit-risk-ratio) and system-related aspects (e.g. specialists lacking holistic view, interface problems) related to the (long term) use of PIM. While the PRISCUS list does not seem to play a decisive role in general practice, general practitioners are well aware of risks associated with PIM. Our study identifies some starting points for a safer handling of PIM, e.g. stronger dissemination of the PRISCUS list, better compensation of

  18. Space ventures and society long-term perspectives

    Science.gov (United States)

    Brown, W. M.

    1985-01-01

    A futuristic evaluation of mankind's potential long term future in space is presented. Progress in space will not be inhibited by shortages of the Earth's physical resources, since long term economic growth will be focused on ways to constrain industrial productivity by changing social values, management styles, or government competence. Future technological progress is likely to accelerate with an emphasis on international cooperation, making possible such large joint projects as lunar colonies or space stations on Mars. The long term future in space looks exceedingly bright even in relatively pessimistic scenarios. The principal driving forces will be technological progress, commercial and public-oriented satellites, space industrialization, space travel, and eventually space colonization.

  19. Long term testing of PSI-membranes

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J; Brack, H P; Geiger, F; Buechi, F N; Tsukada, A; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

  20. Long-Term Prognosis of Ischemic Stroke in Young Adults

    OpenAIRE

    Varona, Jose F.

    2010-01-01

    There is limited information about long-term prognosis of ischemic stroke in young adults. Giving the potentially negative impact in physical, social, and emotional aspects of an ischemic stroke in young people, providing early accurate long-term prognostic information is very important in this clinical setting. Moreover, detection of factors associated with bad outcomes (death, recurrence, moderate-to-severe disability) help physicians in optimizing secondary prevention strategies. The prese...

  1. Financing long term liabilities (Germany)

    International Nuclear Information System (INIS)

    2003-01-01

    charges and fees levied from the waste producers. Altogether, financial resources for decommissioning are needed for the following steps: the post-operational phase in which the facility is prepared for dismantling after its final shut-down, dismantling of the radioactive part of the facility, management, storage and disposal of the radioactive waste, restoration of the site, licensing and regulatory supervision of all these steps. Additional means are necessary for the management, storage and disposal of the spent fuel. The way in which the availability of financial resources is secured differs between public owned installations and installations of the private power utilities. In Germany, past practices has resulted in singular contaminated sites of limited extent, mainly during the first half of the 20. century. Those contaminated sites have been or are being cleaned up and redeveloped. In large areas of Saxony and Thuringia, the geological formations permitted the surface and underground mining of Uranium ore. Facilities of the former Soviet-German WISMUT Ltd. where ore was mined and processed from 1946 until the early 1990's can be found at numerous sites. In the course of the re-unification of Germany, the soviet shares of the WISMUT were taken over by the Federal Republic of Germany and the closure of the WISMUT facilities was initiated. In that phase the extent of the damages to the environment and of the necessary remediation work became clear. All mining and milling sites are now closed and are under decommissioning. A comprehensive remediation concept covers all WISMUT sites. Heaps and mill-tailing ponds are transferred into a long-term stable condition. The area of the facilities to be remediated amounts to more than 30 km 2 . Heaps cover a total area of ca. 15,5 km 2 , tailing ponds in which the tailings resulting from the Uranium production are stored as sludges cover 6,3 km 2 ). In total, the remediation issues are very complex and without precedent. The

  2. The fatty acid amide hydrolase inhibitor URB597 exerts anti-inflammatory effects in hippocampus of aged rats and restores an age-related deficit in long-term potentiation

    Directory of Open Access Journals (Sweden)

    Murphy Niamh

    2012-04-01

    Full Text Available Abstract Background Several factors contribute to the deterioration in synaptic plasticity which accompanies age and one of these is neuroinflammation. This is characterized by increased microglial activation associated with increased production of proinflammatory cytokines like interleukin-1β (IL-1β. In aged rats these neuroinflammatory changes are associated with a decreased ability of animals to sustain long-term potentiation (LTP in the dentate gyrus. Importantly, treatment of aged rats with agents which possess anti-inflammatory properties to decrease microglial activation, improves LTP. It is known that endocannabinoids, such as anandamide (AEA, have anti-inflammatory properties and therefore have the potential to decrease the age-related microglial activation. However, endocannabinoids are extremely labile and are hydrolyzed quickly after production. Here we investigated the possibility that inhibiting the degradation of endocannabinoids with the fatty acid amide hydrolase (FAAH inhibitor, URB597, could ameliorate age-related increases in microglial activation and the associated decrease in LTP. Methods Young and aged rats received subcutaneous injections of the FAAH inhibitor URB597 every second day and controls which received subcutaneous injections of 30% DMSO-saline every second day for 28 days. Long-term potentiation was recorded on day 28 and the animals were sacrificed. Brain tissue was analyzed for markers of microglial activation by PCR and for levels of endocannabinoids by liquid chromatography coupled to tandem mass spectrometry. Results The data indicate that expression of markers of microglial activation, MHCII, and CD68 mRNA, were increased in the hippocampus of aged, compared with young, rats and that these changes were associated with increased expression of the proinflammatory cytokines interleukin (IL-1β and tumor necrosis factor-α (TNFα which were attenuated by treatment with URB597. Coupled with these changes, we

  3. Long term radiological impact of thorium extraction

    International Nuclear Information System (INIS)

    Menard, S.; Schapira, J.P.

    1995-01-01

    Thorium extraction produces a certain amount of radioactive wastes. Potential long term radiological impact of these residues has been calculated using the recent ICRP-68 ingestion dose factors in connection with the computing code DECAY, developed at Orsay and described in this work. This code solves the well known Bateman's equations which govern the time dependence of a set of coupled radioactive nuclei. Monazites will be very likely the minerals to be exploited first, in case of an extensive use of thorium as nuclear fuel. Because monazites contain uranium as well, mining residues will contain not only the descendants of 232 Th and a certain proportion of non-extracted thorium (taken here to be 5%), but also this uranium, if left in the wastes for economical reasons. If no uranium would be present at all in the mineral, the potential radiotoxicity would strongly decrease in approximately 60 years, at the pace of the 5.8 years period of 228 Ra, which becomes the longest-lived radionuclide of the 4n radioactive family in the residues. Moreover, there is no risk due to radon exhalation, because of the very short period of 220 Rn. These significant differences between uranium and thorium mining have to be considered in view of some estimated long term real radiological impacts due to uranium residues, which could reach a value of the order of 1 mSv/year, the dose limit recommended for the public by the recent ICRP-60. (authors). 15 refs., 4 figs., 3 tabs., 43 appendices

  4. Scientific Understanding from Long Term Observations: Insights from the Long Term Ecological Research (LTER) Program

    Science.gov (United States)

    Gosz, J.

    2001-12-01

    estuaries below by removing all incoming freshwater. At Toolik Lake, long-term experiments of removing top predators from the good web of lakes showed dramatic alterations of lake populations of small fish and zooplankton. In New Mexico, LTER research on small mammal populations is successfully predicting rodent increases and the potential for increased zoonotic diseases such as Hantavirus and bubonic plague. This ability to forecast based on El Nino prediction is being used to increase scientific awareness and public health awareness through media based communication with the public. In Oregon, the Andrews Forest LTER program has had long, strong links with natural resource policy and management. Basic understanding of forest-stream interactions, characteristics of old-growth forests, roles of woody debris in temperate forest ecosystems, invertebrate biodiversity and ecosystem function have been incorporated in management guidelines, plans and regulations for public and private lands throughout the Pacific Northwest. Other examples of the values of long-term research and monitoring will be presented.

  5. NR2B subunit-dependent long-term potentiation enhancement in the rat cortical auditory system in vivo following masking of patterned auditory input by white noise exposure during early postnatal life.

    Science.gov (United States)

    Hogsden, Jennifer L; Dringenberg, Hans C

    2009-08-01

    The composition of N-methyl-D-aspartate (NMDA) receptor subunits influences the degree of synaptic plasticity expressed during development and into adulthood. Here, we show that theta-burst stimulation of the medial geniculate nucleus reliably induced NMDA receptor-dependent long-term potentiation (LTP) of field postsynaptic potentials recorded in the primary auditory cortex (A1) of urethane-anesthetized rats. Furthermore, substantially greater levels of LTP were elicited in juvenile animals (30-37 days old; approximately 55% maximal potentiation) than in adult animals (approximately 30% potentiation). Masking patterned sound via continuous white noise exposure during early postnatal life (from postnatal day 5 to postnatal day 50-60) resulted in enhanced, juvenile-like levels of LTP (approximately 70% maximal potentiation) relative to age-matched controls reared in unaltered acoustic environments (approximately 30%). Rats reared in white noise and then placed in unaltered acoustic environments for 40-50 days showed levels of LTP comparable to those of adult controls, indicating that white noise rearing results in a form of developmental arrest that can be overcome by subsequent patterned sound exposure. We explored the mechanisms mediating white noise-induced plasticity enhancements by local NR2B subunit antagonist application in A1. NR2B subunit antagonists (Ro 25-6981 or ifenprodil) completely reversed white noise-induced LTP enhancement at concentrations that did not affect LTP in adult or age-matched controls. We conclude that white noise exposure during early postnatal life results in the maintenance of juvenile-like, higher levels of plasticity in A1, an effect that appears to be critically dependent on NR2B subunit activation.

  6. A Long-term Plan for Kalk

    DEFF Research Database (Denmark)

    2017-01-01

    In this case, the author demonstrates together with the owner-manager of KALK A/S, Mr Rasmus Jorgensen, how to use the Family Business Map to frame a constructive discussion about long-term planning. The Family Business Map is a tool for long-term planning in family firms developed by Professor...

  7. Detrimental role of prolonged sleep deprivation on adult neurogenesis

    Directory of Open Access Journals (Sweden)

    Carina eFernandes

    2015-04-01

    Full Text Available Adult mammalian brains continuously generate new neurons, a phenomenon called neurogenesis. Both environmental stimuli and endogenous factors are important regulators of neurogenesis. Sleep has an important role in normal brain physiology and its disturbance causes very stressful conditions, which disrupt normal brain physiology. Recently, an influence of sleep in adult neurogenesis has been established, mainly based on sleep deprivation studies. This review provides an overview on how rhythms and sleep cycles regulate hippocampal and subventricular zone neurogenesis, discussing some potential underlying mechanisms. In addition, our review highlights some interacting points between sleep and neurogenesis in brain function, such as learning, memory and mood states, and provides some insights on the effects of antidepressants and hypnotic drugs on neurogenesis.

  8. Mild prenatal protein malnutrition increases alpha2C-adrenoceptor density in the cerebral cortex during postnatal life and impairs neocortical long-term potentiation and visuo-spatial performance in rats.

    Science.gov (United States)

    Soto-Moyano, Rubén; Valladares, Luis; Sierralta, Walter; Pérez, Hernán; Mondaca, Mauricio; Fernández, Victor; Burgos, Héctor; Hernández, Alejandro

    2005-06-01

    Mild reduction in the protein content of the mother's diet from 25 to 8% casein, calorically compensated by carbohydrates, does not alter body and brain weights of rat pups at birth, but leads to significant enhancements in the concentration and release of cortical noradrenaline during early postnatal life. Since central noradrenaline and some of its receptors are critically involved in long-term potentiation (LTP) and memory formation, this study evaluated the effect of mild prenatal protein malnutrition on the alpha2C-adrenoceptor density in the frontal and occipital cortices, induction of LTP in the same cortical regions and the visuo-spatial memory. Pups born from rats fed a 25% casein diet throughout pregnancy served as controls. At day 8 of postnatal age, prenatally malnourished rats showed a threefold increase in neocortical alpha2C-adrenoceptor density. At 60 days-of-age, alpha2C-adrenoceptor density was still elevated in the neocortex, and the animals were unable to maintain neocortical LTP and presented lower visuo-spatial memory performance. Results suggest that overexpression of neocortical alpha2C-adrenoceptors during postnatal life, subsequent to mild prenatal protein malnutrition, could functionally affect the synaptic networks subserving neocortical LTP and visuo-spatial memory formation.

  9. Long-term potentiation in the CA1 hippocampus induced by NR2A subunit-containing NMDA glutamate receptors is mediated by Ras-GRF2/Erk map kinase signaling.

    Directory of Open Access Journals (Sweden)

    Shan-xue Jin

    Full Text Available BACKGROUND: NMDA-type glutamate receptors (NMDARs are major contributors to long-term potentiation (LTP, a form of synaptic plasticity implicated in the process of learning and memory. These receptors consist of calcium-permeating NR1 and multiple regulatory NR2 subunits. A majority of studies show that both NR2A and NR2B-containing NMDARs can contribute to LTP, but their unique contributions to this form of synaptic plasticity remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we show that NR2A and NR2B-containing receptors promote LTP differently in the CA1 hippocampus of 1-month old mice, with the NR2A receptors functioning through Ras-GRF2 and its downstream effector, Erk Map kinase, and NR2B receptors functioning independently of these signaling molecules. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that NR2A-, but not NR2B, containing NMDA receptors induce LTP in pyramidal neurons of the CA1 hippocampus from 1 month old mice through Ras-GRF2 and Erk. This difference add new significance to the observation that the relative levels of these NMDAR subtypes is regulated in neurons, such that NR2A-containing receptors become more prominent late in postnatal development, after sensory experience and synaptic activity.

  10. Long-Term Effects of Concussion on Electrophysiological Indices of Attention in Varsity College Athletes: An Event-Related Potential and Standardized Low-Resolution Brain Electromagnetic Tomography Approach

    Science.gov (United States)

    Molfese, Dennis L.

