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Andra long term memory project - 59277  

International Nuclear Information System (INIS)

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 historyas well as broad history

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A cost of long-term memory in Drosophila  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may hel...

Mery, Frederic; Kawecki, Tadeusz J.

2005-01-01

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Long-term memories in online users' selecting activities  

Science.gov (United States)

In this paper, we investigate the long-term memory effect in the behavior of online users. Two user-oriented online movie systems are used in this study. Due to the short length of the series, the balanced estimation of diffusion entropy approach is used to evaluate scaling-invariance in selecting activities of users in the two online movie systems. Our results indicate that persistence (long-term memory) exists widely in the movie selecting series. However, there is generally significant difference between a user's objective and subjective behaviors. Additionally, statistically, the long-term memory depends on activity levels, as results show that the much more active a users' group, the stronger the long-term memory will be. These findings provide a new criterion for constructing reasonable models, and can help understand how individuals' behaviors form a collective behavior of an online society.

Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie

2014-07-01

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Long-term memory, sleep, and the spacing effect.  

Science.gov (United States)

Many studies have shown that memory is enhanced when study sessions are spaced apart rather than massed. This spacing effect has been shown to have a lasting benefit to long-term memory when the study phase session follows the encoding session by 24 hours. Using a spacing paradigm we examined the impact of sleep and spacing gaps on long-term declarative memory for Swahili-English word pairs by including four spacing delay gaps (massed, 12 hours same-day, 12 hours overnight, and 24 hours). Results showed that a 12-hour spacing gap that includes sleep promotes long-term memory retention similar to the 24-hour gap. The findings support the importance of sleep to the long-term benefit of the spacing effect. PMID:23521365

Bell, Matthew C; Kawadri, Nader; Simone, Patricia M; Wiseheart, Melody

2014-01-01

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The neuronal response at extended timescales: long-term correlations without long-term memory  

Science.gov (United States)

Long term temporal correlations frequently appear at many levels of neural activity. We show that when such correlations appear in isolated neurons, they indicate the existence of slow underlying processes and lead to explicit conditions on the dynamics of these processes. Moreover, although these slow processes can potentially store information for long times, we demonstrate that this does not imply that the neuron possesses a long memory of its input, even if these processes are bidirectionally coupled with neuronal response. We derive these results for a broad class of biophysical neuron models, and then fit a specific model to recent experiments. The model reproduces the experimental results, exhibiting long term (days-long) correlations due to the interaction between slow variables and internal fluctuations. However, its memory of the input decays on a timescale of minutes. We suggest experiments to test these predictions directly. PMID:24744724

Soudry, Daniel; Meir, Ron

2014-01-01

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Long-Term Memory: Scaling of Information to Brain Size  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The material bases of information - paper, computer discs - usually scale with information quantity. Large quantities of information usually require large material bases. Conventional wisdom has it that human long-term memory locates within brain tissue, and so might be expected to scale with brain size which, in turn, depends on cranial capacity. Large memories, as in savants, should always require large heads. Small heads should always scale with small memories. While it w...

Forsdyke, Donald R.

2013-01-01

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Time of Day and Retrieval from Long-term Memory.  

Science.gov (United States)

Three separate groups of women performed a semantic classification task during the morning, afternoon, or evening. Results were directly opposite findings that short-term memory performance declines as the day progresses. It is suggested that physiological arousal, which rises through the day, may benefit retrieval efficiency from long-term

Millar, Keith; And Others

1980-01-01

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A quantitative proteomic analysis of long-term memory  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Memory is the ability to store, retain, and later retrieve learned information. Long-term memory (LTM formation requires: DNA transcription, RNA translation, and the trafficking of newly synthesized proteins. Several components of these processes have already been identified. However, due to the complexity of the memory formation process, there likely remain many yet to be identified proteins involved in memory formation and persistence. Results Here we use a quantitative proteomic method to identify novel memory-associated proteins in neural tissue taken from animals that were trained in vivo to form a long-term memory. We identified 8 proteins that were significantly up-regulated, and 13 that were significantly down-regulated in the LTM trained animals as compared to two different control groups. In addition we found 19 proteins unique to the trained animals, and 12 unique proteins found only in the control animals. Conclusions These results both confirm the involvement of previously identified memory proteins such as: protein kinase C (PKC, adenylate cyclase (AC, and proteins in the mitogen-activated protein kinase (MAPK pathway. In addition these results provide novel protein candidates (e.g. UHRF1 binding protein on which to base future studies.

Rosenegger David

2010-03-01

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Long-term memory in electricity prices: Czech market evidence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We analyze long-term memory properties of hourly prices of electricity in the Czech Republic between 2009 and 2012. As the dynamics of the electricity prices is dominated by cycles -- mainly intraday and daily -- we opt for the detrended fluctuation analysis, which is well suited for such specific series. We find that the electricity prices are non-stationary but strongly mean-reverting which distinguishes them from other financial assets which are usually characterized as u...

Kristoufek, Ladislav; Lunackova, Petra

2013-01-01

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Wnt Signaling Is Required for Long-Term Memory Formation  

Directory of Open Access Journals (Sweden)

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 ?-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 ?-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.

Ying Tan

2013-09-01

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Long-term memory of heterospecific vocalizations by African lions  

Science.gov (United States)

Animals that use and evaluate long-distance signals have the potential to glean valuable information about others in their environment via eavesdropping. In those areas where they coexist, African lions (Panthera leo) are a significant eavesdropper on spotted hyenas (Crocuta crocuta), often using hyena vocalizations to locate and scavenge from hyena kills. This relationship was used to test African lions' long-term memory of the vocalizations of spotted hyenas via playback experiments. Hyena whoops and a control sound (Canis lupus howls) were played to three populations of lions in South Africa: (1) lions with past experience of spotted hyenas; (2) lions with current experience; and (3) lions with no experience. The results strongly suggest that lions have the cognitive ability to remember the vocalizations of spotted hyenas even after 10 years with no contact of any kind with them. Such long-term memory of heterospecific vocalizations may be widespread in species that gain fitness benefits from eavesdropping on others, but where such species are sympatric and often interact it may pass unrecognized as short-term memory instead.

Grinnell, Jon; van Dyk, Gus; Slotow, Rob

2005-09-01

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[The long-term memory retrieval following kainic acid administration].  

Science.gov (United States)

Effect of the neurotoxin kainic acid to the food-procuring task were studied in Wistar rats. A single injection of the acid in subconvulsive dose (8 mg/kg) impaired the task performance within some weeks but not immediately after the treatment. Higher doses of kainic acid (10 mg/kg) impaired the task performance within a few hours after treatment for up to 10 days. The treatment did not prevent rat's learning of a new task in the same experimental chamber. The revealed deficit in the long-term memory retrieval might be explained by specific effects of kainic acid upon the hippocampal system. PMID:15462208

Arkhipov, V I; Shevchenko, N A

2004-07-01

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Working Memory, Long-Term Memory, and Medial Temporal Lobe Function  

Science.gov (United States)

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance…

Jeneson, Annette; Squire, Larry R.

2012-01-01

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Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Since William James (1890) first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into th...

Vianna Mo?nica, R. M.; Izquierdo Luciana, A.; Barros Daniela, M.; WALZ ROGER; Medina Jorge, H.; IZQUIERDO IVÁN

2000-01-01

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Long-Term Ecological Monitoring Field Sampling Plan for 2007  

Energy Technology Data Exchange (ETDEWEB)

This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used t determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality.

T. Haney

2007-07-31

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Long-Term Ecological Monitoring Field Sampling Plan for 2007  

International Nuclear Information System (INIS)

This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used to determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality

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Erythropoietin enhances hippocampal long-term potentiation and memory  

Directory of Open Access Journals (Sweden)

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.

El-Kordi Ahmed

2008-09-01

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DNA Methylation Mediates the Discriminatory Power of Associative Long-Term Memory in Honeybees  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Memory is created by several interlinked processes in the brain, some of which require long-term gene regulation. Epigenetic mechanisms are likely candidates for regulating memory-related genes. Among these, DNA methylation is known to be a long lasting genomic mark and may be involved in the establishment of long-term memory. Here we demonstrate that DNA methyltransferases, which induce and maintain DNA methylation, are involved in a particular aspect of associative long-term memory formatio...

Biergans, Stephanie D.; Jones, Julia C.; Treiber, Nadine; Galizia, Giovanni; Szyszka, Paul

2012-01-01

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Long-term memory of individual identity in ant queens  

DEFF Research Database (Denmark)

Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.

Dreier, Stéphanie Agnès Jeanine; Van Zweden, Jelle Stijn

2007-01-01

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Working memory, long-term memory, and medial temporal lobe function  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have be...

Jeneson, Annette; Squire, Larry R.

2012-01-01

 
 
 
 
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Exploring the interaction between working memory and long-term memory: Evidence for the workspace model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is a large range of models of working memory, each with different scopes and emphases. Current interest focuses strongly on the interaction of working memory with long-term memory, as it has become clear that models of working memory alone are incapable of capturing some of our complex cognitive abilities. Most models have contrasting views on how this interaction is implemented. In this thesis, three classes of models are defined, each proposing a different type of interaction. The fir...

Meulen, Marian

2008-01-01

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Musical and Verbal Memory in Alzheimer's Disease: A Study of Long-Term and Short-Term Memory  

Science.gov (United States)

Musical memory was tested in Alzheimer patients and in healthy older adults using long-term and short-term memory tasks. Long-term memory (LTM) was tested with a recognition procedure using unfamiliar melodies. Short-term memory (STM) was evaluated with same/different judgment tasks on short series of notes. Musical memory was compared to verbal…

Menard, Marie-Claude; Belleville, Sylvie

2009-01-01

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Creating the Unforgettable: The Short Story of Mapping Long-Term Memory: Bicentennial Symposium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Memory is a binary process relying on a short-term form lasting minutes to forge and communicate with a long-term form lasting years. Yale’s Bicentennial Symposium opened with a lecture elucidating the obscure process of long-term memory formation. From his decades of research, Nobel Laureate Eric Kandel offered insight into the molecular framework that is long term-memory.

Wang, Samantha X. Y.

2011-01-01

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Subregion-specific p300 conditional knock-out mice exhibit long-term memory impairments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least 400 described interacting proteins including transcription factors known to play a role in long-term memory formation. Thus, CBP and p300 constitute likely candidates for transc...

Oliveira, Ana M. M.; Este?vez, Marcel A.; Hawk, Joshua D.; Grimes, Shannon; Brindle, Paul K.; Abel, Ted

2011-01-01

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The Neural Substrates of Recognition Memory for Verbal Information: Spanning the Divide between Short- and Long-term Memory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the classic categorical divisions in the history of memory research is that between short-term and long-term memory. Indeed, because memory for the immediate past (a few seconds) and memory for the relatively more remote past (several seconds and beyond) are assumed to rely on distinct neural systems, more often than not, memory research has focused either on short- (or “working memory”) or on long-term memory. Using an auditory–verbal continuous recognition paradigm designed for...

Buchsbaum, Bradley R.; Padmanabhan, Aarthi; Berman, Karen Faith

2010-01-01

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Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades  

Directory of Open Access Journals (Sweden)

Full Text Available Since William James (1890 first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.

MÔNICA R.M. VIANNA

2000-09-01

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Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Since William James (1890) first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has be [...] en whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.

MÔNICA R.M., VIANNA; LUCIANA A., IZQUIERDO; DANIELA M., BARROS; ROGER, WALZ; JORGE H., MEDINA; IVÁN, IZQUIERDO.

2000-09-01

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Subregion-Specific p300 Conditional Knock-Out Mice Exhibit Long-Term Memory Impairments  

Science.gov (United States)

Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least 400 described interacting…

Oliveira, Ana M. M.; Estevez, Marcel A.; Hawk, Joshua D.; Grimes, Shannon; Brindle, Paul K.; Abel, Ted

2011-01-01

29

They Saw a Movie: Long-Term Memory for an Extended Audiovisual Narrative  

Science.gov (United States)

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed…

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-01-01

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The histone deacetylase HDAC4 regulates long-term memory in Drosophila.  

Science.gov (United States)

A growing body of research indicates that pharmacological inhibition of histone deacetylases (HDACs) correlates with enhancement of long-term memory and current research is concentrated on determining the roles that individual HDACs play in cognitive function. Here, we investigate the role of HDAC4 in long-term memory formation in Drosophila. We show that overexpression of HDAC4 in the adult mushroom body, an important structure for memory formation, resulted in a specific impairment in long-term courtship memory, but had no affect on short-term memory. Overexpression of an HDAC4 catalytic mutant also abolished LTM, suggesting a mode of action independent of catalytic activity. We found that overexpression of HDAC4 resulted in a redistribution of the transcription factor MEF2 from a relatively uniform distribution through the nucleus into punctate nuclear bodies, where it colocalized with HDAC4. As MEF2 has also been implicated in regulation of long-term memory, these data suggest that the repressive effects of HDAC4 on long-term memory may be through interaction with MEF2. In the same genetic background, we also found that RNAi-mediated knockdown of HDAC4 impairs long-term memory, therefore we demonstrate that HDAC4 is not only a repressor of long-term memory, but also modulates normal memory formation. PMID:24349558

Fitzsimons, Helen L; Schwartz, Silvia; Given, Fiona M; Scott, Maxwell J

2013-01-01

31

Evidence for long-term memory in sea level  

Science.gov (United States)

and attribution of anthropogenic climate change signals in sea level rise (SLR) has experienced considerable attention during the last decades. Here we provide evidence that superimposed on any possible anthropogenic trend there is a significant amount of natural decadal and multidecadal variability. Using a set of 60 centennial tide gauge records and an ocean reanalysis, we find that sea levels exhibit long-term correlations on time scales up to several decades that are independent of any systematic rise. A large fraction of this long-term variability is related to the steric component of sea level, but we also find long-term correlations in current estimates of mass loss from glaciers and ice caps. These findings suggest that (i) recent attempts to detect a significant acceleration in regional SLR might underestimate the impact of natural variability and (ii) any future regional SLR threshold might be exceeded earlier/later than from anthropogenic change alone.

Dangendorf, Sönke; Rybski, Diego; Mudersbach, Christoph; Müller, Alfred; Kaufmann, Edgar; Zorita, Eduardo; Jensen, Jürgen

2014-08-01

32

Excess protein synthesis in Drosophila Fragile X mutants impairs long-term memory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We used Drosophila olfactory memory in order to understand in vivo the molecular basis of cognitive defect in Fragile X syndrome. We observed that Fragile X protein (FMRP) was required acutely and interacted with argonaute1 and staufen in long-term memory (LTM). Occlusion of long-term memory formation in Fragile X mutants could be rescued by protein synthesis inhibitors, suggesting that excess baseline protein synthesis could impact negatively on cognition.

Bolduc, Franc?ois V.; Bell, Kimberly; Cox, Hilary; Broadie, Kendal; Tully, Tim

2008-01-01

33

Distinct dopamine neurons mediate reward signals for short- and long-term memories.  

Science.gov (United States)

Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons. PMID:25548178

Yamagata, Nobuhiro; Ichinose, Toshiharu; Aso, Yoshinori; Plaçais, Pierre-Yves; Friedrich, Anja B; Sima, Richard J; Preat, Thomas; Rubin, Gerald M; Tanimoto, Hiromu

2015-01-13

34

Narrative organisation at encoding facilitated children's long-term episodic memory.  

Science.gov (United States)

This study examined the effect of narrative organisation at encoding on long-term episodic memory in a sample of five- to seven-year-old children (N = 113). At an initial interview, children were asked to narrate a story from a picture book. Six months later, they were interviewed again and asked to recall the story and answer a series of direct questions about the story. Children who initially encoded more information in narrative and produced more complete, complex, cohesive and coherent narratives remembered the story in greater detail and accuracy following the six-month interval, independent of age and verbal skills. The relation between narrative organisation and memory was consistent across culture and gender. These findings provide new insight into the critical role of narrative in episodic memory. PMID:24786637

Wang, Qi; Bui, Van-Kim; Song, Qingfang

2015-06-01

35

Long-term Memory and Volatility Clustering in Daily and High-frequency Price Changes  

CERN Document Server

We study the long-term memory in diverse stock market indices and foreign exchange rates using the Detrended Fluctuation Analysis(DFA). For all daily and high-frequency market data studied, no significant long-term memory property is detected in the return series, while a strong long-term memory property is found in the volatility time series. The possible causes of the long-term memory property are investigated using the return data filtered by the AR(1) model, reflecting the short-term memory property, and the GARCH(1,1) model, reflecting the volatility clustering property, respectively. Notably, we found that the memory effect in the AR(1) filtered return and volatility time series remains unchanged, while the long-term memory property either disappeared or diminished significantly in the volatility series of the GARCH(1,1) filtered data. We also found that in the high-frequency data the long-term memory property may be generated by the volatility clustering as well as higher autocorrelation. Our results i...

Oh, G J; Um, C J; Kim, Seunghwann; Oh, GabJin; Um, Cheol-Jun

2006-01-01

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Early calcium increase triggers the formation of olfactory long-term memory in honeybees  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+ plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i in the brain, we show that: (i blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.

Matsumoto Yukihisa

2009-06-01

37

Lateral Habenula determines long-term storage of aversive memories.  

Directory of Open Access Journals (Sweden)

Full Text Available The Lateral Habenula (LHb is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA. We found that LHb inactivation during IA training does not disrupt memory when assessed 24 hours after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.

Micol Tomaiuolo

2014-05-01

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Endogenous BDNF Is Required for Long-Term Memory Formation in the Rat Parietal Cortex  

Science.gov (United States)

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory

Alonso, Mariana; Bekinschtein, Pedro, Cammarota, Martin; Vianna, Monica R. M.; Izquierdo, Ivan; Medina, Jorge H.

2005-01-01

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Synaptic Scaling Enables Dynamically Distinct Short- and Long-Term Memory Formation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling – a slow process usually ass...

Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wo?rgo?tter, Florentin

2013-01-01

40

Early calcium increase triggers the formation of olfactory long-term memory in honeybees.  

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Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+) plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary an...

Matsumoto Yukihisa; Néant Isabelle; Raymond-Delpech Valérie; Perisse Emmanuel; Leclerc Catherine; Moreau Marc; Sandoz Jean-Christophe

2009-01-01

 
 
 
 
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Function of the Drosophila CPEB protein Orb2 in long-term courtship memory.  

Science.gov (United States)

Both long-term behavioral memory and synaptic plasticity require protein synthesis, some of which may occur locally at specific synapses. Cytoplasmic polyadenylation element-binding (CPEB) proteins are thought to contribute to the local protein synthesis that underlies long-term changes in synaptic efficacy, but a role has not been established for them in the formation of long-term behavioral memory. We found that the Drosophila melanogaster CPEB protein Orb2 is acutely required for long-term conditioning of male courtship behavior. Deletion of the N-terminal glutamine-rich region of Orb2 resulted in flies that were impaired in their ability to form long-term, but not short-term, memory. Memory was restored by expressing Orb2 selectively in fruitless (fru)-positive gamma neurons of the mushroom bodies and by providing Orb2 function in mushroom bodies only during and shortly after training. Our data thus demonstrate that a CPEB protein is important in long-term memory and map the molecular, spatial and temporal requirements for its function in memory formation. PMID:17965711

Keleman, Krystyna; Krüttner, Sebastian; Alenius, Mattias; Dickson, Barry J

2007-12-01

42

Post-Training Intrahippocampal Inhibition of Class I Histone Deacetylases Enhances Long-Term Object-Location Memory  

Science.gov (United States)

Long-term memory formation involves covalent modification of the histone proteins that package DNA. Reducing histone acetylation by mutating histone acetyltransferases impairs long-term memory, and enhancing histone acetylation by inhibiting histone deacetylases (HDACs) improves long-term memory. Previous studies using HDAC inhibitors to enhance…

Hawk, Joshua D.; Florian, Cedrick; Abel, Ted

2011-01-01

43

Interactions between the orbitofrontal cortex and the hippocampal memory system during the storage of long-term memory.  

Science.gov (United States)

It has been proposed that long-term declarative memories are ultimately stored through interactions between the hippocampal memory system and the neocortical association areas that initially processed the to-be-stored information. One association neocortex, the orbitofrontal cortex (OFC) is strongly and reciprocally connected with the hippocampal memory system and plays an important role in odor recognition memory in rats. We will report data from two studies: one that examined the firing of neurons in a task dependent on the parahippocampal region (PHR; including the perirhinal, postrhinal, and entrorhinal cortices), and one examined the firing of OFC neurons performing a task that is presumably dependent on the hippocampus. In the first study, we examined the role of OFC neurons in the continuous odor-guided nonmatching to sample task. While the firing of neurons in the PHR and OFC are similar in this task, there are several notable differences that are consistent with the idea that OFC is a high-order association cortex which interacts extensively with the PHR to store declarative memories. In the second study, we characterized the firing patterns of neurons in the OFC rats performing a passive, 8-odor-sequence memory task. Most interesting were neurons that fired selectively in anticipation of specific odors. We found that hippocampal lesions abolished the anticipatory firing in OFC, suggesting that these anticipatory responses (memory) were in fact dependent on the hippocampus, further supporting the view that the OFC interacts with the hippocampal memory system to store long-term, declarative memories. PMID:17872388

Ramus, Seth J; Davis, Jena B; Donahue, Rachel J; Discenza, Claire B; Waite, Alissa A

2007-12-01

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Genetic modulation of Rpd3 expression impairs long-term courtship memory in Drosophila.  

Science.gov (United States)

There is increasing evidence that regulation of local chromatin structure is a critical mechanism underlying the consolidation of long-term memory (LTM), however considerably less is understood about the specific mechanisms by which these epigenetic effects are mediated. Furthermore, the importance of histone acetylation in Drosophila memory has not been reported. The histone deacetylase (HDAC) Rpd3 is abundant in the adult fly brain, suggesting a post-mitotic function. Here, we investigated the role of Rpd3 in long-term courtship memory in Drosophila. We found that while modulation of Rpd3 levels predominantly in the adult mushroom body had no observed impact on immediate recall or one-hour memory, 24-hour LTM was severely impaired. Surprisingly, both overexpression as well as RNAi-mediated knockdown of Rpd3 resulted in impairment of long-term courtship memory, suggesting that the dose of Rpd3 is critical for normal LTM. PMID:22195015

Fitzsimons, Helen L; Scott, Maxwell J

2011-01-01

45

An Account of Performance in Accessing Information Stored in Long-Term Memory. A Fixed-Links Model Approach  

Science.gov (United States)

Performance in working memory and short-term memory tasks was employed for predicting performance in a long-term memory task in order to find out about the underlying processes. The types of memory were represented by versions of the Posner Task, the Backward Counting Task and the Sternberg Task serving as measures of long-term memory, working…

Altmeyer, Michael; Schweizer, Karl; Reiss, Siegbert; Ren, Xuezhu; Schreiner, Michael

2013-01-01

46

Specific requirement of NMDA receptors for long-term memory consolidation in Drosophila ellipsoid body  

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In humans and many other animals, memory consolidation occurs through multiple temporal phases and usually involves more than one neuroanatomical brain system. Genetic dissection of Pavlovian olfactory learning in Drosophila melanogaster has revealed multiple memory phases, but the predominant view holds that all memory phases occur in mushroom body neurons. Here, we demonstrate an acute requirement for NMDA receptors (NMDARs) outside of the mushroom body during long-term memory (LTM) consoli...

Wu, Chia-lin; Xia, Shouzhen; Fu, Tsai-feng; Wang, Huaien; Chen, Ying-hsiu; Leong, Daniel; Chiang, Ann-shyn; Tully, Tim

2007-01-01

47

A COMPARATIVE STUDY OF SHORT TERM AND LONG TERM MEMORY BETWEEN ATHLETE AND NON ATHLETE  

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The aim of this study was to compare the Short Term Memory and Long Term Memory of Athlete and non Athlete. One hundred college boys (50 Athlete participated in inter-college tournament and 50 non Athlete) from different colleges of north 24 district in West Bengal were considered for this study whose age range between 22 to 25 years. Only, Short Term and Long Term memory were measured for this study. Standard questionnaires were used for this study. The statistical 't' test was a...

GOPAL CHANDRA SAHA; SHANTANU HALDER; PULEN DAS

2013-01-01

48

PKG-Mediated MAPK Signaling Is Necessary for Long-Term Operant Memory in "Aplysia"  

Science.gov (United States)

Signaling pathways necessary for memory formation, such as the mitogen-activated protein kinase (MAPK) pathway, appear highly conserved across species and paradigms. Learning that food is inedible (LFI) represents a robust form of associative, operant learning that induces short- (STM) and long-term memory (LTM) in "Aplysia." We investigated the…

Michel, Maximilian; Green, Charity L.; Eskin, Arnold; Lyons, Lisa C.

2011-01-01

49

The interaction of short-term and long-term memory in phonetic category formation  

Science.gov (United States)

This study examined the role that short-term memory capacity plays in the relationship between novel stimuli (e.g., non-native speech sounds, native nonsense words) and phonetic categories in long-term memory. Thirty native speakers of American English were administered five tests: categorial AXB discrimination using nasal consonants from Malayalam; categorial identification, also using Malayalam nasals, which measured the influence of phonetic categories in long-term memory; digit span; nonword span, a short-term memory measure mediated by phonetic categories in long-term memory; and paired-associate word learning (word-word and word-nonword pairs). The results showed that almost all measures were significantly correlated with one another. The strongest predictor for the discrimination and word-nonword learning results was nonword (r=+0.62) and digit span (r=+0.51), respectively. When the identification test results were partialed out, only nonword span significantly correlated with discrimination. The results show a strong influence of short-term memory capacity on the encoding of phonetic detail within phonetic categories and suggest that long-term memory representations regulate the capacity of short-term memory to preserve information for subsequent encoding. The results of this study will also be discussed with regards to resolving the tension between episodic and abstract models of phonetic category structure.

Harnsberger, James D.

2002-05-01

50

Hormonal and Monoamine Signaling during Reinforcement of Hippocampal Long-Term Potentiation and Memory Retrieval  

Science.gov (United States)

Recently it was shown that holeboard training can reinforce, i.e., transform early-LTP into late-LTP in the dentate gyrus during the initial formation of a long-term spatial reference memory in rats. The consolidation of LTP as well as of the reference memory was dependent on protein synthesis. We have now investigated the transmitter systems…

Korz, Volker; Frey, Julietta U.

2007-01-01

51

Retinoid signaling is necessary for, and promotes long-term memory formation following operant conditioning.  

Science.gov (United States)

Retinoic acid, a metabolite of vitamin A, is proposed to play an important role in vertebrate learning and memory, as well as hippocampal-dependent synaptic plasticity. However, it has not yet been determined whether retinoic acid plays a similar role in learning and memory in invertebrates. In this study, we report that retinoid signaling in the mollusc Lymnaea stagnalis, is required for long-term memory formation following operant conditioning of its aerial respiratory behaviour. Animals were exposed to inhibitors of the RALDH enzyme (which synthesizes retinoic acid), or various retinoid receptor antagonists. Following exposure to these inhibitors, neither learning nor intermediate-term memory (lasting 2 h) was affected, but long-term memory formation (tested at either 24 or 72 h) was inhibited. We next demonstrated that various retinoid receptor agonists promoted long-term memory formation. Using a training paradigm shown only to produce intermediate-term memory (lasting 2 h, but not 24 h) we found that exposure of animals to synthetic retinoids promoted memory formation that lasted up to 30 h. These findings suggest that the role of retinoids in memory formation is ancient in origin, and that retinoid signaling is also important for the formation of implicit memories, in addition to its previously demonstrated role in hippocampal-dependent memories. PMID:24925874

Rothwell, Cailin M; Spencer, Gaynor E

2014-10-01

52

What are the differences between long-term, short-term, and working memory?  

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In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rath...

Cowan, Nelson

2008-01-01

53

PKG-mediated MAPK signaling is necessary for long-term operant memory in Aplysia  

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Signaling pathways necessary for memory formation, such as the mitogen-activated protein kinase (MAPK) pathway, appear highly conserved across species and paradigms. Learning that food is inedible (LFI) represents a robust form of associative, operant learning that induces short- (STM) and long-term memory (LTM) in Aplysia. We investigated the role of MAPK signaling in LFI memory in vivo. Inhibition of MAPK activation in animals prior to training blocked STM and LTM. Discontinuing MAPK signal...

Michel, Maximilian; Green, Charity L.; Eskin, Arnold; Lyons, Lisa C.

2011-01-01

54

Tree ring records capture long-term memory in climate systems  

Science.gov (United States)

Measuring tree rings is a mainstay technique for estimating ancient climatic conditions, with a tree's year-by-year growth reflecting changes in precipitation and temperature. In some cases, paleoclimatological records compiled from tree ring measurements can stretch for thousands of years. Based on recent research, climatologists have found that hydrological and other systems have long-term memory. Drawing on tree ring measurements compiled from across the continental United States, Bowers et al. sought to determine whether such long-term relationships are preserved in ring width measurements. The authors analyzed the Hurst parameter—a measure of long-term memory—of 697 different tree ring records that were collected from 10 tree species from locations across the United States. They found that though each tree species had a different mean value for its Hurst parameter, meaning that each species recorded long-term trends in the climate differently, they all fell within the range suggestive of their being able to properly represent long-term memory.

Schultz, Colin

2013-03-01

55

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats  

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Full Text Available General anesthetics are neurotoxic to neonatal rodents and nonhuman primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long-Evans rat pups were exposed to 1.8% isoflurane for 2 hours on postnatal day (P 7, or for 2 hours each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life.

MarkGBaxter

2013-07-01

56

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats.  

Science.gov (United States)

General anesthetics are neurotoxic to neonatal rodents and non-human primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long-Evans rat pups were exposed to 1.8% isoflurane for 2?h on postnatal day (P) 7, or for 2?h each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life. PMID:23847588

Murphy, Kathy L; Baxter, Mark G

2013-01-01

57

SNAP-25 in hippocampal CA3 region is required for long-term memory formation  

International Nuclear Information System (INIS)

SNAP-25 is a synaptosomal protein of 25 kDa, a key component of synaptic vesicle-docking/fusion machinery, and plays a critical role in exocytosis and neurotransmitter release. We previously reported that SNAP-25 in the hippocampal CA1 region is involved in consolidation of contextual fear memory and water-maze spatial memory (Hou et al. European J Neuroscience, 20: 1593-1603, 2004). SNAP-25 is expressed not only in the CA1 region, but also in the CA3 region, and the SNAP-25 mRNA level in the CA3 region is higher than in the CA1 region. Here, we provide evidence that SNAP-25 in the CA3 region is also involved in learning/memory. Intra-CA3 infusion of SNAP-25 antisense oligonucleotide impaired both long-term contextual fear memory and water-maze spatial memory, with short-term memory intact. Furthermore, the SNAP-25 antisense oligonucleotide suppressed the long-term potentiation (LTP) of field excitatory post-synaptic potential (fEPSP) in the mossy-fiber pathway (DG-CA3 pathway), with no effect on paired-pulse facilitation of the fEPSP. These results are consistent with the notion that SNAP-25 in the hippocampal CA3 region is required for long-term memory formation

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Transcriptional regulation of long-term memory in the marine snail Aplysia  

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Full Text Available Abstract Whereas the induction of short-term memory involves only covalent modifications of constitutively expressed preexisting proteins, the formation of long-term memory requires gene expression, new RNA, and new protein synthesis. On the cellular level, transcriptional regulation is thought to be the starting point for a series of molecular steps necessary for both the initiation and maintenance of long-term synaptic facilitation (LTF. The core molecular features of transcriptional regulation involved in the long-term process are evolutionally conserved in Aplysia, Drosophila, and mouse, and indicate that gene regulation by the cyclic AMP response element binding protein (CREB acting in conjunction with different combinations of transcriptional factors is critical for the expression of many forms of long-term memory. In the marine snail Aplysia, the molecular mechanisms that underlie the storage of long-term memory have been extensively studied in the monosynaptic connections between identified sensory neuron and motor neurons of the gill-withdrawal reflex. One tail shock or one pulse of serotonin (5-HT, a modulatory transmitter released by tail shocks, produces a transient facilitation mediated by the cAMP-dependent protein kinase leading to covalent modifications in the sensory neurons that results in an enhancement of transmitter release and a strengthening of synaptic connections lasting minutes. By contrast, repeated pulses of 5-hydroxytryptamine (5-HT induce a transcription- and translation-dependent long-term facilitation (LTF lasting more than 24 h and trigger the activation of a family of transcription factors in the presynaptic sensory neurons including ApCREB1, ApCREB2 and ApC/EBP. In addition, we have recently identified novel transcription factors that modulate the expression of ApC/EBP and also are critically involved in LTF. In this review, we examine the roles of these transcription factors during consolidation of LTF induced by different stimulation paradigms.

Lee Yong-Seok

2008-06-01

59

Heightened false memory: a long-term sequela of severe closed head injury.  

Science.gov (United States)

Declarative memory impairment is a common long-term sequela of severe closed head injury (CHI). Although veridical memory performance following severe CHI has received attention in the literature, little is known about false memory production in this population. Within the present study, both long-term survivors of severe CHI and matched control participants studied and were tested on six 12-items word lists from the Deese Roediger McDermott (DRM) paradigm. Word lists from the DRM are composed of words that are strongly semantically associated to a non-presented word (i.e., the critical lure). Prior studies have shown that healthy young adults show a high level of false recall and recognition memory for the critical lures, and it was hypothesized individuals with severe CHI would show heightened susceptibility to false memory compared to control participants due to difficulty with monitoring of memory. It was further hypothesized that severe CHI participants would show high confidence in their false memories. Consistent with hypotheses, results indicated that although severe CHI participants remembered fewer actual list items, they made more semantically related intrusion errors (recall) and false-positive responses (recognition) than the control participants. Severe CHI participants also showed greater confidence in their false memories than did control participants. The results are interpreted in the context of theoretical accounts of false memory, and possible structural and functional brain changes that might account for the Severe CHI group's memory performance are discussed. PMID:16814819

Ries, Michele; Marks, William

2006-01-01

60

Devil in the Details? Developmental Dyslexia and Visual Long-Term Memory for Details  

Directory of Open Access Journals (Sweden)

Full Text Available Cognitive theories on causes of developmental dyslexia can be divided into language-specific and general accounts. While the former assume that words are special in that associated processing problems are rooted in language-related cognition (e.g., phonology deficits, the latter propose that dyslexia is rather rooted in a general impairment of cognitive (e.g., visual and/or auditory processing streams. In the present study, we examined to what extent dyslexia (typically characterized by poor orthographic representations may be associated with a general deficit in visual long-term memory for details. We compared object- and detail-related visual long-term memory performance (and phonological skills between dyslexic primary school children and IQ-, age- and gender-matched controls. The results revealed that while the overall amount of long-term memory errors was comparable between groups, dyslexic children exhibited a greater portion of detail-related errors. The results suggest that not only phonological, but also general visual resolution deficits in long-term memory may play an important role in developmental dyslexia.

LynnHuestegge

2014-07-01

 
 
 
 
61

Transgenic Mice Expressing an Inhibitory Truncated Form of p300 Exhibit Long-Term Memory Deficits  

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The formation of many forms of long-term memory requires several molecular mechanisms including regulation of gene expression. The mechanisms directing transcription require not only activation of individual transcription factors but also recruitment of transcriptional coactivators. CBP and p300 are transcriptional coactivators that interact with…

Oliveira, Ana M. M.; Wood, Marcelo A.; McDonough, Conor B.; Abel, Ted

2007-01-01

62

The long-term memory analysis of industrial indices of the Chinese stock market  

International Nuclear Information System (INIS)

The main work of this paper is to apply the fractional market theory and time series analysis for analyzing various industrial indices of the Chinese stock market by rescaling range analysis. Hurst index and the long-term memory of price change in Chinese stock market are studied

63

The Drosophila lingerer protein cooperates with Orb2 in long-term memory formation.  

Science.gov (United States)

Recently mated Drosophila females were shown to be reluctant to copulate and to exhibit rejecting behavior when courted by a male. Males that experience mate refusal by a mated female subsequently attenuate their courtship effort toward not only mated females but also virgin females. This courtship suppression persists for more than a day, and thus represents long-term memory. The courtship long-term memory has been shown to be impaired in heterozygotes as well as homozygotes of mutants in orb2, a locus encoding a set of CPEB RNA-binding proteins. We show that the impaired courtship long-term memory in orb2-mutant heterozygotes is restored by reducing the activity of lig, another putative RNA-binding protein gene, yet on its own the loss-of-function lig mutation is without effect. We further show that Lig forms a complex with Orb2. We infer that a reduction in the Lig levels compensates the Orb2 deficiency by mitigating the negative feedback for Orb2 expression and thereby alleviating defects in long-term memory. PMID:24913805

Kimura, Shingo; Sakakibara, Yasufumi; Sato, Kosei; Ote, Manabu; Ito, Hiroki; Koganezawa, Masayuki; Yamamoto, Daisuke

2014-07-01

64

Competitive short-term and long-term memory processes in spatial habituation.  

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Exposure to a spatial location leads to habituation of exploration such that, in a novelty preference test, rodents subsequently prefer exploring a novel location to the familiar location. According to Wagner's (1981) theory of memory, short-term and long-term habituation are caused by separate and sometimes opponent processes. In the present study, this dual-process account of memory was tested. Mice received a series of exposure training trials to a location before receiving a novelty prefe...

Sanderson, Dj; Bannerman, Dm

2011-01-01

65

Long-Term Behaviors of Stochastic Interest Rate Models with Jumps and Memory  

CERN Document Server

In this paper we show the convergence of the long-term return $t^{-\\mu}\\int_0^tX(s)\\d s$ for some $\\mu\\geq1$, where $X$ is the short-term interest rate which follows an extension of Cox-Ingersoll-Ross type model with jumps and memory, and, as an application, we also investigate the corresponding behavior of two-factor Cox-Ingersoll-Ross model with jumps and memory

Bao, Jianhai

2011-01-01

66

Genetic Modulation of Rpd3 Expression Impairs Long-Term Courtship Memory in Drosophila  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is increasing evidence that regulation of local chromatin structure is a critical mechanism underlying the consolidation of long-term memory (LTM), however considerably less is understood about the specific mechanisms by which these epigenetic effects are mediated. Furthermore, the importance of histone acetylation in Drosophila memory has not been reported. The histone deacetylase (HDAC) Rpd3 is abundant in the adult fly brain, suggesting a post-mitotic function. Here, we investigated ...

Fitzsimons, Helen L.; Scott, Maxwell J.

2011-01-01

67

Sensitivity from short-term memory vs. stability from long-term memory in visual attention method  

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In this paper a special focus on the relationship between sensitivity and stability in a dynamic selective visual attention method is described. In this proposal sensitivity is associated to short-term memory and stability to long-term memory, respectively. In first place, all necessary mechanisms to provide sensitivity to the system are included in order to succeed in keeping the attention in our short-term memory. Frame to frame attention is captured on elements constructed from image pixel...

2005-01-01

68

Temporal lobe surgery in childhood and neuroanatomical predictors of long-term declarative memory outcome.  

Science.gov (United States)

The temporal lobes play a prominent role in declarative memory function, including episodic memory (memory for events) and semantic memory (memory for facts and concepts). Surgical resection for medication-resistant and well-localized temporal lobe epilepsy has good prognosis for seizure freedom, but is linked to memory difficulties in adults, especially when the removal is on the left side. Children may benefit most from surgery, because brain plasticity may facilitate post-surgical reorganization, and seizure cessation may promote cognitive development. However, the long-term impact of this intervention in children is not known. We examined memory function in 53 children (25 males, 28 females) who were evaluated for epilepsy surgery: 42 underwent unilateral temporal lobe resections (25 left, 17 right, mean age at surgery 13.8 years), 11 were treated only pharmacologically. Average follow-up was 9 years (range 5-15). Post-surgical change in visual and verbal episodic memory, and semantic memory at follow-up were examined. Pre- and post-surgical T1-weighted MRI brain scans were analysed to extract hippocampal and resection volumes, and evaluate post-surgical temporal lobe integrity. Language lateralization indices were derived from functional magnetic resonance imaging. There were no significant pre- to postoperative decrements in memory associated with surgery. In contrast, gains in verbal episodic memory were seen after right temporal lobe surgery, and visual episodic memory improved after left temporal lobe surgery, indicating a functional release in the unoperated temporal lobe after seizure reduction or cessation. Pre- to post-surgical change in memory function was not associated with any indices of brain structure derived from MRI. However, better verbal memory at follow-up was linked to greater post-surgical residual hippocampal volumes, most robustly in left surgical participants. Better semantic memory at follow-up was associated with smaller resection volumes and greater temporal pole integrity after left temporal surgery. Results were independent of post-surgical intellectual function and language lateralization. Our findings indicate post-surgical, hemisphere-dependent material-specific improvement in memory functions in the intact temporal lobe. However, outcome was linked to the anatomical integrity of the temporal lobe memory system, indicating that compensatory mechanisms are constrained by the amount of tissue which remains in the operated temporal lobe. Careful tailoring of resections for children undergoing epilepsy surgery may enhance long-term memory outcome. PMID:25392199

Skirrow, Caroline; Cross, J Helen; Harrison, Sue; Cormack, Francesca; Harkness, William; Coleman, Rosie; Meierotto, Ellen; Gaiottino, Johanna; Vargha-Khadem, Faraneh; Baldeweg, Torsten

2015-01-01

69

Depletion of Serotonin Selectively Impairs Short-Term Memory without Affecting Long-Term Memory in Odor Learning in the Terrestrial Slug "Limax Valentianus"  

Science.gov (United States)

The terrestrial slug "Limax" is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC…

Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi; Shirahata, Takaaki; Tsunoda, Makoto

2006-01-01

70

Long-term memory for calls of relatives in cotton-top tamarins (Saguinus oedipus).  

Science.gov (United States)

Recognition of relatives is important for dispersing animals to avoid inbreeding and possibly for developing cooperative, reciprocal relationships between individuals after dispersal. We demonstrate under controlled captive conditions that cotton-top tamarins (Saguinus oedipus) have a long-term memory for long calls of relatives from which they had been separated for periods ranging from 4 to 55 months. Tamarins responded with lower levels of arousal behavior to playbacks of long calls from current mates and from separated relatives compared to calls of unfamiliar, unrelated tamarins. Four tamarins had been out of contact with relatives for more than 4 years and still showed recognition as evidenced by low levels of arousal. Results could not be explained in terms of proximity to former relatives. Long-term memory for vocal signatures of relatives is adaptive and may be much more common than has been demonstrated. PMID:21574684

Matthews, Stephanie; Snowdon, Charles T

2011-08-01

71

Cholestasis progression effects on long-term memory in bile duct ligation rats  

Science.gov (United States)

Background: There is evidence that cognitive functions are affected by some liver diseases such as cholestasis. Bile duct ligation induces cholestasis as a result of impaired liver function and cognition. This research investigates the effect of cholestasis progression on memory function in bile duct ligation rats. Materials and Methods: Male Wistar rats were randomly divided into five groups, which include: control group for BDL-7, control group for BDL-21, sham group (underwent laparotomy without bile duct ligation), BDL-7 group (7 days after bile duct ligation), and BDL-21 group (21 days after bile duct ligation). Step-through passive avoidance test was employed to examine memory function. In all groups, short-term (7 days after foot shock) and long-term memories (21 days after foot shock) were assessed. Results: Our results showed that liver function significantly decreased with cholestasis progression (P < 0.01). Also our findings indicated BDL-21 significantly impaired acquisition time (P < 0.05). Memory retrieval impaired 7 (P < 0.05) and 21 days (P < 0.001) after foot shock in BDL-7 and BDL-21 groups, respectively. Conclusion: Based on these findings, liver function altered in cholestasis and memory (short-term and long-term memory) impaired with cholestasis progression in bile duct ligation rats. Further studies are needed to better insight the nature of progression of brain damage in cholestatic disease. PMID:25371872

Hosseini, Nasrin; Alaei, Hojjatallah; Zarrindast, Mohammad Reza; Nasehi, Mohammad; Radahmadi, Maryam

2014-01-01

72

Making synapses strong: metaplasticity prolongs associativity of long-term memory by switching synaptic tag mechanisms.  

Science.gov (United States)

One conceptual mechanism for the induction of associative long-term memory is that a synaptic tag, set by a weak event, can capture plasticity-related proteins from a nearby strong input, thus enabling associativity between the 2 (synaptic tagging and capture, STC). So far, STC has been observed for only a limited time of 60 min. Nevertheless, association of weak memory forms can occur beyond this period and its mechanism is not well understood. Here we report that metaplasticity induced by ryanodine receptor activation or synaptic activation of metabotropic glutamate receptors prolongs the durability of the synaptic tag, thus extending the time window for associative interactions mediating storage of long-term memory. We provide evidence that such metaplasticity alters the mechanisms of STC from a CaMKII-mediated (in non-primed STC) to a protein kinase Mzeta (PKM?)-mediated process (in primed STC). Thus the association of weak synapses with strong synapses in the "late" stage of associative memory formation occurs only through metaplasticity. The results also reveal that the short-lived, CaMKII-mediated tag may contribute to a mechanism for a fragile form of memory while metaplasticity enables a PKM?-mediated synaptic tag capable of prolonged interactions that induce a more stable form of memory that is resistant to reversal. PMID:23048020

Li, Qin; Rothkegel, Martin; Xiao, Zhi Cheng; Abraham, Wickliffe C; Korte, Martin; Sajikumar, Sreedharan

2014-02-01

73

CNTRICS Imaging Biomarkers Final Task Selection: Long-Term Memory and Reinforcement Learning  

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Functional imaging paradigms hold great promise as biomarkers for schizophrenia research as they can detect altered neural activity associated with the cognitive and emotional processing deficits that are so disabling to this patient population. In an attempt to identify the most promising functional imaging biomarkers for research on long-term memory (LTM), the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative selected “item encoding and r...

Ragland, John D.; Cohen, Neal J.; Cools, Roshan; Frank, Michael J.; Hannula, Deborah E.; Ranganath, Charan

2012-01-01

74

Complex network structure influences processing in long-term and short-term memory  

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Complex networks describe how entities in systems interact; the structure of such networks is argued to influence processing. One measure of network structure, clustering coefficient, C, measures the extent to which neighbors of a node are also neighbors of each other. Previous psycholinguistic experiments found that the C of phonological word-forms influenced retrieval from the mental lexicon (that portion of long-term memory dedicated to language) during the on-line recognition and producti...