    2016-01-01

    Abstract This study investigated the effects of a past concussion on electrophysiological indices of attention in college athletes. Forty-four varsity football athletes (22 with at least one past concussion) participated in three neuropsychological tests and a two-tone auditory oddball task while undergoing high-density event-related potential (ERP) recording. Athletes previously diagnosed with a concussion experienced their most recent injury approximately 4 years before testing. Previously concussed and control athletes performed equivalently on three neuropsychological tests. Behavioral accuracy and reaction times on the oddball task were also equivalent across groups. However, athletes with a concussion history exhibited significantly larger N2 and P3b amplitudes and longer P3b latencies. Source localization using standardized low-resolution brain electromagnetic tomography indicated that athletes with a history of concussion generated larger electrical current density in the left inferior parietal gyrus compared to control athletes. These findings support the hypothesis that individuals with a past concussion recruit compensatory neural resources in order to meet executive functioning demands. High-density ERP measures combined with source localization provide an important method to detect long-term neural consequences of concussion in the absence of impaired neuropsychological performance. PMID:27025905

  11. What Legislators Need to Know about Long-Term Care Insurance.

    Science.gov (United States)

    Landes, David

    This booklet discusses the potential importance to states of long-term care insurance, describes general policy characteristics, and summarizes state actions to both regulate and promote long-term care insurance. It is intended as a resource for legislators and others involved in long-term care financing and public policy formulation. Long-term…

  12. Long-term live cell imaging and automated 4D analysis of drosophila neuroblast lineages.

    Directory of Open Access Journals (Sweden)

    Catarina C F Homem

    Full Text Available The developing Drosophila brain is a well-studied model system for neurogenesis and stem cell biology. In the Drosophila central brain, around 200 neural stem cells called neuroblasts undergo repeated rounds of asymmetric cell division. These divisions typically generate a larger self-renewing neuroblast and a smaller ganglion mother cell that undergoes one terminal division to create two differentiating neurons. Although single mitotic divisions of neuroblasts can easily be imaged in real time, the lack of long term imaging procedures has limited the use of neuroblast live imaging for lineage analysis. Here we describe a method that allows live imaging of cultured Drosophila neuroblasts over multiple cell cycles for up to 24 hours. We describe a 4D image analysis protocol that can be used to extract cell cycle times and growth rates from the resulting movies in an automated manner. We use it to perform lineage analysis in type II neuroblasts where clonal analysis has indicated the presence of a transit-amplifying population that potentiates the number of neurons. Indeed, our experiments verify type II lineages and provide quantitative parameters for all cell types in those lineages. As defects in type II neuroblast lineages can result in brain tumor formation, our lineage analysis method will allow more detailed and quantitative analysis of tumorigenesis and asymmetric cell division in the Drosophila brain.

  13. Delayed behavioral dysfunctions following exposure to ionising radiation: role of neurogenesis

    International Nuclear Information System (INIS)

    Haridas, Seenu; Kumar, Mayank; Manda, Kailash

    2014-01-01

    Being a terminally differentiated organ, the brain has been considered to be a radioresistant one. Traditionally, delayed radiation-induced CNS damage was hypothesized as chiefly attributable to impaired vascular endothelial system and neuroinflammatory glial cell populations. In the recent decades, preclinical studies have focused on the hippocampal dentate gyrus, one of two discrete sites of the brain where adult neurogenesis takes place. Neurogenesis, in such area of the brain takes place throughout the adulthood and makes the brain highly vulnerable to the radiation. Recent investigations, including our own reports indicated that radiation ablates hippocampal neurogenesis, alters neuronal function, and induces neuroinflammation. Since the hippocampus is involved in learning and memory, behavioral adaptation and HPA axis regulation, damage by radiation leads to severe behavioral and cognitive dysfunctions. The present study aimed at evaluating the delayed effects of gamma-irradiation on the cognitive and affective functions, which were further corroborated to changes in neurogenesis. C57BL/6J mice were exposed to whole body irradiation as well as cranial irradiation by gamma-rays at different sub-lethal doses. The behavioral tests, consisting spontaneous motor activity, open field test, novel object recognition test, forced swim test and Morris water maze were performed at 1 month and 5 months post-exposure. Neurogenic potential was evaluated using flow-cytometry (FC) and immuno-histo-chemistry (IHC). The results indicated the significant changes in the affective and cognitive functions at delayed time points of radiation exposure. Profound alteration in the anxiety and depressive phenotype was observed following irradiation. Additionally, both long term and short term memory functions were disrupted, which were attributable to changes in the neurogenic potential as reported in the terms of BrdU positive cells using FC and IHC. Present investigation clearly

  14. The long-term benefits of director stock ownership

    Directory of Open Access Journals (Sweden)

    Brian Bolton

    2009-11-01

    Full Text Available In October 2009, the United States Treasury Department and Congress considered new regulations requiring executives and directors to receive much of their compensation in the form of long-term stock. One concern with this is that it may have negative consequences by entrenching managers and directors over the long term. This study compares the potential benefits of long-term director ownership with the potential costs of entrenchment. Using the dollar amount of stock owned by independent directors, the results suggest that the incentive effect dominates any costs related to entrenchment: firms with greater stock ownership outperform other firms, regardless of the degree of managerial entrenchment that may be present. The implication for policy-makers is that providing directors with incentives through stock ownership can be a very effective corporate governance mechanism.

  15. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    1987-04-01

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  16. Industrial Foundations as Long-Term Owners

    DEFF Research Database (Denmark)

    Thomsen, Steen; Poulsen, Thomas; Børsting, Christa Winther

    Short-termism has become a serious concern for corporate governance, and this has inspired a search for institutional arrangements to promote long-term decision-making. In this paper, we call attention to long-term ownership by industrial foundations, which is common in Northern Europe but little...... known in the rest of the world. We use a unique Danish data set to document that industrial foundations are long-term owners that practice long-term governance. We show that foundation ownership is highly stable compared to other ownership structures. Foundation-owned companies replace managers less...... frequently. They have conservative capital structures with low financial leverage. They score higher on an index of long-termism in finance, investment, and employment. They survive longer. Overall, our paper supports the hypothesis that corporate time horizons are influenced by ownership structures...

  17. Coping with PH over the Long Term

    Science.gov (United States)

    ... a job, a volunteer commitment, or even a hobby can take a toll on long-term survivors ... people find solace in meditation, faith, humor, writing, hobbies and more. Find an outlet that you enjoy ...

  18. Long term effects of radiation in man

    International Nuclear Information System (INIS)

    Tso Chih Ping; Idris Besar

    1984-01-01

    An overview of the long term effects of radiation in man is presented, categorizing into somatic effects, genetic effects and teratogenic effects, and including an indication of the problems that arise in their determination. (author)

  19. Long term liquidity analysis of the firm

    Directory of Open Access Journals (Sweden)

    Jaroslav Gonos

    2009-09-01

    Full Text Available Liquidity control is a very difficult and important function. If the business is not liquid in the long term, it is under threatof bankruptcy, and on the other hand surplus of the cash in hand threaten its future efficiency, because the cash in hand is a sourceof only limited profitability. Long term liquidity is related to the ability of the short term and long term liabilities payment. Articleis trying to point out to the monitoring and analyzing of the long term liquidity in the concrete business, in this case the printing industrycompany. Hereby at the end of the article mentioned monitored and analyzed liquidity is evaluated in the five years time period.

  20. Long Term Care Minimum Data Set (MDS)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Long-Term Care Minimum Data Set (MDS) is a standardized, primary screening and assessment tool of health status that forms the foundation of the comprehensive...

  1. Sleep facilitates long-term face adaptation

    OpenAIRE

    Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

    2013-01-01

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted imag...

  2. NMDA receptor activation and PKC but not PKA lead to the modification of the long-term potentiation in the insular cortex induced by conditioned taste aversion: differential role of kinases in metaplasticity.

    Science.gov (United States)

    Rodríguez-Durán, Luis F; Escobar, Martha L

    2014-06-01

    It has been reported that training in behavioral tasks modifies the ability to induce long-term potentiation (LTP) in an N-methyl-D-aspartate receptor (NMDAR)-dependent manner. This receptor leads to calcium entry into neuronal cells, promoting the activation of protein kinases as protein kinase A (PKA) and protein kinase C (PKC), which contribute significantly to the formation of different types of memories and play a pivotal role in the expression of LTP. Our previous studies involving the insular cortex (IC) have demonstrated that induction of LTP in the basolateral amygdaloid nucleus (BLA)-IC projection prior to conditioned taste aversion (CTA) training enhances the retention of this task. Recently, we showed that CTA training triggers a persistent impairment in the ability to induce subsequent synaptic plasticity on the BLA-IC pathway in a protein synthesis-dependent manner, but the underlying molecular mechanisms remain unclear. In the present study we investigated whether the blockade of NMDAR, as well as the inhibition of PKC and PKA affects the CTA-dependent impairment of the IC-LTP. Thus, CTA-trained rats received high frequency stimulation in the Bla-IC projection in order to induce LTP 48 h after the aversion test. The NMDAR antagonist CPP and the specific inhibitors for PKC (chelerythrine) and PKA (KT-5720) were intracortically administered during the acquisition session. Our results show that the blockade of NMDAR and the inhibition of PKC activity prevent the CTA memory-formation as well as the IC-LTP impairment. Nevertheless, PKA inhibition prevents the memory formation of taste aversion but produces no interference with the CTA-dependent impairment of the IC-LTP. These findings reveal the differential roles of protein kinases on CTA-dependent modification of IC-LTP enhancing our understanding of the effects of memory-related changes on synaptic function. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The effect of chronic stimulation of serotonin receptor type 7 on recognition, passive avoidance memory, hippocampal long-term potentiation, and neuronal apoptosis in the amyloid β protein treated rat.

    Science.gov (United States)

    Shahidi, Siamak; Asl, Sara Soleimani; Komaki, Alireza; Hashemi-Firouzi, Nasrin

    2018-05-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory impairment, neuronal death, and synaptic loss in the hippocampus. Long-term potentiation (LTP), a type of synaptic plasticity, occurs during learning and memory. Serotonin receptor type 7 (5-HTR7) activation is suggested as a possible therapeutic target for AD. The aim of the present study was to examine the effects of chronic treatment with the 5-HTR7 agonist, AS19, on cognitive function, memory, hippocampal plasticity, amyloid beta (Aβ) plaque accumulation, and apoptosis in an adult rat model of AD. AD was induced in rats using Aβ (single 1 μg/μL intracerebroventricular (icv) injection during surgery). The following experimental groups were included: control, sham-operated, Aβ + saline (1 μL icv for 30 days), and Aβ + AS19 (1 μg/μL icv for 30 days) groups. The animals were tested for cognition and memory performance using the novel object recognition and passive avoidance tests, respectively. Next, anesthetized rats were placed in a stereotaxic apparatus for electrode implantation, and field potentials were recorded in the hippocampal dentate gyrus. Lastly, brains were removed and Aβ plaques and neuronal apoptosis were evaluated using Congo red staining and TUNEL assay, respectively. Administration of AS19 in the Aβ rats increased the discrimination index of the novel object recognition test. Furthermore, AS19 treatment decreased time spent in the dark compartment during the passive avoidance test. AS19 also enhanced both the population spike (PS) amplitude and the field excitatory postsynaptic potential (fEPSP) slope evoked potentials of the LTP components. Aβ plaques and neuronal apoptosis were decreased in the AS19-treated Aβ rats. These results indicate that chronic treatment with a 5-HTR7 agonist can prevent Aβ-related impairments in cognition and memory performance by alleviating Aβ plaque accumulation and neuronal apoptosis, hence improving neuronal

  4. Linking adult olfactory neurogenesis to social behavior

    Directory of Open Access Journals (Sweden)

    Claudia E Feierstein

    2012-11-01

    Full Text Available In the adult brain, new neurons are added to two brain areas: the olfactory bulb and the hippocampus. Newly-generated neurons integrate into the preexisting circuits, bringing a set of unique properties, such as increased plasticity and responsiveness to stimuli. However, the functional implications of the constant addition of these neurons remain unclear, although they are believed to be important for learning and memory. The levels of neurogenesis are regulated by a variety of environmental factors, as well as during learning, suggesting that new neurons could be important for coping with changing environmental demands. Notably, neurogenesis has been shown to be physiologically regulated in relation to reproductive behavior: neurogenesis increases in female mice upon exposure to cues of the mating partners, during pregnancy and lactation, and in male mice upon exposure to their offspring. In this scenario, and because of the key contribution of olfaction to maternal behavior, we sought to investigate the contribution of adult-generated neurons in the olfactory system to maternal behavior and offspring recognition. To do so, we selectively disrupted neurogenesis in the olfactory pathway of female mice using focal irradiation. Disruption of adult neurogenesis in the olfactory bulb did not affect maternal behavior, or the ability of female mice to discriminate familiar from unfamiliar pups. However, reduction of olfactory neurogenesis resulted in abnormal social interaction of female mice, specifically with male conspecifics. Because the olfactory system is crucial for sex recognition, we suggest that the abnormal interaction with males could result from the inability to detect or discriminate male-specific odors and could therefore have implications for the recognition of potential mating partners. Here, I review the results of this and other studies, and discuss their implications for our understanding of the function of adult neurogenesis.

  5. Transuranic waste: long-term planning

    International Nuclear Information System (INIS)

    Young, K.C.

    1985-07-01

    Societal concerns for the safe handling and disposal of toxic waste are behind many of the regulations and the control measures in effect today. Transuranic waste, a specific category of toxic (radioactive) waste, serves as a good example of how regulations and controls impact changes in waste processing - and vice versa. As problems would arise with waste processing, changes would be instituted. These changes improved techniques for handling and disposal of transuranic waste, reduced the risk of breached containment, and were usually linked with regulatory changes. Today, however, we face a greater public awareness of and concern for toxic waste control; thus, we must anticipate potential problems and work on resolving them before they can become real problems. System safety analyses are valuable aids in long-term planning for operations involving transuranic as well as other toxic materials. Examples of specific system safety analytical methods demonstrate how problems can be anticipated and resolution initiated in a timely manner having minimal impacts upon allocation of resource and operational goals. 7 refs., 1 fig

  6. Risk assessment for long-term post-accident sequences

    International Nuclear Information System (INIS)

    Ellia-Hervy, A.; Ducamp, F.