Vitevitch, Michael S.; Chan, Kit Ying; Roodenrys, Steven

2012-01-01

75

Long-Term Memory Motion-Compensated Prediction for Robust Video Transmission  

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Long-term memory prediction extends the spatial displacement vector utilized in hybrid video coding by a variable time delay permitting the use of more than one reference frame for motion compensation. This extension provides improved rate-distortion performance. However, motion compensation in combination with transmission errors leads to temporal error propagation that occurs when the reference frames at encoder and decoder differ. In this paper, we present a framework that incorporates an ...

Wiegand, T.; Fa?rber, N.; Stuhlmu?ller, K.; Girod, B.

2000-01-01

76

Demonstration of long-term memory in the parasitic wasp Nasonia vitripennis  

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We studied the formation of protein synthesis-dependent long-term memory (LTM) in the parasitic wasp Nasonia vitripennis Walker (Hymenoptera: Pteromalidae), a parasitoid of fly pupae. Female wasps were trained in one of five different training procedures in the presence of hosts and the odour cinnamon. Six days later the reaction of the wasps towards the odour was tested in a static four-chamber olfactometer. When wasps were trained by a single drilling experience we could not find any reacti...

Schurmann, D.; Sommer, C.; Schinko, A. P. B.; Greschista, M.; Smid, H. M.; Steidle, J. L. M.

2012-01-01

77

Long-term Memory for Calls of Relatives in Cotton-top Tamarins (Saguinus oedipus)  

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Recognition of relatives is important for dispersing animals to avoid inbreeding and possibly for developing cooperative, reciprocal relationships between individuals after dispersal. We demonstrate under controlled captive conditions that cotton-top tamarins (Saguinus oedipus) have a long-term memory for long calls of relatives from which they had been separated for periods ranging from 4 to 55 months. Tamarins responded with lower levels of arousal behavior to playbacks of long calls from c...

Matthews, Stephanie; Snowdon, Charles T.

2011-01-01

78

A clock gene, period, plays a key role in long-term memory formation in Drosophila  

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The cAMP-responsive transcription factor, CREB, is required for formation of long-term memory (LTM) in Drosophila melanogaster and regulates transcription of a circadian clock gene, period (per). Involvement of CREB both in LTM and circadian rhythm raises the possibility that per also plays a role in LTM. Assaying the experience-dependent courtship inhibition in male flies as a measure for LTM, we show here that per mutants are defective in LTM formation. This defect was rescued by induction ...

Sakai, Takaomi; Tamura, Takuya; Kitamoto, Toshihiro; Kidokoro, Yoshiaki

2004-01-01

79

The control of long-term memory: brain systems and cognitive processes.  

Science.gov (United States)

This paper provides a selective review of controlled memory retrieval, i.e., processes, that operate on long-term stored information in the service of current goals and task demands. Binding mechanisms that combine fragments of long-term stored information in response to a retrieval cue, are central for the understanding of the interaction between a retrieval cue and memory-stored information. The paper summarizes empirical evidence showing that ERP slow waves are highly sensitive to the initiation and maintenance of retrieval orientations. It is argued that similar mechanisms of controlled memory retrieval operate in the service of successful remembering and the suppression of unwanted memories (forgetting). The mechanisms can be grouped into two classes: those that enhance retrieval cue processing (cue bias) and those that directly act on memory representations and modulate their accessibility (target bias). From a neuroanatomical point of view, the former class of processes reflects selection mechanisms for internal actions that rely on the integrity of the prefrontal cortex (PFC), whereas the second class of processes can be identified with selective attention mechanisms for which the posterior parietal cortex (PPC) plays an important role. PMID:19944118

Mecklinger, Axel

2010-06-01

80

Neurotrophins play differential roles in short and long-term recognition memory.  

Science.gov (United States)

The neurotrophin family of proteins are believed to mediate various forms of synaptic plasticity in the adult brain. Here we have assessed the roles of these proteins in object recognition memory in the rat, using icv infusions of function-blocking antibodies or the tyrosine kinase antagonist, tyrphostin AG879, to block Trk receptors. We report that tyrphostin AG879 impairs both short-term and long-term recognition memory, indicating a requirement for Trk receptor activation in both processes. The effect of inhibition of each of the neurotrophins with activity-blocking neutralising antibodies was also tested. Treatment with anti-BDNF, anti-NGF or anti-NT4 had no effect on short-term memory, but blocked long-term recognition memory. Treatment with anti-NT3 had no effect on either process. We also assessed changes in expression of neurotrophins and their respective receptors in the hippocampus, dentate gyrus and perirhinal cortex over a 24 h period following training in the object recognition task. We observed time-dependent changes in expression of the Trk receptors and their ligands in the dentate gyrus and perirhinal cortex. The data are consistent with a pivotal role for neurotrophic factors in the expression of recognition memory. PMID:23669064

Callaghan, Charlotte K; Kelly, Aine M

2013-09-01

 
 
 
 
81

Novel long-term anticonvulsant treatment with gabapentin without causing memory impairment in mice.  

Science.gov (United States)

We previously reported that administration of a single dose of gabapentin (GBP) immediately after training improves memory of mice in an inhibitory avoidance task (IA), whereas GBP administered repeatedly for 7 days impairs memory. This is in accordance with the observation that long-term clinical treatment with GBP may be associated with adverse cognitive side effects. In the present work we used a GBP-loaded poly(epsilon-caprolactone) implant, allowing controlled release of the drug and maintenance of constant plasma levels over 1 week. When GBP-loaded implants were inserted subcutaneously into mice, immediately after training in the IA task, memory consolidation was enhanced. Moreover, GBP released from implants had an anticonvulsant action against pentylenetetrazole-induced seizures. These results suggest that maintenance of stable GBP plasma levels could protect against seizures without causing memory impairment. Hence, the adverse cognitive effects might be avoided by stabilizing plasma levels of the drug. PMID:20079694

Blake, Mariano G; Boccia, Mariano M; Carcaboso, Angel M; Chiappetta, Diego A; Höcht, Christian; Krawczyk, María C; Sosnik, Alejandro; Baratti, Carlos M

2010-02-01

82

Slow oscillations in two pairs of dopaminergic neurons gate long-term memory formation in Drosophila.  

Science.gov (United States)

A fundamental duty of any efficient memory system is to prevent long-lasting storage of poorly relevant information. However, little is known about dedicated mechanisms that appropriately trigger production of long-term memory (LTM). We examined the role of Drosophila dopaminergic neurons in the control of LTM formation and found that they act as a switch between two exclusive consolidation pathways leading to LTM or anesthesia-resistant memory (ARM). Blockade, after aversive olfactory conditioning, of three pairs of dopaminergic neurons projecting on mushroom bodies, the olfactory memory center, enhanced ARM, whereas their overactivation conversely impaired ARM. Notably, blockade of these neurons during the intertrial intervals of a spaced training precluded LTM formation. Two pairs of these dopaminergic neurons displayed sustained calcium oscillations in naive flies. Oscillations were weakened by ARM-inducing massed training and were enhanced during LTM formation. Our results indicate that oscillations of two pairs of dopaminergic neurons control ARM levels and gate LTM. PMID:22366756

Plaçais, Pierre-Yves; Trannoy, Séverine; Isabel, Guillaume; Aso, Yoshinori; Siwanowicz, Igor; Belliart-Guérin, Ghislain; Vernier, Philippe; Birman, Serge; Tanimoto, Hiromu; Preat, Thomas

2012-04-01

83

Expectation-driven changes in cortical functional connectivity influence working memory and long-term memory performance  

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Expectations generated by predictive cues increase the efficiency of perceptual processing for complex stimuli (e.g. faces, scenes), however the impact this has on working memory (WM) and long-term memory (LTM) has not yet been investigated. Here, healthy young adults performed delayed-recognition tasks that differed only in stimulus-category expectations, while behavioral and functional magnetic resonance imaging (fMRI) data were collected. Univariate and functional-connectivity analyses wer...

Bollinger, Jacob; Rubens, Michael T.; Zanto, Theodore P.; Gazzaley, Adam

2010-01-01

84

Long-term memory in speech perception: Some new findings on talker variability, speaking rate and perceptual learning *  

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This paper summarizes results from recent studies on the role of long-term memory in speech perception and spoken word recognition. Experiments on talker variability, speaking rate and perceptual learning provide strong evidence for implicit memory for very fine perceptual details of speech. Listeners apparently encode specific attributes of the talker’s voice and speaking rate into long-term memory. Acoustic–phonetic variability does not appear to be “lost” as a result of phonetic an...

Pisoni, David B.

1993-01-01

85

Verapamil enhances the impairing effects of stress on retrieval of long-term memory in rats  

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Full Text Available Introduction: This study investigated an interaction between acute restraint stress and verapamil, as a blocker of L-type voltage sensitive channels on retrieval of long-term memory. Materials and Methods: Young adult male rats were trained in one trial inhibitory avoidance task (1mA, 1.5s footshock. On retention test given 48 hr after training, the latency to re-enter dark compartment and time spent in light chamber of the apparatus were recorded. Thirty min before retention test, the rats were exposed to a 10 min of restraint stress in a Plexiglass with or without prior treatment of verapamil (5, 10, 20 mg/kg. Results: The results showed verapamil pretreatment enhanced the impairing effect of stress on memory retrieval. The applied stress increased circulating corticosterone levels as assessed immediately after the retention test, indicating that stress–induced impairment of memory retrieval is mediated, in part, by increased plasma levels of glucocorticoids. Verapamil did not affect on this response. Conclusion: These findings indicate that acute restraint stress impair retrieval of long-term memory, and provide evidence for the existence of an interaction between stress and L-type voltage calcium channels on this process.

A. Rashidy-Pour

2006-11-01

86

Fragile X mental retardation 1 and Filamin A interact genetically in Drosophila long-term memory  

Directory of Open Access Journals (Sweden)

Full Text Available The last decade has witnessed the identification of single-gene defects associated with an impressive number of mental retardation syndromes. Fragile X syndrome, the most common cause of mental retardation for instance, results from disruption of the FMR1 gene. Similarly, Periventricular Nodular Heterotopia (PNH, which includes cerebral malformation, epilepsy and cognitive disabilities, derives from disruption of the Filamin A gene. While it remains unclear whether defects in common molecular pathways may underlie the cognitive dysfunction of these various syndromes, defects in cytoskeletal structure nonetheless appear to be common to several mental retardation syndromes. FMR1 is known to interact with Rac, profilin, PAK and Ras, which are associated with dendritic spine defects. In Drosophila, disruptions of the dFmr1 gene impair long-term memory, and the Filamin A homolog (cheerio was identified in a behavioral screen for long-term memory mutants. Thus, we investigated the possible interaction between cheerio and dFmr1 during long-term memory (LTM formation in Drosophila. We show that LTM specifically is defective in dFmr1/cheerio double heterozygotes, while it is normal in single heterozygotes for either dFmr1 or cheerio. In dFmr1 mutants, Filamin (Cheerio levels are lower than normal after spaced training. These observations support the notion that decreased actin cross-linking underlies the persistence of long and thin dendritic spines in Fragile X patients and animal models. More generally, our results represent the first demonstration of a genetic interaction between mental retardation genes in an in vivo model system of memory formation.

FrancoisBolduc

2010-01-01

87

Ion beam characterisation of ODS steel samples after long term annealing conditions  

Science.gov (United States)

Oxide dispersion strengthened-reduced activation ferritic martensitic (ODS-RAFM) steels are foreseen as future structural materials for the ITER and DEMO fusion reactors. Microstructure characterisation experiments of these steels were performed in the initial normalized and tempered condition and after long term annealing. Two types of ODS steel samples were studied. Long term annealing of the samples was performed at 700 °C during 5000 h in ambient atmosphere. Samples were analysed by nuclear microprobe techniques before and after the long term annealing experiments and data compared. The uneven yttrium distribution found in the as-received samples produced by one of the suppliers (20-50 ?m Y depleted zones) could not be observed after the long term annealing. This same sample presented significant surface alterations that extend up to 120 ?m. The other sample showed a smaller surface alteration (˜30 ?m) and the formation of Cr-rich clusters 7-10 ?m wide.

Alves, L. C.; Alves, E.; Paúl, A.; da Silva, M. R.; Odriozola, J. A.

2006-08-01

88

Mushroom body ablation impairs short-term memory and long-term memory of courtship conditioning in Drosophila melanogaster.  

Science.gov (United States)

We have evaluated the role of the Drosophila mushroom bodies (MBs) in courtship conditioning, in which experience with mated females causes males to reduce their courtship toward virgins (Siegel and Hall, 1979). Whereas previous studies indicated that MB ablation abolished learning in an olfactory conditioning paradigm (deBelle and Heisenberg, 1994), MB-ablated males were able to learn in the courtship paradigm. They resumed courting at naive levels within 30 min after training, however, while the courtship of control males remained depressed 1 hr after training. We also describe a novel courtship conditioning paradigm that established long-term memory, lasting 9 days. In MB-ablated males, memory dissipated completely within 1 day. Our results indicate that the MBs are not required for learning and immediate recall of courtship conditioning but are required for consolidation of short-term and long-term associative memories. PMID:10624959

McBride, S M; Giuliani, G; Choi, C; Krause, P; Correale, D; Watson, K; Baker, G; Siwicki, K K

1999-12-01

89

Facilitation of long-term object recognition memory by pretraining administration of diphenyl diselenide in mice.  

Science.gov (United States)

Selenium compounds display antioxidant and neuroprotective properties. Diphenyl diselenide (PhSe)(2) is an organic selenium compound that affects a number of neuronal processes. The aim of the present study was to evaluate the effects of the systemic administration of (PhSe)(2) on novel object recognition memory in mice. Adult male CF1 mice were given an i.p. injection of (PhSe)(2) (0.2, 1.0, 5.0, or 25.0 micromol/kg) 30 min before training in an object recognition task. (PhSe)(2) did not affect short-term memory or the total time exploring both objects, but induced a facilitation of retention measured 24 h after training. The present findings show that systemic administration of (PhSe)(2) induces a facilitation of formation of long-term object recognition memory. PMID:12697287

Rosa, Renato M; Flores, Debora G; Appelt, Helmoz R; Braga, Antônio Luiz; Henriques, João Antônio Pêgas; Roesler, Rafael

2003-05-01

90

A phenomenological memristor model for short-term/long-term memory  

Science.gov (United States)

Memristor is considered to be a natural electrical synapse because of its distinct memory property and nanoscale. In recent years, more and more similar behaviors are observed between memristors and biological synapse, e.g., short-term memory (STM) and long-term memory (LTM). The traditional mathematical models are unable to capture the new emerging behaviors. In this article, an updated phenomenological model based on the model of the Hewlett-Packard (HP) Labs has been proposed to capture such new behaviors. The new dynamical memristor model with an improved ion diffusion term can emulate the synapse behavior with forgetting effect, and exhibit the transformation between the STM and the LTM. Further, this model can be used in building new type of neural networks with forgetting ability like biological systems, and it is verified by our experiment with Hopfield neural network.

Chen, Ling; Li, Chuandong; Huang, Tingwen; Ahmad, Hafiz Gulfam; Chen, Yiran

2014-08-01

91

Evidence for two distinct sleep-related long-term memory consolidation processes.  

Science.gov (United States)

Numerous studies examine the effect of a night's sleep on memory consolidation, but few go beyond this short time-scale to test long-lasting effects of sleep on memory. We investigated long-term effects of sleep on typical memory tasks. During the hours following learning, participants slept or stayed awake. We compared recall performance between wake and sleep conditions after delays of up to 6 days. Performance develops in two distinct ways. Word pair, syllable, and motor sequence learning tasks benefit from sleep during the first day after encoding, when compared with daytime or nighttime wakefulness. However, performance in the wake conditions recovers after another night of sleep, so that we observe no lasting effect of sleep. Sleep deprivation before recall does not impair performance. Thus, fatigue cannot adequately explain the lack of long-term effects. We suggest that the hippocampus might serve as a buffer during the retention interval, and consolidation occurs during delayed sleep. In contrast, a non-hippocampal mirror-tracing task benefits significantly from sleep, even when tested after a 4-day delay including recovery sleep. This indicates a dissociation between two sleep-related consolidation mechanisms, which could rely on distinct neuronal processes. PMID:25243990

Schönauer, Monika; Grätsch, Melanie; Gais, Steffen

2015-02-01

92

Strategic search from long-term memory: an examination of semantic and autobiographical recall.  

Science.gov (United States)

Searching long-term memory is theoretically driven by both directed (search strategies) and random components. In the current study we conducted four experiments evaluating strategic search in semantic and autobiographical memory. Participants were required to generate either exemplars from the category of animals or the names of their friends for several minutes. Self-reported strategies suggested that participants typically relied on visualization strategies for both tasks and were less likely to rely on ordered strategies (e.g., alphabetic search). When participants were instructed to use particular strategies, the visualization strategy resulted in the highest levels of performance and the most efficient search, whereas ordered strategies resulted in the lowest levels of performance and fairly inefficient search. These results are consistent with the notion that retrieval from long-term memory is driven, in part, by search strategies employed by the individual, and that one particularly efficient strategy is to visualize various situational contexts that one has experienced in the past in order to constrain the search and generate the desired information. PMID:23885826

Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

2014-01-01

93

Sleep Improves Memory: The Effect of Sleep on Long Term Memory in Early Adolescence  

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Sleep plays an important role in the consolidation of memory. This has been most clearly shown in adults for procedural memory (i.e. skills and procedures) and declarative memory (e.g. recall of facts). The effects of sleep and memory are relatively unstudied in adolescents. Declarative memory is important in school performance and consequent social functioning in adolescents. This is the first study to specifically examine the effects of normal sleep on auditory declarative memory in an earl...

Potkin, Katya Trudeau; Bunney, William E.

2012-01-01

94

Expression of human PQBP-1 in Drosophila impairs long-term memory and induces abnormal courtship.  

Science.gov (United States)

Frame shift mutations of the polyglutamine binding protein-1 (PQBP1) gene lead to total or partial truncation of the C-terminal domain (CTD) and cause mental retardation in human patients. Interestingly, normal Drosophila homologue of PQBP-1 lacks CTD. As a model to analyze the molecular network of PQBP-1 affecting intelligence, we generated transgenic flies expressing human PQBP-1 with CTD. Pavlovian olfactory conditioning revealed that the transgenic flies showed disturbance of long-term memory. In addition, they showed abnormal courtship that male flies follow male flies. Abnormal functions of PQBP-1 or its binding partner might be linked to these symptoms. PMID:16597440

Yoshimura, Natsue; Horiuchi, Daisuke; Shibata, Masao; Saitoe, Minoru; Qi, Mei-Ling; Okazawa, Hitoshi

2006-04-17

95

Solution polymeric optical temperature sensors with long-term memory function powered by supramolecular chemistry.  

Science.gov (United States)

A poly[(2-ethyl-2-oxazoline)-ran-(2-nonyl-2-oxazoline)] copolymer in combination with hydroxypropylated cyclodextrins has been demonstrated to lead to a supramolecular self-assembly process that results in the formation of kinetically trapped thermoresponsive nanoparticles. Selection of the cyclodextrin type provides control over the nanoparticle phase-transition thermodynamics, thus affording optical temperature sensors with an unprecedented, long-term thermal memory function, which is reversible or irreversible. This research also sheds light onto kinetic and dynamic supramolecular assemblies, thus providing important insight because similar supramolecular processes are at the foundation of living matter. PMID:25412901

de la Rosa, Victor R; Hoogenboom, Richard

2015-01-12

96

Long-term potentiation decay and memory loss are mediated by AMPAR endocytosis.  

Science.gov (United States)

Long-term potentiation (LTP) of synaptic strength between hippocampal neurons is associated with learning and memory, and LTP dysfunction is thought to underlie memory loss. LTP can be temporally and mechanistically classified into decaying (early-phase) LTP and nondecaying (late-phase) LTP. While the nondecaying nature of LTP is thought to depend on protein synthesis and contribute to memory maintenance, little is known about the mechanisms and roles of decaying LTP. Here, we demonstrated that inhibiting endocytosis of postsynaptic ?-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid receptors (AMPARs) prevents LTP decay, thereby converting it into nondecaying LTP. Conversely, restoration of AMPAR endocytosis by inhibiting protein kinase M? (PKM?) converted nondecaying LTP into decaying LTP. Similarly, inhibition of AMPAR endocytosis prolonged memory retention in normal animals and reduced memory loss in a murine model of Alzheimer's disease. These results strongly suggest that an active process that involves AMPAR endocytosis mediates the decay of LTP and that inhibition of this process can prolong the longevity of LTP as well as memory under both physiological and pathological conditions. PMID:25437879

Dong, Zhifang; Han, Huili; Li, Hongjie; Bai, Yanrui; Wang, Wei; Tu, Man; Peng, Yan; Zhou, Limin; He, Wenting; Wu, Xiaobin; Tan, Tao; Liu, Mingjing; Wu, Xiaoyan; Zhou, Weihui; Jin, Wuyang; Zhang, Shu; Sacktor, Todd Charlton; Li, Tingyu; Song, Weihong; Wang, Yu Tian

2015-01-01

97

Attention, Working Memory, and Long-Term Memory in Multimedia Learning: An Integrated Perspective Based on Process Models of Working Memory  

Science.gov (United States)

Cognitive models of multimedia learning such as the Cognitive Theory of Multimedia Learning (Mayer 2009) or the Cognitive Load Theory (Sweller 1999) are based on different cognitive models of working memory (e.g., Baddeley 1986) and long-term memory. The current paper describes a working memory model that has recently gained popularity in basic…

Schweppe, Judith; Rummer, Ralf

2014-01-01

98

On the Detection of Long-Term Memory in Short Records  

Science.gov (United States)

Long-term memory is ubiquitous in nature and has important consequences for the occurrence of natural hazards, but its detection often is complicated by the short length of the considered records. Here we study synthetic long-term correlated records of length N that are characterized by a correlation exponent ?, 00)=B· s-? and E=E(B,?,N)= 2B/((2-?)(1-?))· N-?+O(N-1). Due to the finite-size correction E, a direct determination of ? is difficult to achieve and generally leads to an enhanced value of ?. The parameter E also occurs in related quantities, that are characterized by the Hurst-exponent, which describe how the fluctuations of the records in time windows of length s decay with s, for example the variance of the local mean in time windows of length s. We show how to estimate E from a given data set which then allows a more accurate determination of ?. This approach can be applied also to long-term correlated records in the presence of additional white noise, where the determination of ? is particularly difficult (which is the case, e.g. in the records of return intervals between consecutive events above a certain threshold).

Lennartz, S.; Bunde, A.

2008-12-01

99

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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. Abstract in english 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; b)hippocampal 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.

Iván, Izquierdo; Martín, Cammarota; Weber C. Da, Silva; Lia R.M., Bevilaqua; Janine I., Rossato; Juliana S., Bonini; Pamela, Mello; Fernando, Benetti; Jaderson C., Costa; Jorge H., Medina.

2008-03-01

100

The flavonol epicatechin reverses the suppressive effects of a stressor on long-term memory formation.  

Science.gov (United States)

Learning and subsequent memory formation are influenced by both environmental and lifestyle factors, such as stress and diet. Epicatechin, a plant flavonol found in cocoa, red wine and green tea enhances long-term memory (LTM) formation in Lymnaea. By contrast, an ecologically relevant stressor, low-calcium pond water, suppresses LTM formation. We tested the hypothesis that epicatechin overcomes the suppressive effects of the stressor on LTM formation in the continued presence of the stressor. Snails trained in low-calcium pond water exhibit learning but not LTM. Epicatechin (15 mg l(-1)) in control pond water enhances LTM formation. When epicatechin was added to the low-calcium pond water an enhanced LTM similar to that seen in control pond water was observed. Thus, a naturally occurring bioactive plant compound was able to overcome the suppressive effects of an ecologically relevant stressor on LTM formation. PMID:25267853

Knezevic, Bogdan; Lukowiak, Ken

2014-11-15

 
 
 
 
101

Aging impairs protein-synthesis-dependent long-term memory in Drosophila.  

Science.gov (United States)

Although aging is known to impair intermediate-term memory in Drosophila, its effect on protein-synthesis-dependent long-term memory (LTM) is unknown. We show here that LTM is impaired with age, not due to functional defects in synaptic output of mushroom body (MB) neurons, but due to connectivity defects of dorsal paired medial (DPM) neurons with their postsynaptic MB neurons. GFP reconstitution across synaptic partners (GRASP) experiments revealed structural connectivity defects in aged animals of DPM neurons with MB axons in the ? lobe neuropil. As a consequence, a protein-synthesis-dependent LTM trace in the ?/? MB neurons fails to form. Aging thus impairs protein-synthesis-dependent LTM along with the ?/? MB neuron LTM trace by lessening the connectivity of DPM and ?/? MB neurons. PMID:25609631

Tonoki, Ayako; Davis, Ronald L

2015-01-21

102

Roles of NO signaling in long-term memory formation in visual learning in an insect.  

Science.gov (United States)

Many insects exhibit excellent capability of visual learning, but the molecular and neural mechanisms are poorly understood. This is in contrast to accumulation of information on molecular and neural mechanisms of olfactory learning in insects. In olfactory learning in insects, it has been shown that cyclic AMP (cAMP) signaling critically participates in the formation of protein synthesis-dependent long-term memory (LTM) and, in some insects, nitric oxide (NO)-cyclic GMP (cGMP) signaling also plays roles in LTM formation. In this study, we examined the possible contribution of NO-cGMP signaling and cAMP signaling to LTM formation in visual pattern learning in crickets. Crickets that had been subjected to 8-trial conditioning to associate a visual pattern with water reward exhibited memory retention 1 day after conditioning, whereas those subjected to 4-trial conditioning exhibited 30-min memory retention but not 1-day retention. Injection of cycloheximide, a protein synthesis inhibitor, into the hemolymph prior to 8-trial conditioning blocked formation of 1-day memory, whereas it had no effect on 30-min memory formation, indicating that 1-day memory can be characterized as protein synthesis-dependent long-term memory (LTM). Injection of an inhibitor of the enzyme producing an NO or cAMP prior to 8-trial visual conditioning blocked LTM formation, whereas it had no effect on 30-min memory formation. Moreover, injection of an NO donor, cGMP analogue or cAMP analogue prior to 4-trial conditioning induced LTM. Induction of LTM by an NO donor was blocked by DDA, an inhibitor of adenylyl cyclase, an enzyme producing cAMP, but LTM induction by a cAMP analogue was not impaired by L-NAME, an inhibitor of NO synthase. The results indicate that cAMP signaling is downstream of NO signaling for visual LTM formation. We conclude that visual learning and olfactory learning share common biochemical cascades for LTM formation. PMID:23894314

Matsumoto, Yukihisa; Hirashima, Daisuke; Terao, Kanta; Mizunami, Makoto

2013-01-01

103

Long-term odor recognition memory in unipolar major depression and Alzheimer?s disease.  

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Major depression and Alzheimer?s disease (AD) are often observed in the elderly. The identification of specific markers for these diseases could improve their screening. The aim of this study was to investigate long-term odor recognition memory in depressed and AD patients, with a view to identifying olfactory markers of these diseases. We included 20 patients with unipolar major depressive episodes (MDE), 20 patients with mild to moderate AD and 24 healthy subjects. We investigated the cognitive profile and olfactory memory capacities (ability to recognize familiar and unfamiliar odors) of these subjects. Olfactory memory test results showed that AD and depressed patients were characterized by significantly less correct responses and more wrong responses than healthy controls. Detection index did not differ significantly between patients with major depression and those with AD when the results were analyzed for all odors. However, MDE patients displayed an impairment of olfactory memory for both familiar and unfamiliar odors, whereas AD subjects were impaired only in the recognition of unfamiliar odors, with respect to healthy subjects. If preservation of olfactory memory for familiar stimuli in patients with mild to moderate AD is confirmed, this test could be used in clinical practice as a complementary tool for diagnosis. PMID:25262560

Naudin, Marine; Mondon, Karl; El-Hage, Wissam; Desmidt, Thomas; Jaafari, Nematollah; Belzung, Catherine; Gaillard, Philippe; Hommet, Caroline; Atanasova, Boriana

2014-12-30

104

Ecdysone signaling regulates the formation of long-term courtship memory in adult Drosophila melanogaster.  

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Improved survival is likely linked to the ability to generate stable memories of significant experiences. Considerable evidence in humans and mammalian model animals shows that steroid hormones, which are released in response to emotionally arousing experiences, have an important role in the consolidation of memories of such events. In insects, ecdysone is the major steroid hormone, and it is well characterized with respect to its essential role in coordinating developmental transitions such as larval molting and metamorphosis. However, the functions of ecdysone in adult physiology remain largely elusive. Here, we show that 20-hydroxyecdysone (20E), the active metabolite of ecdysone that is induced by environmental stimuli in adult Drosophila, has an important role in the formation of long-term memory (LTM). In male flies, the levels of 20E were found to be significantly increased after courtship conditioning, and exogenous administration of 20E either enhanced or suppressed courtship LTM, depending on the timing of its administration. We also found that mutants in which ecdysone signaling is reduced were defective in LTM, and that an elevation of 20E levels was associated with activation of the cAMP response element binding protein (CREB), an essential regulator of LTM formation. Our results demonstrate that the molting steroid hormone ecdysone in adult Drosophila is critical to the evolutionarily conserved strategy that is used for the formation of stable memories. We propose that ecdysone is able to consolidate memories possibly by recapturing molecular and cellular processes that are used for normal neural development. PMID:19342482

Ishimoto, Hiroshi; Sakai, Takaomi; Kitamoto, Toshihiro

2009-04-14

105

Continuum Climate Variability:. Long-Term Memory, Scaling, and 1/F-NOISE  

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Continuum temperature variability represents the response of the Earth's climate to deterministic external forcing. Scaling regimes are observed which range from hours to millennia with low frequency fluctuations characterizing long-term memory. The presence of 1/f power spectra in weather and climate is noteworthy: (i) In the tropical atmosphere 1/f scaling ranging from hours to weeks is found for several variables; it emerges as superposition of uncorrelated pulses with individual 1/f spectra. (ii) The daily discharge of the Yangtze shows 1/f within one week to one year, although the precipitation spectrum is white. (iii) Beyond one year mid-latitude sea surface temperatures reveal 1/f scaling in large parts of the global ocean. The spectra can be simulated by complex atmosphere-ocean general circulation models and understood as a two layer heat diffusion process forced by an uncorrelated stochastic atmospheric. Long-term memory on time scales up to millennia are the global sea surface temperatures and the Greenland ice core records (GISP2, GRIP) with ?18O temperature proxy data during the Holocene. Complex atmosphere ocean general circulation models reproduce this behavior quantitatively up to millennia without solar variability, interacting land-ice and vegetation components.

Fraedrich, Klaus; Blender, Richard; Zhu, Xiuhua

106

Forward processing of long-term associative memory in monkey inferotemporal cortex.  

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The macaque inferotemporal (IT) cortex, which serves as the storehouse of visual long-term memory, consists of two distinct but mutually interconnected areas: area TE (TE) and area 36 (A36). In the present study, we tested whether memory encoding is put forward at this stage, i.e., whether association between the representations of different but semantically linked objects proceeds forward from TE to A36. To address this question, we trained monkeys in a pair-association (PA) memory task, after which single-unit activities were recorded from TE and A36 during PA trials. Neurons in both areas showed stimulus-selective cue responses (347 in TE, 76 in A36; "cue-selective neurons") that provided, at the population level, mnemonic linkage between the paired associates. The percentage of neurons in which responses to the paired associates were significantly (p A36 (33%). The pair-coding neurons in A36 were further separable into Type1 (68%) and Type2 (32%) on the basis of their initial transient responses after cue stimulus presentation. Type1 neurons, but not Type2 neurons, began to encode association between paired stimuli as soon as they exhibited stimulus selectivity. Thus, the representation of long-term memory encoded by Type1 neurons in A36 is likely substantiated without feedback input from other higher centers. Therefore, we conclude that association between the representations of the paired associates proceeds forward at this critical step within IT cortex, suggesting selective convergence onto a single A36 neuron from two TE neurons that encode separate visual objects. PMID:12684473

Naya, Yuji; Yoshida, Masatoshi; Miyashita, Yasushi

2003-04-01

107

Errors in nonword repetition: bridging short- and long-term memory  

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Full Text Available According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep is a suitable measure of phonological short-term memory for English-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR as a Portuguese-language version. The objectives of the present study were: i to investigate developmental aspects of the phonological memory processing by error analysis in the nonword repetition task, and ii to examine phoneme (substitution, omission and addition and order (migration errors made in the BCPR by 180 normal Brazilian children of both sexes aged 4-10, from preschool to 4th grade. The dominant error was substitution [F(3,525 = 180.47; P < 0.0001]. The performance was age-related [F(4,175 = 14.53; P < 0.0001]. The length effect, i.e., more errors in long than in short items, was observed [F(3,519 = 108.36; P < 0.0001]. In 5-syllable pseudowords, errors occurred mainly in the middle of the stimuli, before the syllabic stress [F(4,16 = 6.03; P = 0.003]; substitutions appeared more at the end of the stimuli, after the stress [F(12,48 = 2.27; P = 0.02]. In conclusion, the BCPR error analysis supports the idea that phonological loop capacity is relatively constant during development, although school learning increases the efficiency of this system. Moreover, there are indications that long-term memory contributes to holding memory trace. The findings were discussed in terms of distinctiveness, clustering and redintegration hypotheses.

F.H. Santos

2006-03-01

108

Protein degradation and protein synthesis in long-term memory formation  

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Full Text Available Long-term memory (LTM formation requires transient changes in the activity of intracellular signaling cascades that are thought to regulate new gene transcription and de novo protein synthesis in the brain. Consistent with this, protein synthesis inhibitors impair LTM for a variety of behavioral tasks when infused into the brain around the time of training or following memory retrieval, suggesting that protein synthesis is a critical step in LTM storage in the brain. However, evidence suggests that protein degradation mediated by the ubiquitin-proteasome system may also be a critical regulator of LTM formation and stability following retrieval. This requirement for increased protein degradation has been shown in the same brain regions in which protein synthesis is required for LTM storage. Additionally, increases in the phosphorylation of proteins involved in translational control parallel increases in protein polyubiquitination and the increased demand for protein degradation is regulated by intracellular signaling molecules thought to regulate protein synthesis during LTM formation. In some cases inhibiting proteasome activity can rescue memory impairments that result from pharmacological blockade of protein synthesis, suggesting that protein degradation may control the requirement for protein synthesis during the memory storage process. Results such as these suggest that protein degradation and synthesis are both critical for LTM formation and may interact to properly “consolidate” and store memories in the brain. Here, we review the evidence implicating protein synthesis and degradation in LTM storage and highlight the areas of overlap between these two opposing processes. We also discuss evidence suggesting these two processes may interact to properly form and store memories. LTM storage likely requires a coordinated regulation between protein degradation and synthesis at multiple sites in the mammalian brain.

Fred J Helmstetter

2014-06-01

109

Different Phases of Long-Term Memory Require Distinct Temporal Patterns of PKA Activity after Single-Trial Classical Conditioning  

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The cAMP-dependent protein kinase (PKA) is known to play a critical role in both transcription-independent short-term or intermediate-term memory and transcription-dependent long-term memory (LTM). Although distinct phases of LTM already have been demonstrated in some systems, it is not known whether these phases require distinct temporal patterns…

Michel, Maximilian; Kemenes, Ildiko; Muller, Uli; Kemenes, Gyorgy

2008-01-01

110

Studies of the reproduction of long-term memory during exposure to kainic Acid.  

Science.gov (United States)

The effects of the neurotoxin kainic acid on a food-producing habit were studied in Wistar rats in an experimental chamber. Single doses of kainic acid at a subconvulsive dose (8 mg/kg, i.p.) were found to impair the habit, onset of impairment being delayed by several weeks rather than immediate. Conversely, administration of the neurotoxin at the convulsive dose (10 mg/kg) impaired reproduction of the habit with onset within several hours after treatment and persistence for periods of up to 10 days, though this dose did not prevent the acquisition of a new food-procuring habit. These defects in the reproduction of long-term memory traces were explained in terms of the characteristics of the effects of kainic acid on the hippocampal system, which is the most susceptible to systemic administration of the neurotoxin. PMID:16132264

Arkhipov, V I; Shevchenko, N A

2005-10-01

111

The effect of crying on long-term memory in infancy.  

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The influence of crying on infants' long-term memory for a learned response was investigated in 3 experiments. In each, infants were trained to move a crib mobile containing 10 identical objects by means of kicking and were then exposed to a reinforcer containing only 2 of these components. This shift in component numerosity produced crying in 53% of the infants. Infants who cried in response to the reward shift evidenced no retention of the contingency 1 week later (Experiment 1) but did have excellent retention at 1 day (Experiment 2). In Experiment 3, a brief reactivation treatment alleviated forgetting at 3 weeks regardless of the presence of crying in response to the change in mobiles. An unexpected recency effect characterized the efficacy of the reactivation treatment. The results indicate that crying in response to the violation of a reward-expectation habit functions as an amnesic agent to produce accelerated forgetting. PMID:4075876

Fagen, J W; Ohr, P S; Fleckenstein, L K; Ribner, D R

1985-12-01

112

Long-term memory in experiments and numerical simulations of hydrodynamic and magnetohydrodynamic turbulence.  

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We analyze time series stemming from experiments and direct numerical simulations of hydrodynamic and magnetohydrodynamic turbulence. Simulations are done in periodic boxes, but with a volumetric forcing chosen to mimic the geometry of the flow in the experiments, the von Kármán swirling flow between two counterrotating impellers. Parameters in the simulations are chosen to (within computational limitations) allow comparisons between the experiments and the numerical results. Conducting fluids are considered in all cases. Two different configurations are considered: a case with a weak externally imposed magnetic field and a case with self-sustained magnetic fields. Evidence of long-term memory and 1/f noise is observed in experiments and simulations, in the case with weak magnetic field associated with the hydrodynamic behavior of the shear layer in the von Kármán flow, and in the dynamo case associated with slow magnetohydrodynamic behavior of the large-scale magnetic field. PMID:25353878

Mininni, P; Dmitruk, P; Odier, P; Pinton, J-F; Plihon, N; Verhille, G; Volk, R; Bourgoin, M

2014-05-01

113

Long-term memory in experiments and numerical simulations of hydrodynamic and magnetohydrodynamic turbulence  

CERN Document Server

We analyze time series stemming from experiments and direct numerical simulations of hydrodynamic and magnetohydrodynamic turbulence. Simulations are done in periodic boxes, but with a volumetric forcing chosen to mimic the geometry of the flow in the experiments, the von K\\'arm\\'an swirling flow between two counter-rotating impellers. Parameters in the simulations are chosen to (within computational limitations) allow comparisons between the experiments and the numerical results. Conducting fluids are considered in all cases. Two different configurations are considered: a case with a weak externally imposed magnetic field, and a case with self-sustained magnetic fields. Evidence of long-term memory and $1/f$ noise is observed in experiments and simulations, in the case with weak magnetic field associated with the hydrodynamic behavior of the shear layer in the von K\\'arm\\'an flow, and in the dynamo case associated with slow magnetohydrodynamic behavior of the large scale magnetic field.

Mininni, Pablo; Odier, Philippe; Pinton, Jean-François; Plihon, Nicolas; Verhille, Gautier; Volk, Romain; Bourgoin, Mickael

2014-01-01

114

Interdisciplinary Approach to the Mental Lexicon: Neural Network and Text Extraction From Long-term Memory  

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Full Text Available The paper touches upon the principles of mental lexicon organization in the light of recent research in psycho- and neurolinguistics. As a focal point of discussion two main approaches to mental lexicon functioning are considered: modular or dual-system approach, developed within generativism and opposite single-system approach, representatives of which are the connectionists and supporters of network models. The paper is an endeavor towards advocating the viewpoint that mental lexicon is complex psychological organization based upon specific composition of neural network. In this regard, the paper further elaborates on the matter of storing text in human mental space and introduces a model of text extraction from long-term memory. Based upon data available, the author develops a methodology of modeling structures of knowledge representation in the systems of artificial intelligence.

Vardan G. Arutyunyan

2013-01-01

115

The effect of cognitive reappraisal on long-term emotional experience and emotional memory.  

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One's ability to properly regulate emotion is critical to psychological and physical well-being. Among various strategies to regulate emotion, cognitive reappraisal has been shown to modulate both emotional experience and emotional memory. However, most studies of reappraisal have focused on reappraisal of negative situations, with reappraisal of positive emotion receiving considerably less attention. In addition, the effects of reappraisal on emotional reactions to stimuli are typically only assessed either immediately or after a short delay, and it remains unclear whether reappraisal effects persist over longer time periods. We investigated the effect of cognitive reappraisal on emotional reactions and long-term episodic memory for positive and negative stimuli. Men and women viewed emotionally negative, positive, and neutral pictures while they were instructed to either increase, decrease, or maintain the initial emotional reactions elicited by the pictures. Subjective ratings of emotional valence and arousal were assessed during the regulation task and again after 1 week. Memory for the pictures was assessed with free recall. Results indicated that pictures accompanied by instructions to increase emotion were better recalled than pictures reappraised to decrease emotion. Modulation of emotional arousal elicited by stimuli persisted over a week, but this effect was observed only for men. These findings suggest that cognitive reappraisal can have long-lasting effects on emotional reactions to stimuli. However, the sex differences observed for the effects of reappraisal on emotional reactions highlight the importance of considering individual differences in the effects of regulation. PMID:24330427

Ahn, Hyeon Min; Kim, Shin Ah; Hwang, In Jae; Jeong, Ji Woon; Kim, Hyun Taek; Hamann, Stephan; Kim, Sang Hee

2013-12-11

116

Consolidation of visual associative long-term memory in the temporal cortex of primates.  

Science.gov (United States)

Neuropsychological theories have proposed a critical role for the interaction between the medial temporal lobe and the neocortex in the formation of long-term memory for facts and events, which has often been tested by learning of a series of paired words or figures in humans. We have examined neural mechanisms underlying the memory "consolidation" process by single-unit recording and molecular biological methods in an animal model of a visual pair-association task in monkeys. In our previous studies, we found that long-term associative representations of visual objects are acquired through learning in the neural network of the anterior inferior temporal (IT) cortex. In this article, we propose the hypothesis that limbic neurons undergo rapid modification of synaptic connectivity and provide backward signals that guide the reorganization of neocortical neural circuits. Two experiments tested this hypothesis: (1) we examined the role of the backward connections from the medial temporal lobe to the IT cortex by injecting ibotenic acid into the entorhinal and perirhinal cortices, which provided massive backward projections ipsilaterally to the IT cortex. We found that the limbic lesion disrupted the associative code of the IT neurons between the paired associates, without impairing the visual response to each stimulus. (2) We then tested the first half of this hypothesis by detecting the expression of immediate-early genes in the monkey temporal cortex. We found specific expression of zif268 during the learning of a new set of paired associates in the pair-association task, most intensively in area 36 of the perirhinal cortex. All these results with the visual pair-association task support our hypothesis and demonstrate that the consolidation process, which was first proposed on the basis of clinico-psychological evidence, can now be examined in primates using neurophysiolocical and molecular biological approaches. PMID:9753597

Miyashita, Y; Kameyama, M; Hasegawa, I; Fukushima, T

1998-01-01

117

Long-term potentiation in bone – a role for glutamate in strain-induced cellular memory?  

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Full Text Available Abstract Background The adaptive response of bone cells to mechanical strain is a primary determinant of skeletal architecture and bone mass. In vivo mechanical loading induces new bone formation and increases bone mineral density whereas disuse, immobilisation and weightlessness induce bone loss. The potency of mechanical strain is such that a single brief period of loading at physiological strain magnitude is able to induce a long-lasting osteogenic response that lasts for days. Although the process of mechanotransduction in bone is incompletely understood, observations that responses to mechanical strain outlast the duration of stimulation necessitate the existence of a form of cellular memory through which transient strain episodes are recorded, interpreted and remembered by bone cells. Recent evidence supports the existence of a complex multicellular glutamate-signalling network in bone that shares functional similarities to glutamatergic neurotransmission in the central nervous system. In neurones, these signalling molecules coordinate synaptic communication required to support learning and memory formation, through a complex process of long-term potentiation. Presentation of the hypothesis We hypothesise that osteoblasts use a cellular mechanism similar or identical to neuronal long-term potentiation in the central nervous system to mediate long-lasting changes in osteogenesis following brief periods of mechanical strain. Testing the hypothesis N-methyl-D-aspartate (NMDA receptor antagonism should inhibit the saturating response of mechanical strain and reduce the enhanced osteogenicity of segregated loading to that of an equivalent period of uninterrupted loading. Changes in ?-amino-3-hydroxy-5-methyl-isoxazole propionate (AMPA receptor expression, localisation and electrophysiological responses should be induced by mechanical strain and inhibited by modulators of neuronal long-term potentiation. Implications of the hypothesis If true, this hypothesis would provide a mechanism through which the skeleton could be pharmacologically primed to enhance or retrieve the normal osteogenic response to exercise. This would form a basis through which novel therapies could be developed to target osteoporosis and other prevalent bone disorders associated with low bone mass.

Genever Paul G

2003-07-01

118

Identification of Gene Expression Changes Associated With Long-Term Memory of Courtship Rejection in Drosophila Males  

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Long-term memory formation in Drosophila melanogaster is an important neuronal function shaping the insect’s behavioral repertoire by allowing an individual to modify behaviors on the basis of previous experiences. In conditioned courtship or courtship suppression, male flies that have been repeatedly rejected by mated females during courtship advances are less likely than naïve males to subsequently court another mated female. This long-term courtship suppression can last for several days...

Winbush, Ari; Reed, Danielle; Chang, Peter L.; Nuzhdin, Sergey V.; Lyons, Lisa C.; Arbeitman, Michelle N.

2012-01-01

119

Better than normal: improved formation of long-term spatial memory in healthy rats treated with levodopa.  

Science.gov (United States)

Dopaminergic signaling modulates learning and memory. Consequently, treatment with the dopamine precursor levodopa ameliorates memory deficits in murine models of Alzheimer's disease. In healthy humans, administration of L-DOPA increases learning and memory. However, it is unknown whether dopamine-enhanced memory can also be modeled in normal animals. We here investigated if in healthy non-food-deprived rats low and high doses of levodopa (20 and 50 mg levodopa/kg bodyweight) increase spatial learning and long-term memory performance in a radial arm maze. After 4 months, rats treated with levodopa during training had significantly better memory of food rewarded arms than vehicle-treated animals. Interestingly, acute learning curves did not differ between levodopa and vehicle animals. This suggests that enhanced dopaminergic signaling may have predominantly acted on the cortical long-term consolidation of newly acquired spatial information. PMID:19043682

Reinholz, Julia; Skopp, Oliver; Breitenstein, Caterina; Winterhoff, Hilke; Knecht, Stefan

2009-02-01

120

Notch-inducible hyperphosphorylated CREB and its ultradian oscillation in long-term memory formation.  