    1987-11-01

    Probabilistic risk analysis, currently conducted by the CEA (French Atomic Energy Commission) for the French replicate series of 900 MWe power plants, has identified accident sequences requiring long-term operation of some systems after the initiating event. They have been named long-term sequences. Quantification of probabilities of such sequences cannot rely exclusively on equipment failure-on-demand data: it must also take into account operating failures, the probability of which increase with time. Specific studies have therefore been conducted for a number of plant systems actuated during these long-term sequences. This has required: - Definition of the most realistic equipment utilization strategies based on existing emergency procedures for 900 MWe French plants. - Evaluation of the potential to repair failed equipment, given accessibility, repair time, and specific radiation conditions for the given sequence. - Definition of the event bringing the long-term sequence to an end. - Establishment of an appropriate quantification method, capable of taking into account the evolution of assumptions concerning equipment utilization strategies or repair conditions over time. The accident sequence quantification method based on realistic scenarios has been used in the risk assessment of the initiating event loss of reactor coolant accident occurring at power and at shutdown. Compared with the results obtained from conventional methods, this method redistributes the relative weight of accident sequences and also demonstrates that the long term can be a significant contribution to the probability of core melt

  7. Long-term Morbidity of Testicular Cancer Treatment.

    Science.gov (United States)

    Fung, Chunkit; Fossa, Sophie D; Williams, Annalynn; Travis, Lois B

    2015-08-01

    Second malignant neoplasms, cardiovascular disease, neurotoxicity and ototoxicity, pulmonary complications, hypogonadism, and nephrotoxicity are potentially life-threatening long-term complications of testicular cancer and its therapy. This article describes the pathogenesis, risks, and management of these late effects experienced by long-term testicular cancer survivors, who are defined as individuals who are disease free 5 years or more after primary treatment. Testicular cancer survivors should follow applicable national guidelines for cancer screening and management of cardiovascular disease risk factors. In addition, health care providers should capitalize on the time of cancer diagnosis as a teachable moment to introduce and promote lifestyle changes. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Very long-term sequelae of craniopharyngioma.

    Science.gov (United States)

    Wijnen, Mark; van den Heuvel-Eibrink, Marry M; Janssen, Joseph A M J L; Catsman-Berrevoets, Coriene E; Michiels, Erna M C; van Veelen-Vincent, Marie-Lise C; Dallenga, Alof H G; van den Berge, J Herbert; van Rij, Carolien M; van der Lely, Aart-Jan; Neggers, Sebastian J C M M

    2017-06-01

    Studies investigating long-term health conditions in patients with craniopharyngioma are limited by short follow-up durations and generally do not compare long-term health effects according to initial craniopharyngioma treatment approach. In addition, studies comparing long-term health conditions between patients with childhood- and adult-onset craniopharyngioma report conflicting results. The objective of this study was to analyse a full spectrum of long-term health effects in patients with craniopharyngioma according to initial treatment approach and age group at craniopharyngioma presentation. Cross-sectional study based on retrospective data. We studied a single-centre cohort of 128 patients with craniopharyngioma treated from 1980 onwards (63 patients with childhood-onset disease). Median follow-up since craniopharyngioma presentation was 13 years (interquartile range: 5-23 years). Initial craniopharyngioma treatment approaches included gross total resection ( n  = 25), subtotal resection without radiotherapy ( n  = 44), subtotal resection with radiotherapy ( n  = 25), cyst aspiration without radiotherapy ( n  = 8), and 90 Yttrium brachytherapy ( n  = 21). Pituitary hormone deficiencies (98%), visual disturbances (75%) and obesity (56%) were the most common long-term health conditions observed. Different initial craniopharyngioma treatment approaches resulted in similar long-term health effects. Patients with childhood-onset craniopharyngioma experienced significantly more growth hormone deficiency, diabetes insipidus, panhypopituitarism, morbid obesity, epilepsy and psychiatric conditions compared with patients with adult-onset disease. Recurrence-/progression-free survival was significantly lower after initial craniopharyngioma treatment with cyst aspiration compared with other therapeutic approaches. Survival was similar between patients with childhood- and adult-onset craniopharyngioma. Long-term health conditions were comparable after

  9. Acute mastoiditis in children: presentation and long term consequences.

    LENUS (Irish Health Repository)

    Glynn, F

    2008-03-01

    Acute mastoiditis, a destructive bacterial infection of the mastoid bone and air cell system, is relatively uncommon today but remains a potentially serious condition. There is a lack of information in the literature regarding the long term otological problems that children may face following an episode of this condition.

  10. Long term results of kissing stents in the aortic bifurcation

    NARCIS (Netherlands)

    Hinnen, J.W.; Konickx, M.A.; Meerwaldt, Robbert; Kolkert, J.L.P.; van der Palen, Jacobus Adrianus Maria; Huisman, A.B.

    2015-01-01

    BACKGROUND: To evaluate the long-term outcome after aortoiliac kissing stent placement and to analyze variables, which potentially influence the outcome of endovascular reconstruction of the aortic bifurcation. METHODS: All patients treated with aortoiliac kissing stents at our institution between

  11. Long-Term Soil Chemistry Changes in Aggrading Forest Ecosystems

    Science.gov (United States)

    Jennifer D. Knoepp; Wayne T. Swank

    1994-01-01

    Assessing potential long-term forest productivity requires identification of the processes regulating chemical changes in forest soils. We resampled the litter layer and upper two mineral soil horizons, A and AB/BA, in two aggrading southern Appalachian watersheds 20 yr after an earlier sampling. Soils from a mixed-hardwood watershed exhibited a small but significant...

  12. Going Solar Yields Long-Term Economical, Educational Benefits

    Science.gov (United States)

    von Moos, Brian

    2009-01-01

    Going solar is not an easy decision, but a long-term investment with a potentially substantial up-front cost. While some schools have enough capital in reserve, can raise bond money, or can solicit sufficient donations, many schools rely on creative financial programs to make a solar energy system economically feasible. Thinking about going solar…

  13. Long-term prisoner in prison isolation

    Directory of Open Access Journals (Sweden)

    Karolina Grudzińska

    2013-06-01

    Full Text Available Long-term prisoner belongs to a particular category of people who are imprisoned in prisons. On the one hand in this group are often heavily demoralized people who committed the most serious crimes, on the other hand it is a group of prisoners, who should be well thought out and programmed the impact of rehabilitation. The situation of man trapped for years poses in a complicated situation not only the prisoners, but also the entire prison staff. They have to take care of the fact that the prison isolation did not cause the state in which convicts form itself in learned helplessness and lack of skills for self-planning and decision-making. In addition, planning the rehabilitation impact of long-term prisoners should not be forgotten that these prisoners in the short or the long term will return to the libertarian environment therefore, should prevent any negative effects of long-term imprisonment. This article presents the main issues related to the execution of imprisonment against long-term prisoners. It is an attempt to systematize the knowledge of this category of people living in prison isolation.

  14. Long-term follow-up study and long-term care of childhood cancer survivors

    Directory of Open Access Journals (Sweden)

    Hyeon Jin Park

    2010-04-01

    Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

  15. Long-Term Prognosis of Plantar Fasciitis

    DEFF Research Database (Denmark)

    Hansen, Liselotte; Krogh, Thøger Persson; Ellingsen, Torkell

    2018-01-01

    , exercise-induced symptoms, bilateral heel pain, fascia thickness, and presence of a heel spur) could predict long-term outcomes, (3) to assess the long-term ultrasound (US) development in the fascia, and (4) to assess whether US-guided corticosteroid injections induce atrophy of the heel fat pad. Study....... The risk was significantly greater for women (P heel...... regardless of symptoms and had no impact on prognosis, and neither did the presence of a heel spur. Only 24% of asymptomatic patients had a normal fascia on US at long-term follow-up. A US-guided corticosteroid injection did not cause atrophy of the heel fat pad. Our observational study did not allow us...

  16. Long-term dependence in exchange rates

    Directory of Open Access Journals (Sweden)

    A. Karytinos

    2000-01-01

    Full Text Available The extent to which exchange rates of four major currencies against the Greek Drachma exhibit long-term dependence is investigated using a R/S analysis testing framework. We show that both classic R/S analysis and the modified R/S statistic if enhanced by bootstrapping techniques can be proven very reliable tools to this end. Our findings support persistence and long-term dependence with non-periodic cycles for the Deutsche Mark and the French Franc series. In addition a noisy chaos explanation is favored over fractional Brownian motion. On the contrary, the US Dollar and British Pound were found to exhibit a much more random behavior and lack of any long-term structure.

  17. Long term planning for wind energy development

    International Nuclear Information System (INIS)

    Trinick, M.

    1995-01-01

    In a planning system intended to be governed primarily by policies in statutory plans a reasonable horizon for long term planning is 10 years or longer. Because of statutory requirements, developers have no option but to pay due regard to, and take a full part in, long term planning. The paper examines the type of policies which have emerged in the last few years to cater for wind energy development. It canvasses the merits of different types of policies. Finally, it discusses the policy framework which may emerge to cater for development outside NFFO. (Author)

  18. Long-term characteristics of nuclear emulsion

    International Nuclear Information System (INIS)

    Naganawa, N; Kuwabara, K

    2010-01-01

    Long-term characteristics of the nuclear emulsion so called 'OPERA film' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

  19. Long-term characteristics of nuclear emulsion

    Science.gov (United States)

    Naganawa, N.; Kuwabara, K.

    2010-02-01

    Long-term characteristics of the nuclear emulsion so called ``OPERA film'' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

  20. Long-term home care scheduling

    DEFF Research Database (Denmark)

    Gamst, Mette; Jensen, Thomas Sejr

    In several countries, home care is provided for certain citizens living at home. The long-term home care scheduling problem is to generate work plans spanning several days such that a high quality of service is maintained and the overall cost is kept as low as possible. A solution to the problem...... provides detailed information on visits and visit times for each employee on each of the covered days. We propose a branch-and-price algorithm for the long-term home care scheduling problem. The pricing problem generates one-day plans for an employee, and the master problem merges the plans with respect...

  1. Sex-Dependent and Independent Effects of Long-Term Voluntary Wheel Running on Bdnf mRNA and Protein Expression

    OpenAIRE

    Venezia, Andrew C.; Guth, Lisa M.; Sapp, Ryan M.; Spangenburg, Espen E.; Roth, Stephen M.

    2016-01-01

    The beneficial effects of physical activity on brain health (synaptogenesis, neurogenesis, enhanced synaptic plasticity, improved learning and memory) appear to be mediated through changes in region-specific expression of neurotrophins, transcription factors, and postsynaptic receptors, though investigations of sex differences in response to long-term voluntary wheel running are limited.

  2. Experiences of long-term tranquillizer use

    DEFF Research Database (Denmark)

    Skinhoj, K T; Larsson, S; Helweg-Joergensen, S

    2001-01-01

    , the psychodynamic perspective is integrated within a multi-dimensional model that considers biological, cognitive, identity, gender and social learning factors. The analysis reveals the possibility of achieving a detailed understanding of the dynamic processes involved in the development of long-term tranquillizer...

  3. Long-Term Orientation in Trade

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, D.

    2008-01-01

    Trust does not work in the same way across cultures. This paper presents an agent model of behavior in trade across Hofstedes cultural dimension of long-term vs. short-term orientation. The situation is based on a gaming simulation, the Trust and Tracing game. The paper investigates the

  4. Safety of long-term PPI therapy

    DEFF Research Database (Denmark)

    Reimer, Christina

    2013-01-01

    Proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. Long-term use is becoming increasingly common, in some cases without a proper indication. A large number of mainly observational studies on a very wide range of possible associations have been publishe...... to a careful evaluation of the indication for PPI treatment....

  5. Long term consequences of early childhood malnutrition

    NARCIS (Netherlands)

    Kinsey, B.H.; Hoddinott, J; Alderman, H.

    2006-01-01

    This paper examines the impact of pre-school malnutrition on subsequent human capital formation in rural Zimbabwe using a maternal fixed effects - instrumental variables (MFE-IV) estimator with a long term panel data set. Representations of civil war and drought shocks are used to identify

  6. Financial Incentives in Long-Term Care

    NARCIS (Netherlands)

    P.L.H. Bakx (Pieter)

    2015-01-01

    markdownabstract__Abstract__ Long-term care (ltc) aims to help individuals to cope with their impairments. In my thesis, I describe ltc financing alternatives and their consequences for the allocation of ltc. This thesis consists of two parts. In the first part, I investigate how alternative ways

  7. Long-term outcomes of patellofemoral arthroplasty.

    NARCIS (Netherlands)

    Jonbergen, J.P.W. van; Werkman, D.M.; Barnaart, L.F.; Kampen, A. van

    2010-01-01

    The purpose of this study was to correlate the long-term survival of patellofemoral arthroplasty with primary diagnosis, age, sex, and body mass index. One hundred eighty-five consecutive Richards type II patellofemoral arthroplasties were performed in 161 patients with isolated patellofemoral

  8. Long-Term Memory and Learning

    Science.gov (United States)

    Crossland, John

    2011-01-01

    The English National Curriculum Programmes of Study emphasise the importance of knowledge, understanding and skills, and teachers are well versed in structuring learning in those terms. Research outcomes into how long-term memory is stored and retrieved provide support for structuring learning in this way. Four further messages are added to the…

  9. The 2013 Long-Term Budget Outlook

    Science.gov (United States)

    2013-09-01

    number of years, leading to substantial additional federal spending. For example, the nation could experience a massive earthquake, a nuclear meltdown...budget surpluses remaining after paying down publicly held debt available for redemption . a. For comparison with the current long-term projections, CBO

  10. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

    Kaul, Alexander; Burkart, Werner; Grosche, Bernd; Jung, Thomas; Martignoni, Klaus; Stephan, Guenther

    1997-01-01

    This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

  11. Pituitary diseases : long-term psychological consequences

    NARCIS (Netherlands)

    Tiemensma, Jitske

    2012-01-01

    Nowadays, pituitary adenomas can be appropriately treated, but patients continue to report impaired quality of life (QoL) despite long-term remission or cure. In patients with Cushing’s disease, Cushing’s syndrome or acromegaly, doctors should be aware of subtle cognitive impairments and the

  12. The long term stability of lidar calibrations

    DEFF Research Database (Denmark)

    Courtney, Michael; Gayle Nygaard, Nicolai

    Wind lidars are now used extensively for wind resource measurements. One of the requirements for the data to be accepted in support of project financing (so-called ‘banka-bility’) is to demonstrate the long-term stability of lidar cali-brations. Calibration results for six Leosphere WindCube li...

  13. Rebalancing for Long-Term Investors

    NARCIS (Netherlands)

    Driessen, Joost; Kuiper, Ivo

    2017-01-01

    In this study we show that the rebalance frequency of a multi-asset portfolio has only limited impact on the utility of a long-term passive investor. Although continuous rebalancing is optimal, the loss of a suboptimal strategy corresponds to up to only 30 basis points of the initial wealth of the

  14. Simulation of a Potential CO2 Storage in the West Paris Basin: Site Characterization and Assessment of the Long-Term Hydrodynamical and Geochemical Impacts Induced by the CO2 Injection

    Directory of Open Access Journals (Sweden)

    Estublier Audrey

    2017-07-01

    Full Text Available This article presents the preliminary results of a study carried out as part of a demonstration project of CO2 storage in the Paris Basin. This project funded by ADEME (French Environment and Energy Management Agency and several industrial partners (TOTAL, ENGIE, EDF, Lafarge, Air Liquide, Vallourec aimed to study the possibility to set up an experimental infrastructure of CO2 transport and storage. Regarding the storage, the objectives were: (1 to characterize the selected site by optimizing the number of wells in a CO2 injection case of 200 Mt over 50 years in the Trias, (2 to simulate over time the CO2 migration and the induced pressure field, and (3 to analyze the geochemical behavior of the rock over the long term (1,000 years. The preliminary site characterization study revealed that only the southern area of Keuper succeeds to satisfy this injection criterion using only four injectors. However, a complementary study based on a refined fluid flow model with additional secondary faults concluded that this zone presents the highest potential of CO2 injection but without reaching the objective of 200 Mt with a reasonable number of wells. The simulation of the base scenario, carried out before the model refinement, showed that the overpressure above 0.1 MPa covers an area of 51,869 km2 in the Chaunoy formation, 1,000 years after the end of the injection, which corresponds to the whole West Paris Basin, whereas the CO2 plume extension remains small (524 km2. This overpressure causes brine flows at the domain boundaries and a local overpressure in the studied oil fields. Regarding the preliminary risk analysis of this project, the geochemical effects induced by the CO2 injection were studied by simulating the fluid-rock interactions with a coupled geochemical and fluid flow model in a domain limited to the storage complex. A one-way coupling of two models based on two domains fitting into each other was developed using dynamic boundary

  15. Long-term selenium status in humans

    International Nuclear Information System (INIS)

    Baskett, C.K.; Spate, V.L.; Mason, M.M.; Nichols, T.A.; Williams, A.; Dubman, I.M.; Gudino, A.; Denison, J.; Morris, J.S.

    2001-01-01

    The association of sub-optimal selenium status with increased risk factors for some cancers has been reported in two recent epidemiological studies. In both studies the same threshold in selenium status was observed, below which, cancer incidence increased. To assess the use of nails as a biologic monitor to measure the long-term selenium status, an eight-year longitudinal study was undertaken with a group of 11 adult subjects, 5 women and 6 men. Selenium has been measured by instrumental neutron activation analysis. Differences between fingernails and toenails with be discussed. In addition, the results will be discussed in the context of the long-term stability of the nail monitor to measure selenium status during those periods when selenium determinants are static; and the changes that occur as a result of selenium supplementation. (author)

  16. Influenza in long-term care facilities.

    Science.gov (United States)

    Lansbury, Louise E; Brown, Caroline S; Nguyen-Van-Tam, Jonathan S

    2017-09-01

    Long-term care facility environments and the vulnerability of their residents provide a setting conducive to the rapid spread of influenza virus and other respiratory pathogens. Infections may be introduced by staff, visitors or new or transferred residents, and outbreaks of influenza in such settings can have devastating consequences for individuals, as well as placing extra strain on health services. As the population ages over the coming decades, increased provision of such facilities seems likely. The need for robust infection prevention and control practices will therefore remain of paramount importance if the impact of outbreaks is to be minimised. In this review, we discuss the nature of the problem of influenza in long-term care facilities, and approaches to preventive and control measures, including vaccination of residents and staff, and the use of antiviral drugs for treatment and prophylaxis, based on currently available evidence. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  17. Long-Term Ownership by Industrial Foundations

    DEFF Research Database (Denmark)

    Børsting, Christa Winther; Kuhn, Johan Moritz; Poulsen, Thomas

    2016-01-01

    in Denmark. Industrial foundations are independent legal entities without owners or members typically with the dual objective of preserving the company and using excess profits for charity. We use a unique Danish data set to examine the governance of foundation-owned companies. We show that they are long......-term in several respects. Foundations hold on to their shares for longer. Foundation-owned companies replace managers less frequently. They have more conservative capital structures with less leverage. Their companies survive longer. Their business decisions appear to be more long term. This paper supports...... the hypothesis that time horizons are influenced by ownership structures and particularly that industrial foundations promote longtermism. Policymakers which are interested in promoting longtermism should allow and perhaps even encourage the creation of industrial foundations. More generally they should consider...

  18. Analysis of long-term energy scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Lemming, J.; Morthorst, P.E.

    1998-09-01

    When addressing the role of fusion energy in the 21. century, the evaluation of possible future structures in the electricity market and the energy sector as a whole, can be a useful tool. Because fusion energy still needs demonstration, commercialized fusion energy is not likely to be a reality within the next few decades. Therefore long-term scenarios are needed describing the energy markets, which fusion energy eventually will be part of. This report performs an analysis of two of the most detailed existing long-term scenarios describing possible futures of the energy system. The aim is to clarify the frames in which the future development of the global energy demand, as well as the structure of the energy system can be expected to develop towards the year 2100. (au) 19 refs.

  19. Long-term effects of radiation

    International Nuclear Information System (INIS)

    Smith, J.; Smith, T.

    1981-01-01

    It is pointed out that sources of long-term damage from radiation are two-fold. People who have been exposed to doses of radiation from initial early fallout but have recovered from the acute effects may still suffer long-term damage from their exposure. Those who have not been exposed to early fallout may be exposed to delayed fallout, the hazards from which are almost exclusively from ingesting strontium, caesium and carbon isotopes present in food; the damage caused is relatively unimportant compared with that caused by the brief doses from initial radiation and early fallout. A brief discussion is presented of the distribution of delayed long-lived isotope fallout, and an outline is sketched of late biological effects, such as malignant disease, cataracts, retarded development, infertility and genetic effects. (U.K.)

  20. Long-term sealing of openings in salt formations

    International Nuclear Information System (INIS)

    Walter, F.; Stockmann, N.; Yaramanci, U.; Laurens, J.F.

    1993-01-01

    Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in those potential pathways to prevent radioactive release to the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made of compressed salt-powder are understood to be the first choice long-term sealing material. Seals built from salt bricks will be ductile. The permeability of the salt bricks is assumed to be in the order of 2*10 -15 m 2 . Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. The permeability of the mortar decreases with its salt content to approx. 2*10 -14 m 2 . Moistened saliferous clay may show temporary swelling. Sealing experiments will be carried out in the Asse salt mine. Long-term seals will be built into holes of 1 m diameter. The contact and merging of the brick-wall with the surrounding rock salt will be investigated in long-term tests. Within the in situ sealing program a number of geophysical methods are applied. Acoustic emission measurements are used to study the effects of high pressure gas injection and a geoelectrical observation program is aiming to estimate the permeability in and around the long-term seal. High frequency electromagnetic methods contribute to the knowledge of the petrophysical rock properties. 11 refs., 12 figs

  1. Long term economic relationships from cointegration maps

    Science.gov (United States)

    Vicente, Renato; Pereira, Carlos de B.; Leite, Vitor B. P.; Caticha, Nestor

    2007-07-01

    We employ the Bayesian framework to define a cointegration measure aimed to represent long term relationships between time series. For visualization of these relationships we introduce a dissimilarity matrix and a map based on the sorting points into neighborhoods (SPIN) technique, which has been previously used to analyze large data sets from DNA arrays. We exemplify the technique in three data sets: US interest rates (USIR), monthly inflation rates and gross domestic product (GDP) growth rates.

  2. Murine model of long term obstructive jaundice

    Science.gov (United States)

    Aoki, Hiroaki; Aoki, Masayo; Yang, Jing; Katsuta, Eriko; Mukhopadhyay, Partha; Ramanathan, Rajesh; Woelfel, Ingrid A.; Wang, Xuan; Spiegel, Sarah; Zhou, Huiping; Takabe, Kazuaki

    2016-01-01

    Background With the recent emergence of conjugated bile acids as signaling molecules in cancer, a murine model of obstructive jaundice by cholestasis with long-term survival is in need. Here, we investigated the characteristics of 3 murine models of obstructive jaundice. Methods C57BL/6J mice were used for total ligation of the common bile duct (tCL), partial common bile duct ligation (pCL), and ligation of left and median hepatic bile duct with gallbladder removal (LMHL) models. Survival was assessed by Kaplan-Meier method. Fibrotic change was determined by Masson-Trichrome staining and Collagen expression. Results 70% (7/10) of tCL mice died by Day 7, whereas majority 67% (10/15) of pCL mice survived with loss of jaundice. 19% (3/16) of LMHL mice died; however, jaundice continued beyond Day 14, with survival of more than a month. Compensatory enlargement of the right lobe was observed in both pCL and LMHL models. The pCL model demonstrated acute inflammation due to obstructive jaundice 3 days after ligation but jaundice rapidly decreased by Day 7. The LHML group developed portal hypertension as well as severe fibrosis by Day 14 in addition to prolonged jaundice. Conclusion The standard tCL model is too unstable with high mortality for long-term studies. pCL may be an appropriate model for acute inflammation with obstructive jaundice but long term survivors are no longer jaundiced. The LHML model was identified to be the most feasible model to study the effect of long-term obstructive jaundice. PMID:27916350

  3. Long-term course of opioid addiction.

    Science.gov (United States)

    Hser, Yih-Ing; Evans, Elizabeth; Grella, Christine; Ling, Walter; Anglin, Douglas

    2015-01-01

    Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed.

  4. Long-term economic outlook. Annual review

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    This review provides economic growth forecast tables for Ontario, Canada, the US, Western Europe, and Japan. Economic growth, government policy, the long-term prospects for inflation, interest rates and foreign exchange rates, trends in the Canadian dollar, and energy markets and prices are also reviewed. Data generally cover 1965-2025. Appendices give a summary of historical and forecast data. 18 figs., 16 tabs.

  5. Long-term data storage in diamond

    OpenAIRE

    Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A.

    2016-01-01

    The negatively charged nitrogen vacancy (NV?) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV? optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multic...

  6. French Approach for Long Term Storage Safety

    International Nuclear Information System (INIS)

    Marciano, Jacob; Carreton, Jean-Pierre; Lizot, Marie Therese; Lhomme, Veronique

    2014-01-01

    IRSN presents its statement regarding long-term storage facilities; in France, the regulatory documents do not define the long term duration. The storage facility lifetime can only be appreciated according to the needs and materials stored therein. However, the magnitude of the long-term can be estimated at a few hundred years compared to a few decades for current storage. Usually, in France, construction of storage facilities is driven from the necessity various necessities, linked to the management of radioactive material (eg spent fuel) and to the management of radioactive waste. Because of the variety of 'stored materials and objects' (fission product solutions, plutonium oxide powders, activated solids, drums containing technological waste, spent fuel...), a great number of storage facility design solutions have been developed (surface, subsurface areas, dry or wet conditions...) in the World. After describing the main functions of a storage facility, IRSN displays the safety principles and the associated design principles. The specific design principles applied to particular storage (dry or wet spent fuel storage, depleted uranium or reprocessed uranium storage, plutonium storage, waste containing tritium storage, HLW and ILLW storage...) are also presented. Finally, the concerns due to the long-term duration storage and related safety assessment are developed. After discussing these issues, IRSN displays its statement. The authorization procedures governing the facility lifetime are similar to those of any basic nuclear installation, the continuation of the facility operation remaining subject to periodic safety reviews (in France, every 10 years). The applicant safety cases have to show, that the safety requirements are always met; this requires, at minimum, to take into account at the design stage, comfortable design margins. (author)

  7. Accounting of Long-Term Biological Assets

    OpenAIRE

    Valeriy Mossakovskyy; Vasyl Korytnyy

    2015-01-01

    The article is devoted to generalization of experience in valuation of long-term biological assets of plant-growing and animal-breeding, and preparation of suggestions concerning improvement of accounting in this field. Recommendations concerning accounting of such assets are given based on the study of accounting practice at specific agricultural company during long period of time. Authors believe that fair value is applicable only if price level for agricultural products is fixed by the gov...

  8. Optimal long-term contracting with learning

    OpenAIRE

    He, Zhiguo; Wei, Bin; Yu, Jianfeng; Gao, Feng

    2016-01-01

    We introduce uncertainty into Holmstrom and Milgrom (1987) to study optimal long-term contracting with learning. In a dynamic relationship, the agent's shirking not only reduces current performance but also increases the agent's information rent due to the persistent belief manipulation effect. We characterize the optimal contract using the dynamic programming technique in which information rent is the unique state variable. In the optimal contract, the optimal effort is front-loaded and decr...

  9. Timber joints under long-term loading

    DEFF Research Database (Denmark)

    Feldborg, T.; Johansen, M.

    This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were...... integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering....

  10. Inflation Hedging for Long-Term Investors

    OpenAIRE

    Shaun K. Roache; Alexander P. Attie

    2009-01-01

    Long-term investors face a common problem-how to maintain the purchasing power of their assets over time and achieve a level of real returns consistent with their investment objectives. While inflation-linked bonds and derivatives have been developed to hedge the effects of inflation, their limited supply and liquidity lead many investors to continue to rely on the indirect hedging properties of traditional asset classes. In this paper, we assess these properties over different time horizons,...

  11. Long term evolution 4G and beyond

    CERN Document Server

    Yacoub, Michel; Figueiredo, Fabrício; Tronco, Tania

    2016-01-01

    This book focus on Long Term Evolution (LTE) and beyond. The chapters describe different aspects of research and development in LTE, LTE-Advanced (4G systems) and LTE-450 MHz such as telecommunications regulatory framework, voice over LTE, link adaptation, power control, interference mitigation mechanisms, performance evaluation for different types of antennas, cognitive mesh network, integration of LTE network and satellite, test environment, power amplifiers and so on. It is useful for researchers in the field of mobile communications.