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Notch is a cell surface receptor that is known to regulate developmental processes by establishing physical contact between neighboring cells. Many recent studies show that it also plays an important role in the formation of long-term memory (LTM) in adults, implying that memory formation requires regulation at the level of cell-cell contacts among brain cells. Neither the target of Notch activity in LTM formation nor the underlying mechanism of regulation is known. We report here results of our studies in adult Drosophila melanogaster showing that Notch regulates dCrebB-17A, the CREB protein. CREB is a transcriptional factor that is pivotal for intrinsic and synaptic plasticity involved in LTM formation. Notch in conjunction with PKC activity upregulates the level of a hyperphosphorylated form of CREB (hyper-PO4 CREB) and triggers its ultradian oscillation, both of which are linked to LTM formation. One of the sites that is phosphorylated in hyper-PO4 CREB is serine 231, which is the functional equivalent of mammalian CREB serine 133, the phosphorylation of which is an important regulator of CREB functions. Our data suggest the model that Notch and PKC activities generate a cyclical accumulation of cytoplasmic hyper-PO4 CREB that is a precursor for generating the nuclear CREB isoforms. Cyclical accumulation of CREB might be important for repetitive aspects of LTM formation, such as memory consolidation. Because Notch, PKC, and CREB have been implicated in many neurodegenerative diseases (e.g., Alzheimer's disease), our data might also shed some light on memory loss and dementia. PMID:23904617

Zhang, Jiabin; Little, Christopher J; Tremmel, Daniel M; Yin, Jerry C P; Wesley, Cedric S

2013-07-31

 
 
 
 
121

Membrane-associated glucocorticoid activity is necessary for modulation of long-term memory via chromatin modification  

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Glucocorticoid hormones enhance the consolidation of long-term memory of emotionally arousing training experiences. This memory enhancement requires activation of the cAMP-dependent kinase pathway and the subsequent phosphorylation of cAMP response-element binding (CREB) protein. Here, we demonstrate that glucocorticoids enhance the consolidation of hippocampus-dependent and hippocampus-independent aspects of object recognition memory via chromatin modification. More specifically, systemic co...

Roozendaal, Benno; Hernandez, Angelina; Cabrera, Sara M.; Hagewoud, Roelina; Malvaez, Melissa; Stefanko, Daniel P.; Haettig, Jakob; Wood, Marcelo A.

2010-01-01

122

DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment?  

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Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. ...

Wittmann, Bianca C.; Tan, Geoffrey C.; Lisman, John E.; Dolan, Raymond J.; Du?zel, Emrah

2013-01-01

123

Introgression of Brown Norway chromosome 1 onto the fawn hooded hypertensive background rescues long-term fear memory deficits.  

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The isolation of genes influencing long-term memory is critical for an understanding of learning at the molecular level. Recently, chromosomal substitution rat strains, known as consomics, have been developed. Here we report the results of the first study on aversive learning and memory with these consomic rats. We compared the Fawn Hooded Hypertensive (FHH) and Brown Norway (BN) parent strains with a Brown Norway chromosome 1 substitution on the FHH background (FHH-1(BN)). Results indicated that while all strains had normal short-term memory, the FHH animals were impaired relative to BN in tests of long-term memory for a discrete auditory cue. This deficit was rescued by the introgression of the BN1 chromosome onto the FHH background. Furthermore, the FHH-1(BN) consomic showed an enhancement in long-term contextual fear memory relative to the FHH strain. These changes were not due to differences in pain sensitivity as both strains performed equally on two different pain tests. These results provide preliminary support that consomic rat strains can be a useful tool in identifying genes related to long-term fear memory formation. PMID:19757016

Jarome, Timothy J; Kwapis, Janine L; Nye, Steven H; Helmstetter, Fred J

2010-01-01

124

[Short-and long-term effects of cannabinoids on memory, cognition and mental illness].  

Science.gov (United States)

Marijuana is considered the most commonly used drug in the world, with estimated millions of users. There is dissent in the medical world about the positive and negative effects of marijuana, and recently, a large research effort has been directed to that domain. The main influencing drug ingredient is THC, which acts on the cannabinoid system and binds to the CB1 receptor. The discovery of the receptor led to the finding of an endogenous ligand, anandamide, and another receptor-CB2. The researchers also discovered that cannabinoids have extensive biological activity, and its short and long-term effects may cause cognitive and emotional deficiencies. Findings show that the short-term effects, such as shortterm memory and verbal Learning, are reversible. However, despite the accumulation of evidence about long-term cognitive damage due to cannabis use, it is difficult to find unequivocal results, arising from the existence of many variables such as large differences between cannabis users, frequency of use, dosage and endogenous brain compensation. Apart from cognitive damage, current studies investigate how marijuana affects mental illness: a high correlation between cannabis use and schizophrenia was found and a high risk to undergo a psychotic attack. Furthermore, patients with schizophrenia who used cannabis showed a selective neuro-psychological disruption, and similar cognitive deficiencies and brain morphological changes were found among healthy cannabis users and schizophrenia patients. In contrast to the negative effects of marijuana including addiction, there are the medical uses: reducing pain, anxiety and nausea, increasing appetite and an anti-inflammatory activity. Medicalization of marijuana encourages frequent use, which may elevate depression. PMID:24483000

Sagie, Shira; Eliasi, Yehuda; Livneh, Ido; Bart, Yosi; Monovich, Einat

2013-12-01

125

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2010  

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The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 10 and 11, 2010. The U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, analyzed the samples. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectroscopy and for tritium using the conventional and enriched methods.

None

2011-01-10

126

Rio Blanco, Colorado, Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2009  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco, Colorado, Site, for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 13 and 14, 2009. Samples were analyzed by the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectroscopy and tritium using the conventional and enriched methods.

127

Rio Blanco, Colorado, Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2009  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco, Colorado, Site, for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 13 and 14, 2009. Samples were analyzed by the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectroscopy and tritium using the conventional and enriched methods.

None

2009-12-21

128

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2009  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 11 and 12, 2009. Samples were analyzed by the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectroscopy and for tritium using the conventional and enriched methods

129

Differential role of entorhinal and hippocampal nerve growth factor in short- and long-term memory modulation  

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Full Text Available We studied the effects of infusion of nerve growth factor (NGF into the hippocampus and entorhinal cortex of male Wistar rats (250-300 g, N = 11-13 per group on inhibitory avoidance retention. In order to evaluate the modulation of entorhinal and hippocampal NGF in short- and long-term memory, animals were implanted with cannulae in the CA1 area of the dorsal hippocampus or entorhinal cortex and trained in one-trial step-down inhibitory avoidance (foot shock, 0.4 mA. Retention tests were carried out 1.5 h or 24 h after training to measure short- and long-term memory, respectively. Immediately after training, rats received 5 µl NGF (0.05, 0.5 or 5.0 ng or saline per side into the CA1 area and entorhinal cortex. The correct position of the cannulae was confirmed by histological analysis. The highest dose of NGF (5.0 ng into the hippocampus blocked short-term memory (P < 0.05, whereas the doses of 0.5 (P < 0.05 and 5.0 ng (P < 0.01 NGF enhanced long-term memory. NGF administration into the entorhinal cortex improved long-term memory at the dose of 5.0 ng (P < 0.05 and did not alter short-term memory. Taken as a whole, our results suggest a differential modulation by entorhinal and hippocampal NGF of short- and long-term memory.

Walz R.

2005-01-01

130

Long-Term T-Cell-Mediated Immunologic Memory to Hepatitis B Vaccine in Young Adults Following Neonatal Vaccination.  

Science.gov (United States)

Background: The long-term duration of cell-mediated immunity induced by neonatal hepatitis B virus (HBV) vaccination is unknown. Objectives: Study was designed to determine the cellular immunity memory status among young adults twenty years after infantile HB immunization. Patients and Methods: Study subjects were party selected from a recent seroepidemiologic study in young adults, who had been vaccinated against HBV twenty years earlier. Just before and ten to 14 days after one dose of HBV vaccine booster injection, blood samples were obtained and sera concentration of cytokines (interleukin 2 and interferon) was measured. More than twofold increase after boosting was considered positive immune response. With regard to the serum level of antibody against HBV surface antigen (HBsAb) before boosting, the subjects were divided into four groups as follow: GI, HBsAb titer < 2; GII, titer 2 to 9.9; GIII, titer 10 to 99; and GIV, titers ? 100 IU/L. Mean concentration level (MCL) of each cytokines for each group at preboosting and postboosting and the proportion of responders in each groups were determined. Paired descriptive statistical analysis method (t test) was used to compare the MCL of each cytokines in each and between groups and the frequency of responders in each group. Results: Before boosting, among 176 boosted individuals, 75 (42.6%) had HBsAb 10 IU/L and were considered seroprotected. Among 101 serosusceptible persons, more than 80% of boosted individuals showed more than twofold increase in cytokines concentration, which meant positive HBsAg-specific cell-mediated immunity. MCL of both cytokines after boosting in GIV were decreased more than twofold, possibly because of recent natural boosting. Conclusions: Findings showed that neonatal HBV immunization was efficacious in inducing long-term immunity and cell-mediated immune memory for up to two decades, and booster vaccination are not required. Further monitoring of vaccinated subjects for HBV infections are recommended. PMID:25368659

Saffar, Hiva; Saffar, Mohammed Jafar; Ajami, Abolghasem; Khalilian, Ali Reza; Shams-Esfandabad, Kian; Mirabi, Araz Mohammad

2014-01-01

131

Molecular mechanisms underlying formation of long-term reward memories and extinction memories in the honeybee (Apis mellifera).  

Science.gov (United States)

The honeybee (Apis mellifera) has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a flower's characteristic features with a reward in a way that resembles olfactory appetitive classical conditioning, a learning paradigm that is used to study mechanisms underlying learning and memory formation in the honeybee. Due to a plethora of studies on appetitive classical conditioning and phenomena related to it, the honeybee is one of the best characterized invertebrate model organisms from a learning psychological point of view. Moreover, classical conditioning and associated behavioral phenomena are surprisingly similar in honeybees and vertebrates, suggesting a convergence of underlying neuronal processes, including the molecular mechanisms that contribute to them. Here I review current thinking on the molecular mechanisms underlying long-term memory (LTM) formation in honeybees following classical conditioning and extinction, demonstrating that an in-depth analysis of the molecular mechanisms of classical conditioning in honeybees might add to our understanding of associative learning in honeybees and vertebrates. PMID:25225299

Eisenhardt, Dorothea

2014-10-01

132

A clock gene, period, plays a key role in long-term memory formation in Drosophila.  

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The cAMP-responsive transcription factor, CREB, is required for formation of long-term memory (LTM) in Drosophila melanogaster and regulates transcription of a circadian clock gene, period (per). Involvement of CREB both in LTM and circadian rhythm raises the possibility that per also plays a role in LTM. Assaying the experience-dependent courtship inhibition in male flies as a measure for LTM, we show here that per mutants are defective in LTM formation. This defect was rescued by induction of a wild-type per transgene in a per-null mutant, and overexpression of per enhanced LTM formation in the wild-type background. Furthermore, we found that synaptic transmission through per-expressing cells is most likely to be required during retrieval of LTM. In contrast, mutations in other clock genes (timeless, dClock, and cycle) did not affect LTM formation. Thus, independent of the core oscillator of circadian clock, per plays a key role in LTM formation. PMID:15522971

Sakai, Takaomi; Tamura, Takuya; Kitamoto, Toshihiro; Kidokoro, Yoshiaki

2004-11-01

133

Effects of Different Types of True-False Questions on Memory Awareness and Long-Term Retention  

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This study investigated the effects of two different true-false questions on memory awareness and long-term retention of knowledge. Participants took four subsequent knowledge tests on curriculum learning material that they studied at different retention intervals prior to the start of this study (i.e. prior to the first test). At the first and…

Schaap, Lydia; Verkoeijen, Peter; Schmidt, Henk

2014-01-01

134

HDAC Inhibition Modulates Hippocampus-Dependent Long-Term Memory for Object Location in a CBP-Dependent Manner  

Science.gov (United States)

Transcription of genes required for long-term memory not only involves transcription factors, but also enzymatic protein complexes that modify chromatin structure. Chromatin-modifying enzymes, such as the histone acetyltransferase (HAT) CREB (cyclic-AMP response element binding) binding protein (CBP), are pivotal for the transcriptional regulation…

Haettig, Jakob; Stefanko, Daniel P.; Multani, Monica L.; Figueroa, Dario X.; McQuown, Susan C.; Wood, Marcelo A.

2011-01-01

135

Naringin Enhances CaMKII Activity and Improves Long-Term Memory in a Mouse Model of Alzheimer's Disease.  

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The Amyloid-? (A?)-induced impairment of hippocampal synaptic plasticity is an underlying mechanism of memory loss in the early stages of Alzheimer's disease (AD) in human and mouse models. The inhibition of the calcium/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation plays an important role in long-term memory. In this study, we isolated naringin from Pomelo peel (a Citrus species) and studied its effect on long-term memory in the APPswe/PS1dE9 transgenic mouse model of AD. Three-month-old APPswe/PS1dE9 transgenic mice were randomly assigned to a vehicle group, two naringin (either 50 or 100 mg/kg body weight/day) groups, or an Aricept (2 mg/kg body weight/day) group. After 16 weeks of treatment, we observed that treatment with naringin (100 mg/kg body weight/day) enhanced the autophosphorylation of CaMKII, increased the phosphorylation of the ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) receptor at a CaMKII-dependent site and improved long-term learning and memory ability. These findings suggest that the increase in CaMKII activity may be one of the mechanisms by which naringin improves long-term cognitive function in the APPswe/PS1dE9 transgenic mouse model of AD. PMID:23478434

Wang, Dong-Mei; Yang, Ya-Jun; Zhang, Li; Zhang, Xu; Guan, Fei-Fei; Zhang, Lian-Feng

2013-01-01

136

Serological Memory and Long-term Protection to Novel H1N1 Influenza Virus After Skin Vaccination  

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Background.?A major goal in influenza vaccine development is induction of serological memory and cellular responses to confer long-term protection and limit virus spread after infection. Here, we investigate induction of long-lived immunity against the 2009 H1N1 virus after skin vaccination.

Koutsonanos, Dimitrios G.; Del Pilar Martin, Maria; Zarnitsyn, Vladimir G.; Jacob, Joshy; Prausnitz, Mark R.; Compans, Richard W.; Skountzou, Ioanna

2011-01-01

137

Fan-Shaped Body Neurons Are Involved in "Period"-Dependent Regulation of Long-Term Courtship Memory in "Drosophila"  

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In addition to its established function in the regulation of circadian rhythms, the "Drosophila" gene "period" ("per") also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of "per" in subsets of brain neurons enhance and…

Sakai, Takaomi; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro

2012-01-01

138

Dietary Cholesterol Concentration and Duration Degrade Long-Term Memory of Classical Conditioning of the Rabbit's Nictitating Membrane Response  

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A rabbit model of Alzheimer's disease based on feeding a cholesterol diet for eight weeks shows sixteen hallmarks of the disease, including learning and memory changes. Although we have shown 2% cholesterol and copper in water can retard learning, other studies show feeding dietary cholesterol before learning can improve acquisition whereas feeding cholesterol after learning can degrade long-term memory. We explored this issue by manipulating cholesterol concentration and duration following c...

Jimena Gonzalez-Joekes; Roger Bell; Burhans, Lauren B.; Schreurs, Bernard G.; Smith-bell, Carrie A.; Desheng Wang

2012-01-01

139

On the interplay between short and long term memory in the power-law cross-correlations setting  

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We focus on emergence of the power-law cross-correlations from processes with both short and long term memory properties. In the case of correlated error-terms, the power-law decay of the cross-correlation function comes automatically with the characteristics of separate processes. Bivariate Hurst exponent is then equal to an average of separate Hurst exponents of the analyzed processes. Strength of short term memory has no effect on these asymptotic properties. Implications...

Kristoufek, Ladislav

2014-01-01

140

Evidence for long-term memory of the mucosal immune system: milk secretory immunoglobulin A against Shigella lipopolysaccharides.  

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Although the common mucosal immune system has generally been considered to have only short-term memory, recent data suggest that long-term memory exists for Shigella virulence plasmid antigens. Because such antigens might cross-react with environmental antigens, we investigated milk for the persistence of antibodies to the specific Shigella lipopolysaccharide (LPS) antigens. Enzyme-linked immunosorbent assays to detect secretory immunoglobulin A (sIgA) against Shigella flexneri and Shigella s...

Hayani, K. C.; Guerrero, M. L.; Ruiz-palacios, G. M.; Gomez, H. F.; Cleary, T. G.

1991-01-01

 
 
 
 
141

A Diffusion Model Analysis of Adult Age Differences in Episodic and Semantic Long-Term Memory Retrieval  

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Two experiments investigated adult age differences in episodic and semantic long-term memory tasks, as a test of the hypothesis of specific age-related decline in context memory. Older adults were slower and exhibited lower episodic accuracy than younger adults. Fits of the diffusion model (R. Ratcliff, 1978) revealed age-related increases in nondecisional reaction time for both episodic and semantic retrieval. In Experiment 2, an age difference in boundary separation also indicated an age-re...

Spaniol, Julia; Madden, David J.; Voss, Andreas

2006-01-01

142

Effect of zinc supplementation of pregnant rats on short-term and long-term memory of their offspring  

International Nuclear Information System (INIS)

To see the dose dependent effects of zinc chloride on the short-term and long-term memory in a shuttle box (rats). Six pair adult wistar rats were taken for this experiment. One group of pregnant rats received a daily oral dose of 20 mg/kg Zn as zinc chloride and the remaining groups received a daily oral dose of (30, 50, 70,100 mg/kg) zinc chloride for two weeks by gavage. One month after birth, a shuttle box was used to test short-term and long-term memory. Two criteria were considered to behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment showed that oral administration of ZnCl/sub 2/ with (20, 30, 50 mg/kg/day) doses after 2 weeks at the stage of pregnancy, can improve the working memory of their offspring (p<0.05). Where as ZnCl/sub 2/ with 30 mg/kg/day dose has been more effective than other doses (p<0.001). But rat which received ZnCl/sub 2/ with 100 mg/kg/day at the stage of pregnancy, has shown significant impairment in working (short-term) memory of their offspring (p<0.05) and there was no significant difference in reference (long-term) memory 3 for any of groups. This study has demonstrated that zinc chloride consumption with 30 mg/kg/day dose for two weeks at the stage of pregnancy in rats, has positive effect on short-term memory on their offspring. But consumption of enhanced zinc 100 mg/kg/day in pregnant rats can cause short-term memory impairment. On the other hand, zinc supplementation such the other hand, zinc supplementation such as zinc chloride has no effect on long-term memory. (author)

143

Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants  

DEFF Research Database (Denmark)

Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose solution, the insect extends its maxilla–labium to absorb the solution (maxilla–labium extension response). We differentially conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning. Cycloheximide did not impair acquisition of either short-term memory (10¿min) or early and late mid-term memories (1 or 12¿h). These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.

Guerrieri, Fernando Javier; D'Ettorre, Patrizia

2011-01-01

144

2010 Survey on long-term preservation of information and memory for geological disposal of radioactive waste  

International Nuclear Information System (INIS)

Preservation of information and memory across generations is a cross-cutting theme of increasing importance for radioactive waste management. Because of the experience accumulated by the advanced national programmes that the RWMC represents, and the breadth of its related high-level initiatives, the Committee is uniquely placed internationally to combine resources and help develop state-of-the-art guidance on the long-term preservation of information and memory. In the context of fostering knowledge consolidation and transfer (KCT), the RWMC has already identified - in its reference document on KCT - the area of inter-generational transfer of knowledge as one of two areas needing development. In 2009, the RWMC decided to implement its programme of work in the area of information preservation and long-term memory as a series of projects or lines of actions opened by the RWMC and supervised by its Bureau. In order to better define its first series of projects the RWMC preformed a survey of its organisations needs and available materials and experience. At its meeting in 2010 the RWMC determined that the survey materials provided by organisations from 12 NEA countries constitute a good contribution to the literature in this field, and certainly to the upcoming projects. They provide as well a good baseline of information against which to measure progress a few years hence. This document reports the answers provided by organisations from 12 countries (Belgium, Canada, Finland, France, Hungary, Japan, Korea, Spain, Sweden, Switzerland, United Kingdom, and the USA,) to five questions related to long-term preservation of information and memory in the field of geological disposal. The questions are as follows: o What specific priority areas for long-term memory development have been identified in your agencies/countries? Which are the time scales of largest interest? o Do these priority proceed from good practice or/and from specific laws, regulations, policies exist in your country that set out requirements for long-term memory in long-term waste management? o How far advanced are you regarding establishing an action plan for long-term information and memory preservation in the field of geological disposal? Are you addressing the following RWMC questions: What information should be preserved? Why? Where? How should it be preserved? Which target groups? Which time horizons? What suggestions do you have for possible areas of focus for RWMC? (e.g. an international project that may assist Members?) What are the untapped areas that deserve more attention? Would you have studies, reports, policies that you might share with RWMC members? (author)

145

Two Pairs of Mushroom Body Efferent Neurons Are Required for Appetitive Long-Term Memory Retrieval in Drosophila  

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Full Text Available One of the challenges facing memory research is to combine network- and cellular-level descriptions of memory encoding. In this context, Drosophila offers the opportunity to decipher, down to single-cell resolution, memory-relevant circuits in connection with the mushroom bodies (MBs, prominent structures for olfactory learning and memory. Although the MB-afferent circuits involved in appetitive learning were recently described, the circuits underlying appetitive memory retrieval remain unknown. We identified two pairs of cholinergic neurons efferent from the MB ? vertical lobes, named MB-V3, that are necessary for the retrieval of appetitive long-term memory (LTM. Furthermore, LTM retrieval was correlated to an enhanced response to the rewarded odor in these neurons. Strikingly, though, silencing the MB-V3 neurons did not affect short-term memory (STM retrieval. This finding supports a scheme of parallel appetitive STM and LTM processing.

Pierre-Yves Plaçais

2013-11-01

146

Anatomical organization of forward fiber projections from area TE to perirhinal neurons representing visual long-term memory in monkeys.  

Science.gov (United States)

A number of studies have shown that the perirhinal (PRh) cortex, which is part of the medial temporal lobe memory system, plays an important role in declarative long-term memory. The PRh cortex contains neurons that represent visual long-term memory. The aim of the present study is to characterize the anatomical organization of forward projections that mediate information flow from visual area TE to memory neurons in the PRh cortex. In monkeys performing a visual pair-association memory task, we conducted an extensive mapping of neuronal responses in the anteroventral part of area TE (TEav) and area 36 (A36) of the PRh cortex. Then, three retrograde tracers were separately injected into A36 and the distribution of retrograde labels in TEav was analyzed. We focused on the degree of divergent projections from TEav to memory neurons in A36, because the highly divergent nature of these forward fiber projections has been implicated in memory function. We found that the degree of divergent projection to memory neurons in A36 was smaller from the TEav neurons selective to learned pictures than from the nonselective TEav neurons. This result demonstrates that the anatomical difference (the divergence) correlates with the physiological difference (selectivity of TEav neurons to the learned pictures). Because the physiological difference is attributed to whether the projections are involved in information transmission required for memory neurons in A36, it can be speculated that the reduced divergent projection resulted from acquisition of visual long-term memory, possibly through retraction of the projecting axon collaterals. PMID:12651941

Yoshida, Masatoshi; Naya, Yuji; Miyashita, Yasushi

2003-04-01

147

Long-term Calibration Considerations during Subcutaneous Microdialysis Sampling in Mobile Rats  

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The level at which implanted sensors and sampling devices maintain their calibration is an important research area. In this work, microdialysis probes with identical geometry and different membranes, polycarbonate/polyether (PC) or polyethersulfone (PES), were used with internal standards (vitamin B12 (MW 1355), antipyrine (MW 188) and 2-deoxyglucose (2-DG, MW 164)) and endogenous glucose to investigate changes in their long-term calibration after implantation into the subcutaneous space of S...

Mou, Xiaodun; Lennartz, Michelle; Loegering, Daniel J.; Stenken, Julie A.

2010-01-01

148

Do serotonin(1-7) receptors modulate short and long-term memory?  

Science.gov (United States)

Evidence from invertebrates to human studies indicates that serotonin (5-hydroxytryptamine; 5-HT) system modulates short- (STM) and long-term memory (LTM). This work is primarily focused on analyzing the contribution of 5-HT, cholinergic and glutamatergic receptors as well as protein synthesis to STM and LTM of an autoshaping learning task. It was observed that the inhibition of hippocampal protein synthesis or new mRNA did not produce a significant effect on autoshaping STM performance but it did impair LTM. Both non-contingent protein inhibition and 5-HT depletion showed no effects. It was basically the non-selective 5-HT receptor antagonist cyproheptadine, which facilitated STM. However, the blockade of glutamatergic and cholinergic transmission impaired STM. In contrast, the selective 5-HT(1B) receptor antagonist SB-224289 facilitated both STM and LTM. Selective receptor antagonists for the 5-HT(1A) (WAY100635), 5-HT(1D) (GR127935), 5-HT(2A) (MDL100907), 5-HT(2C/2B) (SB-200646), 5-HT(3) (ondansetron) or 5-HT(4) (GR125487), 5-HT(6) (Ro 04-6790, SB-399885 and SB-35713) or 5-HT(7) (SB-269970) did not impact STM. Nevertheless, WAY100635, MDL100907, SB-200646, GR125487, Ro 04-6790, SB-399885 or SB-357134 facilitated LTM. Notably, some of these changes shown to be independent of food-intake. Concomitantly, these data indicate that '5-HT tone via 5-HT(1B) receptors' might function in a serial manner from STM to LTM, whereas working in parallel using 5-HT(1A), 5-HT(2A), 5-HT(2B/2C), 5-HT(4), or 5-HT(6) receptors. PMID:17224282

Meneses, A

2007-05-01

149

NF-?B p50 subunit knockout impairs late LTP and alters long term memory in the mouse hippocampus  

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Full Text Available Abstract Background Nuclear factor kappa B (NF-?B is a transcription factor typically expressed with two specific subunits (p50, p65. Investigators have reported that NF-?B is activated during the induction of in vitro long term potentiation (LTP, a paradigm of synaptic plasticity and correlate of memory, suggesting that NF-?B may be necessary for some aspects of memory encoding. Furthermore, NF-?B has been implicated as a potential requirement in behavioral tests of memory. Unfortunately, very little work has been done to explore the effects of deleting specific NF-?B subunits on memory. Studies have shown that NF-?B p50 subunit deletion (p50?/? leads to memory deficits, however some recent studies suggest the contrary where p50?/? mice show enhanced memory in the Morris water maze (MWM. To more critically explore the role of the NF-?B p50 subunit in synaptic plasticity and memory, we assessed long term spatial memory in vivo using the MWM, and synaptic plasticity in vitro utilizing high frequency stimuli capable of eliciting LTP in slices from the hippocampus of NF-?B p50?/? versus their controls (p50+/+. Results We found that the lack of the NF-?B p50 subunit led to significant decreases in late LTP and in selective but significant alterations in MWM tests (i.e., some improvements during acquisition, but deficits during retention. Conclusions These results support the hypothesis that the NF-? p50 subunit is required in long term spatial memory in the hippocampus.

Oikawa Kensuke

2012-07-01

150

Failure of delayed nonsynaptic neuronal plasticity underlies age-associated long-term associative memory impairment  

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Full Text Available Abstract Background Cognitive impairment associated with subtle changes in neuron and neuronal network function rather than widespread neuron death is a feature of the normal aging process in humans and animals. Despite its broad evolutionary conservation, the etiology of this aging process is not well understood. However, recent evidence suggests the existence of a link between oxidative stress in the form of progressive membrane lipid peroxidation, declining neuronal electrical excitability and functional decline of the normal aging brain. The current study applies a combination of behavioural and electrophysiological techniques and pharmacological interventions to explore this hypothesis in a gastropod model (Lymnaea stagnalis feeding system that allows pinpointing the molecular and neurobiological foundations of age-associated long-term memory (LTM failure at the level of individual identified neurons and synapses. Results Classical appetitive reward-conditioning induced robust LTM in mature animals in the first quartile of their lifespan but failed to do so in animals in the last quartile of their lifespan. LTM failure correlated with reduced electrical excitability of two identified serotonergic modulatory interneurons (CGCs critical in chemosensory integration by the neural network controlling feeding behaviour. Moreover, while behavioural conditioning induced delayed-onset persistent depolarization of the CGCs known to underlie appetitive LTM formation in this model in the younger animals, it failed to do so in LTM-deficient senescent animals. Dietary supplementation of the lipophilic anti-oxidant ?-tocopherol reversed the effect of age on CGCs electrophysiological characteristics but failed to restore appetitive LTM function. Treatment with the SSRI fluoxetine reversed both the neurophysiological and behavioural effects of age in senior animals. Conclusions The results identify the CGCs as cellular loci of age-associated appetitive learning and memory impairment in Lymnaea and buttress the hypothesis that lipid peroxidation-dependent depression of intrinsic excitability is a hallmark of normal neuronal aging. The data implicate both lipid peroxidation-dependent non-synaptic as well as apparently lipid peroxidation-independent synaptic mechanisms in the age-dependent decline in behavioural plasticity in this model system.

Watson Shawn N

2012-08-01

151

Memory and long-term potentiation (LTP) dissociated: Normal spatial memory despite CA1 LTP elimination with Kv1.4 antisense  

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Long-term potentiation (LTP) in the hippocampal slice preparation has been proposed as an in vitro model for long-term memory. However, correlation of LTP with memory in living animals has been difficult to demonstrate. Furthermore, in the last few years evidence has accumulated that dissociate the two. Because potassium channels might determine the weight of synapses in networks, we studied the role of Kv1.4, a presynaptic A-type voltage-dependent K+ channel, in both memory and LTP. Reverse ...

Meiri, Noam; Sun, Miao-kun; Segal, Zachary; Alkon, Daniel L.

1998-01-01

152

Does sustained ERP activity in posterior lexico-semantic processing areas during short-term memory tasks only reflect activated long-term memory?  

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We challenge Ruchkin et al.'s claim in reducing short-term memory (STM) to the active part of long-term memory (LTM), by showing that their data cannot rule out the possibility that activation of posterior brain regions could also reflect the contribution of a verbal STM buffer.

Majerus, Steve; Linden, Martial; Collette, Fabienne; Salmon, Eric

2003-01-01

153

Long-term maintenance of smartphone and PDA use in individuals with moderate to severe memory impairment.  

Science.gov (United States)

In an earlier paper we described a structured, theory-driven training programme which was administered to 10 individuals with moderate-to-severe memory impairment. All individuals received an errorless-fading-of-cues protocol in the use of personal digital assistants (PDAs) or smartphones (Svoboda, Richards, Leach, & Mertens, 2012 ) and demonstrated generalisation of acquired skills to day-to-day memory challenges. Maintenance of intervention gains over the long-term is another indicator of successful generalisation. Here we present the maintenance of device use in the same group of individuals 12 to 19?months after programme completion. A within-subject, ABABB multi-case experimental design was used to evaluate the impact of PDA or smartphone use on day-to-day memory functioning at baseline, immediately post-intervention, at return to baseline, and at short-term and long-term follow-up. Results presented here focus predominantly on long-term follow-up. All 10 individuals showed maintenance of gains in day-to-day functioning as quantified across several ecologically valid questionnaire and task-based measures. This was corroborated by family members with whom six of the participants resided. This study further demonstrates the programme's clinical effectiveness in enabling individuals with moderate-to-severe memory impairment to function more independently and with greater confidence up to 19?months following programme completion. PMID:24945553

Svoboda, Eva; Richards, Brian; Yao, Christie; Leach, Larry

2014-06-19

154

A Transcription Factor-Binding Domain of the Coactivator CBP Is Essential for Long-Term Memory and the Expression of Specific Target Genes  

Science.gov (United States)

Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with…

Oliveira, Ana M. M.; Brindle, Paul K.; Abel, Ted; Wood, Marcelo A.; Attner, Michelle A.

2006-01-01

155

Identification of gene expression changes associated with long-term memory of courtship rejection in Drosophila males.  

Science.gov (United States)

Long-term memory formation in Drosophila melanogaster is an important neuronal function shaping the insect's behavioral repertoire by allowing an individual to modify behaviors on the basis of previous experiences. In conditioned courtship or courtship suppression, male flies that have been repeatedly rejected by mated females during courtship advances are less likely than naïve males to subsequently court another mated female. This long-term courtship suppression can last for several days after the initial rejection period. Although genes with known functions in many associative learning paradigms, including those that function in cyclic AMP signaling and RNA translocation, have been identified as playing critical roles in long-term conditioned courtship, it is clear that additional mechanisms also contribute. We have used RNA sequencing to identify differentially expressed genes and transcript isoforms between naïve males and males subjected to courtship-conditioning regimens that are sufficient for inducing long-term courtship suppression. Transcriptome analyses 24 hours after the training regimens revealed differentially expressed genes and transcript isoforms with predicted and known functions in nervous system development, chromatin biology, translation, cytoskeletal dynamics, and transcriptional regulation. A much larger number of differentially expressed transcript isoforms were identified, including genes previously implicated in associative memory and neuronal development, including fruitless, that may play functional roles in learning during courtship conditioning. Our results shed light on the complexity of the genetics that underlies this behavioral plasticity and reveal several new potential areas of inquiry for future studies. PMID:23173095

Winbush, Ari; Reed, Danielle; Chang, Peter L; Nuzhdin, Sergey V; Lyons, Lisa C; Arbeitman, Michelle N

2012-11-01

156

On the role of the hippocampus in the acquisition, long-term retention and semanticisation of memory  

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A consensus on how to characterise the anterograde and retrograde memory processes that are lost or spared after hippocampal damage has not been reached. In this thesis, I critically re-examine the empirical literature and the assumptions behind current theories. I formulate a coherent view of what makes a task hippocampally dependent at acquisition and how this relates to its long-term fate. Findings from a neural net simulation indicate the plausibility of my proposals. My...

Gingell, Sarah M.

2005-01-01

157

Comparable Analysis of Long-term Memory of EUR/USD Based on Non-parametrical Statistics  

Directory of Open Access Journals (Sweden)

Full Text Available Non-parameter statistical methods of classical R/S, revised R/S and V/S was proposed in long-term Memory of EUR/USD. It was concluded through comparable analysis that: (1 Through Normality Test of Return Sequences of EUR/USD Daily Closing Prices, the experimental results imply that bias of daily return sequences of EUR/USD is not equal to zero, and the curve appears to high peak and fat tail. (2 Jarque-Bera test is adopted. The estimated values reject the null hypothesis of normal distribution. (3 The paper estimates daily return series of EUR/USD using classical R/S method. The results show that Hurst exponent is equal to 0.612425; the statistical cycle is 160 days; the correlative scale is close to 1.3432. This study's conclusion was that long-term memory exists in daily return time series of EUR/USD is proved.Key words: rescaled range (R/S analysis; rescaled variance (V/S analysis; long-term memory

Yan-xi LI

2010-09-01

158

Vividness of visual imagery and incidental recall of verbal cues, when phenomenological availability reflects long-term memory accessibility  

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Full Text Available The relationship between vivid visual mental images and unexpected recall (incidental recall was replicated, refined and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal-cues (controlled on several verbal properties and then, on a trial-by-trial basis, rate the vividness of their images; thirty minutes later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest. Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ, as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories.

AmedeoD'Angiulli

2013-02-01

159

Fan-shaped body neurons are involved in period-dependent regulation of long-term courtship memory in Drosophila.  

Science.gov (United States)

In addition to its established function in the regulation of circadian rhythms, the Drosophila gene period (per) also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of per in subsets of brain neurons enhance and suppress LTM, respectively, and (2) suppression of synaptic transmission during memory retrieval in the same neuronal subsets leads to defective LTM. Further analysis strongly suggests that the brain region critical for per-dependent LTM regulation is the fan-shaped body, which is involved in sleep-induced enhancement of courtship LTM. PMID:23154928

Sakai, Takaomi; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro

2012-01-01

160

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2012 at Rulison, Colorado  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 8, 2012. The samples were shipped to GEL Laboratories in Charleston, South Carolina, for analysis. All requested analyses were successfully completed. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry; tritium was analyzed using two methods. The conventional tritium method has a detection limit on the order of 400 pCi/L, and a select set of samples was analyzed for tritium using the enriched method, which has a detection limit on the order of 3 pCi/L.

None

2012-12-06

 
 
 
 
161

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2012 at Rulison, Colorado  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 8, 2012. The samples were shipped to GEL Laboratories in Charleston, South Carolina, for analysis. All requested analyses were successfully completed. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry; tritium was analyzed using two methods. The conventional tritium method has a detection limit on the order of 400 pCi/L, and a select set of samples was analyzed for tritium using the enriched method, which has a detection limit on the order of 3 pCi/L.

162

Improved long-term memory via enhancing cGMP-PKG signaling requires cAMP-PKA signaling.  

Science.gov (United States)

Memory consolidation is defined by the stabilization of a memory trace after acquisition, and consists of numerous molecular cascades that mediate synaptic plasticity. Commonly, a distinction is made between an early and a late consolidation phase, in which early refers to the first hours in which labile synaptic changes occur, whereas late consolidation relates to stable and long-lasting synaptic changes induced by de novo protein synthesis. How these phases are linked at a molecular level is not yet clear. Here we studied the interaction of the cyclic nucleotide-mediated pathways during the different phases of memory consolidation in rodents. In addition, the same pathways were studied in a model of neuronal plasticity, long-term potentiation (LTP). We demonstrated that cGMP/protein kinase G (PKG) signaling mediates early memory consolidation as well as early-phase LTP, whereas cAMP/protein kinase A (PKA) signaling mediates late consolidation and late-phase-like LTP. In addition, we show for the first time that early-phase cGMP/PKG signaling requires late-phase cAMP/PKA-signaling in both LTP and long-term memory formation. PMID:24813825

Bollen, Eva; Puzzo, Daniela; Rutten, Kris; Privitera, Lucia; De Vry, Jochen; Vanmierlo, Tim; Kenis, Gunter; Palmeri, Agostino; D'Hooge, Rudi; Balschun, Detlef; Steinbusch, Harry M W; Blokland, Arjan; Prickaerts, Jos

2014-10-01

163

Memory T and memory B cells share a transcriptional program of self-renewal with long-term hematopoietic stem cells  

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The only cells of the hematopoietic system that undergo self-renewal for the lifetime of the organism are long-term hematopoietic stem cells and memory T and B cells. To determine whether there is a shared transcriptional program among these self-renewing populations, we first compared the gene-expression profiles of naïve, effector and memory CD8+ T cells with those of long-term hematopoietic stem cells, short-term hematopoietic stem cells, and lineage-committed progenitors. Transcripts aug...

Luckey, Chance John; Bhattacharya, Deepta; Goldrath, Ananda W.; Weissman, Irving L.; Benoist, Christophe; Mathis, Diane

2006-01-01

164

Mushroom body neuronal remodelling is necessary for short-term but not for long-term courtship memory in Drosophila.  

Science.gov (United States)

The remodelling of neurons during their development is considered necessary for their normal function. One fundamental mechanism involved in this remodelling process in both vertebrates and invertebrates is axon pruning. A well-documented case of such neuronal remodelling is the developmental axon pruning of mushroom body ? neurons that occurs during metamorphosis in Drosophila. The ? neurons undergo pruning of larval-specific dendrites and axons at metamorphosis, followed by their regrowth as adult-specific dendrites and axons. We recently revealed a molecular cascade required for this pruning. The nuclear receptor ftz-f1 activates the expression of the steroid hormone receptor EcR-B1, a key component for ? remodelling, and represses expression of Hr39, an ftz-f1 homologous gene. If ectopically expressed in the ? neurons, HR39 inhibits normal pruning, probably by competing with endogenous FTZ-F1, which results in decreased EcR-B1 expression. The mushroom bodies are a bilaterally symmetric structure in the larval and adult brain and are involved in the processing of different types of olfactory memory. How memory is affected in pruning-deficient adult flies that possess larval-stage neuronal circuitry will help to explain the functional role of neuron remodelling. Flies overexpressing Hr39 are viable as adults and make it possible to assess the requirement for wild-type mushroom body pruning in memory. While blocking mushroom body neuron remodelling impaired memory after short-term courtship conditioning, long-term memory was normal. These results show that larval pruning is necessary for adult memory and that expression of courtship short-term memory and long-term memory may be parallel and independent. PMID:22571719

Redt-Clouet, Christelle; Trannoy, Séverine; Boulanger, Ana; Tokmatcheva, Elena; Savvateeva-Popova, Elena; Parmentier, Marie-Laure; Preat, Thomas; Dura, Jean-Maurice

2012-06-01

165

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011 at Rulison, Colorado  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 18, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method. The laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

166

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011 at Rulison, Colorado  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 18, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method. The laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

None

2012-05-10

167

The role of reconsolidation and the dynamic process of long-term memory formation and storage  

Directory of Open Access Journals (Sweden)

Full Text Available It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the physical changes underlying the encoding and processing of the information (memory trace or engram remain in a fragile state for some time. However, over time, the new memory becomes increasingly resistant to disruption until it is consolidated. Retrieval or reactivation of an apparently consolidated memory can render the memory labile again, and reconsolidation is the process that occurs to mediate its restabilization. Reconsolidation also evolves with the age of the memory: Young memories are sensitive to postreactivation disruption, but older memories are more resistant. Why does a memory become labile again if it is retrieved or reactivated? Here I suggest that the main function of reconsolidation is to contribute to the lingering consolidation process and mediate memory strengthening. I also discuss the literature and results regarding the influence of the passage of time on the reconsolidation of memory. These points have important implications for the use of reconsolidation in therapeutic settings.

CristinaMAlberini

2011-03-01

168

Four-Month-Old Infants’ Long-Term Memory for a Stressful Social Event  

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Infants clearly show an early capacity for memory for inanimate emotionally neutral events. However, their memory for social stress events has received far less attention. The aim of the study was to investigate infants’ memory for a stressful social event (i.e., maternal unresponsiveness during the Still-Face paradigm) after a 15-day recall interval using changes in behavioral responses and salivary post-stress cortisol reactivity as measures of memory. Thirty-seven infants were exposed to...

Montirosso, Rosario; Tronick, Ed; Morandi, Francesco; Ciceri, Francesca; Borgatti, Renato

2013-01-01

169

Long-term sequelae of critical illness: memories and health-related quality of life  

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Impaired health-related quality of life after critical illness has been demonstrated in a number of studies. It is not clear exactly how or why critical illness and intensive care lead to impaired health status, but understanding this association is an important step to improving long-term outcomes of the critically ill. There is growing evidence that neuro-psychological symptoms play a significant role in this impairment and that management of patients in the intensive care unit (ICU) may in...

Hough, Catherine Lee; Curtis, J. Randall

2005-01-01

170

Attention Problems, Phonological Short-Term Memory, and Visuospatial Short-Term Memory: Differential Effects on Near- and Long-Term Scholastic Achievement  

Science.gov (United States)

The current study examined individual differences in children's phonological and visuospatial short-term memory as potential mediators of the relationship among attention problems and near- and long-term scholastic achievement. Nested structural equation models revealed that teacher-reported attention problems were associated negatively with…

Sarver, Dustin E.; Rapport, Mark D.; Kofler, Michael J.; Scanlan, Sean W.; Raiker, Joseph S.; Altro, Thomas A.; Bolden, Jennifer

2012-01-01

171

Olfaction, Emtion & the Amygdala: arousal-dependent modulation of long-term autobiographical memory and its association with olfaction  

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Full Text Available The sense of smell is set apart from other sensory modalities. Odours possess the capacity to trigger immediately strong emotional memories. Moreover, odorous stimuli provide a higher degree of memory retention than other sensory stimuli. Odour perception, even in its most elemental form - olfaction - already involves limbic structures. This early involvement is not paralleled in other sensory modalities. Bearing in mind the considerable connectivity with limbic structures, and the fact that an activation of the amygdala is capable of instantaneously evoking emotions and facilitating the encoding of memories, it is unsurprising that the sense of smell has its characteristic nature. The aim of this review is to analyse current understanding of higher olfactory information processing as it relates to the ability of odours to spontaneously cue highly vivid, affectively toned, and often very old autobiographical memories (episodes known anecdotally as Proust phenomena. Particular emphasis is placed on the diversity of functions attributed to the amygdala. Its role in modulating the encoding and retrieval of long-term memory is investigated with reference to lesion, electrophysiological, immediate early gene, and functional imaging studies in both rodents and humans. Additionally, the influence of hormonal modulation and the adrenergic system on emotional memory storage is outlined. I finish by proposing a schematic of some of the critical neural pathways that underlie the odour-associated encoding and retrieval of emotionally toned autobiographical memories.

Mark Hughes

2004-01-01

172

Differential role of entorhinal and hippocampal nerve growth factor in short- and long-term memory modulation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english We studied the effects of infusion of nerve growth factor (NGF) into the hippocampus and entorhinal cortex of male Wistar rats (250-300 g, N = 11-13 per group) on inhibitory avoidance retention. In order to evaluate the modulation of entorhinal and hippocampal NGF in short- and long-term memory, ani [...] mals were implanted with cannulae in the CA1 area of the dorsal hippocampus or entorhinal cortex and trained in one-trial step-down inhibitory avoidance (foot shock, 0.4 mA). Retention tests were carried out 1.5 h or 24 h after training to measure short- and long-term memory, respectively. Immediately after training, rats received 5 µl NGF (0.05, 0.5 or 5.0 ng) or saline per side into the CA1 area and entorhinal cortex. The correct position of the cannulae was confirmed by histological analysis. The highest dose of NGF (5.0 ng) into the hippocampus blocked short-term memory (P

R., Walz; R., Roesler; A., Reinke; M.R., Martins; J., Quevedo; I., Izquierdo.

2005-01-01

173

Long-Term Memory Shapes the Primary Olfactory Center of an Insect Brain  

Science.gov (United States)

The storage of stable memories is generally considered to rely on changes in the functional properties and/or the synaptic connectivity of neural networks. However, these changes are not easily tractable given the complexity of the learning procedures and brain circuits studied. Such a search can be narrowed down by studying memories of specific…

Hourcade, Benoit; Perisse, Emmanuel; Devaud, Jean-Marc; Sandoz, Jean-Christophe

2009-01-01

174

Creation of Long-Term Coherent Optical Memory via Controlled Nonlinear Interactions in Bose-Einstein Condensates  

International Nuclear Information System (INIS)

A Bose-Einstein condensate confined in an optical dipole trap is used to generate long-term coherent memory for light, and storage times of more than 1 s are observed. Phase coherence of the condensate as well as controlled manipulations of elastic and inelastic atomic scattering processes are utilized to increase the storage fidelity by several orders of magnitude over previous schemes. The results have important applications for creation of long-distance quantum networks and for generation of entangled states of light and matter.