  12. Long-Term Care Services for Veterans

    Science.gov (United States)

    2017-02-14

    includes but is not limited to home physical , occupational, or speech therapy ; wound care; and intravenous (IV) care. A VA physician determines that a...restoring/rehabilitating the veteran’s health, such as skilled nursing care, physical therapy , occupational therapy , and IV therapy Same as HBPC... geriatric evaluation,  palliative care,  adult day health care,  homemaker/home health aide care,  respite care, Long-Term Care Services for

  13. Waste transmutation with minimal fuel cycle long-term risk

    Energy Technology Data Exchange (ETDEWEB)

    Slessarev, I.; Salvatores, M.; Uematsu, M. [Direction des Reacteurs Nucleaires, Cadarache (France)

    1995-10-01

    Hybrid systems (source-driven subcritical reactors), are investigated at CEA, mainly from a conceptual point of view, in order to assess their potential to transmute radioactive wastes (mainly long-lived fission products, LLFP) and their potential to insure a minimal long-term radiological risk related both to the fuel inventory inside the system and to the full fuel cycle (mass flows, reprocessing transport, waste disposal). The physics of these systems has been explored and work is in progress both in the field of basic data and INC code validation, in the frame of international collaborations and in the field of conceptual design studies. The most interesting feature of subcritical source-driven system is related to the possibility to obtain an {open_quotes}excess{close_quotes} of neutrons per fission, which can be used to reduce the long-term radiological risk. A specific example will be discussed here.

  14. Sexuality and Physical Intimacy in Long Term Care: Sexuality, long term care, capacity assessment

    OpenAIRE

    Lichtenberg, Peter A.

    2014-01-01

    Sexuality and sexual needs in older adults remains a neglected area of clinical intervention, particularly so in long term care settings. Because older adults in medical rehabilitation and long term care beds present with significant frailties, and often significant neurocognitive disorders it makes it difficult for occupational therapists and other staff to evaluate the capacity of an older adult resident to participate in sexual relationships. The current paper reviews the current literatur...

  15. Sex steroids and neurogenesis.

    Science.gov (United States)

    Heberden, Christine

    2017-10-01

    The brain has long been known as a dimorphic organ and as a target of sex steroids. It is also a site for their synthesis. Sex steroids in numerous ways can modify cerebral physiology, and along with many processes adult neurogenesis is also modulated by sex steroids. This review will focus on the effects of the main steroids, estrogens, androgens and progestogens, and unveil some aspects of their partly disclosed mechanisms of actions. Gonadal steroids act on different steps of neurogenesis: cell proliferation seems to be increased by estrogens only, while androgens and progestogens favor neuronal renewal by increasing cell survival; differentiation is a common target. Aging is characterized by a cognitive deficiency, paralleled by a decrease in the rate of neuronal renewal and in the levels of circulating gonadal hormones. Therefore, the effects of gonadal hormones on the aging brain are important to consider. The review will also be expanded to related molecules which are agonists to the nuclear receptors. Sex steroids can modify adult neuronal renewal and the extensive knowledge of their actions on neurogenesis is essential, as it can be a leading pathway to therapeutic perspectives. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Late Protein Synthesis-Dependent Phases in CTA Long-Term Memory: BDNF Requirement

    OpenAIRE

    Martínez-Moreno, Araceli; Rodríguez-Durán, Luis F.; Escobar, Martha L.

    2011-01-01

    It has been proposed that long-term memory persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related long-term memo...

  17. Health economic potential of early nutrition programming: a model calculation of long-term reduction in blood pressure and related morbidity costs by use of long-chain polyunsaturated fatty acid-supplemented formula.

    Science.gov (United States)

    Straub, Niels; Grunert, Philipp; von Kries, Rüdiger; Koletzko, Berthold

    2011-12-01

    The reported effect sizes of early nutrition programming on long-term health outcomes are often small, and it has been questioned whether early interventions would be worthwhile in enhancing public health. We explored the possible health economic consequences of early nutrition programming by performing a model calculation, based on the only published study currently available for analysis, to evaluate the effects of supplementing infant formula with long-chain polyunsaturated fatty acids (LC-PUFAs) on lowering blood pressure and lowering the risk of hypertension-related diseases in later life. The costs and health effects of LC-PUFA-enriched and standard infant formulas were compared by using a Markov model, including all relevant direct and indirect costs based on German statistics. We assessed the effect size of blood pressure reduction from LC-PUFA-supplemented formula, the long-term persistence of the effect, and the effect of lowered blood pressure on hypertension-related morbidity. The cost-effectiveness analysis showed an increased life expectancy of 1.2 quality-adjusted life-years and an incremental cost-effectiveness ratio of -630 Euros (discounted to present value) for the LC-PUFA formula in comparison with standard formula. LC-PUFA nutrition was the superior strategy even when the blood pressure-lowering effect was reduced to the lower 95% CI. Breastfeeding is the recommended feeding practice, but infants who are not breastfed should receive an appropriate infant formula. Following this model calculation, LC-PUFA supplementation of infant formula represents an economically worthwhile prevention strategy, based on the costs derived from hypertension-linked diseases in later life. However, because our analysis was based on a single randomized controlled trial, further studies are required to verify the validity of this thesis.

  18. Nutritional Factors Affecting Adult Neurogenesis and Cognitive Function.

    Science.gov (United States)

    Poulose, Shibu M; Miller, Marshall G; Scott, Tammy; Shukitt-Hale, Barbara

    2017-11-01

    Adult neurogenesis, a complex process by which stem cells in the hippocampal brain region differentiate and proliferate into new neurons and other resident brain cells, is known to be affected by many intrinsic and extrinsic factors, including diet. Neurogenesis plays a critical role in neural plasticity, brain homeostasis, and maintenance in the central nervous system and is a crucial factor in preserving the cognitive function and repair of damaged brain cells affected by aging and brain disorders. Intrinsic factors such as aging, neuroinflammation, oxidative stress, and brain injury, as well as lifestyle factors such as high-fat and high-sugar diets and alcohol and opioid addiction, negatively affect adult neurogenesis. Conversely, many dietary components such as curcumin, resveratrol, blueberry polyphenols, sulforaphane, salvionic acid, polyunsaturated fatty acids (PUFAs), and diets enriched with polyphenols and PUFAs, as well as caloric restriction, physical exercise, and learning, have been shown to induce neurogenesis in adult brains. Although many of the underlying mechanisms by which nutrients and dietary factors affect adult neurogenesis have yet to be determined, nutritional approaches provide promising prospects to stimulate adult neurogenesis and combat neurodegenerative diseases and cognitive decline. In this review, we summarize the evidence supporting the role of nutritional factors in modifying adult neurogenesis and their potential to preserve cognitive function during aging. © 2017 American Society for Nutrition.

  19. Long-term variability of precipitation in Republic of Macedonia

    International Nuclear Information System (INIS)

    Slavov, Nikola; Marinova, Tania; Ristevski, Pece

    2004-01-01

    During the last century a great attention has been spared to the water resources of the territories of different countries in the world. In the last decades investigations were directed towards the long-term variability of precipitation in the basic regions of agricultural production. Among these investigations the results that indicate decreasing of precipitation amounts during the potential crop-growing season are of especially great interest because precipitation decreasing affects harmfully crop production and population feeding. The purpose of the present work is to study the long-term variability of monthly precipitation sums for 5 representative meteorological stations in Republic of Macedonia: Skopje, Bitola, Prilep, Stip and Demir Kapija for the period 1925-2000. The duration and periodicity of precipitation variations are analyzed on the base of 5-years smooth values for different seasons, warm and cold half-year and for year. The tendencies of trend for the period 1925-2000 are found out.(Author)

  20. Long-term monitoring for closed special sites

    International Nuclear Information System (INIS)

    Golchert, N.W.; Sedlet, J.

    1987-01-01

    A methodology is presented for planning and implementing a long-term environmental monitoring program for closed special radioactive waste disposal sites. The steps in the method involve collection of the available background information on the site history, site and area characteristics, waste inventory, pathway analysis, prior monitoring programs, applicable standards, and the legal/regulatory requirements. This information is coupled with factors such as experience, half-life, radionuclide migration rates, and potential hazard to develop a monitoring program. As an example, a site-specific long-term monitoring program is described for the AMAX site using the available information. Sampling techniques and practices for the monitoring program are discussed and techniques and practices expected to be available in the future are considered. 7 references, 2 tables

  1. Long-term visual health risks from solar ultraviolet radiation

    International Nuclear Information System (INIS)

    Waxler, M.

    1987-01-01

    Ocular exposure to the ultraviolet radiation (UV) contained in sunlight may result in long-term visual health problems. UV plays a role in the etiology of cataracts and possibly in the etiology of visual impairments associated with solar retinopathy, retinopathy of prematurity, ocular aging, cystoid macular edema, retinitis pigmentosa, and senile macular degeneration. The exact does relationships between known UV bioeffects and these ocular problems is, however, uncertain. Thus, there are questions about the extent to which protective measures should be taken to reduce UV exposure of the eye. This paper identifies the long-term visual health problems potentially associated with ocular exposure to solar UV; proposes worst-case assumptions for the role of solar UV in these visual problems; and recommends protective measures based on damage thresholds and worst-case assumptions

  2. DRIVERS OF LONG-TERM CONVERGENCE. FOCUS ON ROMANIA

    Directory of Open Access Journals (Sweden)

    MANUELA UNGURU

    2014-11-01

    Full Text Available With initial low levels of income per capita, a declining population and relatively modest economic growth rates, there are little prospects of diminishing the gap between Romania and the EU countries. Nevertheless, in the long term, convergence is expected. The question then arises, “What are the drivers and their likely potential to boost economic growth and the catching-up process?”. This paper presents shortly the theoretical background of economic convergence and then focuses on the assessment of possible paths of Romania’s convergence towards the EU. Based on the existing long-term macroeconomic projections and the assessment of the possible future developments of the drivers of economic growth, we have built three scenarios of economic convergence, highlighting the possible timespan of convergence. We have employed growth accounting methods to decompose output growth rate into production factors’ contributions (capital and labour and total factor productivity.

  3. Archiving Primary Data: Solutions for Long-Term Studies.

    Science.gov (United States)

    Mills, James A; Teplitsky, Céline; Arroyo, Beatriz; Charmantier, Anne; Becker, Peter H; Birkhead, Tim R; Bize, Pierre; Blumstein, Daniel T; Bonenfant, Christophe; Boutin, Stan; Bushuev, Andrey; Cam, Emmanuelle; Cockburn, Andrew; Côté, Steeve D; Coulson, John C; Daunt, Francis; Dingemanse, Niels J; Doligez, Blandine; Drummond, Hugh; Espie, Richard H M; Festa-Bianchet, Marco; Frentiu, Francesca; Fitzpatrick, John W; Furness, Robert W; Garant, Dany; Gauthier, Gilles; Grant, Peter R; Griesser, Michael; Gustafsson, Lars; Hansson, Bengt; Harris, Michael P; Jiguet, Frédéric; Kjellander, Petter; Korpimäki, Erkki; Krebs, Charles J; Lens, Luc; Linnell, John D C; Low, Matthew; McAdam, Andrew; Margalida, Antoni; Merilä, Juha; Møller, Anders P; Nakagawa, Shinichi; Nilsson, Jan-Åke; Nisbet, Ian C T; van Noordwijk, Arie J; Oro, Daniel; Pärt, Tomas; Pelletier, Fanie; Potti, Jaime; Pujol, Benoit; Réale, Denis; Rockwell, Robert F; Ropert-Coudert, Yan; Roulin, Alexandre; Sedinger, James S; Swenson, Jon E; Thébaud, Christophe; Visser, Marcel E; Wanless, Sarah; Westneat, David F; Wilson, Alastair J; Zedrosser, Andreas

    2015-10-01

    The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. New Developments in Long-Term Downhole Monitoring Arrays

    Directory of Open Access Journals (Sweden)

    Jochem Kück

    2006-03-01

    Full Text Available The long-term observation of active geological processes is a major research goal in an increasing number of scientific drilling projects. An extended monitoring phase within a potentially hostile environment (e.g., temperature, pressure, salinity requires new long-lasting and robust instrumentation currently unavailable from either industry or academia. Extended exposure of instrument packages to extreme conditions will typically cause seals to weaken and fail,electronic parts to break under permanent load, and sensors to degrade or develop strong drift. In the framework of scientific exploration, there are currently several major research projects targeting fault zone drilling and in situ measurements to monitor physical and chemical conditions before, during, and after seismic events. Planning has now begun for tool development, testing, and continuous long-term monitoring for the San Andreas Fault Zone Observatory at Depth, SAFOD (Parkfi eld, Calif., U.S.A.; See article on page 32..

  5. LONG-TERM OUTCOME IN PEDIATRIC TRICHOTILLOMANIA.

    Science.gov (United States)

    Schumer, Maya C; Panza, Kaitlyn E; Mulqueen, Jilian M; Jakubovski, Ewgeni; Bloch, Michael H

    2015-10-01

    To examine long-term outcome in children with trichotillomania. We conducted follow-up clinical assessments an average of 2.8 ± 0.8 years after baseline evaluation in 30 of 39 children who previously participated in a randomized, double-blind, placebo-controlled trial of N-acetylcysteine (NAC) for pediatric trichotillomania. Our primary outcome was change in hairpulling severity on the Massachusetts General Hospital Hairpulling Hospital Hairpulling Scale (MGH-HPS) between the end of the acute phase and follow-up evaluation. We also obtained secondary measures examining styles of hairpulling, comorbid anxiety and depressive symptoms, as well as continued treatment utilization. We examined both correlates and predictors of outcome (change in MGH-HPS score) using linear regression. None of the participants continued to take NAC at the time of follow-up assessment. No significant changes in hairpulling severity were reported over the follow-up period. Subjects reported significantly increased anxiety and depressive symptoms but improvement in automatic pulling symptoms. Increased hairpulling symptoms during the follow-up period were associated with increased depression and anxiety symptoms and increased focused pulling. Older age and greater focused pulling at baseline assessment were associated with poor long-term prognosis. Our findings suggest that few children with trichotillomania experience a significant improvement in trichotillomania symptoms if behavioral treatments are inaccessible or have failed to produce adequate symptom relief. Our findings also confirm results of previous cross-sectional studies that suggest an increased risk of depression and anxiety symptoms with age in pediatric trichotillomania. Increased focused pulling and older age among children with trichotillomania symptoms may be associated with poorer long-term prognosis. © 2015 Wiley Periodicals, Inc.

  6. Long-term EEG in children.

    Science.gov (United States)

    Montavont, A; Kaminska, A; Soufflet, C; Taussig, D

    2015-03-01

    Long-term video-EEG corresponds to a recording ranging from 1 to 24 h or even longer. It is indicated in the following situations: diagnosis of epileptic syndromes or unclassified epilepsy, pre-surgical evaluation for drug-resistant epilepsy, follow-up of epilepsy or in cases of paroxysmal symptoms whose etiology remains uncertain. There are some specificities related to paediatric care: a dedicated pediatric unit; continuous monitoring covering at least a full 24-hour period, especially in the context of pre-surgical evaluation; the requirement of presence by the parents, technician or nurse; and stronger attachment of electrodes (cup electrodes), the number of which is adapted to the age of the child. The chosen duration of the monitoring also depends on the frequency of seizures or paroxysmal events. The polygraphy must be adapted to the type and topography of movements. It is essential to have at least an electrocardiography (ECG) channel, respiratory sensor and electromyography (EMG) on both deltoids. There is no age limit for performing long-term video-EEG even in newborns and infants; nevertheless because of scalp fragility, strict surveillance of the baby's skin condition is required. In the specific context of pre-surgical evaluation, long-term video-EEG must record all types of seizures observed in the child. This monitoring is essential in order to develop hypotheses regarding the seizure onset zone, based on electroclinical correlations, which should be adapted to the child's age and the psychomotor development. Copyright © 2015. Published by Elsevier SAS.

  7. Long-term governance for sustainability

    International Nuclear Information System (INIS)

    Martell, M.

    2007-01-01

    Meritxell Martell spoke of the long-term aspects of radioactive waste management. She pointed out that decision-making processes need to be framed within the context of sustainability, which means that a balance should be sought between scientific considerations, economic aspects and structural conditions. Focusing on structural aspects, Working Group 3 of COWAM-Spain came to the conclusion that the activity of the regulator is a key factor of long-term management. Another finding is that from a sustainability perspective multi-level governance is more effective for coping with the challenges of radioactive waste management than one tier of government-making decisions. The working group also felt that the current Local Information Committees need to evolve towards more institutionalized and legitimized mechanisms for long-term involvement. Ms. Martell introduced a study comparing the efficiency of economic instruments to advance sustainable development in nuclear communities vs. municipalities in mining areas. The study found that funds transferred to nuclear zones had become a means to facilitate local acceptance of nuclear facilities rather than a means to promote socio-economic development. Another finding is that economic instruments are not sufficient guarantees of sustainable development by themselves; additional preconditions include leadership, vision and entrepreneur-ship on the part of community leaders, private or public investments, among others. Finally, Ms. Martell summarised the challenges faced by the Spanish radioactive waste management programme, which include the need for strategic thinking, designing the future in a participatory fashion, and working with local and regional governments and citizens to devise mechanisms for social learning, economic development and environmental protection. (author)

  8. Long-term deconditioning of gas-filled surge arresters

    Science.gov (United States)

    Stanković, Koviljka; Brajović, Dragan; Alimpijević, Mališa; Lončar, Boris

    2016-07-01

    pressure that is as high as possible (with pd = const), and that the electrode active surface should have a marked microscopic topography. In addition to this, an essential conclusion for GFSA manufacturers is that long-term system deconditioning is caused by impurities and adsorbed gases that appear at electrode during the state of rest. Out of these two causes, the influence of impurities is probably the dominant one, which is proved by considerably reduced long-term deconditioning in the case of noble metal electrodes, not susceptible to corrosion. This has also been confirmed by a less distinct effect of long-term deconditioning in the case of sandblasted electrodes that have a stronger tendency towards gas adsorption and a weaker tendency towards corrosion. However, it has been shown that adding of the third electrode (that is concentric to the main electrode system) on a free floating potential along with usage of sandblasted electrodes and with smaller interelectrode distance significantly reduces the effects of the long-term deconditioning.

  9. Long term aspects of uranium tailings management

    International Nuclear Information System (INIS)

    Bragg, K.

    1980-05-01

    This paper sets out the background issues which lead to the development of interim close-out criteria for uranium mill tailings. It places the current state-of-the-art for tailings management into both a national and international perspective and shows why such interim criteria are needed now. There are seven specific criteria proposed dealing with the need to have: passive barriers, limits on surface water recharge, durable systems, long term performance guarantees, limits to access, controls on water and airborne releases and finally to have a knowledge of exposure pathways. This paper is intended to serve as a focus for subsequent discussions with all concerned parties. (auth)

  10. Human Behaviour in Long-Term Missions

    Science.gov (United States)

    1997-01-01

    In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

  11. Optimal Long-Term Financial Contracting

    OpenAIRE

    Peter M. DeMarzo; Michael J. Fishman

    2007-01-01

    We develop an agency model of financial contracting. We derive long-term debt, a line of credit, and equity as optimal securities, capturing the debt coupon and maturity; the interest rate and limits on the credit line; inside versus outside equity; dividend policy; and capital structure dynamics. The optimal debt-equity ratio is history dependent, but debt and credit line terms are independent of the amount financed and, in some cases, the severity of the agency problem. In our model, the ag...

  12. Designing indicators of long-term energy supply security

    International Nuclear Information System (INIS)

    Jansen, J.C.; Van Arkel, W.G.; Boots, M.G.

    2004-01-01

    To our knowledge, so far amazingly little research work has been undertaken to construct meaningful indicators of long-run energy supply security for a particular nation or region. Currently, in addressing energy supply security, policy makers tend to emphasise short-term supply disruptions. In contrast, this pre-study accords with the broader Sustainability Outlook in considering the long-term perspective. This report starts with taking stock, in a concise way, of the official EU energy outlook and issues related to the opportunities to administer changes in the energy mix at the level of major energy use categories. Then a brief survey of relevant literature is made on long-term strategies to ensure survival of systems - be it biological, social, etc. - in an environment largely characterised by high uncertainty and a lot of unchartered territory. We found the work of Andrew Stirling very inspiring in this context. Based on his work and considering the limitations of the present research activity, we retained the Shannon index as the best 'simple' indicator of diversity. In the core of the report, the Shannon index is elaborated into four indicators of long-term energy supply security. Stepwise, additional aspects of long-term energy supply security are introduced. These aspects are: Diversification of energy sources in energy supply; Diversification of imports with respect to imported energy sources; Long-term political stability in regions of origin; The resource base in regions of origin, including the home region/country itself. After small adjustments to allow for data availability, these indicators were applied to the reference year 2030 of four long-term scenarios with data of base year 1995 and projections for underlying variables provided by the Netherlands Environmental Assessment Agency (MNP). Preliminary interpretation of the results suggests the usefulness of the indicators presented in this report. A second activity undertaken in this report was

  13. Global long-term cost dynamics of offshore wind electricity generation

    NARCIS (Netherlands)

    Gernaat, David E H J; Van Vuuren, Detlef P.; Van Vliet, Jasper; Sullivan, Patrick; Arent, Douglas J.

    2014-01-01

    Using the IMAGE/TIMER (The Targets IMage Energy Regional) long-term integrated assessment model, this paper explores the regional and global potential of offshore wind to contribute to global electricity production. We develop long-term cost supply curve for offshore wind, a representation of the

  14. Long-term ecological research in a human-dominated world

    Science.gov (United States)

    G. Philip Robertson; Scott L. Collins; David R. Foster; Nicholas Brokaw; Hugh W. Ducklow; Ted L. Gragson; Corinna Gries; Stephen K. Hamilton; A. David McGuire; John C. Moore; Emily H. Stanley; Robert B. Waide; Mark W. Williams

    2012-01-01

    The US Long Term Ecological Research (LTER) Network enters its fourth decade with a distinguished record of achievement in ecological science. The value of long-term observations and experiments has never been more important for testing ecological theory and for addressing today’s most difficult environmental challenges. The network’s potential for tackling emergent...

  15. Fatigue and quality of life in breast cancer survivors: temporal courses and long-term pattern

    NARCIS (Netherlands)

    Schmidt, M.E.; Chang-Claude, J.; Vrieling, A.; Heinz, J.; Flesch-Janys, D.; Steindorf, K.

    2012-01-01

    INTRODUCTION: Fatigue is a frequent problem during and after cancer treatment. We investigated different courses of fatigue from pre-diagnosis, through therapy, to long-term survivorship and evaluated potential implications on long-term quality of life (QoL). METHODS: Breast cancer patients

  16. On the Role of Neurogenesis and Neural Plasticity in the Evolution of Animal Personalities and Stress Coping Styles

    DEFF Research Database (Denmark)

    Overli, Oyvind; Sorensen, Christina

    2016-01-01

    and neurogenesis have received recent attention. This work reveals that brain cell proliferation and neurogenesis are associated with heritable variation in stress coping style, and they are also differentially affected by short- and long-term stress in a biphasic manner. Routine-dependent and inflexible behavior...... are conserved throughout the vertebrate subphylum, including factors affecting perception, learning, and memory of stimuli and events. Here we review conserved aspects of the contribution of neurogenesis and other aspects of neural plasticity to stress coping. In teleost fish, brain cell proliferation...

  17. Long-term environmental behaviour of radionuclides

    International Nuclear Information System (INIS)

    Brechignac, F.; Moberg, L.; Suomela, M.

    2000-04-01

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: i) redistribution in the soil-plant system, ii) modelling, iii) countermeasures, iv) runoff v) spatial variations, and vi) dose assessment. The long term behaviour of the radionuclides 137 Cs, 90 Sr and 239-240 Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  18. Craniopharyngioma in Children: Long-term Outcomes

    Science.gov (United States)

    STEINBOK, Paul

    2015-01-01

    The survival rate for childhood craniopharyngioma has been improving, with more long-term survivors. Unfortunately it is rare for the patient to be normal, either from the disease itself or from the effects of treatment. Long-term survivors of childhood craniopharyngioma suffer a number of impairments, which include visual loss, endocrinopathy, hypothalamic dysfunction, cerebrovascular problems, neurologic and neurocognitive dysfunction. Pituitary insufficiency is present in almost 100%. Visual and hypothalamic dysfunction is common. There is a high risk of metabolic syndrome and increased risk of cerebrovascular disease, including stroke and Moyamoya syndrome. Cognitive, psychosocial, and emotional problems are prevalent. Finally, there is a higher risk of premature death among survivors of craniopharyngioma, and often this is not from tumor recurrence. It is important to consider craniopharyngioma as a chronic disease. There is no perfect treatment. The treatment has to be tailored to the individual patient to minimize dysfunction caused by tumor and treatments. So “cure” of the tumor does not mean a normal patient. The management of the patient and family needs multidisciplinary evaluation and should involve ophthalmology, endocrinology, neurosurgery, oncology, and psychology. Furthermore, it is also important to address emotional issues and social integration. PMID:26345668

  19. Institutionalization and Organizational Long-term Success

    Directory of Open Access Journals (Sweden)

    Denise L. Fleck

    2007-05-01

    Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization’s relations with the environment, clearly contributing to environmental institutionalization.

  20. Neo bladder long term follow-up

    International Nuclear Information System (INIS)

    Fakhr, I.; Mohamed, A. M.; Moustafa, A.; Al-Sherbiny, M.; Salama, M.

    2013-01-01

    One of the commonest forms of orthotopic bladder substitution for bladder cancer surivors, used in our institute, is the use of ileocecal segment. Sometimes, the need for Indiana pouch heterotropic continent diversion arises. Aim: To compare the long-term effect of orthotopic ileocecal bladder and heterotropic Indiana pouch following radical cystectomy in bladder cancer patients. Patients and methods: Between January 2008 and December 2011, 91 patients underwent radical cystectomy/anterior pelvic exentration and ortho topic ileocecal bladder reconstruction (61 patients) and Indiana pouch (30 patients), when orthotopic diversion could not be technically or oncologically feasible. Results: Convalescence was uneventful in most patients. All minor and major urinary leakage cases, in both diversions groups, where successfully conservatively treated. Only one patient in the ileocecal group with major urinary leak required re-exploration with successful revision of uretro-colonic anastomosis. Only one patient in the Indiana pouch group had accidentally discovered sub-centimetric stone, which was simply expelled. The overall survival proportion of ileocecal group was 100% compared to 80% in the Indiana pouch group (p < 0.001). The disease free survival proportion of ileocecal group was 90.8% compared to 80% in the Indiana pouch group (p = 0.076). Effective comparative daytime and nighttime urinary continence as well as renal function deterioration were not statistically significant between both reconstruction types. Conclusion: Both ileocecal bladder and Indiana pouch are safe procedures in regard to long-term effects over kidney function following radical cystectomy

  1. Toward a comprehensive long term nicotine policy.

    Science.gov (United States)

    Gray, N; Henningfield, J E; Benowitz, N L; Connolly, G N; Dresler, C; Fagerstrom, K; Jarvis, M J; Boyle, P

    2005-06-01

    Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source.

  2. Long term ground movement of TRISTAN synchrotron

    International Nuclear Information System (INIS)

    Endo, K.; Ohsawa, Y.; Miyahara, M.

    1989-01-01

    The long term ground movement is estimated through the geological survey before a big accelerator is planned. For the case of TRISTAN-MR (main ring), its site was surveyed to reflect the underground information to the building prior to the construction. The movement of the synchrotron magnet mainly results from the structure of the tunnel. If an individual movement of the magnet exceeds a certain threshold limit, it gives a significant effect on the particle behavior in a synchrotron. Height of the quadrupole magnets were observed periodically during past two years at the TRISTAN-MR and their height differences along the 3 km circumference of the accelerator ring were decomposed into the Fourier components depicting the causes of the movements. Results shows the movement of the tunnel foundation which was also observed by the simultaneous measurement of both magnets and fiducial marks on the tunnel wall. The long term movement of the magnets is summarized with the geological survey prior to construction. 1 ref., 6 figs., 1 tab

  3. Long-term environmental behaviour of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Brechignac, F.; Moberg, L.; Suomela, M

    2000-04-01

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  4. Long-term preservation of anammox bacteria.

    Science.gov (United States)

    Rothrock, Michael J; Vanotti, Matias B; Szögi, Ariel A; Gonzalez, Maria Cruz Garcia; Fujii, Takao

    2011-10-01

    Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass was frozen or lyophilized at two different freezing temperatures (-60°C and in liquid nitrogen (-200°C)) in skim milk media (with and without glycerol), and the reactivation of anammox activity was monitored after a 4-month storage period. Of the different preservation treatments tested, only anammox biomass preserved via freezing in liquid nitrogen followed by lyophilization in skim milk media without glycerol achieved stoichiometric ratios for the anammox reaction similar to the biomass in both the parent bioreactor and in the freshly harvested control treatment. A freezing temperature of -60°C alone, or in conjunction with lyophilization, resulted in the partial recovery of the anammox bacteria, with an equal mixture of anammox and nitrifying bacteria in the reactivated biomass. To our knowledge, this is the first report of the successful reactivation of anammox biomass preserved via sub-zero freezing and/or lyophilization. The simple preservation protocol developed from this study could be beneficial to accelerate the integration of anammox-based processes into current treatment systems through a highly efficient starting anammox biomass.