175

Creation of long-term coherent optical memory via controlled nonlinear interactions in Bose-Einstein condensates  

CERN Document Server

A Bose-Einstein condensate confined in an optical dipole trap is used to generate long-term coherent memory for light, and storage times of more than one second are observed. Phase coherence of the condensate as well as controlled manipulations of elastic and inelastic atomic scattering processes are utilized to increase the storage fidelity by several orders of magnitude over previous schemes. The results have important applications for creation of long-distance quantum networks and for generation of entangled states of light and matter.

Zhang, Rui; Hau, Lene Vestergaard

2009-01-01

176

Odor-enriched environment rescues long-term social memory, but does not improve olfaction in social isolated adult mice.  

Science.gov (United States)

Prolonged permanence of animals under social isolation (SI) arouses a variety of psychological symptoms like aggression, stress, anxiety and depression. However, short-term SI is commonly used to evaluate social memory. Interestingly, the social memory cannot be accessed with delays higher than 30min in SI mice. Our hypothesis is that SI with intermediate duration, like one week (1w), impairs the long-term storage of new social information (S-LTM), without affecting anxiety or other types of memories, because the SI compromises the olfactory function of the animal. Our results demonstrated that SI impaired S-LTM, without affecting other kinds of memory or anxiety. In addition, the SI increased the latency in the buried-food finding task, but did not affect the habituation or the discrimination of odors. Next, we postulated that if continuous input to the olfactory system is fundamental for the maintenance of the olfactory function and social memory persistence, isolated mice under odor-enriched environment (OEE) should behave like group-housed (GH) animals. In fact, the OEE prevented the S-LTM deficit imposed by the SI. However, OEE did not restore the SI mice olfaction to the GH mice level. Our results suggest that SI modulates olfaction and social memory persistence, probably, by independent mechanisms. We also showed for the first time that OEE rescued S-LTM in SI mice through a mechanism not necessarily involved with olfaction. PMID:22226622

Gusmão, Isabela D; Monteiro, Brisa M M; Cornélio, Guilherme O S; Fonseca, Cristina S; Moraes, Márcio F D; Pereira, Grace S

2012-03-17

177

Memory and learning sequelae in long-term survivors of acute lymphoblastic leukemia: association with attention deficits.  

Science.gov (United States)

A systematic study of verbal and nonverbal memory and learning was undertaken in long-term survivors of acute lymphoblastic leukemia to assess the incidence and pattern of impairments and to determine the relationship between these deficits and computed tomography (CT) brain scan abnormalities. Twenty-three children who had received cranial irradiation (2,400 cGy) and intrathecal chemotherapy as central nervous system (CNS) preventive therapy and who were off all therapy for at least 4 years were evaluated. On the basis of their CT brain scan findings, patients were divided into three groups: those with intracerebral calcifications (n = 5), those with cortical atrophy (n = 8), and those with normal CT findings (n = 10). Significant deficits in verbal memory (p less than 0.025) and verbal learning (p less than 0.05) were observed that were associated with the presence and type of CT brain scan abnormalities; the greatest impairments were observed in patients with calcifications. No significant differences between CT scan groups were found for nonverbal memory and learning. Previous evaluation of attentional processing in these patients using reaction time tests had revealed the presence of deficits primarily in the ability to sustain attention. Combining those data with findings from the present study showed that memory impairments, particularly those in short-term memory, were primarily attributable to an underlying attentional defect that affect the encoding stage of memory processing. PMID:2116096

Brouwers, P; Poplack, D

1990-01-01

178

Memory and learning sequelae in long-term survivors of acute lymphoblastic leukemia: Association with attention deficits  

Energy Technology Data Exchange (ETDEWEB)

A systematic study of verbal and nonverbal memory and learning was undertaken in long-term survivors of acute lymphoblastic leukemia to assess the incidence and pattern of impairments and to determine the relationship between these deficits and computed tomography (CT) brain scan abnormalities. Twenty-three children who had received cranial irradiation (2,400 cGy) and intrathecal chemotherapy as central nervous system (CNS) preventive therapy and who were off all therapy for at least 4 years were evaluated. On the basis of their CT brain scan findings, patients were divided into three groups: those with intracerebral calcifications (n = 5), those with cortical atrophy (n = 8), and those with normal CT findings (n = 10). Significant deficits in verbal memory (p less than 0.025) and verbal learning (p less than 0.05) were observed that were associated with the presence and type of CT brain scan abnormalities; the greatest impairments were observed in patients with calcifications. No significant differences between CT scan groups were found for nonverbal memory and learning. Previous evaluation of attentional processing in these patients using reaction time tests had revealed the presence of deficits primarily in the ability to sustain attention. Combining those data with findings from the present study showed that memory impairments, particularly those in short-term memory, were primarily attributable to an underlying attentional defect that affect the encoding stage of memory processing.

Brouwers, P.; Poplack, D. (National Cancer Institute, Bethesda, MD (USA))

179

Memory and learning sequelae in long-term survivors of acute lymphoblastic leukemia: Association with attention deficits  

International Nuclear Information System (INIS)

A systematic study of verbal and nonverbal memory and learning was undertaken in long-term survivors of acute lymphoblastic leukemia to assess the incidence and pattern of impairments and to determine the relationship between these deficits and computed tomography (CT) brain scan abnormalities. Twenty-three children who had received cranial irradiation (2,400 cGy) and intrathecal chemotherapy as central nervous system (CNS) preventive therapy and who were off all therapy for at least 4 years were evaluated. On the basis of their CT brain scan findings, patients were divided into three groups: those with intracerebral calcifications (n = 5), those with cortical atrophy (n = 8), and those with normal CT findings (n = 10). Significant deficits in verbal memory (p less than 0.025) and verbal learning (p less than 0.05) were observed that were associated with the presence and type of CT brain scan abnormalities; the greatest impairments were observed in patients with calcifications. No significant differences between CT scan groups were found for nonverbal memory and learning. Previous evaluation of attentional processing in these patients using reaction time tests had revealed the presence of deficits primarily in the ability to sustain attention. Combining those data with findings from the present study showed that memory impairments, particularly those in short-term memory, were primarily attributable to an underlying attentional defect that affect the encoding stage ofl defect that affect the encoding stage of memory processing

180

Electrical stunning and hibernation: suggestion of new terms for short- and long-term cardiac memory.  

Science.gov (United States)

Persistent T wave changes following resumption of sinus rhythm induced by pacing or arrhythmias that cause altering of ventricular activation sequence are named "cardiac memory". After this initial definition there has been a discussion whether such T wave changes are primary, secondary or pseudoprimary. In addition according to the results of pathophysiological studies investigating the mechanism and nature of this repolarization abnormality some authors have preferred to use the term "electrical remodelling" instead of cardiac memory. But these two terms are still not well defined. In this article, the previous terms are discussed and a new term instead of cardiac memory is introduced. PMID:15294266

Zoghi, Mehdi; Nalbantgil, Sanem

2004-09-01

 
 
 
 
181

Rapid consolidation to a radish and protein synthesis-dependent long-term memory after single-session appetitive olfactory conditioning in Drosophila.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In Drosophila, formation of aversive olfactory long-term memory (LTM) requires multiple training sessions pairing odor and electric shock punishment with rest intervals. In contrast, here we show that a single 2 min training session pairing odor with a more ethologically relevant sugar reinforcement forms long-term appetitive memory that lasts for days. Appetitive LTM has some mechanistic similarity to aversive LTM in that it can be disrupted by cycloheximide, the dCreb2-b transcriptional rep...

Krashes, Mj; Waddell, S

2008-01-01

182

Mice overexpressing type 1 adenylyl cyclase show enhanced spatial memory flexibility in the absence of intact synaptic long-term depression  

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There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca2+-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated long-term potentiation (LTP) but impaired long-term depression (LTD) at the hippocampal Shaffer collateral-CA1 synapses. However, following the induction of LTP, low-fr...

Zhang, Ming; Wang, Hongbing

2013-01-01

183

Errors in nonword repetition: bridging short- and long-term memory  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep) is a suitable measure of phonological short-term memory for Englis [...] h-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR) as a Portuguese-language version. The objectives of the present study were: i) to investigate developmental aspects of the phonological memory processing by error analysis in the nonword repetition task, and ii) to examine phoneme (substitution, omission and addition) and order (migration) errors made in the BCPR by 180 normal Brazilian children of both sexes aged 4-10, from preschool to 4th grade. The dominant error was substitution [F(3,525) = 180.47; P

F.H., Santos; O.F.A., Bueno; S.E., Gathercole.

2006-03-01

184

Stress administered prior to encoding impairs neutral but enhances emotional long-term episodic memories  

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Stressful events frequently comprise both neutral and emotionally arousing information, yet the impact of stress on emotional and neutral events is still not fully understood. The hippocampus and frontal cortex have dense concentrations of receptors for stress hormones, such as cortisol, which at high levels can impair performance on hippocampally dependent memory tasks. Yet, the same stress hormones can facilitate memory for emotional information, which involves interactions between the hipp...

Payne, Jessica D.; Jackson, Eric D.; Hoscheidt, Siobhan; Ryan, Lee; Jacobs, W. Jake; Nadel, Lynn

2007-01-01

185

An fMRI study of long-term everyday memory using SenseCam.  

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We used a novel automatic camera, SenseCam, to investigate recognition memory for real-life events at a 5-month retention interval. Using fMRI we assessed recollection and familiarity memory using the remember/know procedure. Recollection evoked no medial temporal lobe (MTL) activation compared to familiarity and new responses. Instead, recollection activated diverse regions in neocortex including medial prefrontal cortex. We observed decreased activation in anterior hippocampus/ anterior par...

Milton, F.; Muhlert, N.; Butler, Cr; Smith, A.; Benattayallah, A.; Zeman, Az

2011-01-01

186

Ecdysone signaling regulates the formation of long-term courtship memory in adult Drosophila melanogaster  

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Improved survival is likely linked to the ability to generate stable memories of significant experiences. Considerable evidence in humans and mammalian model animals shows that steroid hormones, which are released in response to emotionally arousing experiences, have an important role in the consolidation of memories of such events. In insects, ecdysone is the major steroid hormone, and it is well characterized with respect to its essential role in coordinating developmental transitions such ...

Ishimoto, Hiroshi; Sakai, Takaomi; Kitamoto, Toshihiro

2009-01-01

187

Long-term habituation (LTH in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory  

Directory of Open Access Journals (Sweden)

Full Text Available A decade of studies on long-term habituation (LTH in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP (³15 trials, intertrial interval (ITI of 171 s invariably yielded LTH, while a weak training protocol (WTP (£10 trials, ITI = 171 s invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining. The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

H. Maldonado

1997-07-01

188

Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed [...] context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (³15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, while a weak training protocol (WTP) (£10 trials, ITI = 171 s) invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA) activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining). The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

H., Maldonado; A., Romano; D., Tomsic.

1997-07-01

189

Effect of Oral Aluminum Chloride Administration During Lactation on Short and Long-Term Memory of Their Offspring  

Directory of Open Access Journals (Sweden)

Full Text Available To study the relationship between aluminum chloride (AlCl3 and memory of their offspring male. Five groups of adult Wistar rats (200 ± 30 were taken for this experiment. Female rats were concurrently exposed (0, 200, 400, 600 and 800 mg/kg/day of aluminum administered as AlCl3 in drinking water for two weeks. Forty-five after birth, a shuttle box was used to test memory. This experiment showed that maternal dietary exposure Alcl3 (200, 400 and 600 mg/kg/day doses after two weeks during lactation, there were no different on the working memory of their offspring for any of groups. But rat which received AlCl3 800 mg/kg/day during lactation, has shown significant impairment in working memory of their offspring (p < 0.001 (p < 0.05. This study has demonstrated that (200, 400 and 600 mg/kg/day AlCl3 consumption for two weeks during lactation had no effect. But consumption of AlCl3 800 mg/kg/day during lactation, can impairment in (short-term and long-term memory of their offspring.

Moazedi Ahmad Ali

2008-01-01

190

On the scaling ranges of detrended fluctuation analysis for long-term memory correlated short series of data  

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We examine the scaling regime for the detrended fluctuation analysis (DFA)-the most popular method used to detect the presence of long-term memory in data and the fractal structure of time series. First, the scaling range for DFA is studied for uncorrelated data as a function of time series length L and the correlation coefficient of the linear regression R2 at various confidence levels. Next, a similar analysis for artificial short series of data with long-term memory is performed. In both cases the scaling range ? is found to change linearly-both with L and R2. We show how this dependence can be generalized to a simple unified model describing the relation ?=?(L,R2,H) where H (1/2?H?1) stands for the Hurst exponent of the long range autocorrelated signal. Our findings should be useful in all applications of DFA technique, particularly for instantaneous (local) DFA where a huge number of short time series has to be analyzed at the same time, without possibility of checking the scaling range in each of them separately.

Grech, Dariusz; Mazur, Zygmunt

2013-05-01

191

Improvement in long term and visuo-spatial memory following chronic pioglitazone in mouse model of Alzheimer's disease.  

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Peroxisome proliferator-activated receptor-gamma (PPAR-?) agonists (thiazolidinediones) are widely prescribed for the treatment of type-II diabetes mellitus. Recently, PPAR-? agonists have shown neuroprotective effects in neurodegenerative disorders. The current study was carried out to investigate the effects of chronic administration of pioglitazone, a PPAR-? agonist, on cognitive impairment in a mouse model of Alzheimer's disease induced by scopolamine. Scopolamine was administered in a dose of 1mg/kg intraperitoneally (i.p.). Cognitive functions were assessed using step-down latency (SDL) on a passive avoidance apparatus and escape latency in Morris water maze test. Pioglitazone was also investigated for its effects on parameters of oxidative stress by measuring malondialdehyde (MDA) and reduced glutathione (GSH) levels in the brain. Scopolamine produced significant reduction in SDL and prolongation of escape latency indicating cognitive impairment in mice. Pioglitazone (20 and 40 mg/kg, i.p.), administered for 21 days, showed significant dose-dependent improvement in scopolamine-induced dysfunctions in long-term and visuo-spatial memory in passive avoidance and Morris water maze tests, respectively. Furthermore, pioglitazone significantly prevented the fall in GSH levels and elevation in brain MDA levels induced by scopolamine. These results demonstrate that pioglitazone offers protection against scopolamine-induced dysfunctions in long-term and visuo-spatial memory, possibly due to its antioxidant action, and therefore, could have a therapeutic potential in Alzheimer's disease. PMID:22503969

Gupta, Rachna; Gupta, Lalit Kumar

2012-08-01

192

An optical model for implementing Parrondo’s game and designing stochastic game with long-term memory  

International Nuclear Information System (INIS)

Highlights: ? Using a photon propagating through a designed array of beam splitters to simulate Parrondo’s game paradox. ? Design the optical flowchart for implementing Parrondo history-dependent game paradox. ? Design new game with long-term memory on a designed tree lattice and loop lattice. - Abstract: An optical model for a photon propagating through a designed array of beam splitters is developed to give a physical implementation of Parrondo’s game and Parrondo’s history-dependent game. The winner in this optical model is a photon passed the beam splitter. The loser is a photon being reflected by the beam splitter. The optical beam splitter is the coin-tosser. We designed new games with long-term memory by using this optical diagram method. The optical output of the combined game of two losing games could be a win, or a loss, or an oscillation between win and loss. The modern technology to implement this optical model is well developed. A circularly polarized photon is a possible candidate for this physical implementation in laboratory.

193

Lead (Pb+2) impairs long-term memory and blocks learning-induced increases in hippocampal protein kinase C activity  

International Nuclear Information System (INIS)

The long-term storage of information in the brain known as long-term memory (LTM) depends on a variety of intracellular signaling cascades utilizing calcium (Ca2+) and cyclic adenosine monophosphate as second messengers. In particular, Ca+2/phospholipid-dependent protein kinase C (PKC) activity has been proposed to be necessary for the transition from short-term memory to LTM. Because the neurobehavioral toxicity of lead (Pb+2) has been associated to its interference with normal Ca+2 signaling in neurons, we studied its effects on spatial learning and memory using a hippocampal-dependent discrimination task. Adult rats received microinfusions of either Na+ or Pb+2 acetate in the CA1 hippocampal subregion before each one of four training sessions. A retention test was given 7 days later to examine LTM. Results suggest that intrahippocampal Pb+2 did not affect learning of the task, but significantly impaired retention. The effects of Pb+2 selectively impaired reference memory measured in the retention test, but had no effect on the general performance because it did not affect the latency to complete the task during the test. Finally, we examined the effects of Pb+2 on the induction of hippocampal Ca+2/phospholipid-dependent PKC activity during acquisition training. The results showed that Pb+2 interfered with the learning-induced activation of Ca+2/phospholipid-dependent PKC on day 3 of acquisition. Overall, our results indicate that Pb+2 causes cognitive impairments in adult rats and that such effects might be subserved by interference with Ca+2-related signaling mechanisms required for normal LTM

194

Inhibition of PKM? in Nucleus Accumbens Core Abolishes Long-Term Drug Reward Memory  

Science.gov (United States)

During abstinence, memories of drug-associated cues persist for many months, and exposure to these cues often provokes relapse to drug use. The mechanisms underlying the maintenance of these memories are unknown. A constitutively active atypical protein kinase C (PKC) isozyme, protein kinase M ? (PKM?), is required for maintenance of spatial memory, conditioned taste aversion, and other memory forms. We used conditioned place preference (CPP) and conditioned place aversion (CPA) procedures to study the role of nucleus accumbens PKM? in the maintenance of drug reward and aversion memories in rats. Morphine CPP training (10 mg/kg, 4 pairings) increased PKM? levels in accumbens core but not shell. Injections of the PKM? inhibitor ? inhibitory peptide (ZIP) into accumbens core but not shell after CPP training blocked morphine CPP expression for up to 14 d after injections. This effect was mimicked by the PKC inhibitor chelerythrine, which inhibits PKM?, but not by the conventional and novel PKC inhibitor staurosporine, which does not effectively inhibit PKM?. ZIP injections into accumbens core after training also blocked the expression of cocaine (10 mg/kg) and high-fat food CPP but had no effect on CPA induced by naloxone-precipitated morphine withdrawal. Accumbens core injections of Tat-GluR23Y, which inhibits GluR2-dependent AMPA receptor endocytosis, prevented the impairment in morphine CPP induced by local ZIP injections, indicating that the persistent effect of PKM? is on GluR2-containing AMPA receptors. Results indicate that PKM? activity in accumbens core is a critical cellular substrate for the maintenance of memories of relapse-provoking reward cues during prolonged abstinence periods. PMID:21471379

Li, Yan-qin; Xue, Yan-xue; He, Ying-ying; Li, Fang-qiong; Xue, Li-fen; Xu, Chun-mei; Sacktor, Todd Charlton; Shaham, Yavin

2011-01-01

195

Uncertainties in Air Exchange using Continuous-Injection, Long-Term Sampling Tracer-Gas Methods  

Energy Technology Data Exchange (ETDEWEB)

The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-sampled, through the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.

Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.

2013-12-01

196

DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment.  

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Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. We also investigated how the neural processing of appetitive and aversive motivation and episodic memory were modulated by dopaminergic mechanisms. To that end, participants were selected on the basis of their genotype for a variable number of tandem repeat polymorphism of the dopamine transporter (DAT) gene. The resulting groups were carefully matched for the 5-HTTLPR polymorphism of the serotonin transporter gene. Recognition memory for cues from both motivational categories was enhanced in participants homozygous for the 10-repeat allele of the DAT, the functional effects of which are not known yet, but not in heterozygous subjects. In comparison with heterozygous participants, 10-repeat homozygous participants also showed increased striatal activity for anticipation of motivational outcomes compared to neutral outcomes. In a subsequent memory analysis, encoding activity in striatum and hippocampus was found to be higher for later recognized items in 10-repeat homozygotes compared to 9/10-repeat heterozygotes. These findings suggest that processing of appetitive and aversive motivation in the human striatum involve the dopaminergic system and that dopamine plays a role in memory for both types of motivational information. In accordance with animal studies, these data support the idea that encoding of motivational events depends on dopaminergic processes in the hippocampus. PMID:23911780

Wittmann, Bianca C; Tan, Geoffrey C; Lisman, John E; Dolan, Raymond J; Düzel, Emrah

2013-09-01

197

Reprint of: DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment.  

Science.gov (United States)

Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. We also investigated how the neural processing of appetitive and aversive motivation and episodic memory were modulated by dopaminergic mechanisms. To that end, participants were selected on the basis of their genotype for a variable number of tandem repeat polymorphism of the dopamine transporter (DAT) gene. The resulting groups were carefully matched for the 5-HTTLPR polymorphism of the serotonin transporter gene. Recognition memory for cues from both motivational categories was enhanced in participants homozygous for the 10-repeat allele of the DAT, the functional effects of which are not known yet, but not in heterozygous subjects. In comparison with heterozygous participants, 10-repeat homozygous participants also showed increased striatal activity for anticipation of motivational outcomes compared to neutral outcomes. In a subsequent memory analysis, encoding activity in striatum and hippocampus was found to be higher for later recognized items in 10-repeat homozygotes compared to 9/10-repeat heterozygotes. These findings suggest that processing of appetitive and aversive motivation in the human striatum involve the dopaminergic system and that dopamine plays a role in memory for both types of motivational information. In accordance with animal studies, these data support the idea that encoding of motivational events depends on dopaminergic processes in the hippocampus. PMID:24139823

Wittmann, Bianca C; Tan, Geoffrey C; Lisman, John E; Dolan, Raymond J; Düzel, Emrah

2013-10-01

198

Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"  

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The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

Amano, Hisayuki; Maruyama, Ichiro N.

2011-01-01

199

Activation of MAPK Is Necessary for Long-Term Memory Consolidation Following Food-Reward Conditioning  

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Although an important role for the mitogen-activated protein kinase (MAPK) has been established for memory consolidation in a variety of learning paradigms, it is not known if this pathway is also involved in appetitive classical conditioning. We address this question by using a single-trial food-reward conditioning paradigm in the freshwater…

Ribeiro, Maria J.; Schofield, Michael G.; Kemenes, Ildiko; O'Shea, Michael; Kemenes, Gyorgy; Benjamin, Paul R.

2005-01-01

200

Two Distinct Origins of Long-Term Learning Effects in Verbal Short-Term Memory  

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Verbal short-term memory (STM) is highly sensitive to learning effects: digit sequences or nonword sequences which have been rendered more familiar via repeated exposure are recalled more accurately. In this study we show that sublist-level, incidental learning of item co-occurrence regularities affects immediate serial recall of words and…

Majerus, Steve; Perez, Trecy Martinez; Oberauer, Klaus

2012-01-01

 
 
 
 
201

Making the case that episodic recollection is attributable to operations occurring at retrieval rather than to content stored in a dedicated subsystem of long-term memory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first–person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer’s personal past. In this paper I expand on this definition of episodic memory. Specific...

StanKlein

2013-01-01

202

CBP is required for both short-term and long-term memory formation  

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CREB binding protein (CBP) is a transcriptional co-activator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated conditional knockout (cKO) mice in which CBP is completely inactivated in excitatory neurons of the postnatal forebrain. Histological analysis revealed normal neuronal morphology and absence of age-de...

Chen, Guiquan; Zou, Xiaoyan; Watanabe, Hirotaka; Deursen, Jan M.; Shen, Jie

2010-01-01

203

Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.  

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Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions. PMID:23724089

Conejo, Nélida María; Cimadevilla, José Manuel; González-Pardo, Héctor; Méndez-Couz, Marta; Arias, Jorge Luis

2013-01-01

204

Interaction between mode of learning and subjective experience: Translation effects in long-term memory.  

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It has been suggested that writing auditorily presented words at encoding involves distinctive translation processes between visual and auditory domains, leading to the formation of distinctive memory traces at retrieval. This translation effect leads to higher levels of recognition than the writing of visually presented words, a non-translation effect. The present research investigated whether writing and the other translation effect of vocalisation (vocalising visually presented words) would be present in tests of recall, recognition memory and whether these effects are based on the subjective experience of remembering or knowing. Experiment 1 found a translation effect in the auditory domain in recall, as the translation effect of writing yielded higher recall than both non-translation effects of vocalisation and silently hearing. Experiment 2 found a translation effect in the visual domain in recognition, as the translation effect of vocalisation yielded higher recognition than both non-translation effects of writing and silently reading. This translation effect was attributable to the subjective experience of remembering rather than knowing. The present research therefore demonstrates the beneficial effect of translation in both recall and recognition, with the effect of vocalisation in recognition being based on rich episodic remembering. PMID:24528147

Rackie, James M; Brandt, Karen R; Eysenck, Michael W

2015-04-01

205

How Chunks, Long-Term Working Memory and Templates Offer a Cognitive Explanation for Neuroimaging Data on Expertise Acquisition: A Two-Stage Framework  

Science.gov (United States)

Our review of research on PET and fMRI neuroimaging of experts and expertise acquisition reveals two apparently discordant patterns in working-memory-related tasks. When experts are involved, studies show activations in brain regions typically activated during long-term memory tasks that are not observed with novices, a result that is compatible…

Guida, Alessandro; Gobet, Fernand; Tardieu, Hubert; Nicolas, Serge

2012-01-01

206

The relationship between NMDA receptors and microwave induced learning and memory impairment: a long term observation on Wistar rats.  

Science.gov (United States)

Abstract Purpose: In the present study, we intended to investigate whether the high power microwave could cause the continuous disorders of learning and memory in Wistar rats and to explore the underlying mechanisms. Materials and methods: 80 Wistar rats were exposed to a 2.856 GHz pulsed microwave source at a power density of 0 mW/cm(2) and 50 mW/cm(2) microwave for 6 min. The spatial memory ability, the structure of the hippocampus, contents of amino acids neurotransmitters in hippocampus and the expression of N-methyl-D-aspartic acid receptors (NMDAR) subunit 1, 2A and 2B (NR1, NR2A and NR2B) were detected at 1 m, 3 m, 6 m, 9 m, 12 m and 18 m after microwave exposure. Results: Our results showed that the microwave exposed rats showed consistent deficiencies in spatial learning and memory. The level of amino acid neurotransmitters also decreased after microwave radiation. The ratio of glutamate (Glu) and gammaaminobutyric acid (GABA) significantly decreased at 6 m. Besides, the hippocampus showed varying degrees of degeneration of neurons, increased postsynaptic density and blurred synaptic clefts in the exposure group. The NR1 and NR2B expression showed a significant decrease, especially the NR2B expression. Conclusions: This study indicated that the content of amino acids neurotransmitters, the expression of NMDAR subunits and the variation of hippocampal structure might contribute to the long term cognitive impairment after microwave exposure. PMID:25426698

Wang, Hui; Peng, Ruiyun; Zhao, Li; Wang, Shuiming; Gao, Yabing; Wang, Lifeng; Zuo, Hongyan; Dong, Ji; Xu, Xinping; Zhou, Hongmei; Su, Zhentao

2014-11-26

207

Long-term social recognition memory in adult male rats: factor analysis of the social and non-social behaviors  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english A modified version of the intruder-resident paradigm was used to investigate if social recognition memory lasts at least 24 h. One hundred and forty-six adult male Wistar rats were used. Independent groups of rats were exposed to an intruder for 0.083, 0.5, 2, 24, or 168 h and tested 24 h after the [...] first encounter with the familiar or a different conspecific. Factor analysis was employed to identify associations between behaviors and treatments. Resident rats exhibited a 24-h social recognition memory, as indicated by a 3- to 5-fold decrease in social behaviors in the second encounter with the same conspecific compared to those observed for a different conspecific, when the duration of the first encounter was 2 h or longer. It was possible to distinguish between two different categories of social behaviors and their expression depended on the duration of the first encounter. Sniffing the anogenital area (49.9% of the social behaviors), sniffing the body (17.9%), sniffing the head (3%), and following the conspecific (3.1%), exhibited mostly by resident rats, characterized social investigation and revealed long-term social recognition memory. However, dominance (23.8%) and mild aggression (2.3%), exhibited by both resident and intruders, characterized social agonistic behaviors and were not affected by memory. Differently, sniffing the environment (76.8% of the non-social behaviors) and rearing (14.3%), both exhibited mostly by adult intruder rats, characterized non-social behaviors. Together, these results show that social recognition memory in rats may last at least 24 h after a 2-h or longer exposure to the conspecific.

P.J., Moura; S.T., Meirelles; G.F., Xavier.

2010-07-01

208

Access to long-term optical memories using photon echoes retrieved from semiconductor spins  

Science.gov (United States)

The ability to store optical information is important for both classical and quantum communication. Achieving this in a comprehensive manner (converting the optical field into material excitation, storing this excitation, and releasing it after a controllable time delay) is greatly complicated by the many, often conflicting, properties of the material. More specifically, optical resonances in semiconductor quantum structures with high oscillator strength are inevitably characterized by short excitation lifetimes (and, therefore, short optical memory). Here, we present a new experimental approach to stimulated photon echoes by transferring the information contained in the optical field into a spin system, where it is decoupled from the optical vacuum field and may persist much longer. We demonstrate this for an n-doped CdTe/(Cd,Mg)Te quantum well, the storage time of which could be increased by more than three orders of magnitude, from the picosecond range up to tens of nanoseconds.

Langer, L.; Poltavtsev, S. V.; Yugova, I. A.; Salewski, M.; Yakovlev, D. R.; Karczewski, G.; Wojtowicz, T.; Akimov, I. A.; Bayer, M.

2014-11-01

209

D-cycloserine prevents relational memory deficits and suppression of long-term potentiation induced by scopolamine in the hippocampus.  

Science.gov (United States)

Previous research has demonstrated that systemic D-cycloserine (DCS), a partial agonist of the N-methyl-D-aspartate receptor (NMDAR), enhances memory processes in different learning paradigms and attenuates mnemonic deficits produced by diverse pharmacological manipulations. In the present study two experiments were conducted in rats to investigate whether DCS administered in the hippocampus may rescue relational memory deficits and improve deficient synaptic plasticity, both induced by an intracerebral injection of the muscarinic receptor antagonist scopolamine (SCOP). In experiment 1, we assessed whether DCS would prevent SCOP-induced amnesia in an olfactory learning paradigm requiring the integrity of the cholinergic system, the social transmission of food preference (STFP). The results showed that DCS (10 ?g/site) injected into the ventral hippocampus (vHPC) before STFP acquisition compensated the 24-h retention deficit elicited by post-training intra-vHPC SCOP (40 ?g/site), although it did not affect memory expression in non-SCOP treated rats. In experiment 2, we evaluated whether the perfusion of DCS in hippocampal slices may potentiate synaptic plasticity in CA1 synapses and thus recover SCOP-induced deficits in long-term potentiation (LTP). We found that DCS (50 µM and 100 µM) was able to rescue SCOP (100 µM)-induced LTP maintenance impairment, in agreement with the behavioral findings. Additionally, DCS alone (50 µM and 100 µM) enhanced field excitatory postsynaptic potentials prior to high frequency stimulation, although it did not significantly potentiate LTP. Our results suggest that positive modulation of the NMDAR, by activation of the glycine-binding site, may compensate relational memory impairments due to hippocampal muscarinic neurotransmission dysfunction possibly through enhancements in LTP maintenance. PMID:25453488

Portero-Tresserra, Marta; Del Olmo, Nuria; Martí-Nicolovius, Margarita; Guillazo-Blanch, Gemma; Vale-Martínez, Anna

2014-11-01

210

Hearing Loss Is Negatively Related to Episodic and Semantic Long-Term Memory but Not to Short-Term Memory  

Science.gov (United States)

Purpose: To test the relationship between degree of hearing loss and different memory systems in hearing aid users. Method: Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without…

Ronnberg, Jerker; Danielsson, Henrik; Rudner, Mary; Arlinger, Stig; Sternang, Ola; Wahlin, Ake; Nilsson, Lars-Goran

2011-01-01

211

Monosynaptic connections made by the sensory neurons of the gill- and siphon-withdrawal reflex in Aplysia participate in the storage of long-term memory for sensitization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have found that in the gill- and siphon- withdrawal reflex of Aplysia, the memory for short-term sensitization grades smoothly into long-term memory with increased amounts of sensitization training. One cellular locus for the storage of the memory underlying short-term sensitization is the set of monosynaptic connections between the siphon sensory cells and the gill and siphon motor neurons. We have now also found that these same monosynaptic connections participate in the storage of the m...

Frost, William N.; Castellucci, Vincent F.; Hawkins, Robert D.; Kandel, Eric R.

1985-01-01

212

Short and long-term memory are modulated by multiple isoforms of the fragile X mental retardation protein  

Science.gov (United States)

The diversity of protein isoforms arising from alternative splicing is thought to modulate fine-tuning of synaptic plasticity. Fragile X mental retardation protein (FMRP), a neuronal RNA binding protein, exists in isoforms as a result of alternative splicing, but the contribution of these isoforms to neural plasticity are not well understood. We show that two isoforms of D. melanogaster FMRP (dFMR1) have differential roles in mediating neural development and behavior functions conferred by the dfmr1 gene. These isoforms differ in the presence of a protein interaction module that is related to prion domains and is functionally conserved between FMRPs. Expression of both isoforms is necessary for optimal performance in tests of short and long-term memory of courtship training. The presence or absence of the protein interaction domain may govern the types of ribonucleoprotein (RNP) complexes dFMR1 assembles into, with different RNPs regulating gene expression in a manner necessary for establishing distinct phases of memory formation. PMID:20463240

Banerjee, Paromita; Schoenfeld, Brian P.; Bell, Aaron J.; Choi, Catherine H.; Bradley, Michael P.; Hinchey, Paul; Kollaros, Maria; Park, Jae H.; McBride, Sean M.J.; Dockendorff, Thomas C.

2010-01-01

213

Short- and long-term memory are modulated by multiple isoforms of the fragile X mental retardation protein.  

Science.gov (United States)

The diversity of protein isoforms arising from alternative splicing is thought to modulate fine-tuning of synaptic plasticity. Fragile X mental retardation protein (FMRP), a neuronal RNA binding protein, exists in isoforms as a result of alternative splicing, but the contribution of these isoforms to neural plasticity are not well understood. We show that two isoforms of Drosophila melanogaster FMRP (dFMR1) have differential roles in mediating neural development and behavior functions conferred by the dfmr1 gene. These isoforms differ in the presence of a protein interaction module that is related to prion domains and is functionally conserved between FMRPs. Expression of both isoforms is necessary for optimal performance in tests of short- and long-term memory of courtship training. The presence or absence of the protein interaction domain may govern the types of ribonucleoprotein (RNP) complexes dFMR1 assembles into, with different RNPs regulating gene expression in a manner necessary for establishing distinct phases of memory formation. PMID:20463240

Banerjee, Paromita; Schoenfeld, Brian P; Bell, Aaron J; Choi, Catherine H; Bradley, Michael P; Hinchey, Paul; Kollaros, Maria; Park, Jae H; McBride, Sean M J; Dockendorff, Thomas C

2010-05-12

214

Long-term geoelectrical monitoring of laboratory freeze-thaw experiments on bedrock samples  

Science.gov (United States)

Much attention has recently focussed on the continuous and near-real-time geophysical monitoring of permafrost-affected bedrock with permanently installed sensor arrays. It is hoped that such efforts will enhance process understanding in such environments (permafrost degradation, weathering mechanisms) and augment our capability to predict future instabilities of rock walls and slopes. With regard to electrical methods for example, recent work has demonstrated that temperature-calibrated electrical resistivity tomography (ERT) is capable of imaging recession and re-advance of rock permafrost in response to the ambient temperature regime. However, field experience also shows that several fundamental improvements to ERT methodology are still required to achieve the desired sensitivity, spatial-temporal resolution and long-term robustness that must underpin continuous geophysical measurements. We have applied 4D geoelectrical tomography to monitoring laboratory experiments simulating permafrost growth, persistence and thaw in bedrock over a period of 26 months. Six water-saturated samples of limestone and chalk of varying porosity represented lithologies commonly affected by permafrost-related instability. Time-lapse imaging of the samples was undertaken during multiple successive freeze-thaw cycles, emulating annual seasonal change over several decades. Further experimental control was provided by simultaneous measurements of vertical profiles of temperature and moisture content within the bedrock samples. These experiments have helped develop an alternative methodology for the volumetric imaging of permafrost bedrock and tracking active layer dynamics. Capacitive resistivity imaging (CRI), a technique based upon low-frequency, capacitively-coupled measurements emulates ERT methodology, but without the need for galvanic contact on frozen rock. The latter is perceived as a key potential weakness, which could lead to significant limitations as a result of the variable quality of contact between sensors and the host material as it freezes and thaws. Our experiments have directly compared the CRI and ERT approaches. Numerical simulation of dense capacitive multi-sensor geometries shows that the basic assumptions of CRI remain valid for our experimental setup; as a consequence, conventional ERT methodology (including time-lapse inversion) becomes applicable to the capacitive measurements. Permafrost processes tend to be multi-scale in space and time; any imaging technique must therefore be capable of resolving subtle changes in rock properties over a range of spatial scales and long periods of time. Frequent data acquisition (three times per 24-hour period) allowed us to obtain 3D resistivity models of all samples as the freeze-thaw experiment progressed. Data from different stages of the simulated seasonal cycles show that CRI is capable of imaging temperature-dominated changes in resistivity, associated with an approximate temperature range between 20°C and -5°C. Volumetric temperature models of the samples were obtained using calibration curves determined by separate freeze-thaw experiments using identical material. Below the freezing point temperature dominates the resistivity response and the resistivity-based temperature models show very good agreement with point estimates from temperature probes. The CRI and ERT methodologies both hold promise for the systematic and strategic assessment of the thermal state of bedrock permafrost in the field using geoelectrical monitoring.

Kuras, Oliver; Uhlemann, Sebastian; Murton, Julian; Krautblatter, Michael

2014-05-01

215

Historical review of long-term soil sampling for environmental surveillance at the Hanford Site and vicinity  

Energy Technology Data Exchange (ETDEWEB)

Soil samples have been collected routinely from the environs of the Hanford Site and analyzed since 1971. Correct interpretation of results depends on samples being collected from the same locations, the locations remaining relatively undisturbed, and collection and analytical procedures remaining the same or being equivalent. Historical files, documents, and annual environmental reports were reviewed to evaluate these factors. It was determined that 20 soil sampling locations, 11 onsite and 9 offsite, were established between 1971 and 1977 and represent long-term sampling locations. Sample collection and analytical procedures have remained essentially the same since 1971. The physical ecological attributes of each long-term soil sampling location were evaluated. During the review of historical records, a few results for 1970, 1971, and 1972 were noted as previously unreported in annual or special reports. These results are included in Appendix A. To complete the record, results previously reported in annual environmental reports are given in Appendix B. Global Positioning System (GPS) reading for 20 long-term soil sampling locations are provided in Appendix C.

Price, K.R.; Rickard, W.H.

1997-08-01

216

Verbal working and long-term episodic memory associations with white matter microstructure in normal aging investigated using tract-based spatial statistics.  

Science.gov (United States)

Reductions in the integrity of white matter microstructure are thought to be a significant cause of age-related decline in mnemonic abilities, including working memory (WM) and long-term episodic memory (LTM). This study uses tract-based spatial statistics (TBSS) applied to diffusion tensor magnetic resonance images to explore correlations between white matter microstructure and verbal WM and LTM in a sample of 98 normal older adults. WM performance was associated with microstructure in left fronto-parietal pathways and LTM was associated with bilateral fronto-temporal pathways. Interhemispheric-frontal pathways (genu of the corpus callosum) were associated with both types of mnemonic function. We hypothesize that in normal aging, damage to certain white matter pathways may reduce the dynamic efficiency of mnemonic abilities by disrupting the connections within multiple distributed networks. By correlating white matter with two mnemonic functions in the same analysis, we have demonstrated that regional white matter networks may share common mnemonic functions but also may be differentiated for memory types. PMID:23957226

Charlton, Rebecca A; Barrick, Thomas R; Markus, Hugh S; Morris, Robin G

2013-09-01

217

Long-term memory traces for language sounds are highly context-sensitive: an MEG/ERF study  

DEFF Research Database (Denmark)

Introduction: An early component of the auditory event-related potential (ERP), the mismatch negativity (MMN), has been shown to be sensitive to native phonemic language sound contrasts compared to non-native or allophonic language sound contrasts. So far this has not been attested for different phonetic contexts. In the present study we investigated the mismatch field (MMF) response (the magnetic counterpart of the MMN) of native Danish speakers to the Danish phonetic contrast of [t]-[d] in two different phonetic contexts: One in which the sound contrast was phonemic ([tæ] versus [dæ]), and one in which the sound contrast was allophonic ([æt] versus [æd]), i.e. its phonemic status was neutralized. Methods: The stimuli consisted of the four Danish syllables: [tæ] and [dæ] (meaning ‘take’ and ‘then’, respectively), and [æt] and [æd] (both meaning ‘that’). These were presented in a passive listening MMN paradigm while participants’ MEG was recorded. [tæ] and [æt] acted as standards, and [dæ] and [æd] thus as deviants, respectively. Results: Comparing brain responses to the deviants and the standards, only the phonemic [tæ]-[dæ] contrast showed significant effects (FWE-corrected at p<0.05 at the cluster-level) within the typical MMN time range (100 to 300 ms after deviance onset) and over both hemispheres. Comparing the differences between the two contrasts ([dæ]-[tæ] minus [æd]-[æt]), the phonemic context elicited significantly larger MMF responses than the allophonic context (FWE-corrected at p<0.05 at the cluster-level), again over both hemispheres and within the typical MMN time range. Conclusion: By manipulating the immediate phonetic context in an oddball paradigm, we demonstrate that the human brain’s MMF response to language sounds is highly context-sensitive. This has important impact on the proposed long-term memory traces for native phonological categories. In order to generate different MMF responses to the same language sound contrast depending on the phonetic context, these long-term memory traces must thus be context-sensitive themselves or exist as separate traces for the context-dependent allophones of the phonological categories.

Nielsen, Andreas HØjlund; Gebauer, Line

218

Groundwater sampling in Olkiluoto, Eurajoki from borehole OL-KR6 during a long-term pumping test in 2005  

International Nuclear Information System (INIS)

A long-term pumping test from borehole OL-KR6 in Olkiluoto was initiated in 2001. Since then, flow and in situ EC measurements, as well as groundwater sampling from specific sampling sections have been performed yearly. The aim of this study was to get information on the potential connections via fractures both to the sea and to deep saline groundwater during long-term pumping of the open borehole. In 2005 four groundwater samples were collected from four different sampling depths (98.5-100.5 m, 120-125 m, 135-137 m and 422-425 m) from borebole OL-KR6. The groundwater samples were taken from packed-off sections by means of PAVE equipment. The water types of groundwater samples from OL-KR6 were Na-Cl (for samples from 98.5-100.5 m and 135-137 m depths) and Na-Ca-Cl (for samples from 120-125 m and 422-425 m depths). The sample from depth 422-425 m was saline (TDS> 10000mg/L), while other waters were brackish (1000 mg < TDS <10000 mg/L). This study presents the sampling methods and the analysis results of groundwater samples from deep borehole OL-KR6. A comparison between the results of the in situ EC measurements and the EC results measured during groundwater sampling is presented. This report also contains a short comparison of the results obtained during the long-term pumping test during 2001-2005. (orig.)

219

Novel interactive effects of darkness and retinoid signaling in the ability to form long-term memory following aversive operant conditioning.  

Science.gov (United States)

The vitamin A metabolite, retinoic acid, is important for memory formation and hippocampal synaptic plasticity in vertebrate species. In our studies in the mollusc Lymnaea stagnalis, we have shown that retinoic acid plays a role in memory formation following operant conditioning of the aerial respiratory behaviour. Inhibition of either retinaldehyde dehydrogenase (RALDH) or the retinoid receptors prevents long-term memory (LTM) formation, whereas synthetic retinoid receptor agonists promote memory formation by converting intermediate-term memory (ITM) into LTM. In this study, animals were exposed to constant darkness in order to test whether light-sensitive retinoic acid would promote memory formation. However, we found that exposure to constant darkness alone (in the absence of retinoic acid) enhanced memory formation. To determine whether the memory-promoting effects of darkness could override the memory-inhibiting effects of the retinoid signaling inhibitors, we exposed snails to RALDH inhibitors or a retinoid receptor antagonist in constant darkness. We found that darkness overcame the inhibitory effects of RALDH inhibition, but did not overcome the inhibitory effects of the retinoid receptor antagonist. We also tested whether constant darkness and training affected the mRNA levels of the retinoid metabolic enzymes RALDH and Cyp26, or the mRNA levels of the retinoid receptors, but found no significant effect. Overall, these data demonstrate an interaction between environmental light conditions and the retinoid signaling pathway, which influence long-term memory formation in a mollusc. PMID:25062644

Rothwell, Cailin M; Simmons, Jason; Peters, Grace; Spencer, Gaynor E

2014-10-01

220

Making the case that episodic recollection is attributable to operations occurring at retrieval rather than to content stored in a dedicated subsystem of long-term memory.  

Science.gov (United States)

Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first-person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer's personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (1) the core features assumed unique to episodic memory are shared by semantic memory, (2) episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, "enabling" systems. Although these systems-ownership, self, subjective temporality, and agency-are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (3) the type of subjective awareness provided by episodic recollection (autonoetic) is relational rather than intrinsic-i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory. PMID:23378832

Klein, Stanley B

2013-01-01

 
 
 
 
221

Naringin Enhances CaMKII Activity and Improves Long-Term Memory in a Mouse Model of Alzheimer’s Disease  

Directory of Open Access Journals (Sweden)

Full Text Available The Amyloid-? (A?-induced impairment of hippocampal synaptic plasticity is an underlying mechanism of memory loss in the early stages of Alzheimer's disease (AD in human and mouse models. The inhibition of the calcium/calmodulin-dependent protein kinase II (CaMKII autophosphorylation plays an important role in long-term memory. In this study, we isolated naringin from Pomelo peel (a Citrus species and studied its effect on long-term memory in the APPswe/PS1dE9 transgenic mouse model of AD. Three-month-old APPswe/PS1dE9 transgenic mice were randomly assigned to a vehicle group, two naringin (either 50 or 100 mg/kg body weight/day groups, or an Aricept (2 mg/kg body weight/day group. After 16 weeks of treatment, we observed that treatment with naringin (100 mg/kg body weight/day enhanced the autophosphorylation of CaMKII, increased the phosphorylation of the ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA receptor at a CaMKII-dependent site and improved long-term learning and memory ability. These findings suggest that the increase in CaMKII activity may be one of the mechanisms by which naringin improves long-term cognitive function in the APPswe/PS1dE9 transgenic mouse model of AD.