  5. Andra long term memory project - 59277

    International Nuclear Information System (INIS)

    Charton, Patrick; Boissier, Fabrice; Martin, Guillaume

    2012-01-01

    Document available in abstract form only. Full text of publication follows: Long term memory of repositories is required by safety, reversibility and social expectations. Thus Andra has implemented since 2010 a long-term memory project to reinforce and diversify its current arrangements in this field, as well as to explore opportunities to extend memory keeping over thousands years. The project includes opportunity studies of dedicated facilities. The 'Ecotheque' and 'Geotheque' projects contribute to memory respectively through environmental and geological samples preservation. The options of creating (i) an archive centre for Andra's interim and permanent archives, (ii) an artist center to study the contribution of arts to memory preservation, (iii) a museum of radioactive waste disposal history and technology (radium industry..., sea disposal, current solutions...) are considered. Other studies provided by the project examine our heritage. This includes the continuity of languages and symbolic systems, the continuity of writing and engraving methods, the archaeology of landscapes (memory of the earths evolution, multi-century memory of industrial and agricultural landscapes), the archaeology practices (how might a future archaeologist be interested in our current activity?), the preservation of historical sites and industrial memory, the continuity of institutional organizations, the memory and history of science evolution as well as broad history

  6. Long term creep behavior of concrete

    International Nuclear Information System (INIS)

    Kennedy, T.W.

    1975-01-01

    This report presents the findings of an experimental investigation to evaluate the long term creep behavior of concrete subjected to sustained uniaxial loads for an extended period of time at 75 0 F. The factors investigated were (1) curing time (90, 183, and 365 days); (2) curing history (as-cast and air-dried); and (3) uniaxial stress (600 and 2400 psi). The experimental investigation applied uniaxial compressive loads to cylindrical concrete specimens and measured strains with vibrating wire strain gages that were cast in the concrete specimen along the axial and radial axes. Specimens cured for 90 days prior to loading were subjected to a sustained load for a period of one year, at which time the loads were removed; the specimens which were cured for 183 or 365 days, however, were not unloaded and have been under load for 5 and 4.5 years, respectively. The effect of each of the above factors on the instantaneous and creep behavior is discussed and the long term creep behavior of the specimens cured for 183 or 365 days is evaluated. The findings of these evaluations are summarized. (17 figures, 10 tables) (U.S.)

  7. Sleep facilitates long-term face adaptation.

    Science.gov (United States)

    Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

    2013-10-22

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation--which are usually not considered to play a relevant role in mnemonic processes--with learning and memory, and at the same time reveal a new function of sleep in cognition.

  8. Group long-term care insurance: decision-making factors and implications for financing long-term care.

    Science.gov (United States)

    Stum, Marlene S

    2008-01-01

    This study proposes and tests a systemic family decision-making framework to understand group long-term care insurance (LTCI) enrollment decisions. A random sample of public employees who were offered group LTCI as a workplace benefit were examined. Findings reveal very good predictive efficacy for the overall conceptual framework with a pseudo R2 value of .687, and reinforced the contributions of factors within the family system. Enrollees were more likely to have discussed the decision with others, used information sources, and had prior experience when compared to non-enrollees. Perceived health status, financial knowledge, attitudes regarding the role of private insurance, risk taking, and coverage features were additional factors related to enrollment decisions. The findings help to inform policymakers about the potential of LTCI as one strategy for financing long-term care.

  9. Salt brickwork as long-term sealing in salt formations

    International Nuclear Information System (INIS)

    Walter, F.; Yaramanci, U.

    1993-01-01

    Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in these potential pathways to prevent radioactive release into the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made from compressed salt-powder are understood to be the first choice long-term sealing material. Seals built of salt bricks will be ductile. Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. This provides for the good adhesive strength of the mortar to the bricks and the high shear-strength of the mortar itself. To test the interaction of rock salt with an emplaced long-term seal, experiments will be carried out in situ, in the Asse salt mine in Germany. Simple borehole sealing experiments will be performed in horizontal holes and a complicated drift sealing experiment is planned, to demonstrate the technology of sealing a standard size drift or shaft inside a disturbed rock mass. Especially, the mechanical stability of the sealing system has to be demonstrated

  10. Birds choose long-term partners years before breeding

    Science.gov (United States)

    Teitelbaum, Claire S.; Converse, Sarah J.; Mueller, Thomas

    2017-01-01

    Pair bonds can provide social benefits to long-term monogamous species alongside their benefits for reproduction. However, little is known about when these bonds form, in particular how long they are present before breeding. Previous studies of pair formation in long-term monogamous birds have been rather data-limited, but for many migratory birds they report pair formation on the wintering grounds. We provide the first systematic investigation of prebreeding association patterns of long-term monogamous pairs by examining entire life histories based on tracking data of migratory whooping cranes, Grus americana. We found that a substantial portion (62%) of breeding pairs started associating at least 12 months before first breeding, with 16 of 58 breeding pairs beginning to associate over 2 years before first breeding. For most pairs, these associations with future breeding partners also became unique and distinguishable from association patterns with nonpartner individuals 12 months before first breeding. In addition, 60% of pair associations began before at least one partner had reached nominal sexual maturity. Most pairs began associating in the late spring upon arrival at the summer grounds, while associations beginning at other times of the year were rare. Patterns in the associations of pairs prior to breeding can point to the potential benefits of prebreeding relationships, for instance providing support in competitive interactions or increasing partner familiarity.

  11. Short-term soil bioassays may not reveal the full toxicity potential for nanomaterials; bioavailability and toxicity of silver ions (AgNO₃) and silver nanoparticles to earthworm Eisenia fetida in long-term aged soils.

    Science.gov (United States)

    Diez-Ortiz, Maria; Lahive, Elma; George, Suzanne; Ter Schure, Anneke; Van Gestel, Cornelis A M; Jurkschat, Kerstin; Svendsen, Claus; Spurgeon, David J

    2015-08-01

    This study investigated if standard risk assessment hazard tests are long enough to adequately provide the worst case exposure for nanomaterials. This study therefore determined the comparative effects of the aging on the bioavailability and toxicity to earthworms of soils dosed with silver ions and silver nanoparticles (Ag NP) for 1, 9, 30 & 52 weeks, and related this to the total Ag in the soil, Ag in soil pore water and earthworm tissue Ag concentrations. For ionic Ag, a classical pattern of reduced bioavailability and toxicity with time aged in the soil was observed. For the Ag NP, toxicity increased with time apparently driven by Ag ion dissolution from the added Ag NPs. Internal Ag in the earthworms did not always explain toxicity and suggested the presence of an internalised, low-toxicity Ag fraction (as intact or transformed NPs) after shorter aging times. Our results indicate that short-term exposures, without long-term soil aging, are not able to properly assess the environmental risk of Ag NPs and that ultimately, with aging time, Ag ion and Ag NP effect will merge to a common value. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

    Directory of Open Access Journals (Sweden)

    Bruno P. Carreira

    2015-01-01

    Full Text Available Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO. In these conditions, NO promotes proliferation of neural stem cells (NSC in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA induced seizure mouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.

  13. Long-term care financing: lessons from France.

    Science.gov (United States)

    Doty, Pamela; Nadash, Pamela; Racco, Nathalie

    2015-06-01

    POLICY POINTS: France's model of third-party coverage for long-term services and supports (LTSS) combines a steeply income-adjusted universal public program for people 60 or older with voluntary supplemental private insurance. French and US policies differ: the former pay cash; premiums are lower; and take-up rates are higher, in part because employer sponsorship, with and without subsidization, is more common-but also because coverage targets higher levels of need and pays a smaller proportion of costs. Such inexpensive, bare-bones private coverage, especially if marketed as a supplement to a limited public benefit, would be more affordable to those Americans currently most at risk of "spending down" to Medicaid. An aging population leads to a growing demand for long-term services and supports (LTSS). In 2002, France introduced universal, income-adjusted, public long-term care coverage for adults 60 and older, whereas the United States funds means-tested benefits only. Both countries have private long-term care insurance (LTCI) markets: American policies create alternatives to out-of-pocket spending and protect purchasers from relying on Medicaid. Sales, however, have stagnated, and the market's viability is uncertain. In France, private LTCI supplements public coverage, and sales are growing, although its potential to alleviate the long-term care financing problem is unclear. We explore whether France's very different approach to structuring public and private financing for long-term care could inform the United States' long-term care financing reform efforts. We consulted insurance experts and conducted a detailed review of public reports, academic studies, and other documents to understand the public and private LTCI systems in France, their advantages and disadvantages, and the factors affecting their development. France provides universal public coverage for paid assistance with functional dependency for people 60 and older. Benefits are steeply income

  14. THE SOCIAL ENVIRONMENT AND NEUROGENESIS IN THE ADULT MAMMALIAN BRAIN

    Directory of Open Access Journals (Sweden)

    Claudia eLieberwirth

    2012-05-01

    Full Text Available Adult neurogenesis—the formation of new neurons in adulthood—has been shown to be modulated by a variety of endogenous (e.g., trophic factors, neurotransmitters, and hormones as well as exogenous (e.g., physical activity and environmental complexity factors. Research on exogenous regulators of adult neurogenesis has focused primarily on the non-social environment. Most recently, however, evidence has emerged suggesting that the social environment can also affect adult neurogenesis. The present review details the effects of adult-adult (e.g., mating, conspecific, and chemosensory signal exposure and adult-offspring (e.g., gestation, parenthood, and exposure to offspring interactions on adult neurogenesis. In addition, the effects of a stressful social environment (e.g., lack of social support and dominant-subordinate interactions on adult neurogenesis are reviewed. The underlying hormonal mechanisms and potential functional significance of adult-generated neurons in mediating social behaviors are also discussed.

  15. Long-term stability of salivary cortisol

    DEFF Research Database (Denmark)

    Garde, A H; Hansen, Åse Marie

    2005-01-01

    either stored in small vials or spiked to polyester Salivette tampons before analysis for cortisol using Spectria RIA kits. The effects of storage were evaluated by a linear regression model (mixed procedure) on a logarithmic scale. No effects on cortisol concentrations were found after storage of saliva......The measurement of salivary cortisol provides a simple, non-invasive, and stress-free measure frequently used in studies of the hypothalamic-pituitary-adrenal axis activity. In research projects, samples are often required to be stored for longer periods of time either because of the protocol...... of the project or because of lack of funding for analysis. The aim of the present study was to explore the effects of long-term storage of samples on the amounts of measurable cortisol. Ten pools of saliva were collected on polyester Salivette tampons from five subjects. After centrifugation the samples were...

  16. Long-term cryogenic space storage system

    Science.gov (United States)

    Hopkins, R. A.; Chronic, W. L.

    1973-01-01

    Discussion of the design, fabrication and testing of a 225-cu ft spherical cryogenic storage system for long-term subcritical applications under zero-g conditions in storing subcritical cryogens for space vehicle propulsion systems. The insulation system design, the analytical methods used, and the correlation between the performance test results and analytical predictions are described. The best available multilayer insulation materials and state-of-the-art thermal protection concepts were applied in the design, providing a boiloff rate of 0.152 lb/hr, or 0.032% per day, and an overall heat flux of 0.066 Btu/sq ft hr based on a 200 sq ft surface area. A six to eighteen month cryogenic storage is provided by this system for space applications.

  17. Long-term control of root growth

    Science.gov (United States)

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene

    1992-05-26

    A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin.

  18. Long term performance of radon mitigation systems

    International Nuclear Information System (INIS)

    Prill, R.; Fisk, W.J.

    2002-01-01

    Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes

  19. Rising Long-term Interest Rates

    DEFF Research Database (Denmark)

    Hallett, Andrew Hughes

    Rather than chronicle recent developments in European long-term interest rates as such, this paper assesses the impact of increases in those interest rates on economic performance and inflation. That puts us in a position to evaluate the economic pressures for further rises in those rates......, the first question posed in this assignment, and the scope for overshooting (the second question), and then make some illustrative predictions of future interest rates in the euro area. We find a wide range of effects from rising interest rates, mostly small and mostly negative, focused on investment...... till the emerging European recovery is on a firmer basis and capable of overcoming increases in the cost of borrowing and shrinking fiscal space. There is also an implication that worries about rising/overshooting interest rates often reflect the fact that inflation risks are unequally distributed...

  20. Prediction of long-term creep curves

    International Nuclear Information System (INIS)

    Oikawa, Hiroshi; Maruyama, Kouichi

    1992-01-01

    This paper aims at discussing how to predict long-term irradiation enhanced creep properties from short-term tests. The predictive method based on the θ concept was examined by using creep data of ferritic steels. The method was successful in predicting creep curves including the tertiary creep stage as well as rupture lifetimes. Some material constants involved in the method are insensitive to the irradiation environment, and their values obtained in thermal creep are applicable to irradiation enhanced creep. The creep mechanisms of most engineering materials definitely change at the athermal yield stress in the non-creep regime. One should be aware that short-term tests must be carried out at stresses lower than the athermal yield stress in order to predict the creep behavior of structural components correctly. (orig.)

  1. Hanford grout: predicting long-term performance

    International Nuclear Information System (INIS)

    Sewart, G.H.; Mitchell, D.H.; Treat, R.L.; McMakin, A.H.

    1987-01-01

    Grouted disposal is being planned for the low-level portion of liquid radioactive wastes at the Hanford site in Washington state. The performance of the disposal system must be such that it will protect people and the environment for thousands of years after disposal. To predict whether a specific grout disposal system will comply with existing and foreseen regulations, a performance assessment (PA) is performed. Long-term PAs are conducted for a range of performance conditions. Performance assessment is an inexact science. Quantifying projected impacts is especially difficult when only scant data exist on the behavior of certain components of the disposal system over thousands of years. To develop defensible results, we are honing the models and obtaining experimental data. The combination of engineered features and PA refinements is being used to ensure that Hanford grout will meet its principal goal: to protect people and the environment in the future

  2. Long-term opioid therapy in Denmark

    DEFF Research Database (Denmark)

    Birke, H; Ekholm, Ola; Sjøgren, P

    2017-01-01

    significantly associated with initiation of L-TOT in individuals with CNCP at baseline. During follow-up, L-TOT in CNCP patients increased the likelihood of negative changes in pain interference with work (OR 9.2; 95% CI 1.9-43.6) and in moderate activities (OR 3.7; 95% CI 1.1-12.6). The analysis of all......,145). A nationally representative subsample of individuals (n = 2015) completed the self-administered questionnaire in both 2000 and 2013. Collected information included chronic pain (≥6 months), health behaviour, self-rated health, pain interference with work activities and physical activities. Long-term users were...... individuals indicated a dose-response relationship between longer treatment duration and the risk of experiencing negative changes. CONCLUSIONS: Individuals on L-TOT seemed not to achieve the key goals of opioid therapy: pain relief, improved quality of life and functional capacity. SIGNIFICANCE: Long...