Lian-Feng Zhang

2013-03-01

222

Naringin Enhances CaMKII Activity and Improves Long-Term Memory in a Mouse Model of Alzheimer’s Disease  

Science.gov (United States)

The Amyloid-? (A?)-induced impairment of hippocampal synaptic plasticity is an underlying mechanism of memory loss in the early stages of Alzheimer’s disease (AD) in human and mouse models. The inhibition of the calcium/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation plays an important role in long-term memory. In this study, we isolated naringin from Pomelo peel (a Citrus species) and studied its effect on long-term memory in the APPswe/PS1dE9 transgenic mouse model of AD. Three-month-old APPswe/PS1dE9 transgenic mice were randomly assigned to a vehicle group, two naringin (either 50 or 100 mg/kg body weight/day) groups, or an Aricept (2 mg/kg body weight/day) group. After 16 weeks of treatment, we observed that treatment with naringin (100 mg/kg body weight/day) enhanced the autophosphorylation of CaMKII, increased the phosphorylation of the ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) receptor at a CaMKII-dependent site and improved long-term learning and memory ability. These findings suggest that the increase in CaMKII activity may be one of the mechanisms by which naringin improves long-term cognitive function in the APPswe/PS1dE9 transgenic mouse model of AD. PMID:23478434

Wang, Dong-Mei; Yang, Ya-Jun; Zhang, Li; Zhang, Xu; Guan, Fei-Fei; Zhang, Lian-Feng

2013-01-01

223

Long-Term Memory for Place Learning Is Facilitated by Expression of cAMP Response Element-Binding Protein in the Dorsal Hippocampus  

Science.gov (United States)

Extensive research has shown that the hippocampus is necessary for consolidation of long-term spatial memory in rodents. We reported previously that rats using a place strategy to solve a cross maze task showed sustained phosphorylation of hippocampus cyclic AMP response element-binding protein (CREB), a transcription factor implicated in…

Brightwell, Jennifer J.; Smith, Clayton A.; Neve, Rachael L.; Colombo, Paul J.

2007-01-01

224

One week of motor adaptation induces structural changes in primary motor cortex that predict long-term memory one year later  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The neural bases of motor adaptation have been extensively explored in human and non-human primates. A network including the cerebellum, primary motor and the posterior parietal cortex appears to be crucial for this type of learning. Yet, to date, it is unclear whether these regions contribute directly or indirectly to the formation of motor memories. Here we trained subjects on a complex visuomotor rotation associated with long-term memory (in the order of months) to identify potential sites...

Landi, Sofia M.; Baguear, Federico; Della-maggiore, Valeria

2011-01-01

225

The Effect of Zinc Supplementation of Lactating Rats on Short-Term and Long-Term Memory of Their Male Offspring  

Directory of Open Access Journals (Sweden)

Full Text Available Background: In this study the effect of zinc chloride (ZnCl2 administration on the short-term and long-term memory of rats were assessed. Methods: We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. Results: This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats’ offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term of their offspring (P<0.05. There was no significant difference in reference (long-term memory of all groups. Conclusion: Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment.

Mohammad Karami

2013-12-01

226

PKA Increases in the Olfactory Bulb Act as Unconditioned Stimuli and Provide Evidence for Parallel Memory Systems: Pairing Odor with Increased PKA Creates Intermediate- and Long-Term, but Not Short-Term, Memories  

Science.gov (United States)

Neonatal odor-preference memory in rat pups is a well-defined associative mammalian memory model dependent on cAMP. Previous work from this laboratory demonstrates three phases of neonatal odor-preference memory: short-term (translation-independent), intermediate-term (translation-dependent), and long-term (transcription- and…

Grimes, Matthew T.; Harley, Carolyn W.; Darby-King, Andrea; McLean, John H.

2012-01-01

227

Measuring Workload Differences Between Short-term Memory and Long-term Memory Scenarios in a Simulated Flight Environment  

Science.gov (United States)

Four highly experienced Air Force pilots each flew four simulated flight scenarios. Two scenarios required a great deal of aircraft maneuvering. The other two scenarios involved less maneuvering, but required remembering a number of items. All scenarios were designed to be equaly challenging. Pilot's Subjective Ratings for Activity-level, Complexity, Difficulty, Stress, and Workload were higher for the manuevering scenarios than the memory scenarios. At a moderate workload level, keeping the pilots active resulted in better aircraft control. When required to monitor and remember items, aircraft control tended to decrease. Pilots tended to weigh information about the spatial positioning and performance of their aircraft more heavily than other items.

Berg, S. L.; Sheridan, T. B.

1984-01-01

228

Long term durability of radon remedial measures in a sample of UK homes  

International Nuclear Information System (INIS)

A study to determine the long term effectiveness of commonly used radon remedial methods over a 15 year period is discussed. The overall failure rate for remediation systems was 63%, with roughly equal rates for passive and active type systems. The fans used in active systems performed better than expected, with many of them exceeding manufacturers’ stated life spans by several years. The study found that all types of remedial measure can last more than ten years, but also found examples for all measures that failed in less than five years. This supports HPA advice that homes should be retested every 5–10 years. It was also noted that householders found it difficult to detect failures in passive systems. The need for a follow-up study is discussed, in light of likely changes in building practices and materials during the last twenty years. (paper)

229

Underestimation of toluene diisocyanate concentration using long-term sampling with 1-(2-methoxyphenyl) piperazine impregnated filters.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Occupational exposure to toluene diisocyanate (TDI) is a known occupational hazard and the occupational exposure limits in air are very low. One of the most common methods to monitor exposure to isocyanates is to sample air through filters impregnated with 1-(2-methoxyphenyl) piperazine (2MP). In one earlier field study it was found that long-term sampling with 2MP-filters underestimated the exposure compared with consecutive short-term samples of TDI. The aim of this study was to confirm tha...

Mattsson, Christian; Lindh, Christian; Tinnerberg, Ha?kan

2008-01-01

230

Groundwater sampling in Olkiluoto, Eurajoki from drillhole OL-KR6 during a long-term pumping test in 2007  

International Nuclear Information System (INIS)

A long-term pumping test in drillhole OL-KR6 in Olkiluoto was initiated in 2001. Flow and in situ EC measurements as well as groundwater sampling from specific sampling sections have since then been performed yearly. The aim of the study was to obtain information on potential connections via fractures both to the sea and to deep saline groundwater during long-term pumping of the open drillhole. In 2007, four groundwater samples were collected at four different sampling depths (98.5-100.5 m, 125-130 m, 135-137 m and 422-425 m). The groundwater samples were taken in stages using PAVE equipment. The water types found in the groundwater samples from OL-KR6 were Na-Ca-Cl (for samples taken at depths of 98.5-100.5 m and 125-130 m) and Na-Cl (for samples taken at depths of 135-137 m and 422-425 m). The sample taken at depth 422-425 m was saline (TDS> 10000 mg/l), while the other samples were brackish (1000 mg 2O after the air correction had been made. The dominant gas in the groundwater samples was nitrogen. Carbon dioxide was the second dominant gas, except in sample OL-KR6/422-425 m, in which methane, instead, was the second dominant gas. All the samples also contained helium, ethane and argon. Small amounts of ethene, acetylene and propane were found in some samples. No hydrogen or propene was detected in the samples. The dissolved gas concentrations were higher in the OL-KR6 samples in 2006 than in the two previous years. In 2007, the dissolved gas concentration was again lower. One conclusion from this and the previous studies is that changes in the three upper sampling points were most remarkable in 2001-2002 just after pumping started. Otherwise, water compositions were invariable. (orig.)

231

Prediction of long-term (5 years) conversion to dementia using neuropsychological tests in a memory clinic setting.  

Science.gov (United States)

The use of neuropsychological tests to detect cognitive decline in the initial phases of Alzheimer's disease (AD) has faced significant limitations, namely the fact that most cohort studies of conversion to dementia had relatively short follow-up periods. The aim of the present study is to assess the predictive value for future conversion to dementia of a comprehensive neuropsychological battery applied to a cohort of non-demented patients followed-up for 5 years. Participants (n = 250) were selected from the Cognitive Complaints Cohort (CCC) having cognitive complaints, assessment with a comprehensive neuropsychological battery, and a follow-up period of 5 years (unless patients have converted to dementia earlier). During the follow-up period (2.6 ± 1.8 years for converters and 6.1 ± 2.1 years for non-converters), 162 patients (64.8%) progressed to dementia (mostly AD), and 88 (35.2%) did not. A Linear Discriminant Analysis (LDA) model constituted by Digit Span backward, Semantic Fluency, Logical Memory (immediate recall), and Forgetting Index significantly discriminated converters from non-converters (? Wilks = 0.64; ?(2) (4) = 81.95; p accuracy values (78.8%, 79.9% and 78.6%, respectively) of the neuropsychological tests to predict long-term conversion to dementia. The present results show that it is possible to predict, on the basis of the initial clinical and neuropsychological evaluation, whether non-demented patients with cognitive complaints will probably convert to dementia, or remain stable, at a reasonably long and clinically relevant term. PMID:23263232

Silva, Dina; Guerreiro, Manuela; Santana, Isabel; Rodrigues, Ana; Cardoso, Sandra; Maroco, João; de Mendonça, Alexandre

2013-01-01

232

The effect of long term administration of ascorbic acid on the learning and memory deficits induced by diabetes in rat  

Directory of Open Access Journals (Sweden)

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Ascorbic acid improves cognitive impairments in several experimental models. Diabetes causes learning and memory deficits. In this study we hypothesized that chronic treatment with ascorbic acid (100mg/kg, p.o would affect on the passive avoidance learning (PAL and memory in control and streptozocin-induced diabetic rats."n"nMethods: Diabetes was induced by a single i.p. injection of STZ (60mg/kg. The rats were considered diabetic if plasma glucose levels exceeded 250mg/dl on three days after STZ injection. Treatment was begun at the onset of hyperglycemia. PAL was assessed 30 days later. Retention test was done 24 h after training. At the end, animals were weighted and blood samples were drawn for plasma glucose measurement."n"nResults: Diabetes caused impairment in acquisition and retrieval processes of PAL and memory in rats. Ascorbic acid treatment improved learning and memory in control rats and reversed learning and memory deficits in diabetic rats. Ascorbic acid administration also improved the body weight loss and hyperglycemia of diabetics. Hypoglycemic and antioxidant properties of the vitamin may be involved in the memory improving effects of such treatment."n"nConclusion: These results show that ascorbic acid administration to rats for 30 days from onset of diabetes alleviated the negative influence of diabetes on learning and memory. Comparing with other nootropic drugs, vitamins have fewer side effects. Therefore, this regimen may provide a new potential alternative for prevention of the impaired cognitive functions associated with diabetes after confirming by clinical trials.

Parisa Hasanein

2010-04-01

233

Long-term stellar activity variations of stars from the HARPS M-dwarf sample: Comparison between activity indices  

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We used four known chromospheric activity indicators to measure long-term activity variations in a sample of 23 M-dwarf stars from the HARPS planet search program. We compared the indices using weighted Pearson correlation coefficients and found that in general (i) the correlation between $S_{CaII}$ and \\ion{Na}{i} is very strong and does not depend on the activity level of the stars, (ii) the correlation between our $S_{CaII}$ and H$\\alpha$ seems to depend on the activity l...

Da Silva, J. Gomes; Santos, N. C.; Bonfils, X.

2010-01-01

234

The effect of frequency and duration of training sessions on acquisition and long-term memory in dogs  

DEFF Research Database (Denmark)

Most domestic dogs are subjected to some kind of obedience training, often on a frequent basis, but the question of how often and for how long a dog should be trained has not been fully investigated. Optimizing the training as much as possible is not only an advantage in the training of working dogs such as guide dogs and police dogs, also the training of family dogs can benefit from this knowledge. We studied the effect of frequency and duration of training sessions on acquisition and on long-term memory. Forty-four laboratory Beagles were divided into 4 groups and trained by means of operant conditioning and shaping to perform a traditional obedience task, each dog having a total of 18 training sessions. The training schedules of the 4 groups differentiated in frequency (1–2 times per week vs. daily) and duration (1 training session vs. 3 training sessions in a row). Acquisition was measured as achieved training level at a certain time. The dogs’ retention of the task was tested four weeks post-acquisition.Results demonstrated that dogs trained 1–2 times per week had significantly better acquisition than daily trained dogs, and that dogs trained only 1 session a day had significantly better acquisition than dogs trained 3 sessions in a row. The interaction between frequency and duration of training sessions was also significant, suggesting that the two affect acquisition differently depending on the combination of these. The combination of weekly training and one session resulted in the highest level of acquisition, whereas the combination of daily training and three sessions in a row resulted in the lowest level of acquisition. Daily training in one session produced similar results as weekly training combined with three sessions in a row. Training schedule did not affect retention of the learned task; all groups had a high level of retention after 4 weeks. The results of the study can be used to optimize training in dogs, which is important since the number of training sessions often is a limiting factor in practical dog training. The results also suggest that, once a task is learned, it is likely to be remembered for a period of at least four weeks after last practice, regardless of frequency and duration of the training sessions.

Demant, Helle; Ladewig, Jan

2011-01-01

235

Critical Role of Nitric Oxide-cGMP Cascade in the Formation of cAMP-Dependent Long-Term Memory  

Science.gov (United States)

Cyclic AMP pathway plays an essential role in formation of long-term memory (LTM). In some species, the nitric oxide (NO)-cyclic GMP pathway has been found to act in parallel and complementary to the cAMP pathway for LTM formation. Here we describe a new role of the NO-cGMP pathway, namely, stimulation of the cAMP pathway to induce LTM. We have…

Aonuma, Hitoshi; Mizunami, Makoto; Matsumoto, Yukihisa; Unoki, Sae

2006-01-01

236

Long-term storage of salivary cortisol samples at room temperature  

Science.gov (United States)

Collection of saliva samples for the measurement of cortisol during space flights provides a simple technique for studying changes in adrenal function due microgravity. In the present work, several methods for preserving saliva cortisol at room temperature were investigated using radioimmunoassays for determining cortisol in saliva samples collected on a saliva-collection device called Salivettes. It was found that a pretreatment of Salivettes with citric acid resulted in preserving more than 85 percent of the salivary cortisol for as long as six weeks. The results correlated well with those for a sample stored in a freezer on an untreated Salivette.

Chen, Yu-Ming; Cintron, Nitza M.; Whitson, Peggy A.

1992-01-01

237

Prenatal exposure to a cannabinoid agonist produces memory deficits linked to dysfunction in hippocampal long-term potentiation and glutamate release  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To investigate the possible long-term consequences of gestational exposure to cannabinoids on cognitive functions, pregnant rats were administered with the CB1 receptor agonist WIN 55,212-2 (WIN), at a dose (0.5 mg/kg) that causes neither malformations nor overt signs of toxicity. Prenatal WIN exposure induced a disruption of memory retention in 40- and 80-day-old offspring subjected to a passive avoidance task. A hyperactive behavior at the ages of 12 and 40 days was also found. The memory i...

Mereu, Giampaolo; Fa?, Mauro; Ferraro, Luca; Cagiano, Raffaele; Antonelli, Tiziana; Tattoli, Maria; Ghiglieri, Veronica; Tanganelli, Sergio; Gessa, Gian Luigi; Cuomo, Vincenzo

2003-01-01

238

Direct and long-term detection of gene doping in conventional blood samples.  

Science.gov (United States)

The misuse of somatic gene therapy for the purpose of enhancing athletic performance is perceived as a coming threat to the world of sports and categorized as 'gene doping'. This article describes a direct detection approach for gene doping that gives a clear yes-or-no answer based on the presence or absence of transgenic DNA in peripheral blood samples. By exploiting a priming strategy to specifically amplify intronless DNA sequences, we developed PCR protocols allowing the detection of very small amounts of transgenic DNA in genomic DNA samples to screen for six prime candidate genes. Our detection strategy was verified in a mouse model, giving positive signals from minute amounts (20??l) of blood samples for up to 56 days following intramuscular adeno-associated virus-mediated gene transfer, one of the most likely candidate vector systems to be misused for gene doping. To make our detection strategy amenable for routine testing, we implemented a robust sample preparation and processing protocol that allows cost-efficient analysis of small human blood volumes (200??l) with high specificity and reproducibility. The practicability and reliability of our detection strategy was validated by a screening approach including 327 blood samples taken from professional and recreational athletes under field conditions. PMID:20811468

Beiter, T; Zimmermann, M; Fragasso, A; Hudemann, J; Niess, A M; Bitzer, M; Lauer, U M; Simon, P

2011-03-01

239

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco site for the LTHMP on May 16 and 17, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method, because the laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

240

Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco site for the LTHMP on May 16 and 17, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method, because the laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

None

2011-12-21

 
 
 
 
241

An evaluation of long-term preservation methods for brown bear (Ursus arctos) faecal DNA samples  

Science.gov (United States)

Relatively few large-scale faecal DNA studies have been initiated due to difficulties in amplifying low quality and quantity DNA template. To improve brown bear faecal DNA PCR amplification success rates and to determine post collection sample longevity, five preservation methods were evaluated: 90% ethanol, DETs buffer, silica-dried, oven-dried stored at room temperature, and oven-dried stored at -20??C. Preservation effectiveness was evaluated for 50 faecal samples by PCR amplification of a mitochondrial DNA (mtDNA) locus (???146 bp) and a nuclear DNA (nDNA) locus (???200 bp) at time points of one week, one month, three months and six months. Preservation method and storage time significantly impacted mtDNA and nDNA amplification success rates. For mtDNA, all preservation methods had ??? 75% success at one week, but storage time had a significant impact on the effectiveness of the silica preservation method. Ethanol preserved samples had the highest success rates for both mtDNA (86.5%) and nDNA (84%). Nuclear DNA amplification success rates ranged from 26-88%, and storage time had a significant impact on all methods but ethanol. Preservation method and storage time should be important considerations for researchers planning projects utilizing faecal DNA. We recommend preservation of faecal samples in 90% ethanol when feasible, although when collecting in remote field conditions or for both DNA and hormone assays a dry collection method may be advantageous.

Murphy, M.A.; Waits, L.P.; Kendall, K.C.; Wasser, S.K.; Higbee, J.A.; Bogden, R.

2002-01-01

242

Cyclic Nucleotide-Gated Channels, Calmodulin, Adenylyl Cyclase, and Calcium/Calmodulin-Dependent Protein Kinase II Are Required for Late, but Not Early, Long-Term Memory Formation in the Honeybee  

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Memory is a dynamic process that allows encoding, storage, and retrieval of information acquired through individual experience. In the honeybee "Apis mellifera," olfactory conditioning of the proboscis extension response (PER) has shown that besides short-term memory (STM) and mid-term memory (MTM), two phases of long-term memory (LTM)…

Matsumoto, Yukihisa; Sandoz, Jean-Christophe; Devaud, Jean-Marc; Lormant, Flore; Mizunami, Makoto; Giurfa, Martin

2014-01-01

243

Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC affects differently working and long-term memory on two foraging tasks  

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Full Text Available Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable

PABLO ESPINA-MARCHANT

2006-01-01

244

An Optimal Sampling Design for Observing and Validating Long-Term Leaf Area Index with Temporal Variations in Spatial Heterogeneities  

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Full Text Available A sampling strategy to define elementary sampling units (ESUs for an entire site at the kilometer scale is an important step in the validation process for moderate-resolution leaf area index (LAI products. Current LAI-sampling strategies are unable to consider the vegetation seasonal changes and are better suited for single-day LAI product validation, whereas the increasingly used wireless sensor network for LAI measurement (LAINet requires an optimal sampling strategy across both spatial and temporal scales. In this study, we developed an efficient and robust LAI Sampling strategy based on Multi-temporal Prior knowledge (SMP for long-term, fixed-position LAI observations. The SMP approach employed multi-temporal vegetation index (VI maps and the vegetation classification map as a priori knowledge. The SMP approach minimized the multi-temporal bias of the VI frequency histogram between the ESUs and the entire site and maximized the nearest-neighbor index to ensure that ESUs were dispersed in the geographical space. The SMP approach was compared with four sampling strategies including random sampling, systematic sampling, sampling based on the land-cover map and a sampling strategy based on vegetation index prior knowledge using the PROSAIL model-based simulation analysis in the Heihe River basin. The results indicate that the ESUs selected using the SMP method spread more evenly in both the multi-temporal feature space and geographical space over the vegetation cycle. By considering the temporal changes in heterogeneity, the average root-mean-square error (RMSE of the LAI reference maps can be reduced from 0.12 to 0.05, and the relative error can be reduced from 6.1% to 2.2%. The SMP technique was applied to assign the LAINet ESU locations at the Huailai Remote Sensing Experimental Station in Beijing, China, from 4 July to 28 August 2013, to validate three MODIS C5 LAI products. The results suggest that the average R2, RMSE, bias and relative uncertainty for the three MODIS LAI products were 0.60, 0.33, ?0.11, and 12.2%, respectively. The MCD15A2 product performed best, exhibiting a RMSE of 0.20, a bias of ?0.07 and a relative uncertainty of 7.4%. Future efforts are needed to obtain more long-term validation datasets using the SMP approach on different vegetation types for validating moderate-resolution LAI products in time series.

Yelu Zeng

2015-01-01

245

The Less Things Change, the More They Are Different: Contributions of Long-Term Synaptic Plasticity and Homeostasis to Memory  

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An important cellular mechanism contributing to the strength and duration of memories is activity-dependent alterations in the strength of synaptic connections within the neural circuit encoding the memory. Reversal of the memory is typically correlated with a reversal of the cellular changes to levels expressed prior to the stimulation. Thus, for…

Schacher, Samuel; Hu, Jiang-Yuan

2014-01-01

246

Long-term course of ADHD symptoms from childhood to early adulthood in a community sample.  

Science.gov (United States)

Comparatively little information is available from population-based studies on subgroup trajectories of attention-deficit/hyperactivity disorder (ADHD) core symptoms of inattention and hyperactivity-impulsivity (particularly as defined by DSM-IV and ICD-10). Recent report of a subgroup with high and increasing inattention symptoms across development requires replication. To identify the different trajectory subgroups for inattention, hyperactivity-impulsivity and total symptoms of ADHD in children and adolescents aged 7-19 years. Eleven birth cohorts from 2,593 families with children and adolescents who had parent ratings for the outcome measures of inattention, hyperactivity-impulsivity or total symptoms were considered. Data were analysed using an accelerated longitudinal design and growth mixture modelling was applied to detect subgroups. For all three outcome measures, three trajectories with low (78.3-83.3 %), moderate (13.4-18.8 %) and high (2.8-3.2 %) symptom levels were detected. Course within these subgroups was largely comparable across outcome domains. In general, a decrease in symptoms with age was observed in all severity subgroups, although the developmental course was stable for the high subgroups of inattention and total symptoms. About 3 % of children in a community-based sample follow a course with a high level of ADHD symptoms. In this high trajectory group, hyperactivity-impulsivity symptoms decrease with age from 7 to 19 years, whilst inattention and total symptoms are stable. There was no evidence for an increase in symptoms across childhood/adolescence in any of the severity groups. PMID:25395380

Döpfner, Manfred; Hautmann, Christopher; Görtz-Dorten, Anja; Klasen, Fionna; Ravens-Sieberer, Ulrike

2014-11-14

247

Long-term stellar activity variations of stars from the HARPS M-dwarf sample: Comparison between activity indices  

CERN Document Server

We used four known chromospheric activity indicators to measure long-term activity variations in a sample of 23 M-dwarf stars from the HARPS planet search program. We compared the indices using weighted Pearson correlation coefficients and found that in general (i) the correlation between $S_{CaII}$ and \\ion{Na}{i} is very strong and does not depend on the activity level of the stars, (ii) the correlation between our $S_{CaII}$ and H$\\alpha$ seems to depend on the activity level of the stars, and (iii) there is no strong correlation between $S_{CaII}$ and \\ion{He}{i} for these type of stars.

da Silva, J Gomes; Bonfils, X

2010-01-01

248

2D Thermoluminescence imaging of dielectric surface long term charge memory of plasma surface interaction in DBD discharges  

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The charge trapping effect due to the exposure of alumina surfaces to plasma has been studied in a volume dielectric barrier discharge (DBD) in Ar and He noble gases. The long lasting charge trapping of alumina dielectric plates, used as barriers in DBDs, is evidenced by an ex situ thermoluminescence (TL) experiment performed with a standard and a custom two-dimensional (2D)-TL apparatus. The spatial density of trapped surface charges is found to be strongly correlated to the plasma morphology, and the surface spatial memory lasted for several minutes to hours after plasma exposure. In the case of Ar, the plasma channel impact signature on the surface shows a higher equivalent radiation dose with respect to the surface plasma wave and the post-discharge species signature. As a consequence, for the development of discharges, inside the dielectric surface the availability of lower energy trapped electrons is larger in the first region of plasma impact. The reported spatial memory increases the likelihood of the occurrence of plasma filaments in the same position in different runs. In He plasmas, the dielectric barrier shows an almost uniform distribution of trapped charges, meaning that there is no preferred region for the development of the discharge. In all cases a slight asymmetry was shown in the direction of the gas flow. This can be interpreted as being due to the long-living species moving in the direction of the gas flow, corresponding with the TL side experiment on the sample exposed to the plasma afterglow. The maximum values and the integral of the 2D-TL images showed a linear relation with the total charge per ac cycle, corresponding with findings for the TL glow curve. In conclusion, 2D-TL images allow the retrieval of information regarding the plasma surface interaction such as the plasma morphology, trap sites and their activation temperature.

Ambrico, Paolo F.; Ambrico, Marianna; Schiavulli, Luigi; De Benedictis, Santolo

2014-07-01

249

Olfaction, Emotion, and the Amygdala: arousal-dependent modulation of long-term autobiographical memory and its association with olfaction: beginning to unravel the Proust phenomenon?  

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Full Text Available The sense of smell is set apart from other sensory modalities. Odours possess the capacity to trigger immediately strong emotional memories. Moreover, odorous stimuli provide a higher degree of memory retention than other sensory stimuli. Odour perception, even in its most elemental form - olfaction - already involves limbic structures. This early involvement is not paralleled in other sensory modalities. Bearing in mind the considerable connectivity with limbic structures, and the fact that an activation of the amygdala is capable of instantaneously evoking emotions and facilitating the encoding of memories, it is unsurprising that the sense of smell has its characteristic nature. The aim of this review is to analyse current understanding of higher olfactory information processing as it relates to the ability of odours to spontaneously cue highly vivid, affectively toned, and often very old autobiographical memories (episodes known anecdotally as Proust phenomena. Particular emphasis is placed on the diversity of functions attributed to the amygdala. Its role in modulating the encoding and retrieval of long-term memory is investigated with reference to lesion, electrophysiological, immediate early gene, and functional imaging studies in both rodents and humans. Additionally, the influence of hormonal modulation and the adrenergic system on emotional memory storage is outlined. I finish by proposing a schematic of some of the critical neural pathways that underlie the odour-associated encoding and retrieval of emotionally toned autobiographical memories.

Mark Hughes

2004-06-01

250

Preservation of vaccine-induced long-term B cell memory and the effects of immunosuppressive treatment  

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Immune memory after vaccination is largely dependent on the combination of antibody production from long-lived plasma cells, and a supporting pool of antigen-primed memory B cells. It has been observed that individuals with certain immunosuppressive conditions or treatments have a weakened B cell memory, but the mechanisms behind remain elusive. The aim of this thesis was to evaluate B cell immunity in healthy children, and how HIV-1 infection, antineoplastic therapy, and rheum...

Ingelman-sundberg, Hanna M.

2015-01-01

251

Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants  

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Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein sy...

Guerrieri, Fernando Javier; D Ettorre, Patrizia; Deveaud, J-m; Giurfa, M.

2011-01-01

252

Sampling strategies and stopping criteria for stochastic dual dynamic programming: a case study in long-term hydrothermal scheduling  

Energy Technology Data Exchange (ETDEWEB)

The long-term hydrothermal scheduling is one of the most important problems to be solved in the power systems area. This problem aims to obtain an optimal policy, under water (energy) resources uncertainty, for hydro and thermal plants over a multi-annual planning horizon. It is natural to model the problem as a multi-stage stochastic program, a class of models for which algorithms have been developed. The original stochastic process is represented by a finite scenario tree and, because of the large number of stages, a sampling-based method such as the Stochastic Dual Dynamic Programming (SDDP) algorithm is required. The purpose of this paper is two-fold. Firstly, we study the application of two alternative sampling strategies to the standard Monte Carlo - namely, Latin hypercube sampling and randomized quasi-Monte Carlo - for the generation of scenario trees, as well as for the sampling of scenarios that is part of the SDDP algorithm. Secondly, we discuss the formulation of stopping criteria for the optimization algorithm in terms of statistical hypothesis tests, which allows us to propose an alternative criterion that is more robust than that originally proposed for the SDDP. We test these ideas on a problem associated with the whole Brazilian power system, with a three-year planning horizon. (orig.)

Homem-de-Mello, Tito [University of Illinois at Chicago, Department of Mechanical and Industrial Engineering, Chicago, IL (United States); Matos, Vitor L. de; Finardi, Erlon C. [Universidade Federal de Santa Catarina, LabPlan - Laboratorio de Planejamento de Sistemas de Energia Eletrica, Florianopolis (Brazil)

2011-03-15

253

FXR1P limits long-term memory, long-lasting synaptic potentiation, and de novo GluA2 translation.  

Science.gov (United States)

Translational control of mRNAs allows for rapid and selective changes in synaptic protein expression that are required for long-lasting plasticity and memory formation in the brain. Fragile X Related Protein 1 (FXR1P) is an RNA-binding protein that controls mRNA translation in nonneuronal cells and colocalizes with translational machinery in neurons. However, its neuronal mRNA targets and role in the brain are unknown. Here, we demonstrate that removal of FXR1P from the forebrain of postnatal mice selectively enhances long-term storage of spatial memories, hippocampal late-phase long-term potentiation (L-LTP), and de novo GluA2 synthesis. Furthermore, FXR1P binds specifically to the 5' UTR of GluA2 mRNA to repress translation and limit the amount of GluA2 that is incorporated at potentiated synapses. This study uncovers a mechanism for regulating long-lasting synaptic plasticity and spatial memory formation and reveals an unexpected divergent role of FXR1P among Fragile X proteins in brain plasticity. PMID:25456134

Cook, Denise; Nuro, Erin; Jones, Emma V; Altimimi, Haider F; Farmer, W Todd; Gandin, Valentina; Hanna, Edith; Zong, Ruiting; Barbon, Alessandro; Nelson, David L; Topisirovic, Ivan; Rochford, Joseph; Stellwagen, David; Béïque, Jean-Claude; Murai, Keith K

2014-11-20

254

Role of constitutive calcium-independent phospholipase A2 beta in hippocampo-prefrontal cortical long term potentiation and spatial working memory.  

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Calcium independent phospholipase A2 (iPLA2) is an 85kDa protein that catalyzes the hydrolysis of the sn-2 acyl ester bond of glycerophospholipids to liberate free fatty acids and lysophospholipids. In this study, we determined the role of constitutive iPLA2? in long term potentiation (LTP) of the hippocampo-prefrontal cortical pathway in vivo. We also examined the effect of iPLA2? knockdown using the rewarded alternation in T-maze task, a test of spatial working memory which is dependent on this pathway. Intracortical injection of an inhibitor to iPLA2, bromoenol lactone (BEL) or antisense oligonucleotide to iPLA2? in the prefrontal cortex abolished induction of hippocampo-prefrontal cortical LTP. Moreover, iPLA2 inhibition and antisense knockdown resulted in increased errors in the rewarded alternation in T-maze task, indicating negative effects on spatial working memory. BEL or antisense injection did not produce DNA fragmentation in the cortex as demonstrated by TUNEL assay. Results confirm a role of constitutive iPLA2? in hippocampo-prefrontal cortical synaptic plasticity in vivo, and add to previous observations of a role of iPLA2 in hippocampal LTP in vitro, and long-term memory retrieval. They may be relevant in Alzheimer's disease, and other neurodegenerative conditions that are associated with changes in iPLA2. PMID:25180675

Shalini, Suku-Maran; Chew, Wee-Siong; Rajkumar, Ramamoorthy; Dawe, Gavin S; Ong, Wei-Yi

2014-12-01

255

Behavioral assessment of Alzheimer's transgenic mice following long-term Abeta vaccination: task specificity and correlations between Abeta deposition and spatial memory.  

Science.gov (United States)

Long-term vaccinations with human beta-amyloid peptide 1-42 (Abeta1-42) have recently been shown to prevent or markedly reduce Abeta deposition in the PDAPP transgenic model of Alzheimer's disease (AD). Using a similar protocol to vaccinate 7.5-month-old APP (Tg2576) and APP+PS1 transgenic mice over an 8-month period, we previously reported modest reductions in brain Abeta deposition at 16 months. In these same mice, Abeta vaccinations had no deleterious behavioral effects and, in fact, benefited the mice by providing partial protection from age-related deficits in spatial working memory in the radial arm water maze task (RAWM) at 15.5 months. By contrast, control-vaccinated transgenic mice exhibited impaired performance throughout the entire RAWM test period at 15.5 months. The present study expands on our initial report by presenting additional behavioral results following long-term Abeta vaccination, as well as correlational analyses between cognitive performance and Abeta deposition in vaccinated animals. We report that 8 months of Abeta vaccinations did not reverse an early-onset balance beam impairment in transgenic mice. Additionally, in Y-maze testing at 16 months, all mice showed comparable spontaneous alternation irrespective of genotype or vaccination status. Strong correlations were nonetheless present between RAWM performance and extent of "compact" Abeta deposition in both the hippocampus and the frontal cortex of vaccinated APP+PS1 mice. Our results suggest that the behavioral protection of long-term Abeta vaccinations is task specific, with preservation of hippocampal-associated working memory tasks most likely to occur. In view of the early short-term memory deficits exhibited by AD patients, Abeta vaccination of presymptomatic AD patients could be an effective therapeutic to protect against such cognitive impairments. PMID:11788052

Arendash, G W; Gordon, M N; Diamond, D M; Austin, L A; Hatcher, J M; Jantzen, P; DiCarlo, G; Wilcock, D; Morgan, D

2001-11-01

256

Muscle tension induced after learning enhances long-term narrative and visual memory in healthy older adults.  

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Arousing events are better remembered than mundane events. Indeed, manipulation of arousal, such as by muscle tension, can influence memory even when it occurs shortly after learning. Indeed, our founding study showed this approach can raise delayed memory performance in older adults to a level comparable to that of unaided young adults. Yet, systematic studies, especially those investigating different modalities or types of memory, have not been done. This study investigated the effects of a brief bout of isometric exercise via handgrip on narrative and visuospatial episodic memory in healthy elders. Forty-seven participants completed the Logical Memory subtest of the Wechsler Memory Scales III (LM) and the Benton Visual Retention Test (BVRT), followed alternately by no treatment and by moderately squeezing a sand-filled latex ball for 1-min (counterbalanced order and test forms). Isometric exercise significantly increased both positive and negative affect ratings. Retention was tested 2 weeks later. Delayed recall and recognition of LM was enhanced by arousal relative to control, as was recognition of the BVRT. The results extend past findings that muscle tension induced after learning modulates memory consolidation, extending findings in elders to suggest that a simple form of isometric exercise can have practical effects, such as aiding memory for stories and images. PMID:24434768

Nielson, Kristy A; Wulff, Laura L; Arentsen, Timothy J

2014-03-01

257

A meta-synthesis of qualitative research on perceptions of people with long-term neurological conditions about group-based memory rehabilitation.  

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The effectiveness of memory rehabilitation based on randomised controlled trials and meta-analyses has been inconclusive, but patient reports based on qualitative studies have been largely positive. We conducted a meta-synthesis of qualitative studies of group-based memory rehabilitation programmes for people with neurological conditions. Based on systematic searches of electronic databases and reference lists, five papers (87 participants) were selected. Quality appraisal of papers was conducted by two independent reviewers using the Critical Appraisal Skills Programme tool. Data synthesis was guided by the meta-ethnography approach. Five higher order themes were elicited. These suggested that memory rehabilitation was associated with insight and acceptance of participants' neurological condition and resultant cognitive deficits. The therapeutic effects of the groups, with social support and leisure activities, helped with participants' confidence. There were improvements in memory related to better self-awareness and learning to use new skills and strategies to compensate for memory deficits. These improvements also related to other psychological effects, in terms of positively affected mood, confidence and fatigue. Ultimately, these changes had a positive impact on daily life, with changes seen in the personal, inter-personal and professional spheres. Therefore, this synthesis of qualitative studies suggests that memory rehabilitation offers positive outcomes for people with long-term neurological conditions. PMID:25366270

das Nair, Roshan; Martin, Kristy-Jane; Sinclair, Emma J

2014-11-01

258

An exemplar-familiarity model predicts short-term and long-term probe recognition across diverse forms of memory search.  

Science.gov (United States)

Experiments were conducted to test a modern exemplar-familiarity model on its ability to account for both short-term and long-term probe recognition within the same memory-search paradigm. Also, making connections to the literature on attention and visual search, the model was used to interpret differences in probe-recognition performance across diverse conditions that manipulated relations between targets and foils across trials. Subjects saw lists of from 1 to 16 items followed by a single item recognition probe. In a varied-mapping condition, targets and foils could switch roles across trials; in a consistent-mapping condition, targets and foils never switched roles; and in an all-new condition, on each trial a completely new set of items formed the memory set. In the varied-mapping and all-new conditions, mean correct response times (RTs) and error proportions were curvilinear increasing functions of memory set size, with the RT results closely resembling ones from hybrid visual-memory search experiments reported by Wolfe (2012). In the consistent-mapping condition, new-probe RTs were invariant with set size, whereas old-probe RTs increased slightly with increasing study-test lag. With appropriate choice of psychologically interpretable free parameters, the model accounted well for the complete set of results. The work provides support for the hypothesis that a common set of processes involving exemplar-based familiarity may govern long-term and short-term probe recognition across wide varieties of memory- search conditions. PMID:24749963

Nosofsky, Robert M; Cox, Gregory E; Cao, Rui; Shiffrin, Richard M

2014-11-01

259

Social Investigation and Long-Term Recognition Memory Performance in 129S1/SvImJ and C57BL/6JOlaHsd Mice and Their Hybrids  

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When tested for their behavioural performance, the mixed genetic background of transgenic mice is a critical, but often ignored, issue. Such issues can arise because of the significant differences in defined behavioural parameters between embryonic stem cell donor and recipient strains. In this context, the commonly used stem cell donor strain ‘129’ shows ‘deficits’ in different paradigms for learning and long-term memory. We investigated the long-term social recognition memory perfor...

Ha?dicke, Jana; Engelmann, Mario

2013-01-01

260

Newcastle disease virotherapy induces long-term survival and tumor-specific immune memory in orthotopic glioma through the induction of immunogenic cell death.  

Science.gov (United States)

The oncolytic features of several naturally oncolytic viruses have been shown on Glioblastoma Multiforme cell lines and in xenotransplant models. However, orthotopic glioma studies in immunocompetent animals are lacking. Here we investigated Newcastle disease virus (NDV) in the orthotopic, syngeneic murine GL261 model. Seven days after tumor induction, mice received NDV intratumorally. Treatment significantly prolonged median survival and 50% of animals showed long-term survival. We demonstrated immunogenic cell death (ICD) induction in GL261 cells after NDV infection, comprising calreticulin surface exposure, release of HMGB1 and increased PMEL17 cancer antigen expression. Uniquely, we found absence of secreted ATP. NDV-induced ICD occurred independently of caspase signaling and was blocked by Necrostatin-1, suggesting the contribution of necroptosis. Autophagy induction following NDV infection of GL261 cells was demonstrated as well. In vivo, elevated infiltration of IFN-?(+) T cells was observed in NDV-treated tumors, along with reduced accumulation of myeloid derived suppressor cells. The importance of a functional adaptive immune system in this paradigm was demonstrated in immunodeficient Rag2(-/-) mice and in CD8(+) T cell depleted animals, where NDV slightly prolonged survival, but failed to induce long-term cure. Secondary tumor induction with GL261 cells or LLC cells in mice surviving long-term after NDV treatment, demonstrated the induction of a long-term, tumor-specific immunological memory response by ND virotherapy. For the first time, we describe the therapeutic activity of NDV against GL261 tumors, evidenced in an orthotopic mouse model. The therapeutic effect relies on the induction of ICD in the tumor cells, which primes adaptive antitumor immunity. PMID:25208916

Koks, Carolien A; Garg, Abhishek D; Ehrhardt, Michael; Riva, Matteo; Vandenberk, Lien; Boon, Louis; Vleeschouwer, Steven De; Agostinis, Patrizia; Graf, Norbert; Van Gool, Stefaan W

2015-03-01

 
 
 
 
261

Analysis of regulatory T-cells and of their naïve and memory-like subsets in long-term treated aviremic HIV+ patients and untreated viremic patients  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose of the study: Although HIV infection impacts the proportion and phenotype of regulatory T-cells (Tregs, discrepant results have been reported depending on the surface markers employed to characterize them and on the patient populations. In addition, the effects of a long-term combined antiretroviral therapy (cART on Treg cells have not been thoroughly documented. Our study investigated the frequency and number of Tregs and their phenotype in two different groups of HIV-infected patients: one aviremic undergoing long-term cART and one viremic naïve to cART showing a similar CD4+ cell count. Methods: Thirty-six HIV+ patients with sustained suppression of plasma viremia (<37 copies/mL on effective cART for more than 6 years and 22 HIV+patients naïve to cART and without clinical signs of opportunistic infections or tumors at the time of study (untreated group were included in the study. Healthy donors (HD were used as control. Flow cytometry on fresh whole blood was used to quantify total Tregs (defined as CD25+CD127low/-CD4+ cells and the following Treg subsets: naïve (CD45RA+CCR7+ Tregs, central-memory like Tregs (CD45RA-CCR7+, TregCM, effector-memory like Tregs (CD45RA-CCR7?, TregEM Statistical comparisons of the percentages and number of Tregs and Treg subpopulations were performed by ANOVA or Kruskal-Wallis test. Analysis of covariance was employed in order to adjust for the effect of the age. The Spearman's test was used to assess correlations. Summary of results: In viremic untreated and aviremic long-term cART-treated patients the percentage and number of the total Treg cells were not different from those of HD. However, the analysis of Treg phenotype showed a marked redistribution of the Treg subpopulations: in the untreated viremic patients, both the percentage and number of the TregCM subset decreased compared to HD and cART-treated patients, whereas only the percentage of naïve Tregs increased. In particular, the percentage of TregCM was inversely correlated with the viral load (r=?0.51; p=0.016. Conclusions: In our aviremic long-term cART-treated and viremic untreated patients, the total Treg cell population seems to be unaffected by HIV infection. However, our results showed that the analysis of the naïve and memory-like Treg subsets may provide a better understanding of the real contribution of Tregs in HIV disease and therapy.

L Imberti

2012-11-01

262

Long-Term Effects of 56Fe Irradiation on Spatial Memory of Mice: Role of Sex and Apolipoprotein E Isoform  

International Nuclear Information System (INIS)

Purpose: To assess whether the effects of cranial 56Fe irradiation on the spatial memory of mice in the water maze are sex and apolipoprotein E (apoE) isoform dependent and whether radiation-induced changes in spatial memory are associated with changes in the dendritic marker microtubule-associated protein 2 (MAP-2) and the presynaptic marker synaptophysin. Methods and Materials: Two-month-old male and female mice expressing human apoE3 or apoE4 received either a 3-Gy dose of cranial 56Fe irradiation (600 MeV/amu) or sham irradiation. Mice were tested in a water maze task 13 months later to assess effects of irradiation on spatial memory retention. After behavioral testing, the brain tissues of these mice were analyzed for synaptophysin and MAP-2 immunoreactivity. Results: After irradiation, spatial memory retention of apoE3 female, but not male, mice was impaired. A general genotype deficit in spatial memory was observed in sham-irradiated apoE4 mice. Strikingly, irradiation prevented this genotype deficit in apoE4 male mice. A similar but nonsignificant trend was observed in apoE4 female mice. Although there was no change in MAP-2 immunoreactivity after irradiation, synaptophysin immunoreactivity was increased in irradiated female mice, independent of genotype. Conclusions: The effects of 56Fe irradiation on the spatial memory retention of mice are critically influenced by sex, and the direction of these effects is influenced by apoEion of these effects is influenced by apoE isoform. Although in female mice synaptophysin immunoreactivity provides a sensitive marker for effects of irradiation, it cannot explain the apoE genotype-dependent effects of irradiation on the spatial memory retention of the mice.

263

Human dendritic cells sequentially matured with CD4+ T cells as a secondary signal favor CTL and long-term T memory cell responses  

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Full Text Available Dendritic cells (DCs are professional antigen-presenting cells involved in the control and initiation of immune responses. In vivo, DCs exposed at the periphery to maturation stimuli migrate to lymph nodes, where they receive secondary signals from CD4+ T helper cells. These DCs become able to initiate CD8+ cytotoxic T lymphocyte (CTL responses. However, in vitro investigations concerning human monocyte-derived DCs have never focused on their functional properties after such sequential maturation. Here, we studied human DC phenotypes and functions according to this sequential exposure to maturation stimuli. As first signals, we used TNF-?/polyI:C mimicking inflammatory and pathogen stimuli and, as second signals, we compared activated CD4+ T helper cells to a combination of CD40-L/ IFN-?. Our results show that a sequential activation with activated CD4+ T cells dramatically increased the maturation of DCs in terms of their phenotype and cytokine secretion compared to DCs activated with maturation stimuli delivered simultaneously. Furthermore, this sequential maturation led to the induction of CTL with a long-term effector and central memory phenotypes. Thus, sequential delivery of maturation stimuli, which includes CD4+ T cells, should be considered in the future to improve the induction of long-term CTL memory in DC-based immunotherapy.

Thomas Simon

2012-01-01

264

Leishmania braziliensis-Reactive T Cells Are Down-Regulated in Long-Term Cured Cutaneous Leishmaniasis, but the Renewal Capacity of T Effector Memory Compartments Is Preserved  

Science.gov (United States)

Leishmania (Viannia) braziliensis control and tissue damage relate to the effector immune response, which in turn affects clinical outcome. Leishmania reactive CD4+ and CD8+ T cells are expanded in long-term healed cutaneous leishmaniasis (hCL) patients but their functional characteristics remain to be determined. This study investigates antigen-specific recall in long-term healed CL caused by L. braziliensis infection. Healed CL subjects were grouped according to the time elapsed since the end of therapy: less than two years and two to five years. Activation phenotype (CD69+ or CD25+) and subpopulations of memory T cell phenotypes [central memory (Tcm): CD45RO+ CCR7+ or effector memory (Tem): CD45RO+ CCR7-] were quantified in ex vivo blood mononuclear cells and after Leishmania antigens stimuli. A reduction in the percentage of activated Leishmania-responder CD4+ and CD8+ T cells in hCL was associated with the time elapsed since clinical cure. Percentage of CD69+ in TCD4+ and TCD8+ cells were negatively correlated with IL-10 levels. Ex vivo analyses showed contracted Tem CD4+ and Tem CD8+ compartments from hCL with long time elapsed since clinical cure, although renewal of these compartments was observed following in vitro exposure to leishmanial stimuli. Our results show that healed L. braziliensis infected patients exhibit a recall response to Leishmania antigens with evident expansion of effector memory T cells. Regulated leishmanial-specific response seems to emerge only about two years after initial contact with the parasite antigens. PMID:24303052

Pereira-Carvalho, Regina; Mendes-Aguiar, Carolina O.; Oliveira-Neto, Manoel P.; Covas, Cláudia J. F.; Bertho, Álvaro L.; Da-Cruz, Alda M.; Gomes-Silva, Adriano

2013-01-01

265

Analyses of fear memory in Arc/Arg3.1-deficient mice: intact short-term memory and impaired long-term and remote memory  

Directory of Open Access Journals (Sweden)

Full Text Available Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1 was originally identified in patients with seizures. It is densely distributed in the hip-pocampus and amygdala in particular. Because the expression of Arc/Arg3.1 is regulated by nerve in-puts, it is thought to be an immediate early gene. As shown both in vitro and in vivo, Arc/Arg3.1 is in-volved in synaptic consolidation and regulates some forms of learning and memory in rats and mice [1,2]. Furthermore, a recent study suggests that Arc/Arg3.1 may play a significant role in signal transmission via AMPA-type glutamate receptors [3-5]. Therefore, we conducted a detailed analysis of fear memory in Arc/Arg3.1-deficient mice. As previously reported, the knockout animals exhib-ited impaired fear memory in both contextual and cued test situations. Although Arc/Arg3.1-deficient mice showed almost the same performance as wild-type littermates 4 hr after a conditioning trial, their performance was impaired in the retention test after 24 hr or longer, either with or without reconsolidation. Immunohistochemical analyses showed an abnormal density of GluR1 in the hip-pocampus of Arc/Arg3.1-deficient mice; however, an application of AMPA potentiator did not improve memory performance in the mutant mice. Memory impairment in Arc/Arg3.1-deficient mice is so ro-bust that the mice provide a useful tool for devel-oping treatments for memory impairment.

Yoshiko Nagaoka

2011-05-01

266

The effect of intrahippocampal microinjection of Naloxone on short –term and long-term memory in adult male rats  

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Introduction:The hippocampus is one for the major centers of learning and memory. Role of the opioid system has been investigated and on the other hand receptors related to this system such as mu-opioid receptors (MOR) are extended in the hippocampus. In this study the effect of Naloxone administration as a mu opioid receptor antagonist on passive avoidance memory in adult male rats was investigated by using shuttle box instrument. Methods:Methods: In this study 45 male adult Wistar rats at r...

Hoda Parsa; Ahmad Ali moazedi; Lotfolah Khajehpour; Mehdi pourmehdi

2012-01-01

267

Deficits in memory and hippocampal long-term potentiation in mice with reduced calbindin D28K expression.  

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The influx of calcium into the postsynaptic neuron is likely to be an important event in memory formation. Among the mechanisms that nerve cells may use to alter the time course or size of a spike of intracellular calcium are cytosolic calcium binding or "buffering" proteins. To consider the role in memory formation of one of these proteins, calbindin D28K, which is abundant in many neurons, including the CA1 pyramidal cells of the hippocampus, transgenic mice deficient in calbindin D28K have...

Molinari, S.; Battini, R.; Ferrari, S.; Pozzi, L.; Killcross, A. S.; Robbins, T. W.; Jouvenceau, A.; Billard, J. M.; Dutar, P.; Lamour, Y.; Baker, W. A.; Cox, H.; Emson, P. C.

1996-01-01

268

The Ubiquitin-Specific Protease 14 (USP14) Is a Critical Regulator of Long-Term Memory Formation  

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Numerous studies have suggested a role for ubiquitin-proteasome-mediated protein degradation in learning-dependent synaptic plasticity; however, very little is known about how protein degradation is regulated at the level of the proteasome during memory formation. The ubiquitin-specific protease 14 (USP14) is a proteasomal deubiquitinating enzyme…

Jarome, Timothy J.; Kwapis, Janine L.; Hallengren, Jada J.; Wilson, Scott M.; Helmstetter, Fred J.

2014-01-01

269

Activin Plays a Key Role in the Maintenance of Long-Term Memory and Late-LTP  

Science.gov (United States)

A recent study has revealed that fear memory may be vulnerable following retrieval, and is then reconsolidated in a protein synthesis-dependent manner. However, little is known about the molecular mechanisms of these processes. Activin [beta]A, a member of the TGF-[beta] superfamily, is increased in activated neuronal circuits and regulates…

Ageta, Hiroshi; Ikegami, Shiro; Miura, Masami; Masuda, Masao; Migishima, Rika; Hino, Toshiaki; Takashima, Noriko; Murayama, Akiko; Sugino, Hiromu; Setou, Mitsutoshi; Kida, Satoshi; Yokoyama, Minesuke; Hasegawa, Yoshihisa; Tsuchida, Kunihiro; Aosaki, Toshihiko; Inokuchi, Kaoru

2010-01-01

270

Long-Term Antibody and Immune Memory Response Induced by Pulmonary Delivery of the Influenza Iscomatrix Vaccine  

Science.gov (United States)

Pulmonary delivery of an influenza Iscomatrix adjuvant vaccine induces a strong systemic and mucosal antibody response. Since an influenza vaccine needs to induce immunological memory that lasts at least 1 year for utility in humans, we examined the longevity of the immune response induced by such a pulmonary vaccination, with and without antigen challenge. Sheep were vaccinated in the deep lung with an influenza Iscomatrix vaccine, and serum and lung antibody levels were quantified for up to 1 year. The immune memory response to these vaccinations was determined following antigen challenge via lung delivery of influenza antigen at 6 months and 1 year postvaccination. Pulmonary vaccination of sheep with the influenza Iscomatrix vaccine induced antigen-specific antibodies in both sera and lungs that were detectable until 6 months postimmunization. Importantly, a memory recall response following antigenic challenge was detected at 12 months post-lung vaccination, including the induction of functional antibodies with hemagglutination inhibition activity. Pulmonary delivery of an influenza Iscomatrix vaccine induces a long-lived influenza virus-specific antibody and memory response of suitable length for annual vaccination against influenza. PMID:22072721

Vujanic, Ana; Snibson, Kenneth J.; Wee, Janet L. K.; Edwards, Stirling J.; Pearse, Martin J.; Scheerlinck, Jean-Pierre Y.

2012-01-01

271

Memories of GAMES: Exploring the Long-Term Impacts of After-School Museum Programming on Girls' Attitudes Towards Science  

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The purpose of this study is to investigate any lasting impacts of the University of Colorado Museum of Natural History's Girls at the Museum Exploring Science (GAMES) Program. Using assessment document analysis, student focus groups, and adult interviews, this study examined whether students' positive associations with science continue after completion of the program and whether the program affects the academic and career choices of past participants. Results from the analysis suggest that GAMES has a generally positive impact on participant attitudes towards science in both the short- and long-term. These results also support existing research in identifying key factors in the success of the program including hands-on activities, exposure to diverse careers and female role models, and the incorporation of authentic objects and experiences. These factors of success can contribute to the evidence base about the role of informal education programs in increasing science participation among women, as well as ways in which schools and universities can collaborate to effectively serve populations that are traditionally underrepresented in the sciences.

Snow, Sarah Elizabeth

272

Enhanced long-term and impaired short-term spatial memory in GluA1 AMPA receptor subunit knockout mice: Evidence for a dual-process memory model  

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The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity of GluA1-dependent synaptic plasticity for short-term memory of recently visited places, but not for the ability to form long-term associations betwee...

Sanderson, Dj; Good, Ma; Skelton, K.; Sprengel, R.; Seeburg, Ph; Rawlins, Jn; Bannerman, Dm

2009-01-01

273

Caffeine suppresses exercise-enhanced long-term and location memory in middle-aged rats: Involvement of hippocampal Akt and CREB signaling.  

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The cognitive function decline is closely related with brain changes generated by age. The ability of caffeine and exercise to prevent memory impairment has been reported in animal models and humans. The purpose of the present study was to investigate whether swimming exercise and caffeine administration enhance memory in middle-aged Wistar rats. Male Wistar rats (18months) received caffeine at a dose of 30mg/kg, 5days per week by a period of 4weeks. Animals were subjected to swimming training with a workload (3% of body weight, 20min per day for 4weeks). After 4weeks, the object recognition test (ORT) and the object location test (OLT) were performed. The results of this study demonstrated that caffeine suppressed exercise-enhanced long-term (ORT) and spatial (OLT) memory in middle-aged and this effect may be related to a decrease in hippocampal p-CREB signaling. This study also provided evidence that the effects of this protocol on memory were not accompanied by alterations in the levels of activated Akt. The [(3)H] glutamate uptake was reduced in hippocampus of rats administered with caffeine and submitted to swimming protocol. PMID:25260559

Cechella, José L; Leite, Marlon R; da Rocha, Juliana T; Dobrachinski, Fernando; Gai, Bibiana M; Soares, Félix A A; Bresciani, Guilherme; Royes, Luiz F F; Zeni, Gilson

2014-09-27

274

Long-term memory traces for familiar spoken words in tonal languages as revealed by the Mismatch Negativity  

Directory of Open Access Journals (Sweden)

Full Text Available Mismatch negativity (MMN, a primary response to an acoustic change and an index of sensory memory, was used to investigate the processing of the discrimination between familiar and unfamiliar Consonant-Vowel (CV speech contrasts. The MMN was elicited by rare familiar words presented among repetitive unfamiliar words. Phonetic and phonological contrasts were identical in all conditions. MMN elicited by the familiar word deviant was larger than that elicited by the unfamiliar word deviant. The presence of syllable contrast did significantly alter the word-elicited MMN in amplitude and scalp voltage field distribution. Thus, our results indicate the existence of word-related MMN enhancement largely independent of the word status of the standard stimulus. This enhancement may reflect the presence of a longterm memory trace for familiar spoken words in tonal languages.

Naiphinich Kotchabhakdi

2004-11-01

275

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  

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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 memo...

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

2014-01-01

276

Long-term safety of radioactive waste disposal. Radioactive analysis of samples from spent fuel leaching experiments  

International Nuclear Information System (INIS)

In order to assess the long-term performance of spent fuel during direct disposal, high burnup fuel (50 MWd/kg U) has been exposed to non-buffered brine solutions and to deionized water under static anaerobic conditions at 25 C. The leaching behaviour of several radionuclides has been observed over periods of approximately 500 d. Currently used radiometric methods (?-, ?-, ?-spectrometry) were applied to the analysis of sample solutions. Due to its low specific activity, uranium was determined using ICP-mass-spectrometry (ICP-MS) or laser induced fluorescence spectrometry (LFS). In order to determine radionuclide concentrations without interferences a preceeding radiochemical separation by ion-exchange, solvent-extraction or extraction chromatography was necessary in most cases. The Sc-isotopes 134/137, which are present in a high excess over other ?-emitting nuclides, were separated using the inorganic ion exchanger ammonium molybdato phosphate (AMP). This step allowed the subsequent ?-spectrometric determination of Am-241, Ag-110m, Ru-106, Sb-125 and Eu-154/155. Activity concentrations of pure ?-emitters like Sr-90, Tc-99, I-129 and Pu-241 were determined by liquid scintillation counting (LSC) after selective separation using extraction chromatography or solvent extraction. The actinides Am-241, Cm-242/244, Pu-238/239/240 and Np-237 were analysed by ?-spectrometry again after selective separation. The direct analysis of uranium by LFS or ICP-MS was hampered by high salt concentrations. Therefore a separation by extraction chromatography turned out to be necessary, too. The analytical procedures used throughout this work are described in detail. (orig.)

277

Long-term superelastic cycling at nano-scale in Cu-Al-Ni shape memory alloy micropillars  

Science.gov (United States)

Superelastic behavior at nano-scale has been studied along cycling in Cu-Al-Ni shape memory alloy micropillars. Arrays of square micropillars were produced by focused ion beam milling, on slides of [001] oriented Cu-Al-Ni single crystals. Superelastic behavior of micropillars, due to the stress-induced martensitic transformation, has been studied by nano-compression tests during thousand cycles, and its evolution has been followed along cycling. Each pillar has undergone more than thousand cycles without any detrimental evolution. Moreover, we demonstrate that after thousand cycles they exhibit a perfectly reproducible and completely recoverable superelastic behavior.

San Juan, J.; Gómez-Cortés, J. F.; López, G. A.; Jiao, C.; Nó, M. L.

2014-01-01

278

Long-term superelastic cycling at nano-scale in Cu-Al-Ni shape memory alloy micropillars  

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Superelastic behavior at nano-scale has been studied along cycling in Cu-Al-Ni shape memory alloy micropillars. Arrays of square micropillars were produced by focused ion beam milling, on slides of [001] oriented Cu-Al-Ni single crystals. Superelastic behavior of micropillars, due to the stress-induced martensitic transformation, has been studied by nano-compression tests during thousand cycles, and its evolution has been followed along cycling. Each pillar has undergone more than thousand cycles without any detrimental evolution. Moreover, we demonstrate that after thousand cycles they exhibit a perfectly reproducible and completely recoverable superelastic behavior.

San Juan, J., E-mail: jose.sanjuan@ehu.es; Gómez-Cortés, J. F. [Dpto. Física Materia Condensada, Facultad de Ciencia y Tecnología, Univ. del País Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); López, G. A.; Nó, M. L. [Dpto. Física Aplicada II, Facultad de Ciencia y Tecnología, Univ. del País Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Jiao, C. [FEI, Achtseweg Noord 5, 5651 GG Eindhoven (Netherlands)

2014-01-06

279

Management of long-term and reversible hysteroscopic sterilization: a novel device with nickel-titanium shape memory alloy  

Science.gov (United States)

Background Female sterilization is the second most commonly used method of contraception in the United States. Female sterilization can now be performed through laparoscopic, abdominal, or hysteroscopic approaches. The hysteroscopic sterilization may be a safer option than sterilization through laparoscopy or laparotomy because it avoids invading the abdominal cavity and undergoing general anaesthesia. Hysteroscopic sterilization mainly includes chemical agents and mechanical devices. Common issues related to the toxicity of the chemical agents used have raised concerns regarding this kind of contraception. The difficulty of the transcervical insertion of such mechanical devices into the fallopian tubes has increased the high incidence of device displacement or dislodgment. At present, Essure® is the only commercially available hysteroscopic sterilization device being used clinically. The system is irreversible and is not effective immediately. Presentation of the hypothesis Our new hysteroscopic sterility system consists of nickel-titanium (NiTi) shape memory alloy and a waterproof membrane. The NiTi alloy is covered with two coatings to avoid toxic Ni release and to prevent stimulation of epithelial tissue growth around the oviducts. Because of the shape memory effect of the NiTi alloy, the device works like an umbrella: it stays collapsed at low temperature before placement and opens by the force of shape memory activated by the body temperature after it is inserted hysteroscopically into the interstitial tubal lumen. The rim of the open device will incise into interstitial myometrium during the process of unfolding. Once the device is fixed, it blocks the tube completely. When the patient no longer wishes for sterilization, the device can be closed by perfusing liquid with low temperature into the uterine cavity, followed by prospective hysteroscopic removal. After the device removal, the fallopian tube will revert to its physiological functions. Testing the hypothesis Currently, experimental and clinical studies are needed to attest the safety, efficiency and reversibility of the novel sterilization device. Implications of the hypothesis If our hypothesis is confirmed, appropriate and reversible contraceptive can be achieved with the device we have designed, which may have significant repercussions for numerous women worldwide. PMID:24999021

2014-01-01

280

Long-term sampling of dioxin-like substances from a clinker kiln stack using alternative fuels.  

Science.gov (United States)

The aim of this work is to characterize atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from a cement production plant where the existing clinker production line was completely replaced by a new state-of-the-art installation. The project started in April 2008 with the installation of a long-term sampling system in the stack of the clinker kiln that used petroleum coke as fuel; PCDD/PCDF and dl-PCB emissions were then evaluated for a two year period. To carry out the second part of the study, in 2010 the sampling system was moved to the new installation in which, apart from conventional fuel, recovered derived fuel (RDF) and WWTP sludge were used as alternative fuels. For both the old and new clinker kilns, PCDD/PCDF emission values were well below the limit established by the European Waste Incineration Directive 2000/76/CE (EWID) of 100 pg I-TEQ/Nm(3); values ranged from 0.43 to 2.02 and from 0.07 to 3.31 pg I-TEQ/Nm(3), respectively. dl-PCBs accounted for approximately 25% of the WHO-TEQ toxicity. These results prove that the installation is capable of reducing PCDD/PCDF and dl-PCB emissions when alternative fuels are integrated into the process. In the case of PCDDs/PCDFs, the major contributions to total TEQ were usually from 2,3,7,8-TCDD (owing to its relative abundance) and 2,3,4,7,8-PeCDF (due to its high I-TEF of 0.5); while for dl-PCBs, the major contribution was from PCB-126. The slight shift in the congener profile between the old and new installations was characterized and a regression model was proposed for dl-PCB emissions depending on the RDF flow rate in the clinker. PMID:24742561

Rivera-Austrui, J; Martinez, K; Marco-Almagro, L; Abalos, M; Abad, E

2014-07-01

 
 
 
 
281

Behavioral perseveration and impairment of long-term memory in rats after intrahippocampal injection of kainic acid in subconvulsive dose.  

Science.gov (United States)

Delayed disturbances of cognitive functions caused by intrahippocampal injection of subconvulsive dose of kainic acid were studied in rats. Animals were behaviorally tested for the presence of cognitive deterioration 1 week after bilateral injection of 0.25 microg kainic acid into the left and right hippocampi. Behavioral tests included the retrieval of a food-procuring task, its experimental extinction, and learning of a new similar task. Kainate-treated rats showed deterioration of performance of the task learned before the treatment: An impairment of the task performance occurred in the first trial of a daily session (each daily session consisted of 10 trials), and beginning from the second trial, the task was performed as rapidly as by control animals. This deterioration of retrieval in the first trial took place during several days, in spite of daily training during the retrieval test. Other disturbances of cognitive functions in kainate-treated rats were revealed in the test of experimental extinction of the response. At the initial step of this test, the rats showed active behavioral perseveration, performing habitual response with short latencies in spite of reinforcement removal. Besides, kainate-treated rats made significantly more responses before full extinction (inhibition of the previously learned response) than the control rats. In the learning test, kainate-treated rats did not exhibit any disturbances: repeated learning was the same as in the control group. Therefore, results showed that hippocampal dysfunctions induced by kainic acid resulted in the following cognitive disturbances: difficulties in memory retrieval and weakening of inhibitory control. These disturbances can be most adequately explained on the basis of the concept, according to which the hippocampus acts as a detector and comparator of new signals, thereby accomplishing selective attention. PMID:17889287

Arkhipov, Vladimir; Kulesskaja, Natalia; Lebedev, Denis

2008-01-01

282

Long-Term Morbidity and Mortality among a Sample of Cocaine-Dependent Black and White Veterans  

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Racial minorities generally exhibit worse health status than do whites. To assess the presence of similar phenomena among long-term cocaine-using veterans, this study examined racial variations in mortality and health status among cocaine-dependent men who were originally recruited at their admissions to cocaine treatment in 1988–1989 and were interviewed approximately 12 years later in 2002–2003. Mortality was higher among whites (15%) than blacks (6%), particularly due to drug overdose...

Yang, Joy C.; Huang, David; Hser, Yih-ing

2006-01-01

283

Two inhibitors of the ubiquitin proteasome system enhance long-term memory formation upon olfactory conditioning in the honeybee (Apis mellifera).  

Science.gov (United States)

In honeybees (Apis mellifera), the proteasome inhibitor Z-Leu-Leu-Leu-CHO (MG132) enhances long-term memory (LTM) formation. Studies in vertebrates using different inhibitors of the proteasome demonstrate the opposite, namely an inhibition of memory formation. The reason for this contradiction remains unclear. MG132 is an inhibitor of the proteasome, but also blocks other proteases. Accordingly, one possible explanation might be that other proteases affected by MG132 are responsible for the enhancement of LTM formation. We test this hypothesis by comparing the effect of MG132 and the more specific proteasome inhibitor clasto-lactacystin beta-lactone (?-lactone). We show that these two inhibitors block the activity of the proteasome in honeybee brains to a similar extent, do not affect the animals' survival but do enhance LTM retention upon olfactory conditioning. Thus, the enhancement of LTM formation is not due to MG132-specific side effects, but to inhibition of a protease targeted by MG132 and ?-lactone, i.e. the proteasome. PMID:25063852

Felsenberg, Johannes; Dyck, Yan; Kloß, Alexander; Dahlmann, Burkhardt; Kloetzel, Peter-Michael; Eisenhardt, Dorothea

2014-10-01

284

Influences of a DRD2 polymorphism on updating of long-term memory representations and caudate BOLD activity: Magnification in aging.  

Science.gov (United States)

A number of genetic polymorphisms are related to individual differences in cognitive performance. Striatal dopamine (DA) functions, associated with cognitive performance, are linked to the TaqIA polymorphism of the DRD2/ANKK1 gene. In humans, presence of an A1 allele of the DRD2/ANKK1-TaqIA polymorphism is related to reduced density of striatal DA D2 receptors. The resource-modulation hypothesis assumes that aging-related losses of neurochemical and structural brain resources modulate the extent to which genetic variations affect cognitive functioning. Here, we tested this hypothesis using functional MRI during long-term memory (LTM) updating in younger and older carriers and noncarriers of the A1-allele of the TaqIa polymorphism. We demonstrate that older A1-carriers have worse memory performance, specifically during LTM updating, compared to noncarriers. Moreover, A1-carriers exhibited less blood oxygen level-dependent (BOLD) activation in left caudate nucleus, a region critical to updating. This effect was only seen in older adults, suggesting magnification of genetic effects on functional brain activity in aging. Further, a positive relationship between caudate BOLD activation and updating performance among non-A1 carriers indicated that caudate activation was behaviorally relevant. These results demonstrate a link between the DRD2/ANKK1-TaqIA polymorphism and neurocognitive deficits related to LTM updating, and provide novel evidence that this effect is magnified in aging. Hum Brain Mapp, 2014. © 2014 Wiley Periodicals, Inc. PMID:25486867

Persson, Jonas; Rieckmann, Anna; Kalpouzos, Grégoria; Fischer, Håkan; Bäckman, Lars

2014-12-01

285

Evaluation of the Quality of Life in Adult Cancer Survivors (QLACS) scale for long-term cancer survivors in a sample of breast cancer survivors  

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Abstract Background This paper evaluates psychometric properties of a recently developed measure focusing on the health-related quality of life (HRQL) of long-term cancer survivors, the Quality of Life in Adult Survivors scale (QLACS), in a sample of breast cancer survivors. This represents an important area of study, given the large number of breast cancer patients surviving many years post diagnosis. Methods Analyses are based on an 8-year follow-up of a sampl...

Foley Kristie; Ip Edward; Avis Nancy E

2006-01-01

286

Dietary omega-3 deficiency reduces BDNF content and activation NMDA receptor and Fyn in dorsal hippocampus: implications on persistence of long-term memory in rats.  

Science.gov (United States)

Omega-3 (n-3) fatty acids are important for adequate brain function and cognition. The aim of the present study was to evaluate how n-3 fatty acids influence the persistence of long-term memory (LTM) in an aversive memory task and to explore the putative mechanism involved. Female rats received isocaloric diets that included n-3 (n-3 group) or not (D group). The adult litters were subjected to an inhibitory avoidance task (0.7 mA, 1.0 seconds foot shock) to elicit persistent LTM. Twelve hours after the training session, the fatty acid profile and the brain derived neurotrophic factor (BDNF) content of the dorsal hippocampus were assessed. In addition, we measured the activation of the NR2B subunit of the N-methyl-d-aspartate (NMDA) receptor and the SRC family protein Fyn. Despite pronounced learning in both groups, the persistence of LTM was abolished in the D group 7 days after the training session. We also observed that the D group presented reductions in hippocampal DHA (22:6 n-3) and BDNF content. Twelve hours after the training session, the D group showed decreased NR2B and Fyn phosphorylation in the dorsal hippocampus, with no change in the total content of these proteins. Further, there was a decrease in the interaction of Fyn with NR2B in the D group, as observed by co-immunoprecipitation. Taken together, these data suggest that n-3 fatty acids influence the persistence of LTM by maintaining adequate levels of DHA and BDNF as well as by influencing the activation of NR2B and Fyn during the period of memory formation. PMID:24621058

Bach, Simone Azevedo; de Siqueira, Letícia V; Müller, Alexandre P; Oses, Jean P; Quatrim, Andreia; Emanuelli, Tatiana; Vinadé, Lúcia; Souza, Diogo O; Moreira, Júlia D

2014-07-01

287

Groundwater sampling at olkiluoto, Eurajoki from the borehole OL-KR6 during a long-term pumping test in 2004  

International Nuclear Information System (INIS)

A long-term pumping test from the borehole OL-KR6 at Olkiluoto was initiated in 2001. Both flow and in situ EC measurements as well as groundwater sampling from specific sections were performed. The aim of this study was to get information on the potential connections via fractures both to the sea and to deep saline groundwater during the long-term pumping of the open borehole. In 2004 four groundwater samples were collected from the borebole OL-KR6 from four different sampling depths (98.5-100.5 m, 125-130 m, 135-137 m and 422-425 m). The groundwater samples were taken from packed-off sections by a membrane pump and two inflatable rubber packers. All groundwater samples taken are of the water type Na-Ca-Cl. They are brackish waters (1000 mg 10000mg/L) and the water type is Na-Cl. This study presents sampling methods and the results of analysis of groundwater samples from the deep borehole OL-KR6. Comparison between the results of the in situ EC measurements and EC results measured during groundwater sampling are presented. This report also contains a short comparison of the results obtained during the long-term pumping test during 2001-2004. Based on the results of this study and on the previous studies, it can be concluded that the pumping of the upper part of the borehole is likely to have caused the changes in salinity at the three sampling sections (except 422-425 m). However, the changes were minor in years 2001-2004. (orig.)

288

Long-term collections  

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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.

Collectes à long terme

2007-01-01

289

Long-term memory of visually cued fear conditioning: roles of the neuronal nitric oxide synthase gene and cyclic AMP response element-binding protein.  

Science.gov (United States)

Nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) has a role in late-phase long-term potentiation (LTP) and long-term memory (LTM) formation. Our recent studies implicated NO signaling in contextual and auditory cued fear conditioning. The present study investigated the role of NO signaling in visually cued fear conditioning. First, visually cued fear conditioning was investigated in wild-type (WT) and nNOS knockout (KO) mice. Second, the effects of pharmacological modulators of NO signaling on the acquisition of visually cued fear conditioning were investigated. Third, plasma levels of corticosterone were measured to determine a relationship between physiological and behavioral responses to fear conditioning. Fourth, levels of extracellular signal-related kinase (ERK1/2) and cyclic AMP response element binding protein (CREB) phosphorylation, downstream of NO signaling, were determined in the amygdala as potential correlates of fear learning. Mice underwent single or multiple (4) spaced trainings that consisted of a visual cue (blinking light) paired with footshock. WT mice acquired cued and contextual LTM following single and multiple trainings. nNOS KO mice acquired neither cued nor contextual LTM following a single training; however, multiple trainings improved contextual but not cued LTM. The selective nNOS inhibitor S-methyl-thiocitrulline (SMTC) impaired cued and contextual LTM in WT mice. The NO donor molsidomine recovered contextual LTM but had no effect on cued LTM in nNOS KO mice. Re-exposure to the visual cue 24 h posttraining elicited freezing response and a marked increase in plasma corticosterone levels in WT but not nNOS KO mice. The expression of CREB phosphorylation (Ser-133) was significantly higher in naive nNOS KO mice than in WT counterparts, and pharmacological modulators of NO had significant effects on levels of CREB phosphorylation and expression. These findings suggest that visual cue-dependent LTM is impaired in nNOS KO mice, and aberrant modulation of CREB in the absence of the nNOS gene may hinder cued and contextual LTM formation. PMID:21073925

Kelley, J B; Anderson, K L; Altmann, S L; Itzhak, Y

2011-02-01

290

Groundwater sampling at Olkiluoto, Eurajoki from the borehole OL-KR6 during a long-term pumping test in 2006  

International Nuclear Information System (INIS)

A long-term pumping test at borehole OL-KR6 at Olkiluoto was initiated in 2001. Since then, flow and in situ EC measurements as well as groundwater sampling from specific sampling sections have been performed yearly. The aim of this study was to obtain information on the potential connections via fractures both to the sea and to deep saline groundwater during long-term pumping of the open borehole. In 2006, four groundwater samples were collected from four different sampling depths (98.5-100.5 m, 125-130 m, 135-137 m and 422-425 m). The groundwater samples were taken in stages using PAVE equipment. The water types found in the groundwater samples from OL-KR6 were Na-Ca-Cl (for samples from depths of 98.5-100.5 m and 125-130 m) and Na-Cl (for samples from depths of 135-137 m and 422-425 m). The sample from depth 422-425 m was saline (TDS> 10000 mg/l), while other waters were brackish (1000 mg < TDS <10000 mg/l). This study presents the sampling methods and analysis results of groundwater samples from deep borehole OL-KR6, and draws a comparison between the results of the in situ EC measurements and the EC results measured during groundwater sampling. This report also contains a short comparison of the results obtained from the long-term pumping test conducted between 2001-2006. In situ EC results and EC results measured in laboratory are in quite good agreement. At sampling depth, 422-425 m, EC increased between 2004-2006. At a depth of 423 m, much variation in situ EC-values indicates that routes of groundwater may change during long-term pumping due to the limited storages of different aquifers or the heterogeneity of the content of groundwater in different locations in the bedrock. The minor systematic difference between in situ and sampling EC at a depth of 136 m was probably due to the different flow fields during flow logging and water sampling. The dominant gas in the groundwater samples was nitrogen. Carbon dioxide was the second dominant gas, except for the OL-KR6/125-130 m sample, where argon was the second dominant. All sample vessels were argon treated before sampling so contamination by argon was possible. In 2006, dissolved gas concentrations were higher in OL-KR6 samples than in the two previous years. Higher concentrations were noticed in nitrogen, carbon dioxide and argon (contamination possible) contents at all sampling depths. One of the conclusions from this and previous studies is that the changes in the three upper sampling points were most remarkable in 2001-2002 just after pumping started. Otherwise, water compositions were invariable. (orig.)

291

Effects of ethanolic extract and naphthoquinones obtained from the bulbs of Cipura paludosa on short-term and long-term memory: involvement of adenosine A? and A?A receptors.  

Science.gov (United States)

Previous studies from our group have indicated important biological properties of the ethanolic extract and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil, including antioxidant, neuroprotective and anti-nociceptive activities. In the present study, the effects of the ethanolic extract and its two naphthoquinones (eleutherine and isoeleutherine) on the short- and long-term memory of adult rodents were assessed in social recognition and inhibitory avoidance tasks. Acute pre-training oral administration of the ethanolic extract improved the short-term social memory in rats as well as facilitated the step-down inhibitory avoidance short- and long-term memory in mice. Moreover, the co-administration of 'non-effective' doses of the extract of Cipura paludosa and the adenosine receptor antagonists caffeine (non-selective), DPCPX (adenosine A1 receptor antagonist) and ZM241385 (adenosine A2A receptor antagonist) improved the social recognition memory of rats. In the inhibitory avoidance task, the co-administration of sub-effective doses of the extract with caffeine or ZM241385, but not with DPCPX, improved the short- and long-term memory of mice. Finally, the acute oral administration of eleutherine and isoeleutherine facilitated the inhibitory avoidance short- and long-term memory in mice. These results demonstrate for the first time the cognitive-enhancing properties of the extract and isolated compounds from the bulbs of Cipura paludosa in rodents and suggest a possible involvement of adenosine A1 and A2A receptors in these effects. PMID:23057724

Lucena, Greice M R S; Matheus, Filipe C; Ferreira, Vania M; Tessele, Priscila B; Azevedo, Mariangela S; Cechinel-Filho, Valdir; Prediger, Rui D

2013-04-01

292

Immunization of mice with the nef gene from Human Immunodeficiency Virus type 1: Study of immunological memory and long-term toxicology  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The human immunodeficiency virus type 1 (HIV-1 regulatory protein, Nef, is an attractive vaccine target because it is involved in viral pathogenesis, is expressed early in the viral life cycle and harbors many T and B cell epitopes. Several clinical trials include gene-based vaccines encoding this protein. However, Nef has been shown to transform certain cell types in vitro. Based on these findings we performed a long-term toxicity and immunogenicity study of Nef, encoded either by Modified Vaccinia virus Ankara or by plasmid DNA. BALB/c mice were primed twice with either DNA or MVA encoding Nef and received a homologous or heterologous boost ten months later. In the meantime, the Nef-specific immune responses were monitored and at the time of sacrifice an extensive toxicological evaluation was performed, where presence of tumors and other pathological changes were assessed. Results The toxicological evaluation showed that immunization with MVAnef is safe and does not cause cellular transformation or other toxicity in somatic organs. Both DNAnef and MVAnef immunized animals developed potent Nef-specific cellular responses that declined to undetectable levels over time, and could readily be boosted after almost one year. This is of particular interest since it shows that plasmid DNA vaccine can also be used as a potent late booster of primed immune responses. We observed qualitative differences between the T cell responses induced by the two different vectors: DNA-encoded nef induced long-lasting CD8+ T cell memory responses, whereas MVA-encoded nef induced CD4+ T cell memory responses. In terms of the humoral immune responses, we show that two injections of MVAnef induce significant anti-Nef titers, while repeated injections of DNAnef do not. A single boost with MVAnef could enhance the antibody response following DNAnef prime to the same level as that observed in animals immunized repeatedly with MVAnef. We also demonstrate the possibility to boost HIV-1 Nef-specific immune responses using the MVAnef construct despite the presence of potent anti-vector immunity. Conclusion This study shows that the nef gene vectored by MVA does not induce malignancies or other adverse effects in mice. Further, we show that when the nef gene is delivered by plasmid or by a viral vector, it elicits potent and long-lasting immune responses and that these responses can be directed towards a CD4+ or a CD8+ T cell response depending on the choice of vector.

Engström Gunnel

2007-07-01

293

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aims. Other stars are known to have magnetic cycles similar to that of the Sun. The relationship between these activity variations and the observed radial-velocity is still not satisfactorily understood. In this first paper our aim is to assess the long-term activity variations in the low end of the main sequence, having in mind a planetary search perspective. Methods. We used a sample of 30 M0-M5.5 stars from the HARPS M-dwarf planet search program with a median timespan of...

Da Silva, J. Gomes; Santos, N. C.; Bonfils, X.; Delfosse, X.; Forveille, T.; Udry, S.

2011-01-01

294

Long Term Evolution (LTE)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Opinnäytetyön tarkoituksena on perehtyä LTE- (Long Term Evolution) järjestelmään. LTE on 3GPP:n (3rd Generation Partnership Project) kehittämä standardi, jonka tavoitteena on taata nopea ja toimiva matkaviestinverkko käyttäjämäärien sekä siirrettävän datan määrän ja laatuvaatimusten kasvaessa jatkuvasti. LTE käyttää downlink-suunnassa OFDMA-tekniikkaa (Orthogonal frequency division multiple access) ja uplink-suunnassa SC-FDMA-tekniikkaa (single carrier frequency divi...

To?ller, Markus

2012-01-01

295

Long-Term Collections  

CERN Multimedia

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.

Comité des collectes à long terme

2011-01-01

296

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices  

CERN Document Server

Aims. Other stars are known to have magnetic cycles similar to that of the Sun. The relationship between these activity variations and the observed radial-velocity is still not satisfactorily understood. In this first paper our aim is to assess the long-term activity variations in the low end of the main sequence, having in mind a planetary search perspective. Methods. We used a sample of 30 M0-M5.5 stars from the HARPS M-dwarf planet search program with a median timespan of observations of 5.2 years. We computed chromospheric activity indicators based on the Ca II H and K, H{\\alpha}, He I D3, and Na I D1 and D2 lines. All data were binned in to average out undesired effects such as rotationally modulated atmospheric inhomogeneities. We searched for long-term variability of each index and determined the correlations between them. Results. While the S_CaII, H{\\alpha}, and Na I indices showed significant variability for a fraction of our stellar sample (39%, 33%, and 37%, respectively), only 10% of our stars pr...

da Silva, J Gomes; Bonfils, X; Delfosse, X; Forveille, T; Udry, S

2011-01-01

297

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program II. Activity and radial velocity  

CERN Document Server

Due to their low mass and luminosity, M dwarfs are ideal targets if one hopes to find low-mass planets similar to Earth by using the radial velocity (RV) method. However, stellar magnetic cycles could add noise or even mimic the RV signal of a long-period companion. Following our previous work that studied the correlation between activity cycles and long-term RV variations for K dwarfs we now expand that research to the lower-end of the main sequence. Our objective is to detect any correlations between long-term activity variations and the observed RV of a sample of M dwarfs. We used a sample of 27 M-dwarfs with a median observational timespan of 5.9 years. The cross-correlation function (CCF) with its parameters RV, bisector inverse slope (BIS), full-width-at-half- maximum (FWHM) and contrast have been computed from the HARPS spectrum. The activity index have been derived using the Na I D doublet. These parameters were compared with the activity level of the stars to search for correlations. We detected RV v...

da Silva, J Gomes; Bonfils, X; Delfosse, X; Forveille, T; Udry, S; Dumusque, X; Lovis, C

2012-01-01

298

A New Framework for Adaptive Sampling and Analysis During Long-Term Monitoring and Remedial Action Management  

Energy Technology Data Exchange (ETDEWEB)

DOE and other Federal agencies are making a significant investment in the development of field analytical techniques, nonintrusive technologies, and sensor technologies that will have a profound impact on the way environmental monitoring is conducted. Monitoring and performance evaluation networks will likely be base on suites of in situ sensors, with physical sampling playing a much more limited role. Designing and using these types of networks effectively will require development of a new paradigm for sampling and analysis of remedial actions, which is the overall goal of this project.

Minsker, Barbara; Albert Valocchi; Barbara Bailey

2008-01-27

299

Collectes à long terme  

CERN Multimedia

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...

Collectes à long terme

2014-01-01

300

Long-Term Record of Sampled Disturbances in Northern Eurasian Boreal Forest from Pre-2000 Landsat Data  

Directory of Open Access Journals (Sweden)

Full Text Available Stand age distribution is an important descriptor of boreal forest structure, which is directly linked to many ecosystem processes including the carbon cycle, the land–atmosphere interaction and ecosystem services, among others. Almost half of the global boreal biome is located in Russia. The vast extent, remote location, and limited accessibility of Russian boreal forests make remote sensing the only feasible approach to characterize these forests to their full extent. A wide variety of satellite observations are currently available to monitor forest change and infer its structure; however, the period of observations is mostly limited to the 2000s era. Reconstruction of wall-to-wall maps of stand age distribution requires merging longer-term site observations of forest cover change available at the Landsat scale at a subset of locations in Russia with the wall-to-wall coverage available from coarse resolution satellites since 2000. This paper presents a dataset consisting of a suite of multi-year forest disturbance samples and samples of undisturbed forests across Russia derived from Landsat Thematic Mapper and Enhanced Thematic Mapper Plus images from 1985 to 2000. These samples provide crucial information regarding disturbance history in selected regions across the Russian boreal forest and are designed to serve as a training and/or validation dataset for coarse resolution data products. The overall accuracy and Kappa coefficient for the entire sample collection was found to be 83.98% and 0.83%, respectively. It is hoped that the presented dataset will benefit subsequent studies on a variety of aspects of the Russian boreal forest, especially in relation to the carbon budget and climate.

Dong Chen

2014-06-01

 
 
 
 
301

Externalizing Psychopathology and Marital Adjustment in Long-Term Marriages: Results from a Large Combined Sample of Married Couples  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The current study evaluated the associations between externalizing psychopathology and marital adjustment in a combined sample of 1,805 married couples. We further considered the role of personality in these associations, as personality has been found to predict both the development of externalizing psychopathology as well as marital distress and instability. Diagnostic interviews assessed Conduct Disorder, adult symptoms of Antisocial Personality Disorder, and Alcohol Dependence. Personality...

Humbad, Mikhila N.; Donnellan, M. Brent; Iacono, William G.; Burt, S. Alexandra

2010-01-01

302

Age-related defects in spatial memory are correlated with defects in the late phase of hippocampal long-term potentiation in vitro and are attenuated by drugs that enhance the cAMP signaling pathway  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To study the physiological and molecular mechanisms of age-related memory loss, we assessed spatial memory in C57BL/B6 mice from different age cohorts and then measured in vitro the late phase of hippocampal long-term potentiation (L-LTP). Most young mice acquired the spatial task, whereas only a minority of aged mice did. Aged mice not only made significantly more errors but also exhibited greater individual differences. Slices from the hippocampus of aged mice exhibited significantly reduce...

Bach, Mary Elizabeth; Barad, Mark; Son, Hyeon; Zhuo, Min; Lu, Yun-fei; Shih, Robert; Mansuy, Isabelle; Hawkins, Robert D.; Kandel, Eric R.

1999-01-01

303

Prenatal diagnosis of trisomy 20 by chorionic villus sampling (CVS): a case report with long-term outcome.  

Science.gov (United States)

A case of prenatally diagnosed non-mosaic trisomy 20 in cells cultured from a chorionic villus sample (CVS)is presented. The term placental karyotype was also non-mosaic trisomy 20. The karyotype of the newborn was 46,XY/47,XY,+20 in foreskin cultures and in a second skin culture; blood lymphocyte culture was 46,XY. Aside from diffuse, hypopigmentary swirls along the lines of Blaschko observed on his extremities and trunk, referred to as hypomelanosis of Ito, the patient is clinically normal at 8 3/4 years of age. In addition, he is one of the oldest reported cases of mosaic trisomy 20 confirmed after birth for which the clinical outcome has been monitored. This case demonstrates that these trisomy 20 findings are compatible with normal psychomotor development and phenotype. PMID:11787033

Steinberg Warren, N; Soukup, S; King, J L; St J Dignan, P

2001-12-01

304

[Stapedectomy: long term results].  

Science.gov (United States)

Stapedectomy, with its most innovatory variations, constitutes the treatment of choice for otoesclerosis. Short term results are spectacular, getting GAP closures of less than 5 dB approximatelly in 94% patients, variations depending on the authors. Long term follow up check results show a gradual auditory deterioration. The aim of this study is to audiometric evolution of patients operated of stapedectomy 7 to 10 years ago in our department and to correlate the results with those obtained by other authors, in an attempt to unify conclusions. PMID:12185900

Hernández Montero, E; Fraile Rodrigo, J; Marín Garrido, C; Sampériz, L Carmen; Llorente Arenas, E; Naya Gálvez, M J; Ortiz García, A

2002-04-01

305

Estimating the long-term effects of stocking domesticated trout into wild brown trout ( Salmo trutta ) populations : an approach using microsatellite DNA analysis of historical and contemporary samples  

DEFF Research Database (Denmark)

Indigenous salmonid fish gene pools are affected by domesticated conspecifics, derived from aquaculture escapes and deliberate releases. Variability was examined at nine microsatellite loci in order to assess the long-term impact of stocking domesticated trout in two brown trout populations. The study was based on analysis of two historical samples (194556), represented by old scale collections, and seven contemporary samples (1986-2000). In one population historical and contemporary samples were remarkably genetically similar despite more than a decade of intense stocking. Estimation of admixture proportions showed a small genetic contribution from domesticated trout (approximately 6%), and individual admixture analysis demonstrated a majority of nonadmixed individuals. The expected genetic contribution by domesticated trout was 64%, assessed from the number of stocked trout and assuming equal survival and reproductive performance of wild and domesticated trout. This demonstrates poor performance and low fitness of domesticated trout in the wild. In another population there was a strong genetic contribution from domesticated trout (between 57% and 88% in different samples), both in samples from a broodstock thought to represent the indigenous population and in a sample of wild spawners. Survival of domesticated trout and admixture with indigenous fish in the broodstock and subsequent stocking into the river, combined with a low population size of native trout relative to the number of stocked trout, could explain the observed introgression. Few nonadmixed individuals remained in the introgressed population, and I discuss how individual admixture analysis can be used to identify and conserve nonintrogressed remains of the population.