  3. Long Term Planning at IQ Metal

    DEFF Research Database (Denmark)

    2017-01-01

    This is a Danish version. This case about long term planning at the owner-managed manufacturing firm IQ Metal shows how the future management and ownership may be organized to utilize owner assets and minimize roadblocks. Initially, the owner-manager Bo Fischer Larsen explains how he acquired...... a stake in 2007 in the company which at that time was named Braendstrup Maskinfabrik. He furthermore expalins how he has developed the company based on a strategic plan focusing on professionalization and outsourcing. Next, the video shows how to type Bo Fischer Larsen's replies to the questions...... in The Owner Strategy Map into the questionnaire available on www.ejerstrategi-kortet.dk. Lastly, the Owner Strategy Map's recommendation of how to organize the future management and ownership of IQ Metal is explained....

  4. Long-term Consequences of Early Parenthood

    DEFF Research Database (Denmark)

    Johansen, Eva Rye; Nielsen, Helena Skyt; Verner, Mette

    (and to lesser extent employment), as fathers appear to support the family, especially when early parenthood is combined with cohabitation with the mother and the child. Heterogeneous effects reveal that individuals with a more favorable socioeconomic background are affected more severely than......Having children at an early age is known to be associated with unfavorable economic outcomes, such as lower education, employment and earnings. In this paper, we study the long-term consequences of early parenthood for mothers and fathers. Our study is based on rich register-based data that......, importantly, merges all childbirths to the children’s mothers and fathers, allowing us to study the consequences of early parenthood for both parents. We perform a sibling fixed effects analysis in order to account for unobserved family attributes that are possibly correlated with early parenthood...

  5. Managing Records for the Long Term - 12363

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, John V. [U.S. Department of Energy, Office of Legacy Management, Morgantown, West Virginia (United States); Gueretta, Jeanie [U.S. Department of Energy, Office of Legacy Management, Grand Junction, Colorado (United States)

    2012-07-01

    The U.S. Department of Energy (DOE) is responsible for managing vast amounts of information documenting historical and current operations. This information is critical to the operations of the DOE Office of Legacy Management. Managing legacy records and information is challenging in terms of accessibility and changing technology. The Office of Legacy Management is meeting these challenges by making records and information management an organizational priority. The Office of Legacy Management mission is to manage DOE post-closure responsibilities at former Cold War weapons sites to ensure the future protection of human health and the environment. These responsibilities include environmental stewardship and long-term preservation and management of operational and environmental cleanup records associated with each site. A primary organizational goal for the Office of Legacy Management is to 'Preserve, Protect, and Share Records and Information'. Managing records for long-term preservation is an important responsibility. Adequate and dedicated resources and management support are required to perform this responsibility successfully. Records tell the story of an organization and may be required to defend an organization in court, provide historical information, identify lessons learned, or provide valuable information for researchers. Loss of records or the inability to retrieve records because of poor records management processes can have serious consequences and even lead to an organisation's downfall. Organizations must invest time and resources to establish a good records management program because of its significance to the organization as a whole. The Office of Legacy Management will continue to research and apply innovative ways of doing business to ensure that the organization stays at the forefront of effective records and information management. DOE is committed to preserving records that document our nation's Cold War legacy, and the

  6. Control of proliferating potential of myeloid leukemia cells during long-term treatment with vitamin D3 analogues and other differentiation inducers in combination with antileukemic drugs: in vitro and in vivo studies.

    Science.gov (United States)

    Kasukabe, T; Honma, Y; Hozumi, M; Suda, T; Nishii, Y

    1987-01-15

    Growth inhibition of murine and human myeloid leukemia cells by differentiation inducers during long-term culture was examined to improve the strategy for therapy of myeloid leukemia by differentiation inducers. When the effect of 1 alpha,25-dihydroxyvitamin D3, a typical differentiation inducer, on proliferation of mouse myeloid leukemia M1 cells was examined at a constant product of time and concentration (480 nM in 20 days), the continuous treatment with 24 nM 1 alpha,25-dihydroxyvitamin D3 was the most effective for inhibition of cell proliferation. After 20 days, the cumulative cell number was reduced about 3 X 10(5) times by continuous treatment with 24 nM 1 alpha,25-dihydroxyvitamin D3. Similar results were obtained when M1 cells were treated continuously with dexamethasone. M1 cells resistant to 1 alpha,25-dihydroxyvitamin D3 appeared about 25 days after the start of continuous treatment with 24 nM 1 alpha,25-dihydroxyvitamin D3. On the other hand, when M1 cells were treated continuously with 1 alpha,25-dihydroxyvitamin D3 and noncytotoxic doses of antileukemic drugs such as 1-beta-D-arabinofuranosylcytosine and daunomycin, resistant cells did not appear for at least 35 days. A similar effect of 1 alpha,25-dihydroxyvitamin D3 and antileukemic drugs on cell proliferation was observed with the human monoblast-like cell line U937. The survival of syngeneic SL mice inoculated with M1 cells was prolonged more by treatment with both 1 alpha-hydroxyvitamin D3 and daunomycin than by treatment with either drug alone. These results suggest that continuous treatment with both differentiation inducers and certain antileukemic drugs may be more effective therapeutically than treatment with a differentiation inducer alone.

  7. Short-term soil bioassays may not reveal the full toxicity potential for nanomaterials; bioavailability and toxicity of silver ions (AgNO3) and silver nanoparticles to earthworm Eisenia fetida in long-term aged soils

    International Nuclear Information System (INIS)

    Diez-Ortiz, Maria; Lahive, Elma; George, Suzanne; Ter Schure, Anneke; Van Gestel, Cornelis A.M.; Jurkschat, Kerstin; Svendsen, Claus; Spurgeon, David J.

    2015-01-01

    This study investigated if standard risk assessment hazard tests are long enough to adequately provide the worst case exposure for nanomaterials. This study therefore determined the comparative effects of the aging on the bioavailability and toxicity to earthworms of soils dosed with silver ions and silver nanoparticles (Ag NP) for 1, 9, 30 & 52 weeks, and related this to the total Ag in the soil, Ag in soil pore water and earthworm tissue Ag concentrations. For ionic Ag, a classical pattern of reduced bioavailability and toxicity with time aged in the soil was observed. For the Ag NP, toxicity increased with time apparently driven by Ag ion dissolution from the added Ag NPs. Internal Ag in the earthworms did not always explain toxicity and suggested the presence of an internalised, low-toxicity Ag fraction (as intact or transformed NPs) after shorter aging times. Our results indicate that short-term exposures, without long-term soil aging, are not able to properly assess the environmental risk of Ag NPs and that ultimately, with aging time, Ag ion and Ag NP effect will merge to a common value. - Highlights: • Toxicity of silver nanoparticles in soils increased with time. • Standard tests do not adequately assess toxicity of silver NPs to earthworms. • Internal Ag in earthworms did not always explain toxicity after shorter aging times. • With aging time, Ag ion and Ag NP effect in soils will merge to a common value. - Toxicity of silver nanoparticles in soils increased with time with the result that commonly applied tests of 28 days exposure with freshly spiked soils do not adequately assess the environmental hazard of silver nanoparticles

  8. Landslide kinematics and their potential controls from hourly to decadal timescales: Insights from integrating ground-based InSAR measurements with structural maps and long-term monitoring data

    Science.gov (United States)

    Schulz, William H.; Coe, Jeffrey A.; Ricci, Pier P.; Smoczyk, Gregory M.; Shurtleff, Brett L.; Panosky, Joanna

    2017-05-01

    Knowledge of kinematics is rudimentary for understanding landslide controls and is increasingly valuable with greater spatiotemporal coverage. However, characterizing landslide-wide kinematics is rare, especially at broadly ranging timescales. We used highly detailed kinematic data obtained using photogrammetry and field mapping during the 1980s and 1990s and our 4.3-day ground-based InSAR survey during 2010 to study kinematics of the large, persistently moving Slumgullion landslide. The landslide was segregated into 11 kinematic elements using the 1980s-1990s data and the InSAR survey revealed most of these elements within a few hours. Averages of InSAR-derived displacement point measures within each element agreed well with higher quality in situ observations; averaging was deemed necessary because adverse look angles for the radar coupled with tree cover on the landslide introduced error in the InSAR results. We found that the landslide moved during 2010 at about half its 1985-1990 speed, but slowing was most pronounced at the landslide head. Gradually decreased precipitation and increased temperature between the periods likely resulted in lower groundwater levels and consequent slowing of the landslide. We used GPS survey results and limit-equilibrium modeling to analyze changing stability of the landslide head from observed thinning and found that its stability increased between the two periods, which would result in its slowing, and the consequent slowing of the entire landslide. Additionally, InSAR results suggested movement of kinematic element boundaries in the head region and our field mapping verified that they moved and changed character, likely because of the long-term increasing head stability. On an hourly basis, InSAR results were near error bounds but suggested landslide acceleration in response to seemingly negligible rainfall. Pore-pressure diffusion modeling suggested that rainfall infiltration affected frictional strength only to shallow depths

  9. Long-Term Follow-Up after Treatment of Cryptorchidism

    DEFF Research Database (Denmark)

    Thorup, Jorgen; Cortes, Dina

    2016-01-01

    -known knowledge on the field is presented.To some extent a smaller testis in a higher scrotal position than normal must be accepted as a fair cosmetic result after orchidopexy in childhood. The smaller testis size is related to the impaired fertility potential of the testis. In cases with atrophy, testicular......When considering long-term prognosis and results in adult age following treatment of cryptorchidism in childhood there are three main issues to be discussed: cosmetics, fertility, and malignancy. In the present review, the most recent research on the topics related to summaries of well...

  10. Oil use and oil dependency: Long-term issues

    International Nuclear Information System (INIS)

    Serot, D.E.; Belzer, D.B.; Guthrie, S.A.; Roop, J.M.

    1989-06-01

    The continued dependence of the United States on imported oil is a matter of increasing concern. Under the direction of the Department of Energy's Office of Policy Integration, Pacific Northwest Laboratory conducted a study which was to examine long-term issues related to oil dependence. Major issues addressed are (1) energy efficiency and the role of new technologies, (2) fuel switching, and (3) regional factors affecting fuel use. The study examines all major end-use sectors in the economy, covering the industrial, commercial, residential, transportation, and electric utility sectors. The potential impacts of efficiency improvements in oil- using equipment are assessed through the year 2000. 107 refs., 8 figs., 9 tabs

  11. Fluoxetine Inhibits Natural Decay of Long-Term Memory via Akt/GSK-3β Signaling.

    Science.gov (United States)

    Yi, Jee Hyun; Zhang, JiaBao; Ko, Sang Yoon; Kwon, Huiyoung; Jeon, Se Jin; Park, Se Jin; Jung, Jiwook; Kim, Byung C; Lee, Young Choon; Kim, Dong Hyun; Ryu, Jong Hoon

    2018-02-09

    Understanding the mechanisms underlying the natural decay of long-term memory can help us find means of extending the duration of long-term memory. However, the neurobiological processes involved in the decay of long-term memory are poorly understood. In the present study, we examined the effect of acute and chronic treatment of fluoxetine on natural decay of long-term memory and the possible mechanism. Late administration of fluoxetine prolonged the persistence of long-term memory in mice, as demonstrated by object location recognition and Barnes maze tests. Fluoxetine altered Akt/glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling in the hippocampus. Late short- and long-term pharmacological inhibition of GSK-3β mimicked the effect of fluoxetine on memory persistence. Pharmacological inhibition of Akt blocked the effect of fluoxetine on memory persistence. Finally, late infusion of fluoxetine increased hippocampal long-term potentiation (LTP) and pharmacological inhibition of GSK-3β blocked the natural decline in LTP. These results demonstrate that GSK-3β might be a key molecule in memory decay process, and fluoxetine extends the period of long-term memory maintenance via Akt/GSK-3β signaling.

  12. Robotics for Long-Term Monitoring

    International Nuclear Information System (INIS)

    Shahin, Sarkis; Duran, Celso

    2002-01-01

    While long-term monitoring and stewardship means many things to many people, DOE has defined it as The physical controls, institutions, information, and other mechanisms needed to ensure protection of people and the environment at sites where DOE has completed or plans to complete cleanup (e.g., landfill closures, remedial actions, and facility stabilization). Across the United States, there are thousands of contaminated sites with multiple contaminants released from multiple sources where contaminants have transported and commingled. The U.S. government and U.S. industry are responsible for most of the contamination and are landowners of many of these contaminated properties. These sites must be surveyed periodically for various criteria including structural deterioration, water intrusion, integrity of storage containers, atmospheric conditions, and hazardous substance release. The surveys, however, are intrusive, time-consuming, and expensive and expose survey personnel to radioactive contamination. In long-term monitoring, there's a need for an automated system that will gather and report data from sensors without costly human labor. In most cases, a SCADA (Supervisory Control and Data Acquisition) unit is used to collect and report data from a remote location. A SCADA unit consists of an embedded computer with data acquisition capabilities. The unit can be configured with various sensors placed in different areas of the site to be monitored. A system of this type is static, i.e., the sensors, once placed, cannot be moved to other locations within the site. For those applications where the number of sampling locations would require too many sensors, or where exact location of future problems is unknown, a mobile sensing platform is an ideal solution. In many facilities that undergo regular inspections, the number of video cameras and air monitors required to eliminate the need for human inspections is very large and far too costly. HCET's remote harsh

  13. Long-Term Clock Behavior of GPS IIR Satellites

    National Research Council Canada - National Science Library

    Epstein, Marvin; Dass, Todd; Rajan, John; Gilmour, Paul

    2007-01-01

    .... Rubidium clocks, as opposed to cesium clocks, have significant long-term drift. The current literature describes an initial model of drift