Hansen, Michael MØller

2002-01-01

306

Mann-Kendall Test for Analysis of Groundwater Contaminant Plume Stability and Evaluation of Sampling Frequency for Long-Term Monitoring - 13233  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a spreadsheet-based approach for applying the Mann-Kendall (MK) Test to identify statistically significant increasing or decreasing concentration trends, stable concentration trends (not increasing or decreasing), and indeterminate concentration trends (no trend) defined by time-series groundwater monitoring data for inorganic, organic, or radiological contaminants. The approach has been applied in support of ongoing long-term monitoring (LTM) of groundwater contamination at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee and elsewhere on the DOE Oak Ridge Reservation (ORR), and has proven effective at minimizing subjective bias in the evaluation and interpretation of contaminant concentration trend data. Application of the approach for the purposes of optimizing groundwater sampling frequency for LTM also is outlined. (authors)

Walker, Jeffrey R.; Harrison, Toby R. [Elvado Environmental LLC, 9724 Kingston Pike, Suite 603, Knoxville, TN 37922 (United States)

2013-07-01

307

Mann-Kendall Test for Analysis of Groundwater Contaminant Plume Stability and Evaluation of Sampling Frequency for Long-Term Monitoring - 13233  

International Nuclear Information System (INIS)

This paper describes a spreadsheet-based approach for applying the Mann-Kendall (MK) Test to identify statistically significant increasing or decreasing concentration trends, stable concentration trends (not increasing or decreasing), and indeterminate concentration trends (no trend) defined by time-series groundwater monitoring data for inorganic, organic, or radiological contaminants. The approach has been applied in support of ongoing long-term monitoring (LTM) of groundwater contamination at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee and elsewhere on the DOE Oak Ridge Reservation (ORR), and has proven effective at minimizing subjective bias in the evaluation and interpretation of contaminant concentration trend data. Application of the approach for the purposes of optimizing groundwater sampling frequency for LTM also is outlined. (authors)

308

Evaluation of the Quality of Life in Adult Cancer Survivors (QLACS scale for long-term cancer survivors in a sample of breast cancer survivors  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background This paper evaluates psychometric properties of a recently developed measure focusing on the health-related quality of life (HRQL of long-term cancer survivors, the Quality of Life in Adult Survivors scale (QLACS, in a sample of breast cancer survivors. This represents an important area of study, given the large number of breast cancer patients surviving many years post diagnosis. Methods Analyses are based on an 8-year follow-up of a sample of breast cancer survivors who participated in an earlier study conducted in 1995. Participants were re-contacted in 2003 and those who were reachable and agreed to participate (n = 94 were surveyed using a variety of measures including the QLACS. Additional follow-up surveys were conducted 2 weeks and one year later. Psychometric tests of the QLACS included test-retest reliability, concurrent and retrospective validity, and responsiveness. Results The QLACS domain and summary scores showed good test-retest reliability (all test-retest correlations were above .7 and high internal consistency. The Generic Summary Score showed convergent validity with other measures designed to assess generic HRQL. The Cancer-Specific Summary score exhibited divergent validity with generic HRQL measures, but not a cancer-related specific measure. The QLACS Cancer-Specific Summary Score demonstrated satisfactory predictive validity for factors that were previously shown to be correlated with HRQL. The QLACS generally demonstrated a high level of responsiveness to life changes. Conclusion The QLACS may serve as a useful measure for assessing HRQL among long-term breast cancer survivors that are not otherwise captured by generic measures or those specifically designed for newly diagnosed patients.

Foley Kristie

2006-12-01

309

Combined meningococcal serogroup A and W135 outer-membrane vesicles activate cell-mediated immunity and long-term memory responses against non-covalent capsular polysaccharide A.  

Science.gov (United States)

Outer-membrane vesicles (OMVs) have inherent adjuvant properties, and many vaccines use OMV as vaccine components. Utilizing the adjuvant properties of OMV could lead to the formulation of vaccines that are less expensive and potentially more immunogenic than covalently conjugated polysaccharide vaccines. We evaluated the adjuvant effect in Balb/c mice of combinations of OMV from Neisseria meningitidis serogroup A and W135 as compared to that of the non-covalently conjugated capsular polysaccharide A. Both antigens were adsorbed onto aluminum hydroxide. The mice were given a booster dose of plain polysaccharide A to stimulate an immunologic memory response. Subclasses determination and cytokine assays demonstrated the capacity of OMV to induce a IgG2a/IgG2b isotype profile and IFN-? production, suggesting the induction of a Th1 pattern immune response. Lymphoproliferative responses to OMVs were high, with affinity maturation of antibodies observed. Bactericidal titers after the booster dose were also observed. Memory B cells and long-term memory T cells were also detected. The results of this study indicate that combined meningococcal serogroup A and W135 OMV can activate cell-mediated immunity and induce a long-term memory response. PMID:23660844

Romeu, Belkis; Lastre, Miriam; García, Luis; Cedré, Bárbara; Mandariote, Aleida; Fariñas, Mildrey; Oliva, Reynaldo; Rosenqvist, Einar; Pérez, Oliver

2014-01-01

310

Long-term effects of CO2 on the mechanical behaviour of faults - a study of samples from a natural CO2 analogue (Entrada Sandstone, Utah, USA)  

Science.gov (United States)

In an attempt to reduce CO2 emissions, CO2 capture and storage in depleted oil and gas reservoirs is seen as one of the most important mitigation strategies. However, in order to achieve safe storage on geological timescales, it is key to maintain integrity of the caprock and any faults penetrating the seal. One of the largest uncertainties lies in the prediction of the effects of fluid-rock interaction on the mechanical integrity and sealing capacity of the reservoir-seal system in the very long term, i.e. on timescales of the order of 103 or 104 years. As chemical interactions in the rock/CO2/brine system are slow, their long-term effects on rock composition, microstructure, mechanical properties and transport properties cannot be properly reproduced in laboratory experiments. One way of addressing this issue is to conduct experiments on reservoir, caprock and fault rock samples taken from natural CO2 reservoir-seal systems, which can serve as natural analogues for CO2 storage fields. The transport and mechanical properties of these rock samples, which have reacted with CO2 over geological timescales, can then be compared with data obtained for laterally equivalent materials that are unaffected by CO2. The observed changes in rock properties can subsequently be used as input for numerical models aimed at assessing the long-term effects of CO2 on reservoir compaction, caprock damage, fault reactivation and fault permeability. We assessed the mechanical behaviour and transport properties of fault rocks. To this end, we performed triaxial direct shear experiments at room temperature under nominally dry conditions, at normal stresses up to 90 MPa and shear velocities of 0.22 -10.9 ?m/s. Simulated fault rocks were prepared by crushing material obtained from surface outcrops of the Entrada Sandstone, one of the CO2-bearing formations from an analogue field under the Colorado Plateau, Utah, USA. Three types of starting material were obtained: 1) red-coloured samples consisting mainly of quartz and feldspar, some minor clay minerals and hematite/goethite grain coatings, 2) yellow-coloured, (so-called) bleached samples additionally containing various amounts of kaolinite, calcite and dolomite, and 3) heavily cemented samples from the surface outcrop of the fault core of the Little Grand Wash Fault, containing a high percentage of carbonates (> 40 wt%). Previous work demonstrates that the bleached samples and the material from the fault were altered as a result of interaction with CO2-rich fluids. Over the experimental range investigated, we measured friction coefficients of 0.55-0.85 for unbleached material and 0.55-0.80 for bleached material, while the fault core material showed higher friction coefficients (0.60-0.95), all showing a minor decrease with decreasing shear velocity and normal stress. Almost all samples showed velocity-strengthening slip behaviour. Overall, the frictional behaviour of Entrada Sandstone does not seem to be strongly influenced by CO2/brine/rock interactions.

Hangx, S. J. T.; Bakker, E.; Spiers, C. J.

2012-04-01

311

Mini-CORK observatories using the MeBo seafloor drill rig - a new development for long-term data acquisition and sampling in shallow boreholes  

Science.gov (United States)

State of the art technology for long-term monitoring of fluid migration within the sea floor is the sealing of a borehole with a Circulation Obviation Retrofit Kit (CORK) after sensor installation and/or fluid sampling devices within the drill string. However, the combined used of a drilling vessels and a remotely operated drilling (ROV) required for a CORK installation in the deep sea is a costly exercise that limits the number of monitoring stations installed. Robotic sea floor drill rigs are a cost effective alternative for shallow drillings down to 50-100 m below sea floor. Here we present a Mini-CORK system that is developed for installation with the sea floor drill rig MeBo. This rig was developed at MARUM Research Centre, University of Bremen in 2005 and can sample the sea floor in water depths up to 2000 m. The MeBo is deployed on the seabed and remotely controlled from the vessel. All required drill tools for wire-line core drilling down to 70 m below sea floor are stored on two rotating magazines and can be loaded below the top drive drill head for assembling the drill string. For one of the upcoming cruises with RV Sonne offshore Japan (Nankai Trough accretionary prism), MeBo will be used for the first time to place observatories. Two different designs have been developed. The first, relatively simple long-term device resembles a MeBo drill rod in its geometry, and contains a pressure and temperature transducer in the borehole plus an identical pair of transducers for seafloor reference. The device also contains a data logger, battery unit, and an acoustic modem so that data can be downloaded at any time from a ship of opportunity. The key element at the base of the observatory rod is a seal at the conical thread to separate the borehole hydraulically from the overlying water body. It is realized by an adapter, which also contains a hotstab hydraulic connection and an electrical connection. The second observatory device is a seafloor unit, which replaces part of the first unit and which is deployed by ROV. In essence, the upper portion of the former observatory is taken away by ROV, and an umbilical containing hydraulic lines and tubing to withdraw formation water from the borehole is plugged into the hotstab female adapter by ROV. At the far end, the umbilical is connected to a seafloor unit with battery power, data logger, P and T transducers, and the same acoustic modem as the former one. In addition, the latter contains osmo samplers and biological chambers (FLOCS) for in situ sampling and experiments. After the envisaged deployment period, the entire unit is replaced while an identical one is prepared on deck and lowered from the vessel. In theory, the MeBo hole infinitely serves as an access to depth since no electronic, but only tubing is lowered into the (open) hole. In summary, long-term borehole installations with MeBo offer an affordable way to measure key physical properties over time and sample the formation fluids for geochemistry and microbiology (in case of the second, ROV-deployed CORK).

Kopf, A.; Freudenthal, T.; Ratmeyer, V.; Bergenthal, M.; Renken, J.; Zabel, M.; Wefer, G.

2011-12-01

312

Long-term effects of CO2 on the mechanical behaviour of faults - a study of samples from a natural CO2 analogue (Entrada Sandstone, Utah, USA)  

Science.gov (United States)

CO2 capture followed by storage in depleted oil and gas reservoirs is currently seen as one of the most promising CO2-mitigation strategies. An important issue in relation to long-term CO2 storage is the prediction of the effects of fluid-rock interaction on the mechanical integrity and sealing capacity of the reservoir-seal system, on timescales of the order of 103 or 104 years. However, the assumed chemical interactions in the rock/CO2/brine system are slow, so that their long-term effects on rock composition, microstructure, mechanical properties and transport properties cannot be reproduced in laboratory experiments. One way to address this is to study the effects of reactions in natural CO2 reservoirs, using a so-called natural analogue approach. We tackled the question of how reactions characterizing natural CO2 fields affect fault friction, fault reactivation potential and seismic vs. aseismic slip stability, as well as transmissivity evolution during and after fault reactivation. Simulated fault gouges were prepared by crushing material obtained from surface outcrops of the Entrada Sandstone, a locally CO2-bearing formation forming an analogue field under the Colorado Plateau, Utah, USA . We used three types of starting material: 1) CO2 unaffected (unbleached) samples consisting mainly of quartz and feldspar, 2) "bleached" samples, and 3) heavily cemented/altered fault rock containing a high percentage of carbonates (> 40 wt%). The latter two were altered as a result of interaction with CO2-rich fluids over geological time. We performed triaxial direct shear experiments on these materials at room temperature under nominally dry conditions, at normal stresses up to 90 MPa and shear velocities of 0.22 -10.9 ?m/s. The results of the experiments yielded friction coefficients (?= ?/?n) of 0.55-0.85 for unbleached sandstone gouge and 0.45-0.80 for bleached material, while the fault material showed systematically higher friction coefficients (0.60-0.95). All simulated gouges showed a decrease in friction coefficient of 20-30% with increasing normal stress up to 90 MPa, with almost all samples showing velocity-strengthening (stable) slip behaviour. Permeability measurements show only minor changes during shear. Overall, our results demonstrated that higher (CO2-related) carbonate content leads to higher frictional strength and increased velocity strengthening (slip stability), notably at low normal stresses. However, preliminary results recently obtained at elevated temperatures show that carbonate-rich samples show velocity-weakening behaviour at 100°C, which is in line with previous studies on pure carbonates. A natural analogue from The Netherlands shows similar results for the chemical alteration of reservoir rock by the presence of naturally long-term stored CO2.

Bakker, E.; Hangx, S.; Spiers, C. J.

2012-12-01

313

Cytoplasmic to nuclear localization of fatty-acid binding protein correlates with specific forms of long-term memory in Drosophila  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We recently reported evidence implicating fatty-acid binding protein (Fabp) in the control of sleep and memory formation. We used Drosophila melanogaster to examine the relationship between sleep and memory through transgenic overexpression of mouse brain-Fabp, Fabp7, or the Drosophila Fabp homolog, (dFabp). The key findings are that 1) a genetically induced increase in daytime consolidated sleep (naps) correlates with an increase in cognitive performance, and 2) a late “window” of memory...

Gerstner, Jason R.; Vanderheyden, William M.; Shaw, Paul J.; Landry, Charles F.; Yin, Jerry Cp

2011-01-01

314

LONG TERM COLLECTIONS  

CERN Multimedia

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 ...

STAFF ASSOCIATION

2010-01-01

315

Long term morphological modelling  

DEFF Research Database (Denmark)

A morphological modelling concept for long term nearshore morphology is proposed and examples of its application are presented and discussed. The model concept combines parameterised representations of the cross-shore morphology, with a 2DH area model for waves, currents and sediment transport in the surf zone. Two parameterization schemes are tested for two different morphological phenomena: 1) Shoreline changes due to the presence of coastal structures and 2) alongshore migration of a nearshore nourishment and a bar by-passing a harbour. In the case of the shoreline evolution calculations, a concept often used in one-line modelling of cross-shore shifting of an otherwise constant shape cross-shore profile is applied for the case of a groyne and a detached breakwater. In the case of alongshore bar/nourishment migration an alternative parameterization is adopted. All examples are presented, analysed and discussed with respect to the question of realistic representation, time scale and general applicability ofthe model concept.

Kristensen, Sten EsbjØrn Technical University of Denmark,

2010-01-01

316

Mice Overexpressing Type 1 Adenylyl Cyclase Show Enhanced Spatial Memory Flexibility in the Absence of Intact Synaptic Long-Term Depression  

Science.gov (United States)

There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca[superscript 2+]-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated…

Zhang, Ming; Wang, Hongbing

2013-01-01

317

Long-term patterns and feeding sites of southern green stink bug (Hemiptera: Pentatomidae) in Hawaii macadamia orchards, and sampling for management decisions.  

Science.gov (United States)

Southern green stink bug (Nezara viridula, Hemiptera: Pentatomidae) is a pest of macadamia nuts, causing pitting to kernels by feeding. In spite of its pest status, many aspects of the ecology of this insect in macadamia orchards are poorly understood. This study analyzes long-term N. viridula damage to macadamia nuts and investigates the extent to which damage to nuts occurs in the tree canopy, prior to nut-drop. We show that there are distinct seasonal peaks in damage detected after harvest and that, over six years of data collection, mean damage levels were fairly low, albeit with spikes in damage levels recorded. Sampling nuts at peak harvest periods from different strata in the trees and from the ground showed that incidence of damaged nuts within the canopy was typically half as high as on the fallen nuts. Damage to fallen nuts may have occurred prior to nut-drop, and continued to accumulate after nut-drop. These results show that management of N. viridula within macadamia canopies, as opposed to only on fallen nuts, is important. A sampling procedure and predictive model for estimating late-season damage based on early-season damage samples is provided. The model uses January and March damage measurements (based on samples with set level of accuracy), mean temperature and month of the year for which damage is predicted. Early-season damage of 6-10% predicts late-season damage levels that should justify N. viridula suppression based on the nominal threshold (13% damage) used by kernel processors to reject nuts based on damage. PMID:17997869

Wright, M G; Follett, P A; Golden, M

2007-12-01

318

Methamphetamine-induced short-term increase and long-term decrease in spatial working memory affects protein Kinase M zeta (PKM?), dopamine, and glutamate receptors  

Science.gov (United States)

Methamphetamine (MA) is a toxic, addictive drug shown to modulate learning and memory, yet the neural mechanisms are not fully understood. We investigated the effects of 2 weekly injections of MA (30 mg/kg) on working memory using the radial 8-arm maze (RAM) across 5 weeks in adolescent-age mice. MA-treated mice show a significant improvement in working memory performance 1 week following the first MA injection compared to saline-injected controls. Following 5 weeks of MA abstinence mice were re-trained on a reference and working memory version of the RAM to assess cognitive flexibility. MA-treated mice show significantly more working memory errors without effects on reference memory performance. The hippocampus and dorsal striatum were assessed for expression of glutamate receptors subunits, GluA2 and GluN2B; dopamine markers, dopamine 1 receptor (D1), dopamine transporter (DAT) and tyrosine hydroxylase (TH); and memory markers, protein kinase M zeta (PKM?) and protein kinase C zeta (PKC?). Within the hippocampus, PKM? and GluA2 are both significantly reduced after MA supporting the poor memory performance. Additionally, a significant increase in GluN2B and decrease in D1 identifies dysregulated synaptic function. In the striatum, MA treatment increased cytosolic DAT and TH levels associated with dopamine hyperfunction. MA treatment significantly reduced GluN2B while increasing both PKM? and PKC? within the striatum. We discuss the potential role of PKM?/PKC? in modulating dopamine and glutamate receptors after MA treatment. These results identify potential underlying mechanisms for working memory deficits induced by MA. PMID:25566006

Braren, Stephen H.; Drapala, Damian; Tulloch, Ingrid K.; Serrano, Peter A.

2014-01-01

319

Methamphetamine-induced short-term increase and long-term decrease in spatial working memory affects protein Kinase M zeta (PKM?), dopamine, and glutamate receptors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Methamphetamine (MA) is a toxic, addictive drug shown to modulate learning and memory, yet the neural mechanisms are not fully understood. We investigated the effects of 2 weekly injections of MA (30 mg/kg) on working memory using the radial 8-arm maze (RAM) across 5 weeks in adolescent-age mice. MA-treated mice show a significant improvement in working memory performance 1 week following the first MA injection compared to saline-injected controls. Following 5 weeks of MA abstinence mice were...

Braren, Stephen H.; Drapala, Damian; Tulloch, Ingrid K.; Serrano, Peter A.

2014-01-01

320

Long-term testing  

Science.gov (United States)

Land-based gas turbines are significantly different from automotive gas turbines in that they are designed to operate for 50,000 h or greater (compared to 5,000-10,000 h). The primary goal of this research is to determine the long-term survivability of ceramic materials for industrial gas turbine applications. Research activities in this program focus on the evaluation of the static tensile creep and stress rupture (SR) behavior of three commercially available structural ceramics which have been identified by the gas turbine manufacturers as leading candidates for use in industrial gas turbines. For each material investigated, a minimum of three temperatures and four stresses will be used to establish the stress and temperature sensitivities of the creep and SR behavior. Because existing data for many candidate structural ceramics are limited to testing times less than 2,000 h, this program will focus on extending these data to times on the order of 10,000 h, which represents the lower limit of operating time anticipated for ceramic blades and vanes in gas turbine engines. A secondary goal of the program will be to investigate the possibility of enhancing life prediction estimates by combining interrupted tensile SR tests and tensile dynamic fatigue tests in which tensile strength is measured as a function of stressing rate. The third goal of this program will be to investigate the effects of water vapor upon the SR behavior of the three structural ceramics chosen for the static tensile studies by measuring the flexural strength as a function of stressing rate at three temperatures.

Ferber, M.; Graves, G. A., Jr.

 
 
 
 
321

Surface analysis of the central and top part of a 1984 JET graphite limiter and of 1984 JET long term samples  

International Nuclear Information System (INIS)

The JET graphite limiter (top and central part) from octant IV as well as long term samples (LTS) and a bellow protection plate all exposed to plasma discharges during the 1984 experimental period have been investigated by means of surface layer analyses techniques. The limiter tiles show characteristic differences in the deposition of metals compared to the 1983 limiter reflecting the higher power loads from the plasma achieved in 1984. Analysis of the LTS reveals a close correlation between erosion sources at the vessel walls of JET and the redeposition areas. This indicates that a major part of the metals eroded at the limiter surface or the wall during normal discharges may not enter the central plasma, but is immediately redeposited close to the area of erosion. Deuterium was found on the sides of the graphite limiter with concentrations exceeding the amount, which could be deposited by simple implantation by at least an order of magnitude. This incidates a codeposition of carbon and deuterium at those areas. (orig.)

322

MHC class I immune proteins are critical for hippocampus-dependent memory and gate NMDAR-dependent hippocampal long-term depression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that specific immune proteins, members of the major histocompatibility complex class I (MHC class I), are essential for normal hippocampus-dependent memory, and...

Nelson, P. Austin; Sage, Jennifer R.; Wood, Suzanne C.; Davenport, Christopher M.; Anagnostaras, Stephan G.; Boulanger, Lisa M.

2013-01-01

323

Beneficial Effects of Tianeptine on Hippocampus-Dependent Long-Term Memory and Stress-Induced Alterations of Brain Structure and Function  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tianeptine is a well-described antidepressant which has been shown to prevent stress from producing deleterious effects on brain structure and function. Preclinical studies have shown that tianeptine blocks stress-induced alterations of neuronal morphology and synaptic plasticity. Moreover, tianeptine prevents stress from impairing learning and memory, and, importantly, demonstrates memory-enhancing properties in the absence of stress. Recent research has indicated that tianeptine works by no...

Carmen Muñoz; Diamond, David M.; Zoladz, Phillip R.

2010-01-01

324

Exercise and Sodium Butyrate Transform a Subthreshold Learning Event into Long-Term Memory via a Brain-Derived Neurotrophic factor-Dependent Mechanism  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We demonstrate that exercise enables hippocampal-dependent learning in conditions that are normally subthreshold for encoding and memory formation, and depends on hippocampal induction of brain-derived neurotrophic factor (BDNF) as a key mechanism. Using a weak training paradigm in an object location memory (OLM) task, we show that sedentary mice are unable to discriminate 24?h later between familiar and novel object locations. In contrast, 3 weeks of prior voluntary exercise...

Intlekofer, Karlie A.; Berchtold, Nicole C.; Malvaez, Melissa; Carlos, Anthony J.; Mcquown, Susan C.; Cunningham, Michael J.; Wood, Marcelo A.; Cotman, Carl W.

2013-01-01

325

LONG TERM COLLECTIONS  

CERN Multimedia

The Committee would like to thank all those, from near and far, who kindly gave donations to the collection organized at the time of the sudden death of our friend and colleague Stephen O'NEALE The sum of 3,615 francs will be sent to the INEPE Association for the education of children in Quito, Ecuador. We are deeply grateful for this gesture from Steve's family and hope that they find comfort in knowing that Steve's memory will live on through the children whose daily lives will be improved by this gift.

2004-01-01

326

Long-term storage of clinical samples in CyMol® medium for PNA- FISH® and culturing from the eSwab™ system  

DEFF Research Database (Denmark)

Objectives: A steadily growing diversity of bacteria is reported in foreign body infections, and culture-independent methods have been shown to supplement established culture methods. Therefore, sampling and preservation of specimens have become an important issue. We report here experience from a prospective clinical study enrolling patients with joint prosthesis-related problems (www.joint-prosthesis-infection-pain.dk). From the patients a range of diagnostic and peroperative specimen types were obtained. Here we report primarily on the utility of different specimen types for culture -independent analytical methods. Methods: Sampling for both culture-dependent and -independent analyses were done over a period of two years. Specimens were transferred directly to the lab, and cultures of tissue biopsies, joint fluid, sonication fluid from the prosthesis components, and eSwab™ (Copan, Italy) were performed within 24 h after sampling. The corresponding specimens for culture-independent methods were storedat -80°C until analyzed in batchs. Specimens for fluorescence in situ hybridization (FISH) analysis were stored for app. one year at -80°C in CyMol® (Copan, Italy), an alcohol based media, before the analyses were conducted. For direct visualization of microorganisms we used both FISH and peptide nucleic acid- fluorescence in situ hybridization (PNA-FISH®, AdvanDx, USA). Both FISH and PNA-FISH® were conducted according to previous publications, with broad range probes. An initial filtration step was performed for some samples in order to concentrate bacteria. Results: We were able to perform FISH and PNA-FISH® on specimens stored for more than one year without further optimization of the hybridization protocol. The broad range probes demonstrated bacteria with a bright signal and a morphology comparable to the isolates obtained by culturing at the time of sampling. The detection limit for both FISH and PNA-FISH® were >10^3 bacteria/mL. With the eSwab™ system we were able to detect a broad range of bacteria including Staphylococcus spp., Streptococcus spp., Enterococcus spp., and Corynebacterium spp. by culture and 16S rRNA gene amplicon sequencing. Conclusion: It is possible to preserve samples for FISH and PNA-FISH® for long-term storage by using CyMol® with an effective detection limit in the order of >10^3 bacteria/mL. Both the morphology and intensity of staining with nucleic acid and PNA probes were distinct. The eSwab™ was a convenient system for documenting a broad range of bacterial pathogens associated with foreign body infections.

Larsen, Lone Heimann; Xu, Yijuan

327

Influence of long-term mineral fertilization on metal contents and properties of soil samples taken from different locations in Hesse, Germany  

Science.gov (United States)

Essential and non-essential metals occur in soils as a result of weathering, industrial processes, fertilization, and atmospheric deposition. Badly adapted cultivation of agricultural soils (declining pH value, application of unsuitable fertilizers) can enhance the mobility of metals and thereby increase their concentrations in agricultural products. As the enrichment of metals in soils occurs over long time periods, monitoring of the long-term impact of fertilization is necessary to assess metal accumulation in agricultural soils. The main objective of this study was to test the effects of different mineral fertilizer variations on soil properties (pH, Corg, and cation exchange capacity (CEC)) and pseudo-total and mobile metal contents of soils after 14 years of fertilizer application and to determine residual effects of the fertilization 8 years after cessation of fertilizer treatment. Soil samples were taken from a field experiment which was carried out at four different locations (210, 260, 360, and 620 m above sea level) in Hesse, Germany. During the study, a significant decrease in soil pH and an evident increase in soil carbon content and cation exchange capacity with fertilization were determined. The CEC of the soils was closely related to their organic C contents. Moreover, pseudo- and mobile metal (Cd, Cu, Mn, Pb, Zn) contents in the soils increased due to application of 14 years of mineral fertilizer treatments (N, P, NP, and NPK) when compared to control plots. Eight years after termination of the fertilization in the soil samples taken from soil profiles of the fertilized plots (NPK) for monitoring the residual effects of the fertilizer application, a decrease of 82.6, 54.2, 48.5, 74.4, and 56.9% in pseudo-total Cd, Cu, Mn, Pb, and Zn contents, respectively, was determined.

Czarnecki, S.; Düring, R.-A.

2015-01-01

328

EUCROMIC (European Collaborative Research on Mosaicism in Chorionic Villus Sampling): New initiatives concerning uniparental disomy research and long-term clinical follow-up  

Energy Technology Data Exchange (ETDEWEB)

Since 1986 the European collaborative study on mosaicism in chorionic villus sampling (CVS), based in Glostrup, Denmark. has been collecting cytogenetic and clinical data on pregnancies in which testing revealed mosaicism or fetal/extrafetal chromosomal discrepancies. From 1986-1992, data on 60,823 samples, including 751 mosaics and 241 nonmosaic discrepancies, was collected. This information has proven helpful in prenatal counseling, by indicating which chromosomes are most often involved in mosaicism, whether the latter is likely to be confirmed in the fetus and/or placenta, and the relationship of cytogenetic results obtained by different culture techniques to pregnancy outcome. Since December 1, 1993 the European collaborative study has been funded by the European Community and by the Swiss government as a concertation project, {open_quotes}EUCROMIC{close_quotes}, a step which has allowed enlargement of the database and broadening of the project goals. Forty-five genetics centers are currently involved in this effort to monitor not only CVS, but changing trends in prenatal diagnosis in Europe. Two ancillary projects, based in Geneva, were initiated in early 1993: long-term clinical follow-up of children born after CVS mosaicism, and a search for uniparental disomy (UPD) in these same children (as well as in abortuses). Clinical data is collected from the initial reporting centers via questionnaires; at the time of writing, clinical follow-up has been obtained for over 250 children liveborn after CVS mosaicism. UPD testing results are received from the individual centers; for those not having the possibility to do the parental origin analyses themselves, testing is offered in one of several EUCROMIC-UPD laboratories.

DeLozier-Blanchet, C.D.; Hahnemann, J.M.; Vejersley, L.O.

1994-09-01

329

MHC Class I Immune Proteins Are Critical for Hippocampus-Dependent Memory and Gate NMDAR-Dependent Hippocampal Long-Term Depression  

Science.gov (United States)

Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that…

Nelson, P. Austin; Sage, Jennifer R.; Wood, Suzanne C.; Davenport, Christopher M.; Anagnostaras, Stephan G.; Boulanger, Lisa M.

2013-01-01

330

The Effect of Insulin and Insulin-Like Growth Factors on Hippocampus- and Amygdala-Dependent Long-Term Memory Formation  

Science.gov (United States)

Recent work has reported that the insulin-like growth factor 2 (IGF2) promotes memory enhancement. Furthermore, impaired insulin or IGF1 functions have been suggested to play a role in the pathogenesis of neurodegeneration and cognitive impairments, hence implicating the insulin/IGF system as an important target for cognitive enhancement and/or…

Stern, Sarah A.; Chen, Dillon Y.; Alberini, Cristina M.

2014-01-01

331

Petrophysical characterization of first ever drilled core samples from an active CO2 storage site, the German Ketzin Pilot Site - Comparison with long term experiments  

Science.gov (United States)

Petrophysical properties like porosity and permeability are key parameters for a safe long-term storage of CO2 but also for the injection operation itself. These parameters may change during and/or after the CO2 injection due to geochemical reactions in the reservoir system that are triggered by the injected CO2. Here we present petrophysical data of first ever drilled cores from a newly drilled well at the active CO2 storage site - the Ketzin pilot site in the Federal State of Brandenburg, Germany. By comparison with pre-injection baseline data from core samples recovered prior to injection, the new samples provide the unique opportunity to evaluate the impact of CO2 on pore size related properties of reservoir and cap rocks at a real injection site under in-situ reservoir conditions. After injection of 61 000 tons CO2, an additional well was drilled and new rock cores were recovered. In total 100 core samples from the reservoir and the overlaying caprock were investigated by NMR relaxation. Permeability of 20 core samples was estimated by nitrogen and porosity by helium pycnometry. The determined data are comparable between pre-injection and post-injection core samples. The lower part of the reservoir sandstone is unaffected by the injected CO2. The upper part of the reservoir sandstone shows consistently slightly lower NMR porosity and permeability values in the post-injection samples when compared to the pre-injection data. This upper sandstone part is above the fluid level and CO2 present as a free gas phase and a possible residual gas saturation of the cores distorted the NMR results. The potash-containing drilling fluid can also influence these results: NMR investigation of twin samples from inner and outer parts of the cores show a reduced fraction of larger pores for the outer core samples together with lower porosities and T2 times. The drill mud penetration depth can be controlled by the added fluorescent tracer. Due to the heterogeneous character of the Stuttgart Formation it is difficult to estimate definite CO2 induced changes from petrophysical measurements. The observed changes are only minor. Several batch experiments on Ketzin samples drilled prior injection confirm the results from investigation of the in-situ rock cores. Core samples of the pre-injection wells were exposed to CO2 and brine in autoclaves over various time periods. Samples were characterized prior to and after the experiments by NMR and Mercury Injection Porosimetry (MIP). The results are consistent with the logging data and show only minor change. Unfortunately, also in these experiments observed mineralogical and petrophysical changes were within the natural heterogeneity of the Ketzin reservoir and precluded unequivocal conclusions. However, given the only minor differences between post-injection well and pre-injection well, it is reasonable to assume that the potential dissolution-precipitation processes appear to have no severe consequences on reservoir and cap rock integrity or on the injection behaviour. This is also in line with the continuously recorded injection operation parameter. These do not point to any changes in reservoir injectivity.|

Zemke, Kornelia; Liebscher, Axel

2014-05-01

332

Field-Based Evaluation of Two Herbaceous Plant Community Composition Sampling Methods for Long-Term Monitoring in Northern Great Plains National Parks  

Science.gov (United States)

The Northern Great Plains Inventory & Monitoring (I&M) Network (Network) of the National Park Service (NPS) consists of 13 NPS units in North Dakota, South Dakota, Nebraska, and eastern Wyoming. The Network is in the planning phase of a long-term program to monitor the health of park ecosystems. Plant community composition is one of the 'Vital Signs,' or indicators, that will be monitored as part of this program for three main reasons. First, plant community composition is information-rich; a single sampling protocol can provide information on the diversity of native and non-native species, the abundance of individual dominant species, and the abundance of groups of plants. Second, plant community composition is of specific management concern. The abundance and diversity of exotic plants, both absolute and relative to native species, is one of the greatest management concerns in almost all Network parks (Symstad 2004). Finally, plant community composition reflects the effects of a variety of current or anticipated stressors on ecosystem health in the Network parks including invasive exotic plants, large ungulate grazing, lack of fire in a fire-adapted system, chemical exotic plant control, nitrogen deposition, increased atmospheric carbon dioxide concentrations, and climate change. Before the Network begins its Vital Signs monitoring, a detailed plan describing specific protocols used for each of the Vital Signs must go through rigorous development and review. The pilot study on which we report here is one of the components of this protocol development. The goal of the work we report on here was to determine a specific method to use for monitoring plant community composition of the herb layer (< 2 m tall).

Symstad, Amy J.; Wienk, Cody L.; Thorstenson, Andy

2006-01-01

333

Beneficial Effects of Tianeptine on Hippocampus-Dependent Long-Term Memory and Stress-Induced Alterations of Brain Structure and Function  

Directory of Open Access Journals (Sweden)

Full Text Available Tianeptine is a well-described antidepressant which has been shown to prevent stress from producing deleterious effects on brain structure and function. Preclinical studies have shown that tianeptine blocks stress-induced alterations of neuronal morphology and synaptic plasticity. Moreover, tianeptine prevents stress from impairing learning and memory, and, importantly, demonstrates memory-enhancing properties in the absence of stress. Recent research has indicated that tianeptine works by normalizing glutamatergic neurotransmission, a mechanism of action that may underlie its effectiveness as an antidepressant. These findings emphasize the value in focusing on the mechanisms of action of tianeptine, and specifically, the glutamatergic system, in the development of novel pharmacotherapeutic strategies in the treatment of depression.

Carmen Muñoz

2010-10-01

334

Long-term environmental stewardship.  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Supplemental Information Source Document is to effectively describe Long-Term Environmental Stewardship (LTES) at Sandia National Laboratories/New Mexico (SNL/NM). More specifically, this document describes the LTES and Long-Term Stewardship (LTS) Programs, distinguishes between the LTES and LTS Programs, and summarizes the current status of the Environmental Restoration (ER) Project.

Nagy, Michael David

2010-08-01

335

An evaluation of a classroom-based intervention to help overcome working memory difficulties and improve long-term academic achievement.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two contrasting forms of classroom-based intervention were implemented with 256 primary school children identified as having working memory (WM) difficulties. In one, teaching staff were trained to provide educational environments that were sensitive to the needs of identified children with WM difficulties. The second form of intervention utilized a behavioral teaching approach in which identified children were provided with regular, brief, and highly focused inputs in relevant basic skills a...

Elliott, J.; Gathercole, S. E.; Alloway, T. P.; Holmes, J.; Kirkwood, H.

2010-01-01

336

Long-term ginsenoside consumption prevents memory loss in aged SAMP8 mice by decreasing oxidative stress and up-regulating the plasticity-related proteins in hippocampus.  

Science.gov (United States)

Ginsenoside, the effective component of ginseng, has been reported to have a neuron protective effect, but the preventive effect on Alzheimer's disease (AD) related memory loss and the underlying mechanisms have not been well determined. The senescence-accelerated mouse (SAM) is a useful model of AD-related memory impairment. In the present study, SAMP8 mice aged 4 months were chronically treated with ginsenoside (3 dose groups were given ginsenoside in drinking water for 7 months). The three groups were treated with ginsenoside 50, 100 and 200 mg/kg per day, respectively. Placebo-treated aged mice and young ones (4 months old) were used as controls. In addition, SAMR1 mice were used as "normal aging" control. The beneficial role of ginsenoside was manifested in the prevention of memory loss in aged SAMP8 mice. The optimal dose of ginsenoside is 100 or 200 mg/kg per day. In ginsenoside treated groups, the Abeta level markedly decreased in hippocampus and antioxidase level significantly increased in serum. In addition, the plasticity-related proteins in hippocampus significantly increased in the two ginsenoside treated groups. The plasticity-related proteins were checked in the present study including postsynaptic density-95 (PSD-95), phosphor-N-methyl-D-aspartate receptor 1 (p-NMDAR1), phospho-calcium-calmodulin dependent kinase II (p-CaMKII), phospho-protein kinase A Catalyticbeta subunit (p-PKA Cbeta) and protein kinase Cgamma subunit (PKCgamma), phospho-CREB (p-CREB) and brain derived neurotrophic factor (BDNF) etc. These findings suggest that the increase of antioxidation and up-regulation of plasticity-related proteins in hippocampus may be one of the mechanisms of ginsenoside on the memory loss prevention in aged SAMP8 mice. PMID:19133247

Zhao, Haifeng; Li, Qiong; Zhang, Zhaofeng; Pei, Xinrong; Wang, Junbo; Li, Yong

2009-02-23

337

Long-Term Central and Effector SHIV-Specific Memory T Cell Responses Elicited after a Single Immunization with a Novel Lentivector DNA Vaccine  

Science.gov (United States)

Prevention of HIV acquisition and replication requires long lasting and effective immunity. Given the state of HIV vaccine development, innovative vectors and immunization strategies are urgently needed to generate safe and efficacious HIV vaccines. Here, we developed a novel lentivirus-based DNA vector that does not integrate in the host genome and undergoes a single-cycle of replication. Viral proteins are constitutively expressed under the control of Tat-independent LTR promoter from goat lentivirus. We immunized six macaques once only with CAL-SHIV-IN? DNA using combined intramuscular and intradermal injections plus electroporation. Antigen-specific T cell responses were monitored for 47 weeks post-immunization (PI). PBMCs were assessed directly ex vivo or after 6 and 12 days of in vitro culture using antigenic and/or homeostatic proliferation. IFN-? ELISPOT was used to measure immediate cytokine secretion from antigen specific effector cells and from memory precursors with high proliferative capacity (PHPC). The memory phenotype and functions (proliferation, cytokine expression, lytic content) of specific T cells were tested using multiparametric FACS-based assays. All immunized macaques developed lasting peripheral CD8+ and CD4+ T cell responses mainly against Gag and Nef antigens. During the primary expansion phase, immediate effector cells as well as increasing numbers of proliferating cells with limited effector functions were detected which expressed markers of effector (EM) and central (CM) memory phenotypes. These responses contracted but then reemerged later in absence of antigen boost. Strong PHPC responses comprising vaccine-specific CM and EM T cells that readily expanded and acquired immediate effector functions were detected at 40/47 weeks PI. Altogether, our study demonstrated that a single immunization with a replication-limited DNA vaccine elicited persistent vaccine-specific CM and EM CD8+ and CD4+ T cells with immediate and readily inducible effector functions, in the absence of ongoing antigen expression. PMID:25337803

Arrode-Brusés, Géraldine; Moussa, Maha; Baccard-Longere, Monique; Villinger, François; Chebloune, Yahia

2014-01-01

338

Long-term central and effector SHIV-specific memory T cell responses elicited after a single immunization with a novel lentivector DNA vaccine.  

Science.gov (United States)

Prevention of HIV acquisition and replication requires long lasting and effective immunity. Given the state of HIV vaccine development, innovative vectors and immunization strategies are urgently needed to generate safe and efficacious HIV vaccines. Here, we developed a novel lentivirus-based DNA vector that does not integrate in the host genome and undergoes a single-cycle of replication. Viral proteins are constitutively expressed under the control of Tat-independent LTR promoter from goat lentivirus. We immunized six macaques once only with CAL-SHIV-IN- DNA using combined intramuscular and intradermal injections plus electroporation. Antigen-specific T cell responses were monitored for 47 weeks post-immunization (PI). PBMCs were assessed directly ex vivo or after 6 and 12 days of in vitro culture using antigenic and/or homeostatic proliferation. IFN-? ELISPOT was used to measure immediate cytokine secretion from antigen specific effector cells and from memory precursors with high proliferative capacity (PHPC). The memory phenotype and functions (proliferation, cytokine expression, lytic content) of specific T cells were tested using multiparametric FACS-based assays. All immunized macaques developed lasting peripheral CD8+ and CD4+ T cell responses mainly against Gag and Nef antigens. During the primary expansion phase, immediate effector cells as well as increasing numbers of proliferating cells with limited effector functions were detected which expressed markers of effector (EM) and central (CM) memory phenotypes. These responses contracted but then reemerged later in absence of antigen boost. Strong PHPC responses comprising vaccine-specific CM and EM T cells that readily expanded and acquired immediate effector functions were detected at 40/47 weeks PI. Altogether, our study demonstrated that a single immunization with a replication-limited DNA vaccine elicited persistent vaccine-specific CM and EM CD8+ and CD4+ T cells with immediate and readily inducible effector functions, in the absence of ongoing antigen expression. PMID:25337803

Arrode-Brusés, Géraldine; Moussa, Maha; Baccard-Longere, Monique; Villinger, François; Chebloune, Yahia

2014-01-01

339

Influence of a combination of two tetrachlorobiphenyl congeners (PCB 47; PCB 77) on thyroid status, choline acetyltransferase (ChAT) activity, and short- and long-term memory in 30-day-old Sprague-Dawley rats  

International Nuclear Information System (INIS)

The important role of thyroid hormones in growth and development, maintenance of body temperature, digestion, cardiac function, and normal brain development can be disrupted by environmental contaminants like polychlorinated biphenyls (PCB). Polychlorinated biphenyls are environmental contaminants that are widespread, persistent, lipophilic, and bioaccumulate through food webs, concentrating in adipose tissue. Placental and lactational PCB exposure of offspring causes metabolic and endocrine disruptions including hypothyroxinemia, spatial learning and memory deficits, neurochemical and neurobehavioral alterations, and reproductive problems. Previous studies in our lab using the individual congeners PCB 47 (2,2',4,4'-tetrachlorobiphenyl, ortho-substituted) and PCB 77 (3,3',4,4'-tetrachlorobiphenyl, non-ortho-substituted) have demonstrated alterations in thyroid hormone levels, alterations in brain choline acetyltransferase (ChAT) activity, and spatial learning deficits. In the present study, pregnant Sprague-Dawley rats were fed a diet with or without a mixture of PCB 47/77 at 1.25 ppm, 12.5 ppm or 25.0 ppm (w/w). Rat pups were swum in the Morris water maze four times a day on days 21-29 in order for the animals to learn the position of a submerged fixed platform. A probe test was run on day 24 (30 min after last swim) for short-term memory, and on day 29 (24 h after the last swim) for long-term memory after removal of the platform. Time spent in the quadrant previouslform. Time spent in the quadrant previously containing the platform was recorded. Rats were decapitated on day 30, serum collected and frozen at -20 deg. ChAT activity was measured radiometrically in basal forebrain and hippocampus. All PCB-treated animals experienced a depression in both triiodothyronine (T3) and thyroxine (T4). The present study found that all doses of PCB depressed ChAT activity in hippocampus with no significant alteration in the basal forebrain. In PCB-treated animals, short-term memory showed a trend toward improvement and long-term memory toward depression, but these trends were not significant. The consequences likely stem from endocrine disruption, especially with regard to the thyroid

340

Accessibility Long Term Perspectives  

Directory of Open Access Journals (Sweden)

Full Text Available Improved accessibility and its correlate lower generalized cost of contact, travel and transport have been sought by dynamic human societies for their economic and social benefits through- out recorded history. The paper will reflect about this process at a number of different spatial and temporal scales based on a conceptual model. Looking back at European history, it will trace the interaction between Christaller's logic of local market areas and the idea of (low contact cost network cities. Focusing on Switzerland since 1950 it will show how network investment changed the relative distribution of population and employment and how this interacted with changes in the preferences of the travelers. Using a recent snapshot of how a substantial sample of Swiss maintain their social networks over often very large areas, it will try to answer the question of what will happen in the future, if the current trend of ever lower costs of contact will persist.

Kay Axhausen

2008-11-01

 
 
 
 
341

Efectos de la escopolamina a corto y largo plazo en la memoria y las habilidades conceptuales / Effects of Short- And Long-Term Scopolamine Intoxication on Memory and Conceptual Skills  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish El uso de este tóxico en Colombia con fines delincuenciales representa un problema social y de salud de proporciones inmensurables, de ahí la importancia de conocer sus efectos a corto y largo plazo en la memoria y las habilidades conceptuales. Se evaluaron los efectos de la intoxicación por escopol [...] amina sobre memoria, categorización y clasificación en 20 sujetos, entre 15 y 60 años. Se utilizó un diseño prospectivo con dos mediciones. Los sujetos fueron evaluados a los cinco días después de egresar de la clínica y a los seis meses. Los no expuestos se evaluaron paralelamente en los dos momentos de la evaluación, por medio de la prueba de memoria de Wechsler, el test de la figura de Rey-Osterrieth, el test de clasificación de tarjetas de Wisconsin y la subprueba de matrices progresivas del WAIS III. Los resultados obtenidos sugieren que la intoxicación por escopolamina provoca deterioro en la memoria y las habilidades conceptuales tanto a corto como a largo plazo. Abstract in english The intoxication by scopolamine is the second cause of acute intoxication in Bogotá and probably in others cities of Colombia. The use of this toxic in criminal attacks represents a social and health problem of immeasurable proportions. The knowledge of its long term effects in cognitive functions a [...] s the memory and conceptual abilities is scarce. In this investigation the effects of intoxication by scopolamine were evaluated in tow different times between a group of 20 people into the 15 and 60 years old, using categorization and classification upon memory and conceptual abilities. The first evaluation was carried out five days after clinic treatments and the second evaluation was made six months later. As the exposed group and as a non exposed group was evaluated parallelly in both moments of the evaluation with the Wechsler memory test, the figure of Rey-Osterrieth test, the Classification of Cards of Wisconsin test, and the progressive matrix of WAIS III subtest. The results suggest that the intoxication by scopolamine causes deterioration in memory and conceptual abilities in short and long term.

Sandra Milena, Camelo Roa; Alfredo, Ardila.

2013-12-01

342

Memória de longo prazo modulada pela memória de curto prazo Memoria a largo plazo modulada por la memoria a corto plazo Long term memory modulated by short term memory  

Directory of Open Access Journals (Sweden)

Full Text Available Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível do que em lados opostos (condição incompatível. Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor do estímulo, a posição deste influencia o Tempo de Reação Manual (TRM. O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível. Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários, encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários, ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo.Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es más rápida cuando el estimulo y la respuesta están del mismo lado (condición compatible, de que cuando están en lados opuestos (condición incompatible. En la prueba de Simon, el color o la forma del estímulo determina la respuesta, pero éste es más rápido cuando hay una correlación espacial entre el estímulo y la respuesta. En este trabajo, estudiamos la modulación del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo índice respondió. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible. Después el voluntario realizó la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrió un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulación de la memoria a largo plazo por la memoria a corto plazo.When a stimulus randomly occurs at left or right, the response is faster when stimulus and response are on the same side (compatible condition than on opposite sides (incompatible condition. In the Simon task, color or shape determines the correct response but it is faster when there is correspondence between stimulus and response key positions. In this research, we studied the Simon effect modulation through a previous spatial compatibility task in which just one index finger presses the keys. Twenty-eight volunteers run compatibility tasks (14 compatible and 14 incompatible. Then, they performed a Simon task in which the correct response was selected by shape. A Simon effect of 24 ms was found in the compatible group. An inverse Simon effect of -16 ms occurred in the incompatible group. These results show long-term memory modulation by task involving short-term memory.

Viviane Moreira-Aguiar

2008-01-01

343

Memória de longo prazo modulada pela memória de curto prazo / Long term memory modulated by short term memory / Memoria a largo plazo modulada por la memoria a corto plazo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível) do que em lados opostos (condição incompatível). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estímulo, a p [...] osição deste influencia o Tempo de Reação Manual (TRM). O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível). Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários), encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo. Abstract in spanish Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es más rápida cuando el estimulo y la respuesta están del mismo lado (condición compatible), de que cuando están en lados opuestos (condición incompatible). En la prueba de Simon, el color o la forma del estímulo de [...] termina la respuesta, pero éste es más rápido cuando hay una correlación espacial entre el estímulo y la respuesta. En este trabajo, estudiamos la modulación del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo índice respondió. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Después el voluntario realizó la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrió un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulación de la memoria a largo plazo por la memoria a corto plazo. Abstract in english When a stimulus randomly occurs at left or right, the response is faster when stimulus and response are on the same side (compatible condition) than on opposite sides (incompatible condition). In the Simon task, color or shape determines the correct response but it is faster when there is correspond [...] ence between stimulus and response key positions. In this research, we studied the Simon effect modulation through a previous spatial compatibility task in which just one index finger presses the keys. Twenty-eight volunteers run compatibility tasks (14 compatible and 14 incompatible). Then, they performed a Simon task in which the correct response was selected by shape. A Simon effect of 24 ms was found in the compatible group. An inverse Simon effect of -16 ms occurred in the incompatible group. These results show long-term memory modulation by task involving short-term memory.

Viviane, Moreira-Aguiar; Allan Pablo, Lameira; Erick Quintas, Conde; Antônio, Pereira Júnior; Carlo Arrigo, Umiltà; Luiz de Gonzaga, Gawryszewski.

344

Booster vaccination of cancer patients with MAGE-A3 protein reveals long-term immunological memory or tolerance depending on priming  

Science.gov (United States)

We previously reported results of a phase II trial in which recombinant MAGE-A3 protein was administered with or without adjuvant AS02B to 18 non-small-cell lung cancer (NSCLC) patients after tumor resection. We found that the presence of adjuvant was essential for the development of humoral and cellular responses against selected MAGE-A3 epitopes. In our current study, 14 patients that still had no evidence of disease up to 3 years after vaccination with MAGE-A3 protein with or without adjuvant received an additional four doses of MAGE-A3 protein with adjuvant AS02B. After just one boost injection, six of seven patients originally vaccinated with MAGE-A3 protein plus adjuvant reached again their peak antibody titers against MAGE-A3 attained during the first vaccination. All seven patients subsequently developed even stronger antibody responses. Furthermore, booster vaccination widened the spectrum of CD4+ and CD8+ T cells against various new and known MAGE-A3 epitopes. In contrast, only two of seven patients originally vaccinated with MAGE-A3 protein alone developed high-titer antibodies to MAGE-A3, and all these patients showed very limited CD4+ and no CD8+ T cell reactivity, despite now receiving antigen in the presence of adjuvant. Our results underscore the importance of appropriate antigen priming using an adjuvant for generating persistent B and T cell memory and allowing typical booster responses with reimmunization. In contrast, absence of adjuvant at priming compromises further immunization attempts. These data provide an immunological rationale for vaccine design in light of recently reported favorable clinical responses in NSCLC patients after vaccination with MAGE-A3 protein plus adjuvant AS02B. PMID:18216244

Atanackovic, Djordje; Altorki, Nasser K.; Cao, Yanran; Ritter, Erika; Ferrara, Cathy A.; Ritter, Gerd; Hoffman, Eric W.; Bokemeyer, Carsten; Old, Lloyd J.; Gnjatic, Sacha

2008-01-01

345

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program II. Activity and radial velocity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Due to their low mass and luminosity, M dwarfs are ideal targets if one hopes to find low-mass planets similar to Earth by using the radial velocity (RV) method. However, stellar magnetic cycles could add noise or even mimic the RV signal of a long-period companion. Following our previous work that studied the correlation between activity cycles and long-term RV variations for K dwarfs we now expand that research to the lower-end of the main sequence. Our objective is to det...

Da Silva, J. Gomes; Santos, N. C.; Bonfils, X.; Delfosse, X.; Forveille, T.; Udry, S.; Dumusque, X.; Lovis, C.

2012-01-01

346

Long-Term Repetition Priming of Briefly Identified Objects  

Science.gov (United States)

The authors provide evidence that long-term memory encoding can occur for briefly viewed objects in a rapid serial visual presentation list, contrary to claims that the brief presentation and quick succession of objects prevent encoding by disrupting a memory consolidation process that requires hundreds of milliseconds of uninterrupted processing.…

Breuer, Andreas T.; Masson, Michael E. J.; Cohen, Anna-Lisa; Lindsay, D. Stephen

2009-01-01

347

Spine Expansion and Stabilization Associated with Long-term Potentiation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Stable expression of long-term synaptic plasticity is critical for the developmental refinement of neural circuits and for some forms of learning and memory. Although structural remodeling of dendritic spines is associated with the stable expression of long term potentiation (LTP), the relationship between structural and physiological plasticity remains unclear. To define whether these two processes are related or distinct, we simultaneously monitored EPSPs and dendritic spines, using combine...

Yang, Yunlei; Wang, Xiao-bin; Frerking, Matthew; Zhou, Qiang

2008-01-01

348

Enhanced Long-Term and Impaired Short-Term Spatial Memory in GluA1 AMPA Receptor Subunit Knockout Mice: Evidence for a Dual-Process Memory Model  

Science.gov (United States)

The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity of…

Sanderson, David J.; Good, Mark A.; Skelton, Kathryn; Sprengel, Rolf; Seeburg, Peter H.; Rawlins, J. Nicholas P.; Bannerman, David M.

2009-01-01

349

Comparing long term energy scenarios  

International Nuclear Information System (INIS)

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

350

Long term stability of power systems  

Energy Technology Data Exchange (ETDEWEB)

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.

Kundur, P.; Gao, B. [Powertech Labs. Inc., Surrey, BC (Canada)

1994-12-31

351

Modelling the dynamics of CaMKII-NMDAR complex related to memory formation in synapses: The possible roles of threonine 286 autophosphorylation of CaMKII in long term potentiation.  

Science.gov (United States)

A synaptic protein, Ca(2+)/Calmodulin dependent protein kinase II (CaMKII), has complex state transitions and facilitates the emergence of long term potentiation (LTP), which is highly correlated to memory formation. Two of the state transitions are critical for LTP: (1) threonine 286 autophosphorylation of CaMKII; and (2) binding to N-methyl-d-aspartate receptor (NMDAR) in the postsynaptic density (PSD) to form CaMKII-NMDAR complex. Both of these state transitions retain the activity of CaMKII when the induction signal disappears which is very important for the long-lasting characteristics of LTP. However, the possible relationships between the state transitions in the emergence of LTP are not well understood. We develop a mathematical model of the formation of CaMKII-NMDAR complex with the full state transitions of CaMKII, including the autophosphorylation, based on ordinary differential equations. In addition, we formulate a probabilistic framework for the binding between CaMKII and NMDAR. The model gives accurate predictions of the behaviours of CaMKII in comparisons to the experimental observations. Using the model, we show that: (1) the formation of CaMKII-NMDAR complex is dependent not only on the binding affinity between CaMKII and NMDAR, but also on the translocation of CaMKII into PSD; and (2) the autophosphorylation is not a requirement for the formation of CaMKII-NMDAR complex, but is important for the rapid formation of CaMKII-NMDAR complex during LTP. PMID:25446714

He, Y; Kulasiri, D; Samarasinghe, S

2015-01-21

352

Evaluation of long-term integrity of spent fuels stored in Idaho National Laboratory. Cover gas sampling inside metal cask and its analysis  

International Nuclear Information System (INIS)

The Idaho National Laboratory (INL) in USA is managing the CASTOR-V/21 metal cask which has stored 21 PWR spent fuel assemblies discharged from Surry nuclear power plant since 1985. After the cask performance test carried out on CASTOR-V/21 in 1985, INL has often made gas sampling and analysis on cover gas taken from inside CASTOR-V/21 to confirm spent fuel integrity using mass spectra and gamma detection techniques. Gas sampling data obtained in the past gas sampling activities, gas sampling procedure and its analysis techniques applied to CASTOR-V/21 are reviewed in this study. The integrity of spent fuels stored in CASTOR-V/21 since 1985 is also evaluated by comparing 85Kr gamma ray in the gas sample data with those of ORIGEN calculation and the results show that the spent fuels stored in CASTOR-V/21 have no defect. Additionally, it is shown that the 85Kr gamma ray measurement technique is available to detect defected fuels with 1% leakage of Kr gas from one rod during storage till 2050. The estimation method of characteristics such as burn-up and initial enrichment on defected fuels, using the ratio of nuclide composition, Xe/Kr and 136Xe/131Xe, is investigated and proposed to specify the defected fuel group in the cask. (author)

353

Estimating the remaining service life of pipeline bend metal with microdamage based on the results from long-term strength tests of solid and notched samples  

Science.gov (United States)

The longevity of solid (smooth) and notched samples made of Grade 12Kh1MF steel is considered. A combined calculation and experimental dependence for determining the effect of stresses and temperature on the remaining service life of metal damaged by single pores and chains of pores is presented.

Gladshtein, V. I.

2012-04-01

354

Long-Term Care Ombudsman Program  

Science.gov (United States)

... Claiming and Long-Term Care Ombudsman Programs The Purpose of the Program and How It Works Long- ... who wish to learn about available home and community based services (HCBS) options and available long-term care (LTC) ...

355

Analysis of Long-term Stored Plasma Samples for Investigation into the Pathophysiology of Vibration-induced White Finger: Preliminary Results  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Blood samples were collected 25?yr ago from hand-arm vibration syndrome patients with vibration-induced white finge/VWF (VWF+ group) and without it (VWF? group), and healthy controls (n=12 in each group), and stored at ?80°C. The subjects provided venous blood twice: at baseline, and after cold exposure at 7°C for 25?min. Blood specimens were analyzed for plasma endothelin-1 (ET-1) by an enzyme-linked immunosorbent assay. Baseline concentration of plasma ET-1 was foun...

Kawano, Yoshinao; Mahbub, Hossain Md; Hase, Ryosuke; Sakamoto, Tatsuo; Harada, Noriaki

2014-01-01

356

Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress : analytical reproducibility and long-term stability of plasma samples subjected to acidic deproteinization  

DEFF Research Database (Denmark)

Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper, the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high-performance liquid chromatography with coulometric detection. In a parallel experiment, stability of human plasma samples treated as above and stored at -80°C for five years was tested in a cohort of 131 individuals. No degradation or shift in the equilibrium between ascorbate and dehydroascorbic acid was observed in either of the experiments. In conclusion, ascorbate and dehydroascorbic acid can be adequately preserved in plasma stored at -80°C following acidic deproteinization with meta-phosphoric acid containing 2 mM EDTA.

Lykkesfeldt, Jens

2007-01-01

357

Long-Term Planning in Higher Education.  

Science.gov (United States)

This report presents the concepts and issues discussed at a Regional Symposium on Long-term Planning in Higher Education held in Dhaka, Bangladesh, September 21-30, 1986. Chapter 1 explores some fundamental issues about the rationale for the objectives of long-term planning. It defines long-term planning in higher education, considers its…

United Nations Educational, Scientific and Cultural Organization, Bangkok (Thailand). Principal Regional Office for Asia and the Pacific.

358

Three-year-olds’ memory for a person met only once at the age of 12 months: Very long-term memory revealed by a late-manifesting novelty preference  

DEFF Research Database (Denmark)

This study examined three-year-olds’ verbal and non-verbal memory for a person met only once after a 28 month interval. Children in the Test group (N=50) had participated in an earlier experiment at our lab at the age of 12 months where they met one of two possible experimenters. At this past event half of the children were tested by one, the other half by the other experimenter. At the follow-up, run by a naïve experimenter, the children were shown two videos from the original experiment in a visual paired comparison task: One with the specific experimenter testing them at the original visit (the Target) and one of the other experimenter (the Foil), with whom they had no experience. When explicitly asked, the children’s responses did not differ from chance. However, eye-tracking data revealed a late-manifesting novelty preference for the “Foil” person indicating memory for the “Target” person met once before.

Kingo, Osman Skjold; Staugaard, SØren RislØv

2014-01-01

359

Long-term corrosion studies  

Energy Technology Data Exchange (ETDEWEB)

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.

Gdowski, G.

1998-05-29

360

Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation  

Energy Technology Data Exchange (ETDEWEB)

Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by which short-term memories are permanently stored, and b) a strong foundation for continued growth of an excellent undergraduate neuroscience program.

Calin-Jageman, Robert J

2009-09-12

 
 
 
 
361

Tiagabine Improves Hippocampal Long-Term Depression in Rat Pups Subjected to Prenatal Inflammation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Maternal inflammation during pregnancy is associated with the later development of cognitive and behavioral impairment in the offspring, reminiscent of the traits of schizophrenia or autism spectrum disorders. Hippocampal long-term potentiation and long-term depression of glutamatergic synapses are respectively involved in memory formation and consolidation. In male rats, maternal inflammation with lipopolysaccharide (LPS) led to a premature loss of long-term depression, occurring between 12 ...

Rideau Batista Novais, Aline; Crouzin, Nadine; Cavalier, Me?lanie; Boubal, Mathilde; Guiramand, Janique; Cohen-solal, Catherine; Jesus Ferreira, Marie-ce?leste; Cambonie, Gilles; Vignes, Michel; Barbanel, Ge?rard

2014-01-01

362

Long-term monitoring for closed sites  

International Nuclear Information System (INIS)

A procedure is presented for planning and implementing a long-term environmental monitoring program for closed low-level radioactive waste disposal sites. The initial task in this procedure is to collect the available information on the legal/regulatory requirements, site and area characteristics, source term, pathway analysis, and prior monitoring results. This information is coupled with parameters such as half-life and retardation factors to develop a monitoring program. As examples, programs are presented for a site that has had little or no waste migration, and for sites where waste has been moved by suface water, by ground water, and by air. Sampling techniques and practices are discussed relative to how a current program would be structured and projections are made on techniques and practices expected to be available in the future. 8 refs., 2 figs

363

Long-term cerebral consequences of sepsis.  

Science.gov (United States)

Sepsis is a potentially fatal whole-body inflammatory state caused by severe infection, in which a maladaptive, system-wide inflammatory response follows initial attempts to eliminate pathogens, leading to a dangerous and often fatal increase in the permeability of the blood-brain barrier. These changes in the blood-brain barrier might lead to a major symptom of sepsis, sepsis-associated encephalopathy, which manifests as confusion with a rapid decline in cognitive functions, especially memory, or coma. Once presumed to be entirely reversible, research suggests that sepsis-associated encephalopathy could lead to permanent neurocognitive dysfunction and functional impairments, even after the patient has recovered. Sepsis might act as a major inflammatory hit and potentially increase the brain's susceptibility to neurodegenerative disease, further deterioration of cognitive ability, and risk of developing dementia in later life. Key opportunities for neuroprotective interventions and after-care for people who have survived sepsis might be lost because the long-term neurocognitive and functional consequences of sepsis are not fully characterised. PMID:24849863

Widmann, Catherine N; Heneka, Michael T

2014-06-01

364

Long-term dynamics of Typha populations  

Science.gov (United States)

The zonation of Typha populations in an experimental pond in Michigan was re-examined 15 years after the original sampling to gain insight into the long-term dynamics. Current distributions of Typha populations were also examined in additional experimental ponds at the site that have been maintained for 23 years. The zonation between T. latifolia and T. angustifolia in the previously studied pond 15 years after the initial sampling revealed that the density and distribution of shoots had not changed significantly. Thus, it appears that previously reported results (based on 7- year old populations) have remained consistent over time. Additional insight into the interaction between these two taxa was sought by comparing mixed and monoculture stands in five experimental ponds that have remained undisturbed for their 23-year history. The maximum depth of T. latifolia, the shallow- water species, was not significantly reduced when growing in the presence of the more flood tolerant T. angustifolia. In contrast, the minimum depth of T. angustifolia was reduced from 0 to 37 cm when in the presence of T. latifolia. When total populations were compared between monoculture and mixed stands, the average density of T. angustifolia shoots was 59.4 percent lower in mixed stands while the density of T. latifolia was 32 percent lower, with T. angustifolia most affected at shallow depths (reduced by 92 percent) and T. latifolia most affected at the deepest depths (reduced by 60 percent). These long-term observations indicate that competitive displacement between Typha taxa has remained stable over time.

Grace, J.B.; Wetzel, R.G.

1998-01-01

365

Studies on long-term inflow forecasting  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis aims to improve knowledge of long-term inflow and streamflow forecasts. A special focus is on the development of a new long-term forecast model and on the evaluation of long-term inflow forecasts. In the first part of the work, a new categorical long-term forecast model is developed and its performance is investigated in four case studies. The forecasts are based only on the current hydrological state of the basin and thus, weather forecasts are not utilised. By using the k-N...

Koskela, Jarkko

2009-01-01

366

How long will long-term potentiation last?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paramount feature of long-term potentiation (LTP) as a memory mechanism is its characteristic persistence over time. Although the basic phenomenology of LTP persistence was established 30 years ago, new insights have emerged recently about the extent of LTP persistence and its regulation by activity and experience. Thus, it is now evident that LTP, at least in the dentate gyrus, can either be decremental, lasting from hours to weeks, or stable, lasting months or longer. Although mechanism...

Abraham, Wickliffe C.

2003-01-01

367

Financing long term liabilities (Germany)  

International Nuclear Information System (INIS)

In Germany the basis for the management of radioactive residues is the polluter-pays principle. All steps of treatment of radioactive waste arising from operation, decommissioning and dismantling including conditioning, interim storage and disposal of radioactive waste have to be financed by the waste producers. The waste producers are responsible for the harmless recycling of the residues or for their orderly management as radioactive waste. The Federal Government is responsible for establishing disposal facilities. Accordingly the waste producers are constructing and operating facilities in which the radioactive residues can be treated and stored until their disposal. As far as the radioactive waste cannot be stored by the producer, waste originating from research, medicine and industry can be stored in surface storage facilities of the federal states. Spent fuel from German NPPs is partly reprocessed in France and UK. The rest has to be disposed off directly in deep geologic formations. Until a repository for spent fuel is available in Germany spent fuel will be stored in interim storage facilities on the sites of the NPPs. The storage will take place in casks in a dry way. In exceptional cases, if the storage at a NPP site is not possible, there are two central storages at Ahaus and Gorleben which are in operation and can be made available as reserve. Radioactive waste returning from the reprocessing of German spent fuel in France and UK is stored in the Gorleben central storage. The Federal Government is aiming to establish a repository in deep geological formations about the year 2030 which shall be available for all types and quantities of radioactive waste. The necessary expenses for the planning and construction of radioactive waste disposal facilities are initially carried by the Federal Government. The Government recovers the costs by contributions or advance payments from the waste producers. The use of storage and disposal facilities is financed by 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 km2. Heaps cover a total area of ca. 15,5 km2, tailing ponds in which the tailings resulting from the Uranium production are stored as sludges cover 6,3 km2). In total, the remediation issues are very complex and without precedent. The implementation of the measures will cover a period of 15 to 20 years depending on the site. The necess

368

Long-Term Low-Level Arsenic Exposure Is Associated with Poorer Neuropsychological Functioning: A Project FRONTIER Study  

Directory of Open Access Journals (Sweden)

Full Text Available Exposure to elements in groundwater (toxic or beneficial is commonplace yet, outside of lead and mercury, little research has examined the impact of many commonly occurring environmental exposures on mental abilities during the aging process. Inorganic arsenic is a known neurotoxin that has both neurodevelopmental and neurocognitive consequences. The aim of this study was to examine the potential association between current and long-term arsenic exposure and detailed neuropsychological functioning in a sample of rural-dwelling adults and elders. Data were analyzed from 434 participants (133 men and 301 women of Project FRONTIER, a community-based participatory research study of the epidemiology of health issues of rural-dwelling adults and elders. The results of the study showed that GIS-based groundwater arsenic exposure (current and long-term was significantly related to poorer scores in language, visuospatial skills, and executive functioning. Additionally, long-term low-level exposure to arsenic was significantly correlated to poorer scores in global cognition, processing speed and immediate memory. The finding of a correlation between arsenic and the domains of executive functioning and memory is of critical importance as these are cognitive domains that reflect the earliest manifestations of Alzheimer’s disease. Additional work is warranted given the population health implications associated with long-term low-level arsenic exposure.

Robert Barber

2011-03-01

369

Evaluation of the effects of long-term storage of bovine ear notch samples on the ability of 2 diagnostic assays to identify calves persistently infected with bovine viral diarrhoea virus  

Directory of Open Access Journals (Sweden)

Full Text Available Research aimed at optimising diagnostic laboratory procedures is central to the development of effective bovine viral diarrhoea virus (BVDV control programmes. BVDV is a singlestranded RNA virus that crosses the placenta to infect foetuses, resulting in reproductive losses due to foetal death or persistently infected calves that die early in life. Persistently infected animals are widely accepted to be the primary reservoir of BVDV and the largest source of infection. This poses important challenges to overall animal/herd health and can cause major losses to the cattle industry. Long-term storage of bovine ear notch samples from calves persistently infected with BVDV may adversely affect the ability of diagnostic assays to detect the virus efficiently. In order to test this hypothesis, ear notch samples from 7 animals were divided into 2 groups. One set was subjected to prompt formalin fixation and the other set stored either as fresh samples without preservatives at –2 °C, or soaked overnight in phosphate buffered saline followed by freezing of the supernatant fluid at –2 °C. Frozen ear notches and ear notch supernatant yielded positive results with an antigen- capture, enzyme linked immunosorbent assay (AC-ELISA for the duration of the study (6 months and optical density (OD values remained significantly within range. There was no significant difference between storing fresh ear notch samples or PBS at –2 °C. However, positive immunohistochemistry (IHC staining on formalin fixed ear notches started to fade between Day 17 and Day 29 when stored at room temperature. It was concluded that fresh ear notches could safely be stored at –2 °C for a period of 6 months prior to testing for BVD viral antigens.

M. van Vuuren

2012-04-01

370

Evaluation of the effects of long-term storage of bovine ear notch samples on the ability of 2 diagnostic assays to identify calves persistently infected with bovine viral diarrhoea virus  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Research aimed at optimising diagnostic laboratory procedures is central to the development of effective bovine viral diarrhoea virus (BVDV) control programmes. BVDV is a singlestranded RNA virus that crosses the placenta to infect foetuses, resulting in reproductive losses due to foetal death or pe [...] rsistently infected calves that die early in life. Persistently infected animals are widely accepted to be the primary reservoir of BVDV and the largest source of infection. This poses important challenges to overall animal/herd health and can cause major losses to the cattle industry. Long-term storage of bovine ear notch samples from calves persistently infected with BVDV may adversely affect the ability of diagnostic assays to detect the virus efficiently. In order to test this hypothesis, ear notch samples from 7 animals were divided into 2 groups. One set was subjected to prompt formalin fixation and the other set stored either as fresh samples without preservatives at -2 ºC, or soaked overnight in phosphate buffered saline followed by freezing of the supernatant fluid at -2 ºC. Frozen ear notches and ear notch supernatant yielded positive results with an antigen-capture, enzyme linked immunosorbent assay (AC-ELISA) for the duration of the study (6 months) and optical density (OD) values remained significantly within range. There was no significant difference between storing fresh ear notch samples or PBS at -2 ºC. However, positive immunohistochemistry (IHC) staining on formalin fixed ear notches started to fade between Day 17 and Day 29 when stored at room temperature. It was concluded that fresh ear notches could safely be stored at -2 ºC for a period of 6 months prior to testing for BVD viral antigens

F, Khan; J H, Vorster; M, van Vuuren; P, Mapham.

371

Methylphenidate amplifies long-term plasticity in the hippocampus via noradrenergic mechanisms.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Methylphenidate treatment is used for Attention Deficit Hyperactivity Disorder and can improve learning and memory. Previously, improvements were considered a by-product of increased attention; however, we hypothesize that methylphenidate directly alters mechanisms underlying learning and memory, and therefore examined its effects on hippocampal long-term potentiation and long-term depression. Methylphenidate enhanced both mechanisms in the absence of presynaptic changes and in a noradrenalin...

Dommett, Ej; Henderson, El; Westwell, Ms; Greenfield, Sa

2008-01-01

372

Long term sampling and measuring program. Joint report for 1987, 1988 and 1989. Within the project: Fallout studies in the Gideaa and Finnsjoe areas after the Chernobyl accident in 1986  

International Nuclear Information System (INIS)

A redistribution and migration study of the Chernobyl fallout begun in 1986. It was realized in an early stage that the fallout from Chernobyl could be used as a large scale tracer study. After one early sampling and measurement it was concluded that at least five of the radioactive nuclides could be used in a long term perspective. The sorption and migration of these elements in geohydrological systems have been investigated during a period of three and a half years and a model of the redistribution is now prepared. The basis for successful modelling of the redistribution of fallout products within a small catchment area is dependent on accurate input. A repeated sampling of geological materials, and 'direct' measurement of gamma radiation in field, will then be needed. This report is a summary of the work that has been performed during 1987, 1988 and 1989 within sampling and measurement of radionuclide content in geological materials and surface vegetation. Migration studies and modelling work are other parts of the project that are not presented here. The collecting of field data is mainly done in a small catchment area (0.74 square km) c.30 km N-E of the city of Oernskoeldsvik county of Vaesternorrland. A minor field study is also done in an area east of Lake Finnsjoen, situated c.50 km north of the city of Uppsala. The conclusions that can be drawn from the Gideaa study site surface measurements are that the gamma radiation in general is decreasing with varying magnitude. But the picture is not all unambiguous. In the subsurface layers of studied soil profiles, an increase can be observed in the upper part of the enriched layer. The outflow of radionuclides with ground water seems to be fairly constant after the peak flow in 1986. Some indications of larger transport and outflow of radionuclides in connection with heavy rain or spring flood is also presented. (authors)

373

Wastewater treatment by soil infiltration: Long-term phosphorus removal  

Science.gov (United States)

Phosphorus (P) leaching from on-site wastewater treatment systems may contribute to eutrophication. In developed countries the most common on-site treatment technique is septic systems with soil infiltration. However, the current knowledge about long term P removal in soil treatment systems is not well developed and the data used for estimation of P losses from such systems are unreliable. In this study we sampled four filter beds from community-scale soil treatment systems with an age of between 14 and 22 years to determine the long-term P removal and to investigate the chemical mechanisms behind the observed removal. For one site the long-term P removal was calculated using a mass balance approach. After analysis of the accumulated P, it was estimated that on average 12% of the long-term P load had been removed by the bed material. This indicates a low overall capacity of soil treatment systems to remove phosphorus. Batch experiments and chemical speciation modelling indicated that calcium phosphate precipitation was not an important long-term P removal mechanism, with the possible exception of one of the sites. More likely, the P removal was induced by AlPO4 precipitation and/or sorption to poorly ordered aluminium compounds, as evidenced by strong relationships between oxalate-extractable Al and P.

Eveborn, David; Kong, Deguo; Gustafsson, Jon Petter

2012-10-01

374

Long-term stability scintillation tiles for LHCb detector  

CERN Document Server

Accelerated thermal aging tests of materials-UPS-923A, UPS-96G, UPS-96GM and their analogues, SCSN-81 (Kuraray) and BC-408 (Bicron)- were made. A forecast of tile lifetime was made for normal conditions of usage (20% reduction of light output and 50% reduction of the bulk attenuation length (BAL) and technical attenuation length (TAL). Scintillator UPS-96GM has the most long-term stability of parameters- more than 11 yr. BC-408 samples have the minimum lifetime ~7 yr. The long-term stability, calculated by light yield reduction, of UPS-96G, UPS-923A and SCSN-81 is 10, 9 and 8 yr, respectively.

Grinyov, B V; Khlapova, N P; Lebedev, V N; Melnychuk, S V; Senchyshyn, V G; 10.1016/j.radmeas.2004.02.018

2004-01-01

375

Long term wet spent nuclear fuel storage  

International Nuclear Information System (INIS)

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

376

Deferred tax and long-term insurers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Focuses on the new AC 102 on Income Taxes, which was issued in March 1999. Discusses several new issues regarding the provision of deferred tax that arose for enterprises in general and for long-term insurers in particular.

Stiglingh, M.; Koornhof, Carolina

2000-01-01

377

Long-term storage of solar heat  

Energy Technology Data Exchange (ETDEWEB)

Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.

Mustacchi, C.; Cena, V.; Rocchi, M.

1981-06-01

378

Long term liquidity analysis of the firm  

Directory of Open Access Journals (Sweden)

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.

Jaroslav Gonos

2009-09-01

379

Anticipating Long-Term Stock Market Volatility  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate the relationship between long-term U.S. stock market risks and the macroeconomic environment using a two component GARCH-MIDAS model. Our results provide strong evidence in favor of counter-cyclical behavior of long-term stock market volatility. Among the various macro variables in our dataset the term spread, housing starts, corporate profits and the unemployment rate have the highest predictive ability for stock market volatility . While the term spread and housing starts are...

Conrad, Christian; Loch, Karin

2012-01-01

380

Paying for Long-Term Performance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Firms, investors, and regulators around the world are now seeking to ensure that the compensation of public company executives is tied to long-term results, in part to avoid incentives for excessive risk taking. This Article examines how best to achieve this objective. Focusing on equity-based compensation, the primary component of executive pay, we identify how such compensation should best be structured to tie pay to long-term performance. We consider the optimal design of limitations on th...

Bebchuk, Lucian Arye; Fried, Jesse M.

2010-01-01

 
 
 
 
381

On the Cryptographic Long Term Security  

Directory of Open Access Journals (Sweden)

Full Text Available In this note we deal with the problem of long-term cryptographic security. We discuss briefly the methods of multiple encryption and signature, and the future influence of Quantum, DNA and Chaos methods in cryptography. Moreover, we propose an encryption and a signature scheme based on the problems of integer factorization and discrete logarithm suitable for applications needing long-term security.

Dimitrios Poulakis

2013-03-01

382

Pediatric HIV Long-Term Nonprogressors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Patients infected with HIV are best categorized along a continuum from rapid progressors to HIV long-term nonprogressors. Long-term nonprogressors (LTNPs) are those in which AIDS develop many years after being infected with HIV, often beyond the 10-year mark, and represent 15–20% of the HIV infected patients. Many of these patients are able to control their infection and maintain undetectable viral loads for long periods of time without antiretroviral therapy. After a comprehensive literatu...

Rimawi, B. H.; Rimawi, R. H.; Micallef, M.; Pinckney, L.; Fowler, S. L.; Dixon, T. C.

2014-01-01

383

Reversing cerebellar long-term depression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The discovery of a postsynaptically expressed form of cerebellar parallel fiber–Purkinje cell long-term potentiation (LTP) raises the question whether this is the long-sought resetting mechanism for long-term depression (LTD). Extracellular monitoring of PC spikes enables stable prolonged recordings of parallel fiber–Purkinje cell synaptic efficacy. LTD, saturated by repeated induction protocols, can be reversed by a single round of postsynaptic LTP or nitric oxide (NO), enabling LTD to b...

Lev-ram, Varda; Mehta, Samar B.; Kleinfeld, David; Tsien, Roger Y.

2003-01-01

384

Long-term e-arhiv  

Digital Repository Infrastructure Vision for European Research (DRIVER)

With expansion of e-business and consequently with creating original electronic documents, legally compliant long-term digital preservation has become a commitment for organizations that do business electronically. Accepted legislation that equalizes the legal validity of electronic documents with their paper original, regulates the operating and preservation of documents, recommendations, existing standards and service and equipment providers for ensuring long-term digital preservation, enab...

Petkovs?ek, Bojan

2011-01-01

385

Toward a comprehensive long term nicotine policy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 comprehen...

Gray, N.; Henningfield, J.; Benowitz, N.; Connolly, G.; Dresler, C.; Fagerstrom, K.; Jarvis, M.; Boyle, P.

2005-01-01

386

Long-Term Interest Rates and Public Debt Maturity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For a sample of sixteen OECD countries over the period 1980-2007 we show that, for given debt-GDP ratio, an increase in the maturity of the public debt by one year lowers its long-term interest rate by around 20-30 basis points. This effect is stronger for countries with higher average inflation or debt.

Sakalauskaite, Ieva; Beetsma, Roel; Giuliodori, Massimo

2013-01-01

387

Robotics for Long-Term Monitoring  

International Nuclear Information System (INIS)

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 te 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-environment surveyor (RHES) is a robotic platform with SCADA capabilities equipped with a sonar-imaging scanner, a high-resolution color CCD camera, and various combinations of sensors. The RHES is controlled remotely via a PC. This paper will discuss the development and application of this system. (authors)

388

[Long-term stability of orthodontic treatment].  

Science.gov (United States)

Aim of this study was to assess long-term stability of orthodontic treatment in a sample of 1016 patients until 10 years postretention. Treatment outcome was measured with the PAR-index at 6 different stages. The mean age of the patients was 12.0 +/- 3.1 year at the start of treatment to 26.3 +/- 2.9 year 10 years postretention. The results show that 67% of the orthodontic treatment result, as measured with the PAR-index, was maintained 10 years postretention. The PAR-scores for the midline and the open bite remained about the same over the years. However, the scores for the lateral occlusion, overjet, reversed overjet, overbite, and contact point displacement of the upper and lower front teeth increased gradually over time. Nearly 50% of the total relapse took place the first two years after retention. The largest change was found for the position of the lower incisors. Ten years postretention their position was even worse than at the start of treatment. PMID:11382976

Kuijpers-Jagtman, A M; Al Yami, E A; van 't Hof, M A

2000-04-01

389

Hormonal changes during long-term isolation.  

Science.gov (United States)

Confinement and inactivity induce considerable psychological and physiological modifications through social and sensory deprivation. The aim of the SFINCSS-99 experiment was to determine the cardiovascular and hormonal pattern of blood volume regulation during long-term isolation and confinement. Simulation experiments were performed in pressurized chambers similar in size to the volumes of modern space vehicles. Group I consisted of four Russian male volunteers, who spent 240 days in a 100-m(3 )chamber. Group II included four males (one German and three Russians) who spent 110 days in isolation (200-m(3) module). The blood samples, taken before, during and after the isolation period, were used to determine haematocrit (Ht), growth hormone (GH), active renin, aldosterone, and osmolality levels. From the urine samples, electrolytes, osmolality, nitrites, nitrates, cortisol, antidiuretic hormone (ADH), aldosterone, normetanephrine and metanephrine levels were determined. The increase in plasma volume (PV) that is associated with a tendency for a decrease in plasma active renin is likely to be due to decreased sympathetic activity, and concords with the changes in urinary catecholamine levels during confinement. Urinary catecholamine levels were significantly higher during the recovery period than during confinement. This suggests that the sympathoadrenal system was activated, and concords with the increase in heart rate. Vascular resistance is determined by not only the vasoconstrictor but also vasodilator systems. The ratio of nitrite/nitrate in urine, as an indicator of nitric oxide release, did not reveal any significant changes. Analysis of data suggests that the duration of the isolation was a main factor involved in the regulation of hormones. PMID:14722779

Custaud, M A; Belin de Chantemele, E; Larina, I M; Nichiporuk, I A; Grigoriev, A; Duvareille, M; Gharib, C; Gauquelin-Koch, G

2004-05-01

390

Collaboration of geldanamycin-activated P70S6K and Hsp70 against beta-amyloid-induced hippocampal apoptosis: an approach to long-term memory and learning.  

Science.gov (United States)

One of the neuropathological hallmarks of Alzheimer's disease (AD) is the accumulation of beta-amyloid peptides (A?) in senile plaques. A?-induced oxidative stress is believed to be responsible for degeneration and apoptosis of neurons and consequent cognitive and memory deficits. Here, we investigated the possible neuroprotective effect of the heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA) against amyloid pathogenesis in adult male Wistar rats. GA or vehicle was injected into the lateral cerebral ventricles of rats 24 h before injection of A? (1-42) in CA1 area of hippocampus. The learning and memory of the rats were assessed 7 days after injection of A? using passive avoidance (PA) task. As potential contributing factors in A?-induced memory decline, we evaluated apoptotic markers and also used terminal-transferase UTP nick end labeling (TUNEL) technique to detect apoptosis in the hippocampus of A?-injected rats. Our behavioral data suggest that GA pretreatment can significantly suppress memory deficits in A?-injected rats. There was also not only a marked increase in Hsp70 level but also upregulated 70 kDa ribosomal protein S6 kinase (p70S6K) in the hippocampus of GA-treated groups with a reduction in apoptotic factors including caspase-3, poly (ADP-ribose) polymerase, Bax/Bcl-2 ratio, and TUNEL-positive cells as well. Thus, we conclude that GA exerts its protective effects against A? (1-42) toxicity and memory deficits, at least in part, by upregulating of Hsp70 and P70S6K. PMID:25576151

Zare, Nayereh; Motamedi, Fereshteh; Digaleh, Hadi; Khodagholi, Fariba; Maghsoudi, Nader

2015-03-01

391

Long-term anhydrobiotic survival in semi-terrestrial micrometazoans  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study represents the first systematic investigation of long-term anhydrobiotic survival in tardigrades, rotifers and nematodes inhabiting mosses and lichens. Sixty-three different samples from public and private collections, kept dry for 9-138 years, were examined. Rotifers of the genus Mniohia and the eutardigrade Ramazzottius oberhaeuseri (hatched from eggs) were found alive from one of the samples (9 years old). These observations represent the longest record for rotifers in the anhyd...

Guidetti, R.; Jo?nsson, Ingemar

2002-01-01

392

Explaining long-term growth in Namibia  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Supply-side economics stresses the importance of analysing and modelling the long-term properties of an economy's production structures in order to investigate each factor of production's impact on final output. This helps to determine how much should be produced, how much is available for consumpti [...] on and, eventually, how an economy can improve its long-term economic growth path. This study applied the neoclassical growth model to Namibia's growth over the period from 1971 to 2005 in order to identify and develop the main supply-side components of long-term economic growth in the country. Along with a production function, behavioural equations were estimated for the factors of production labour demand and capital investment, as well as for the links between prices and wages.

Joel Hinaunye, Eita; Charlotte B, du Toit.

2009-04-01

393

Long-term alteration of cementitious materials  

International Nuclear Information System (INIS)

Long-term alteration of cementitious materials in the geological condition has been discussed for the safety assessment of radioactive waste disposal. This paper describes the status of understanding long-term chemical alteration of cement, by reviewing some of our investigations on this issue in which we developed a thermodynamic incongruent C-S-H dissolution/precipitation model and a reactive transport calculation code. Alteration of C-S-H gel in a saline groundwater and the change of chemical barrier performance of cementitious materials due to the alteration are also discussed. Some key issues to be discussed further are given and suggested for the future studies on the long-term alteration of cementitious materials in the repository environment. (author)

394

Synapse Specificity of Long-Term Potentiation Breaks Down with Aging  

Science.gov (United States)

Memory shows age-related decline. According to the current prevailing theoretical model, encoding of memories relies on modifications in the strength of the synapses connecting the different cells within a neuronal network. The selective increases in synaptic weight are thought to be biologically implemented by long-term potentiation (LTP). Here,…

Ris, Laurence; Godaux, Emile

2007-01-01

395

Long-term outcomes after severe shock.  

Science.gov (United States)

Severe shock is a life-threatening condition with very high short-term mortality. Whether the long-term outcomes among survivors of severe shock are similar to long-term outcomes of other critical illness survivors is unknown. We therefore sought to assess long-term survival and functional outcomes among 90-day survivors of severe shock and determine whether clinical predictors were associated with outcomes. Seventy-six patients who were alive 90 days after severe shock (received ?1 ?g/kg per minute of norepinephrine equivalent) were eligible for the study. We measured 3-year survival and long-term functional outcomes using the Medical Outcomes Study 36-Item Short-Form Health Survey, the EuroQOL 5-D-3L, the Hospital Anxiety and Depression Scale, the Impact of Event Scale-Revised, and an employment instrument. We also assessed the relationship between in-hospital predictors and long-term outcomes. The mean long-term survival was 5.1 years; 82% (62 of 76) of patients survived, of whom 49 were eligible for follow-up. Patients who died were older than patients who survived. Thirty-six patients completed a telephone interview a mean of 5 years after hospital admission. The patients' Physical Functioning scores were below US population norms (P < 0.001), whereas mental health scores were similar to population norms. Nineteen percent of the patients had symptoms of depression, 39% had symptoms of anxiety, and 8% had symptoms of posttraumatic stress disorder. Thirty-six percent were disabled, and 17% were working full-time. Early survivors of severe shock had a high 3-year survival rate. Patients' long-term physical and psychological outcomes were similar to those reported for cohorts of less severely ill intensive care unit survivors. Anxiety and depression were relatively common, but only a few patients had symptoms of posttraumatic stress disorder. This study supports the observation that acute illness severity does not determine long-term outcomes. Even extremely critically ill patients have similar outcomes to general intensive care unit survivor populations. PMID:25394248

Pratt, Cristina M; Hirshberg, Eliotte L; Jones, Jason P; Kuttler, Kathryn G; Lanspa, Michael J; Wilson, Emily L; Hopkins, Ramona O; Brown, Samuel M

2015-02-01

396

Long-term heterosynaptic inhibition in Aplysia.  

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Synaptic transmission between mechanosensory and motor neurons of the gill withdrawal reflex in Aplysia can undergo both short-term and long-term modulation. One form of short-term synaptic depression lasting minutes can be evoked by the peptide Phe-Met-Arg-Phe-amide (FMRFamide), and is mediated by the lipoxygenase pathway of arachidonic acid. We report here using cell culture, that the same monosynaptic sensory-to-motor component of the gill withdrawal reflex can also undergo long-term synap...

Montarolo, Pier Giorgio

1988-01-01

397

Long-term Video-EEG Monitoring for Paroxysmal Events  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Long term video-electroencephalography monitoring (VEM has been widelyused for the diagnosis, classification, and management of seizures. Fewstudies have systemically examined its safety issues and clinical utility. Thisprospective study investigates the general clinical application of long termVEM in the management of paroxysmal events.Methods: This study cohort consisted of patients admitted to the inpatient VEM unit atChang Gung Memorial Hospital (Lin-Kou. Standard 19 channel scalp electroencephalography(EEG, electrocardiography (ECG, and simultaneousvideo images were recorded continuously for 2 full days. Patient characteristics,and clinical, video-EEG and safety data were obtained and analyzed.The diagnosis and management of paroxysmal events before VEM werecompared with those after VEM.Results: Habitual events were recorded in 54.3% of the 129 patients, and VEM had ayield rate of 76% (events recorded or newly recorded interictal discharges indetermining the nature of the events. Eleven patients had seizure clusters, butthere was no status epilepticus or electrode-related injury. After VEM, thediagnostic categories were changed in 41.1% of the patients, and 40.3% hadrevisions in management.Conclusions: Long term VEM is a safe diagnostic tool providing a high diagnostic yieldrate and directing adjustment of management for patients with paroxysmalevents.

Ying-Ying Lee

2009-06-01

398

Immediate and Persistent Transcriptional Correlates of Long-Term Sensitization Training at Different CNS Loci in Aplysia californica  

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Repeated noxious stimulation produces long-term sensitization of defensive withdrawal reflexes in Aplysia californica, a form of long-term memory that requires changes in both transcription and translation. Previous work has identified 10 transcripts which are rapidly up-regulated after long-term sensitization training in the pleural ganglia. Here we use quantitative PCR to begin examining how these transcriptional changes are expressed in different CNS loci related to defensive withdrawal reflexes at 1 and 24 hours after long-term sensitization training. Specifically, we sample from a) the sensory wedge of the pleural ganglia, which exclusively contains the VC nociceptor cell bodies that help mediate input to defensive withdrawal circuits, b) the remaining pleural ganglia, which contain withdrawal interneurons, and c) the pedal ganglia, which contain many motor neurons. Results from the VC cluster show different temporal patterns of regulation: 1) rapid but transient up-regulation of Aplysia homologs of C/EBP, C/EBP?, and CREB1, 2) delayed but sustained up-regulation of BiP, Tolloid/BMP-1, and sensorin, 3) rapid and sustained up-regulation of Egr, GlyT2, VPS36, and an uncharacterized protein (LOC101862095), and 4) an unexpected lack of regulation of Aplysia homologs of calmodulin (CaM) and reductase-related protein (RRP). Changes in the remaining pleural ganglia mirror those found in the VC cluster at 1 hour but with an attenuated level of regulation. Because these samples had almost no expression of the VC-specific transcript sensorin, our data suggests that sensitization training likely induces transcriptional changes in either defensive withdrawal interneurons or neurons unrelated to defensive withdrawal. In the pedal ganglia, we observed only a rapid but transient increase in Egr expression, indicating that long-term sensitization training is likely to induce transcriptional changes in motor neurons but raising the possibility of different transcriptional endpoints in this cell type. PMID:25486125

Herdegen, Samantha; Conte, Catherine; Kamal, Saman; Calin-Jageman, Robert J.; Calin-Jageman, Irina E.

2014-01-01

399

Long-term behavior of bituminized waste  

International Nuclear Information System (INIS)

The long-term properties of bituminized ion exchange resins were studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are related to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product

400

Long-term cropping systems study  

Science.gov (United States)

This long-term study has been conducted on the Agronomy Farm at ARDC since the early 1970’s. In the beginning, the objectives were mainly rela